[CI] (Workflows): run the test and apk lanes on every push to feat/disaggregated

- the MGPipe phases land as a series of pushes and each one needs the full lane; dispatching
  by hand after every merge is a step that gets forgotten
- both entries carry a remove-before-merging-to-dev note: dev's trigger set is what ships

.github/scripts/validate-plugin-apks.sh

@@ -44,12 +44,12 @@ require 'key:MOBILEGL_BACKEND_TYPE' "$plugin_resource_text" 'V2 backend variable
 require 'defaultValue:DirectGLES' "$plugin_resource_text" 'V2 DirectGLES default'
 require 'DirectVulkan' "$plugin_resource_text" 'V2 DirectVulkan option'
 require 'key:MOBILEGL_DISABLE_TIMERQUERY' "$plugin_resource_text" 'V2 timer-query toggle'
-require 'key:MOBILEGL_DISABLE_SUBGROUP' "$plugin_resource_text" 'V2 Vulkan subgroup toggle'
+require 'key:MOBILEGL_MAGMA_DISABLE_SUBGROUP' "$plugin_resource_text" 'V2 Vulkan subgroup toggle'
 require 'key:MOBILEGL_MAGMA_R11G11B10F_FALLBACK' "$plugin_resource_text" 'V2 Magma format fallback toggle'
 require 'key:MOBILEGL_MAGMA_FRAMESINFLIGHT' "$plugin_resource_text" 'V2 Magma frames-in-flight setting'
-require 'key:MOBILEGL_AVOID_SAMPLER_MIPMAP_MIN_FILTER' "$plugin_resource_text" 'V2 sampler workaround toggle'
+require 'key:MOBILEGL_ESPRYT_AVOID_SAMPLER_MIPMAP_MIN_FILTER' "$plugin_resource_text" 'V2 sampler workaround toggle'
 require 'key:MOBILEGL_COHERENT_AS_FLUSH' "$plugin_resource_text" 'V2 coherent-as-flush toggle'
-require 'key:MOBILEGL_USE_ANGLE' "$plugin_resource_text" 'V2 ANGLE toggle'
+require 'key:MOBILEGL_ESPRYT_USE_ANGLE' "$plugin_resource_text" 'V2 ANGLE toggle'
 
 if [[ $(grep -Fc 'fclPlugin_V2' <<<"$plugin_manifest") -ne 1 ]]; then
   echo '::error::Plugin manifest must expose exactly one V2 descriptor' >&2

.github/workflows/apk.yml

@@ -6,6 +6,10 @@ on:
       - dev
       - Feat/Backend-Direct-GLES
       - Feat/Backend-Direct-Vulkan
+      # TEMPORARY, remove before merging the MGPipe work into dev: the disaggregation
+      # branch runs the full lane on every push so a phase's landing is not gated on
+      # someone remembering to dispatch the workflow by hand.
+      - feat/disaggregated
   workflow_dispatch:
 
 jobs:
@@ -417,12 +421,12 @@ jobs:
 
       - name: Retrace and validate
         env:
-          MOBILEGL_USE_ANGLE: ${{ matrix.backend.name == 'DirectGLES' && '1' || '0' }}
+          MOBILEGL_ESPRYT_USE_ANGLE: ${{ matrix.backend.name == 'DirectGLES' && '1' || '0' }}
           MOBILEGL_TRACE_ANGLE_VARIANT: ${{ matrix.case.name == 'minecraft-1.21.4-fabric-iris-bliss-in-world' && '90a62123d794' || 'ec889e6ea831' }}
           MOBILEGL_MAGMA_R11G11B10F_FALLBACK: ${{ matrix.backend.name == 'DirectVulkan' && '1' || '0' }}
-          MOBILEGL_FIX_ITERATIONRP_SUBGROUP_SCRATCH: ${{ matrix.backend.name == 'DirectVulkan' && matrix.case.name == 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' && '1' || '0' }}
-          MOBILEGL_DERIVE_NUM_SUBGROUPS: ${{ matrix.backend.name == 'DirectVulkan' && matrix.case.name == 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' && '1' || '0' }}
-          MOBILEGL_ITERATIONRP_FIX_BARRIER: ${{ matrix.backend.name == 'DirectVulkan' && matrix.case.name == 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' && '1' || '0' }}
+          MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH: ${{ matrix.backend.name == 'DirectVulkan' && matrix.case.name == 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' && '1' || '0' }}
+          MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS: ${{ matrix.backend.name == 'DirectVulkan' && matrix.case.name == 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' && '1' || '0' }}
+          MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER: ${{ matrix.backend.name == 'DirectVulkan' && matrix.case.name == 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' && '1' || '0' }}
         run: |
           apk_file="android-retrace-apks/MobileGL-plugin-trace-release-${GITHUB_SHA}.apk"
           test -f "${apk_file}"

.github/workflows/test.yml

@@ -6,7 +6,19 @@ on:
       - dev
       - Feat/Backend-Direct-GLES
       - Feat/Backend-Direct-Vulkan
+      # TEMPORARY, remove before merging the MGPipe work into dev: the disaggregation
+      # branch runs the full lane on every push so a phase's landing is not gated on
+      # someone remembering to dispatch the workflow by hand.
+      - feat/disaggregated
   workflow_dispatch:
+    inputs:
+      baseline_sha:
+        description: >-
+          The commit monolith-symbol-report compares this tree against. P1's G1 says the pull
+          build is byte-identical to feat/disaggregated@087685d1, and that is what the default
+          names. The trigger set is unchanged: this job runs on workflow_dispatch only.
+        required: false
+        default: "087685d1"
 
 jobs:
   build-linux:
@@ -265,16 +277,26 @@ jobs:
         # crash stack without burning a CI round on an in-workflow debugger.
         env:
           MOBILEGL_ITEST_REQUIRE_GPU: "1"
-          MOBILEGL_FIX_ITERATIONRP_SUBGROUP_SCRATCH: "1"
-          MOBILEGL_DERIVE_NUM_SUBGROUPS: "1"
-          MOBILEGL_ITERATIONRP_FIX_BARRIER: "1"
+          MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH: "1"
+          MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS: "1"
+          MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER: "1"
         run: |
           ulimit -c unlimited
           sudo sysctl -w kernel.core_pattern='/tmp/core.%e.%p'
+          # Second, filtered pass: with the range-invalidating map flush disabled,
+          # the buffer scenarios run on the upload ring's staged-copy tier - which
+          # the default pass never reaches (the map tier absorbs every flush on
+          # Mesa), so without this the Mali fallback tier would have zero CI
+          # coverage. The flag is NOT baked into the ctest ENVIRONMENT properties,
+          # so an inline env reaches the test processes (unlike the ICD pin above).
           if [ "${{ secrets.ACTIONS_STEP_DEBUG }}" = "true" ]; then
             ctest -V -L integration-gpu --no-tests=error
+            MOBILEGL_ESPRYT_DISABLE_INVALIDATE_FLUSH=1 ctest -V -L integration-gpu \
+              -R 'Buffer|Readback|Atomic|Ssbo|Arena' --no-tests=error
           else
             ctest --output-on-failure -L integration-gpu --no-tests=error
+            MOBILEGL_ESPRYT_DISABLE_INVALIDATE_FLUSH=1 ctest --output-on-failure -L integration-gpu \
+              -R 'Buffer|Readback|Atomic|Ssbo|Arena' --no-tests=error
           fi
 
       - name: Upload core dumps
@@ -285,6 +307,399 @@ jobs:
           path: /tmp/core.*
           if-no-files-found: ignore
 
+  # THE THIRD CI MODE (ARCHITECTURE.md 13.2-(2)): the same library, built with the PipeInputs
+  # comparator compiled in, running the integration suite and a trace subset with two state models
+  # in one address space. It is a second build rather than a flag on the first because
+  # MOBILEGL_PIPE_VERIFY is a compile-time option - the snapshot, the entry compare and the
+  # compare-at-read hook do not exist in the shipped library, and are never meant to.
+  build-linux-verify:
+    runs-on: ubuntu-latest
+    timeout-minutes: 120
+    permissions:
+      actions: write
+      contents: read
+    env:
+      BUILD_DIR: build-verify
+      CCACHE_BASEDIR: ${{ github.workspace }}
+      CCACHE_COMPRESS: "true"
+      CCACHE_DIR: ${{ github.workspace }}/.ccache
+      CCACHE_MAXSIZE: 4G
+      CCACHE_NOHASHDIR: "true"
+
+    steps:
+      - name: Set Swap Space
+        uses: pierotofy/set-swap-space@v1.0
+        with:
+          swap-size-gb: 32
+
+      - name: Checkout repo
+        uses: actions/checkout@v6
+        with:
+          submodules: recursive
+
+      - name: Get CMake
+        uses: lukka/get-cmake@v4.3.3
+
+      - name: Restore ccache
+        uses: actions/cache/restore@v5
+        with:
+          path: .ccache
+          key: ${{ runner.os }}-test-${{ github.job }}-ccache-v1
+          restore-keys: |
+            ${{ runner.os }}-test-${{ github.job }}-ccache-
+
+      - name: Prepare Vulkan SDK
+        uses: humbletim/setup-vulkan-sdk@v1.2.1
+        with:
+          vulkan-query-version: 1.4.304.1
+          vulkan-components: Vulkan-Headers, Vulkan-Loader
+          vulkan-use-cache: true
+
+      - name: Update glslang external sources
+        working-directory: 3rdparty/glslang
+        run: python update_glslang_sources.py
+
+      - name: Install build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y ccache clang-20 clang++-20 lld-20 libc++-20-dev libc++abi-20-dev libvulkan-dev libegl1-mesa-dev libgles2-mesa-dev libgl1-mesa-dri mesa-vulkan-drivers ninja-build
+
+      - name: Show installed toolchain
+        run: |
+          ccache --version
+          clang-20 --version
+          clang++-20 --version
+          ld.lld-20 --version || ld.lld --version || true
+          dpkg -l 'libc++*' 'libegl*' 'libgles*' 'mesa*' 'vulkan*' || true
+
+      - name: Configure CMake
+        # Release/INFO like the shipped build on purpose. The poison arms in this configuration
+        # through MOBILEGL_PIPE_VERIFY (PipeInputs.h derives MOBILEGL_PIPE_POISON from it), so this
+        # job needs neither a Debug log level nor MOBILEGL_BUILD_DISAGGREGATED - and a Debug build
+        # would compare a different library from the one the other lanes measure. (build-linux
+        # switches to Debug under ACTIONS_STEP_DEBUG; this job deliberately does not - a Debug
+        # build flips CXX_VISIBILITY_PRESET and arms MOBILEGL_PIPE_POISON through a second, unrelated
+        # arm of its #if, so the debug switch would change what the lane is measuring.)
+        run: |
+          cmake -S . -B "${BUILD_DIR}" -G Ninja \
+            -DCMAKE_C_COMPILER=clang-20 \
+            -DCMAKE_CXX_COMPILER=clang++-20 \
+            -DCMAKE_C_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DMOBILEGL_LOG_ACTIVE_LEVEL=MOBILEGL_LOG_LEVEL_INFO \
+            -DMOBILEGL_BUILD_TEST=ON \
+            -DMOBILEGL_BUILD_BENCHMARK=OFF \
+            -DMOBILEGL_BUILD_INTEGRATION_TEST=ON \
+            -DMOBILEGL_ITEST_VK_ICD=/usr/share/vulkan/icd.d/lvp_icd.json \
+            -DMOBILEGL_BUILD_TRACE_REPLAY=OFF \
+            -DMOBILEGL_PIPE_VERIFY=ON \
+            -DCMAKE_POLICY_VERSION_MINIMUM=3.5
+
+      - name: Build
+        run: cmake --build "${BUILD_DIR}" --parallel "$(nproc)"
+
+      # The lane is worthless if the option silently did not take, and that is a one-character
+      # mistake away at all times (a typo'd -D is not an error in CMake). Two checks, both cheap:
+      # the comparator's entry point must be in the library, and the fill entry point with it.
+      #
+      # `nm` and NOT `nm -D`. The library is built CXX_VISIBILITY_PRESET hidden in every non-Debug
+      # configuration (CMakeLists.txt:600-604) and the MGPipe entry points are plain namespace
+      # functions with no export attribute, so not one of them appears in the DYNAMIC table: on a
+      # perfectly healthy verify build `nm -D --defined-only ... | grep -c MGPipe` answers 0 out of
+      # ~11900 exported symbols, and a gate spelled that way is red forever for a reason that has
+      # nothing to do with what it claims to test. The static symbol table has them as local `t`
+      # entries, this artifact is never stripped, and `No MG_Remote in the pull build` below already
+      # uses this spelling. The symbol count guards the remaining hole: a stripped library would
+      # make both greps fail for a third, silent reason.
+      - name: The verify library really carries the comparator
+        run: |
+          test -f "${BUILD_DIR}/libMobileGL.so"
+          defined=$(nm --defined-only "${BUILD_DIR}/libMobileGL.so" | wc -l)
+          if [ "${defined}" -lt 1000 ]; then
+            echo "::error::nm --defined-only sees only ${defined} symbols in ${BUILD_DIR}/libMobileGL.so - it looks stripped, so the two checks below could not have failed honestly"
+            exit 1
+          fi
+          for entry in MGPipeVerifyInputs MGPipeFillForVerb; do
+            if ! nm --defined-only "${BUILD_DIR}/libMobileGL.so" | grep -q "${entry}"; then
+              echo "::error::libMobileGL.so defines no ${entry}: -DMOBILEGL_PIPE_VERIFY=ON did not take, and every lane that consumes this artifact would run the comparator-free library and pass having compared nothing"
+              exit 1
+            fi
+          done
+          echo "libMobileGL.so defines MGPipeVerifyInputs and MGPipeFillForVerb (${defined} defined symbols)"
+
+      - name: Show ccache stats
+        if: always()
+        run: ccache --show-stats
+
+      - name: Release superseded ccache entry
+        if: github.ref_name == github.event.repository.default_branch
+        env:
+          GH_TOKEN: ${{ github.token }}
+          CACHE_KEY: ${{ runner.os }}-test-${{ github.job }}-ccache-v1
+        run: gh cache delete "${CACHE_KEY}" || true
+
+      - name: Save ccache
+        if: github.ref_name == github.event.repository.default_branch
+        continue-on-error: true
+        uses: actions/cache/save@v5
+        with:
+          path: .ccache
+          key: ${{ runner.os }}-test-${{ github.job }}-ccache-v1
+
+      - name: Package Linux verify runtime
+        run: |
+          mkdir -p ci-artifacts
+          mapfile -t SHARED_LIBS < <(find "${BUILD_DIR}" -type f \( -name '*.so' -o -name '*.so.*' \) -print | sort)
+          tar \
+            --exclude='*/CMakeFiles' \
+            --exclude='*.o' \
+            --exclude='*.a' \
+            --exclude='*.ninja*' \
+            --exclude='build.ninja' \
+            --exclude='cmake_install.cmake' \
+            -czf ci-artifacts/mobilegl-linux-runtime-verify.tgz \
+            "${BUILD_DIR}/CTestTestfile.cmake" \
+            "${BUILD_DIR}/MobileGL/MG_Test" \
+            "${BUILD_DIR}/MobileGL/MG_IntegrationTest" \
+            "${SHARED_LIBS[@]}"
+
+      - name: Upload Linux verify runtime
+        uses: actions/upload-artifact@v7
+        with:
+          name: mobilegl-linux-runtime-verify
+          path: ci-artifacts/mobilegl-linux-runtime-verify.tgz
+          if-no-files-found: error
+
+  # The verify lane itself, plus the two negative controls that keep it falsifiable. The controls
+  # are ALWAYS-ON steps, not a manual exercise: a gate that can only be shown to work by someone
+  # remembering to break it on purpose is a gate that has already stopped working.
+  integration-verify:
+    runs-on: ubuntu-latest
+    timeout-minutes: 180
+    needs: build-linux-verify
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+
+      - name: Get CMake
+        uses: lukka/get-cmake@v4.3.3
+
+      - name: Install runtime dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libvulkan1 libegl1 libegl-mesa0 libgles2 libgl1-mesa-dri mesa-vulkan-drivers
+
+      - name: Download Linux verify runtime
+        uses: actions/download-artifact@v8
+        with:
+          name: mobilegl-linux-runtime-verify
+          path: .
+
+      - name: Unpack Linux verify runtime
+        run: |
+          tar -xzf mobilegl-linux-runtime-verify.tgz
+          test -f build-verify/libMobileGL.so
+
+      - name: Normalize CTest command paths
+        run: |
+          python - <<'PY'
+          from pathlib import Path
+          import re
+
+          for path in Path('build-verify').rglob('CTestTestfile.cmake'):
+              text = path.read_text()
+              text = re.sub(r'"[^"]*/cmake-[^"]*/bin/cmake"', '"cmake"', text)
+              path.write_text(text)
+          PY
+
+      - name: Integration scenarios under MOBILEGL_PIPE_VERIFY
+        working-directory: build-verify
+        # --no-tests=error is half the gate: the verify entries only exist when the library was
+        # configured with -DMOBILEGL_PIPE_VERIFY=ON, so a build that lost the option matches no
+        # tests and reds here instead of reporting a green run of nothing. The other half is
+        # PipeVerifyArmingScenario.Armed, which fails when the library never printed its arming
+        # line - the failure mode a bare `MOBILEGL_PIPE_VERIFY=1` cannot detect by itself.
+        #
+        # SCOPE, stated so nobody reads more into a green than is there: this is every integration
+        # ENTRY under the comparator, not every integration CONFIGURATION. The `integration` job
+        # runs a second, filtered pass with MOBILEGL_ESPRYT_DISABLE_INVALIDATE_FLUSH=1 for the
+        # upload ring's staged-copy tier; that pass is 186 entries here and, at the 5-10x the
+        # comparator costs, is not affordable inside this job's budget. The tier is covered by
+        # `integration`, unverified, and P2 can take it once the comparator's cost is known.
+        env:
+          MOBILEGL_ITEST_REQUIRE_GPU: "1"
+          MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH: "1"
+          MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS: "1"
+          MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER: "1"
+        run: |
+          ulimit -c unlimited
+          sudo sysctl -w kernel.core_pattern='/tmp/core.%e.%p'
+          if [ "${{ secrets.ACTIONS_STEP_DEBUG }}" = "true" ]; then
+            ctest -V -L integration-verify --no-tests=error
+          else
+            ctest --output-on-failure -L integration-verify --no-tests=error
+          fi
+
+      # The arming lanes' logs, and ONLY those. Each lane shares one MOBILEGL_LOG_FILE_PATH and the
+      # library opens it fopen(path, "w"), so after an ambient lane of 400-odd processes the file
+      # holds the LAST one - grepping it would say nothing about the other 405 and would red a
+      # healthy lane whenever the last entry happened not to issue a verb (which is what the
+      # PoisonOmissionScenario parent, the last ambient entry, does by construction: it forks,
+      # execve()s and reads files). The DirectGLES.VerifyArming. / DirectVulkan.VerifyArming.
+      # entries are one process each on a log path nothing else writes, so this grep means exactly
+      # what it says.
+      #
+      # What it proves: arming is a property of (this library, this environment), and these two
+      # processes ran the same library with the same MOBILEGL_PIPE_VERIFY=1 as their ~400 ambient
+      # siblings. It is not, and cannot be, a per-process census - the shared log cannot support one.
+      # It catches the case ctest cannot: an arming entry that SKIPPED still reports green.
+      - name: The verify lanes armed the comparator
+        working-directory: build-verify
+        run: |
+          shopt -s nullglob
+          logs=(MobileGL/MG_IntegrationTest/pipe-verify-arming-*.log)
+          if [ ${#logs[@]} -lt 2 ]; then
+            echo "::error::found ${#logs[@]} pipe-verify-arming-*.log (expected one per backend). The VerifyArming. entries did not run, so nothing in this job establishes that the comparator was ever armed."
+            exit 1
+          fi
+          for log in "${logs[@]}"; do
+            if ! grep -q "MGPipe: verify armed" "${log}"; then
+              echo "::error::${log} carries no arming line: that lane's process ran the whole scenario without the comparator, so every green entry beside it is green for no reason"
+              exit 1
+            fi
+          done
+          echo "arming line present in all ${#logs[@]} arming-lane log(s)"
+
+      # NEGATIVE CONTROL A (gate G4). The knob perturbs one field in the snapshot arm before the
+      # entry compare, so a working comparator must abort the run. This step passes when ctest
+      # FAILS - `if ctest ...; then error` - which is the only shape that can catch a comparator
+      # that silently compares nothing.
+      #
+      # The knob reaches the test process through the JOB environment: no ctest ENVIRONMENT
+      # property on the ambient Verify. entries names it (MG_IntegrationTest/CMakeLists.txt says
+      # so out loud), and a property entry would otherwise override this and the control would
+      # prove nothing. Same precedent as MOBILEGL_ESPRYT_DISABLE_INVALIDATE_FLUSH in `integration`.
+      - name: Negative control A - a corrupted snapshot field must turn the lane red
+        working-directory: build-verify
+        env:
+          MOBILEGL_ITEST_REQUIRE_GPU: "1"
+          MOBILEGL_PIPE_VERIFY_CORRUPT: GetRenderStateParameters
+        run: |
+          FILTER='DirectGLES\.Verify\..*ClearThenReadPixels'
+          # An empty selection would ALSO make ctest exit non-zero (--no-tests=error), and this
+          # step reads non-zero as "the control worked" - so the selection is counted first. A
+          # control that passes because it ran nothing is worse than no control.
+          matched=$(ctest -N -L integration-verify -R "${FILTER}" | grep -cE '^ *Test *#[0-9]+:')
+          if [ "${matched}" -lt 1 ]; then
+            echo "::error::negative control A selected ${matched} tests; its filter no longer matches anything"
+            exit 1
+          fi
+          if ctest --output-on-failure -L integration-verify -R "${FILTER}" --no-tests=error; then
+            echo "::error::MOBILEGL_PIPE_VERIFY_CORRUPT=GetRenderStateParameters left ${matched} verify entries GREEN. The comparator is not comparing, so every green entry above is green for no reason."
+            exit 1
+          fi
+          echo "the corrupted field turned ${matched} selected entries red, as it must"
+
+      # NEGATIVE CONTROL B (gate G5). The omission skips the STAMP of one field for one verb while
+      # still copying its value - indistinguishable from a fill row nobody wrote - so the poison
+      # must abort the glGenerateMipmap. Again: this step passes when ctest fails.
+      #
+      # The entry it targets is PoisonOmissionScenario.WithoutOmissionCompletes, which is green in
+      # the ambient lane above and is the ONLY integration entry in the tree that calls
+      # glGenerateMipmap at all. It deliberately does not skip itself when the knob is set, exactly
+      # so that this control has something to turn red.
+      - name: Negative control B - an omitted fill point must turn the lane red on that verb
+        working-directory: build-verify
+        env:
+          MOBILEGL_ITEST_REQUIRE_GPU: "1"
+          MOBILEGL_PIPE_POISON_OMIT: GenerateMipmap:GetActiveTextureUnit
+        run: |
+          FILTER='DirectGLES\.Verify\.PoisonOmissionScenario\.WithoutOmissionCompletes'
+          matched=$(ctest -N -L integration-verify -R "${FILTER}" | grep -cE '^ *Test *#[0-9]+:')
+          if [ "${matched}" -lt 1 ]; then
+            echo "::error::negative control B selected ${matched} tests; its filter no longer matches anything"
+            exit 1
+          fi
+          if ctest --output-on-failure -L integration-verify -R "${FILTER}" --no-tests=error; then
+            echo "::error::MOBILEGL_PIPE_POISON_OMIT=GenerateMipmap:GetActiveTextureUnit left the verify lane GREEN. The per-verb poison is not armed, so a forgotten fill row would ship silently."
+            exit 1
+          fi
+          echo "the omitted fill point turned the lane red, as it must"
+
+      - name: Upload verify lane logs
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: integration-verify-logs
+          path: build-verify/MobileGL/MG_IntegrationTest/pipe-*.log*
+          if-no-files-found: warn
+
+      - name: Upload core dumps
+        if: failure()
+        uses: actions/upload-artifact@v7
+        with:
+          name: integration-verify-core-dumps
+          path: /tmp/core.*
+          if-no-files-found: ignore
+
+  # MobileGL/MG_Remote/Protocol/generated/protocol_generated.h is COMMITTED, and
+  # flatc is deliberately absent from the default build graph (a codegen step in
+  # the graph is how the earlier branch ended up cross-compiling an arm64 flatc
+  # and trying to run it on the host). This job is what keeps the committed
+  # header honest: build the pinned flatc, regenerate, and fail on any diff.
+  # It needs no MobileGL build, so it does not depend on build-linux.
+  flatc-check:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+
+      - name: Get CMake
+        uses: lukka/get-cmake@v4.3.3
+
+      - name: Check out the FlatBuffers submodule only
+        # Just this one: the schema check has nothing to do with glslang,
+        # SPIRV-Cross or the trace fixtures.
+        run: git submodule update --init 3rdparty/flatbuffers
+
+      - name: Regenerate protocol_generated.h
+        run: python3 scripts/gen_protocol.py --build-dir "${{ runner.temp }}/flatc-build"
+
+      - name: Fail if the committed header is stale
+        run: git diff --exit-code -- MobileGL/MG_Remote/Protocol/generated/protocol_generated.h
+
+  # P0.5 interface-purity gate A (ARCHITECTURE.md:501): the two extracted headers' include closure,
+  # asserted on `-H` output because `nm --undefined-only` is blind to "included but not called" -
+  # a header whose types are never named leaves no symbol behind, and "included at all" is exactly
+  # the coupling P1 and P7 have to sever. Needs a preprocessor and three header submodules, no
+  # CMake configure and no glslang sources, so like pipe-gates it does not depend on build-linux.
+  # The script's own --self-test is always on: a negative control that stopped tripping fails the
+  # job, because a gate that cannot go red is not a gate (ROADMAP.md:7).
+  include-graph-check:
+    name: Include-closure purity gate
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+
+      - name: Check out the three header submodules the closure needs
+        # ska/flat_hash_map.hpp, xxhash.h and vulkan/vulkan.h are the only submodule headers
+        # Includes.h reaches; glslang and spirv_cross are vendored under include/.
+        run: git submodule update --init include/ska 3rdparty/xxHash 3rdparty/Vulkan-Headers
+
+      - name: Install clang and the X11 headers vulkan.h pulls on Linux
+        # Includes.h defines VK_USE_PLATFORM_XLIB_KHR before <vulkan/vulkan.h>, which then
+        # includes <X11/Xlib.h>; without libx11-dev every clang-mode probe dies in the
+        # preprocessor and the gate reports 5 problems that have nothing to do with purity.
+        run: sudo apt-get update && sudo apt-get install -y clang-20 libx11-dev
+
+      - name: Include-closure assertions and negative control
+        run: python3 scripts/check_include_closure.py --mode both --compiler clang++-20 --self-test --require-all
+
   benchmark:
     runs-on: ubuntu-latest
     needs: build-linux
@@ -496,6 +911,7 @@ jobs:
     outputs:
       matrix: ${{ steps.trace-cases.outputs.matrix }}
       names: ${{ steps.trace-cases.outputs.names }}
+      verify-matrix: ${{ steps.trace-cases.outputs.verify-matrix }}
     steps:
       - name: Checkout repo
         uses: actions/checkout@v6
@@ -505,6 +921,9 @@ jobs:
         run: |
           echo "matrix=$(python3 tools/trace_replay/trace_cases.py --ci --format github-test-matrix)" >> "$GITHUB_OUTPUT"
           echo "names=$(python3 tools/trace_replay/trace_cases.py --ci --format names)" >> "$GITHUB_OUTPUT"
+          # The subset the verify build retraces ("verify": true in trace_cases.json). It is a
+          # SUBSET of the matrix above, so retrace-verify needs no fixtures of its own.
+          echo "verify-matrix=$(python3 tools/trace_replay/trace_cases.py --ci --format github-verify-matrix)" >> "$GITHUB_OUTPUT"
 
   trace-fixtures:
     name: trace fixture (${{ matrix.case }})
@@ -644,9 +1063,9 @@ jobs:
           fi
           if [ '${{ matrix.backend }}' = 'DirectVulkan' ] \
              && [ '${{ matrix.case }}' = 'minecraft-1.21.4-fabric-iris-iterationrp-in-world' ]; then
-            export MOBILEGL_FIX_ITERATIONRP_SUBGROUP_SCRATCH=1
-            export MOBILEGL_DERIVE_NUM_SUBGROUPS=1
-            export MOBILEGL_ITERATIONRP_FIX_BARRIER=1
+            export MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH=1
+            export MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS=1
+            export MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER=1
           fi
           # The blended depth-write quirk auto-enables only on Qualcomm, which no CI
           # runner has, so force it on for the OIT case it exists to fix. ForceOn
@@ -718,10 +1137,295 @@ jobs:
           archive: false
           if-no-files-found: error
 
+  # The trace half of the third CI mode. Same replay, same goldens, but the library underneath is
+  # the verify build and MOBILEGL_PIPE_VERIFY=1 is in the environment, so every backend read of
+  # frontend state is checked against a snapshot taken at the verb boundary. Eight cases rather
+  # than the full lane's 40 (tools/trace_replay/trace_cases.json, "verify": true): the comparator
+  # is budgeted at 5-10x, and the full sweep is a phase-exit / workflow_dispatch run.
+  retrace-verify:
+    name: retrace verify (${{ matrix.backend }}, ${{ matrix.case }})
+    runs-on: ubuntu-latest
+    timeout-minutes: 240
+    needs:
+      - build-linux-verify
+      - build-retrace
+      - trace-cases
+      - trace-fixtures
+    if: ${{ always() && needs.build-linux-verify.result == 'success' && needs.build-retrace.result == 'success' && needs.trace-cases.result == 'success' }}
+    strategy:
+      fail-fast: false
+      max-parallel: 4
+      matrix: ${{ fromJSON(needs.trace-cases.outputs.verify-matrix) }}
+
+    steps:
+      - name: Set Swap Space
+        uses: pierotofy/set-swap-space@v1.0
+        with:
+          swap-size-gb: 16
+
+      - name: Checkout repo
+        uses: actions/checkout@v6
+
+      - name: Download trace fixture
+        uses: actions/download-artifact@v8
+        with:
+          name: trace-fixture-${{ matrix.case }}
+          path: trace-fixture-download
+
+      - name: Install trace fixture
+        run: |
+          mkdir -p tools/trace_replay/fixtures
+          find trace-fixture-download -type f -exec cp {} tools/trace_replay/fixtures/ \;
+
+      - name: Get CMake
+        uses: lukka/get-cmake@v4.3.3
+
+      - name: Install runtime dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libvulkan1 libegl1-mesa-dev libgles2-mesa-dev libgl1-mesa-dri mesa-vulkan-drivers
+          test -e /usr/lib/x86_64-linux-gnu/libEGL.so
+          test -e /usr/lib/x86_64-linux-gnu/libGLESv2.so
+
+      - name: Download Linux verify runtime
+        uses: actions/download-artifact@v8
+        with:
+          name: mobilegl-linux-runtime-verify
+          path: .
+
+      - name: Download trace replay
+        uses: actions/download-artifact@v8
+        with:
+          name: mobilegl-trace-replay
+          path: .
+
+      - name: Unpack the VERIFY runtime as the library under test
+        # build-retrace's CTestTestfile.cmake has the absolute path
+        # <workspace>/build-linux/libMobileGL.so frozen into every case, so the swap happens here
+        # rather than through a variable: the verify .so is put where that path points. The nm
+        # check is what makes the swap falsifiable - a run against the ordinary library would
+        # carry no comparator, ignore MOBILEGL_PIPE_VERIFY entirely, and match its golden.
+        #
+        # `nm`, not `nm -D`, for the reason spelled out in build-linux-verify: everything MGPipe is
+        # hidden-visibility in a Release build and the dynamic table has none of it.
+        run: |
+          tar -xzf mobilegl-linux-runtime-verify.tgz
+          tar -xzf mobilegl-trace-replay.tgz
+          test -f build-verify/libMobileGL.so
+          test -f build-retrace/tools/trace_replay/mobilegl_trace_replay
+          mkdir -p build-linux
+          cp build-verify/libMobileGL.so build-linux/libMobileGL.so
+          if ! nm --defined-only build-linux/libMobileGL.so | grep -q MGPipeVerifyInputs; then
+            echo "::error::the library unpacked at build-linux/libMobileGL.so defines no MGPipeVerifyInputs, so this retrace would replay against a comparator-free build and pass on its golden having verified nothing"
+            exit 1
+          fi
+          echo "the library at build-linux/libMobileGL.so is the verify build"
+
+      - name: Retrace and validate under MOBILEGL_PIPE_VERIFY
+        working-directory: build-retrace/tools/trace_replay
+        # run_trace_case.cmake turns MOBILEGL_PIPE_VERIFY into three assertions of its own (the
+        # arming line, no Fatal{PipeVerifyDiffer, no Fatal{UnmigratedPipeInput), so a case that
+        # somehow ran the wrong library reds here instead of passing on its golden.
+        # --timeout 10800: the 1800s cases run 5-10x slower with both comparator arms live, which
+        # is well past ctest's 1500s default.
+        run: |
+          ulimit -c unlimited
+          sudo sysctl -w kernel.core_pattern='/tmp/core.%e.%p'
+          export MOBILEGL_PIPE_VERIFY=1
+          if [ '${{ matrix.backend }}' = 'DirectVulkan' ]; then
+            export MOBILEGL_MAGMA_R11G11B10F_FALLBACK=1
+          fi
+          if [ '${{ matrix.backend }}' = 'DirectVulkan' ] \
+             && [ '${{ matrix.case }}' = 'improved-transparency-minecraft-26.3' ]; then
+            export MOBILEGL_MAGMA_DISABLE_BLENDED_DEPTH_WRITE=1
+          fi
+          ctest -V --no-tests=error --timeout 10800 \
+            -R '^MobileGLTraceReplay\.${{ matrix.case }}\.${{ matrix.backend }}$'
+
+      # The retrace lane's own always-on negative control, on one case so it costs one short trace:
+      # with a snapshot field corrupted, the SAME replay must fail. Without it, "40 traces, zero
+      # divergences" would be a statement about a comparator nobody watched.
+      #
+      # The rerun replays into the SAME case directory, so the verified run's images are put aside
+      # first and restored before the verdict: "Upload actual image" below runs `if: always()` and
+      # would otherwise ship the deliberately corrupted run's output under the name of the good one.
+      # The restore happens whichever way the control goes, which is why the ctest exit status is
+      # captured rather than tested inline.
+      - name: Negative control - a corrupted snapshot field must red this retrace
+        if: ${{ matrix.case == 'OpenRA' && matrix.backend == 'DirectGLES' }}
+        working-directory: build-retrace/tools/trace_replay
+        run: |
+          export MOBILEGL_PIPE_VERIFY=1
+          export MOBILEGL_PIPE_VERIFY_CORRUPT=GetRenderStateParameters
+          GOOD_OUTPUT="${RUNNER_TEMP}/openra-verified-output"
+          rm -rf "${GOOD_OUTPUT}"
+          if [ -d OpenRA ]; then
+            cp -a OpenRA "${GOOD_OUTPUT}"
+          fi
+          set +e
+          ctest -V --no-tests=error --timeout 10800 \
+            -R '^MobileGLTraceReplay\.OpenRA\.DirectGLES$'
+          control_rc=$?
+          set -e
+          if [ -d "${GOOD_OUTPUT}" ]; then
+            rm -rf OpenRA
+            mv "${GOOD_OUTPUT}" OpenRA
+            echo "restored the verified run's OpenRA output over the corrupted rerun's"
+          fi
+          if [ "${control_rc}" -eq 0 ]; then
+            echo "::error::MOBILEGL_PIPE_VERIFY_CORRUPT=GetRenderStateParameters left the OpenRA retrace GREEN, so the comparator is not comparing and the whole verify retrace lane proves nothing."
+            exit 1
+          fi
+          echo "the corrupted field turned the retrace red, as it must (ctest exit ${control_rc})"
+
+      - name: Upload core dumps
+        if: failure()
+        uses: actions/upload-artifact@v7
+        with:
+          name: retrace-verify-core-dumps-${{ matrix.backend }}-${{ matrix.case }}
+          path: /tmp/core.*
+          if-no-files-found: ignore
+
+      - name: Upload actual image
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: retrace-verify-result-${{ matrix.backend }}-${{ matrix.case }}
+          path: |
+            build-retrace/tools/trace_replay/${{ matrix.case }}/actual-images/**
+            build-retrace/tools/trace_replay/${{ matrix.case }}/${{ matrix.backend }}/output/**
+          if-no-files-found: warn
+
+  # G1's own job: the pull build must be the tree before P1, symbol for symbol and byte for byte.
+  # workflow_dispatch only - it builds the library twice from scratch, and its answer is about a
+  # BASELINE rather than about this push, so a per-push run would be measuring the wrong pair.
+  monolith-symbol-report:
+    name: monolith symbol report
+    runs-on: ubuntu-latest
+    timeout-minutes: 180
+    if: ${{ github.event_name == 'workflow_dispatch' }}
+    env:
+      CCACHE_BASEDIR: ${{ github.workspace }}
+      CCACHE_COMPRESS: "true"
+      CCACHE_DIR: ${{ github.workspace }}/.ccache
+      CCACHE_MAXSIZE: 4G
+      CCACHE_NOHASHDIR: "true"
+
+    steps:
+      - name: Set Swap Space
+        uses: pierotofy/set-swap-space@v1.0
+        with:
+          swap-size-gb: 32
+
+      - name: Checkout repo
+        uses: actions/checkout@v6
+        with:
+          submodules: recursive
+          fetch-depth: 0
+
+      - name: Get CMake
+        uses: lukka/get-cmake@v4.3.3
+
+      - name: Restore ccache
+        uses: actions/cache/restore@v5
+        with:
+          path: .ccache
+          key: ${{ runner.os }}-test-${{ github.job }}-ccache-v1
+          restore-keys: |
+            ${{ runner.os }}-test-${{ github.job }}-ccache-
+
+      - name: Prepare Vulkan SDK
+        uses: humbletim/setup-vulkan-sdk@v1.2.1
+        with:
+          vulkan-query-version: 1.4.304.1
+          vulkan-components: Vulkan-Headers, Vulkan-Loader
+          vulkan-use-cache: true
+
+      - name: Install build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y ccache clang-20 clang++-20 lld-20 libc++-20-dev libc++abi-20-dev libvulkan-dev libegl1-mesa-dev libgles2-mesa-dev libgl1-mesa-dri mesa-vulkan-drivers ninja-build binutils
+
+      # Both sides with IDENTICAL flags, LTO off, the same compiler and the same standard library:
+      # symbol_report.py's guard rails (scripts/symbol_report.py) say a mismatched pair "adds"
+      # thousands of symbols and the comparison then means nothing. The library alone - no tests,
+      # no benchmark, no integration test, no trace replay - because those targets do not ship.
+      - name: Build the baseline library (${{ inputs.baseline_sha }})
+        run: |
+          git worktree add ../baseline "${{ inputs.baseline_sha }}"
+          cd ../baseline
+          git submodule update --init --recursive
+          (cd 3rdparty/glslang && python update_glslang_sources.py)
+          cmake -S . -B build-sym-base -G Ninja \
+            -DCMAKE_C_COMPILER=clang-20 -DCMAKE_CXX_COMPILER=clang++-20 \
+            -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DMOBILEGL_LOG_ACTIVE_LEVEL=MOBILEGL_LOG_LEVEL_INFO \
+            -DMOBILEGL_BUILD_TEST=OFF -DMOBILEGL_BUILD_BENCHMARK=OFF \
+            -DMOBILEGL_BUILD_INTEGRATION_TEST=OFF -DMOBILEGL_BUILD_TRACE_REPLAY=OFF \
+            -DMOBILEGL_BUILD_DISAGGREGATED=OFF \
+            -DMOBILEGL_PIPE_PUSH=OFF -DMOBILEGL_PIPE_VERIFY=OFF \
+            -DMOBILEGL_ENABLE_LTO=OFF \
+            -DCMAKE_POLICY_VERSION_MINIMUM=3.5
+          cmake --build build-sym-base --parallel "$(nproc)"
+          cp build-sym-base/libMobileGL.so "${GITHUB_WORKSPACE}/libMobileGL-baseline.so"
+
+      - name: Build the head library
+        run: |
+          (cd 3rdparty/glslang && python update_glslang_sources.py)
+          cmake -S . -B build-sym-head -G Ninja \
+            -DCMAKE_C_COMPILER=clang-20 -DCMAKE_CXX_COMPILER=clang++-20 \
+            -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DMOBILEGL_LOG_ACTIVE_LEVEL=MOBILEGL_LOG_LEVEL_INFO \
+            -DMOBILEGL_BUILD_TEST=OFF -DMOBILEGL_BUILD_BENCHMARK=OFF \
+            -DMOBILEGL_BUILD_INTEGRATION_TEST=OFF -DMOBILEGL_BUILD_TRACE_REPLAY=OFF \
+            -DMOBILEGL_BUILD_DISAGGREGATED=OFF \
+            -DMOBILEGL_PIPE_PUSH=OFF -DMOBILEGL_PIPE_VERIFY=OFF \
+            -DMOBILEGL_ENABLE_LTO=OFF \
+            -DCMAKE_POLICY_VERSION_MINIMUM=3.5
+          cmake --build build-sym-head --parallel "$(nproc)"
+
+      # The monolith must not have grown a remote half. ARCHITECTURE.md:506: MG_Remote lives behind
+      # MOBILEGL_BUILD_DISAGGREGATED and nothing of it may reach a shipped pull build.
+      - name: No MG_Remote in the pull build
+        run: |
+          if nm --defined-only build-sym-head/libMobileGL.so | grep -q MG_Remote; then
+            echo "::error::the pull build defines MG_Remote symbols; the disaggregated half leaked into the monolith"
+            nm --defined-only build-sym-head/libMobileGL.so | grep MG_Remote | head -20
+            exit 1
+          fi
+          echo "no MG_Remote symbols in the pull build"
+
+      - name: Symbol report (G1)
+        run: |
+          python3 scripts/symbol_report.py \
+            --before libMobileGL-baseline.so \
+            --after build-sym-head/libMobileGL.so \
+            --threshold 0 \
+            --fail-on-symbol-set-change \
+            --fail-on-added-bytes 0 \
+            --markdown symbol-report.md \
+            --json symbol-report.json
+
+      - name: Upload the symbol report
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: monolith-symbol-report
+          path: |
+            symbol-report.md
+            symbol-report.json
+          if-no-files-found: error
+
   remove-artifact-clutter:
     name: remove artifact clutter
     runs-on: ubuntu-latest
-    needs: retrace-summary
+    # (d) retrace-verify too: this job deletes the trace-fixture-* artifacts, and the verify
+    # retraces download the same ones.
+    needs:
+      - retrace-summary
+      - retrace-verify
     if: always()
     permissions:
       actions: write
@@ -730,14 +1434,19 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
         run: |
+          # Both retrace lanes, not just the pull one: `retrace verify (backend, case)` downloads
+          # the same trace-fixture-<case> artifact, and a failed verify retrace is exactly when
+          # someone needs that fixture to reproduce locally. The two prefixes are stripped in
+          # order, longest first, because "retrace (" is not a prefix of "retrace verify (".
           declare -A failed_cases=()
           while IFS= read -r job_name; do
-            case_name="${job_name#retrace (*, }"
+            case_name="${job_name#retrace verify (*, }"
+            case_name="${case_name#retrace (*, }"
             case_name="${case_name%)}"
             failed_cases["${case_name}"]=1
           done < <(
             gh api --paginate "repos/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}/jobs?per_page=100" \
-              --jq '.jobs[] | select(.name | startswith("retrace (")) | select(.conclusion == "failure" or .conclusion == "cancelled" or .conclusion == "timed_out" or .conclusion == "action_required") | .name'
+              --jq '.jobs[] | select((.name | startswith("retrace (")) or (.name | startswith("retrace verify ("))) | select(.conclusion == "failure" or .conclusion == "cancelled" or .conclusion == "timed_out" or .conclusion == "action_required") | .name'
           )
 
           if ((${#failed_cases[@]})); then
@@ -768,3 +1477,69 @@ jobs:
           )
 
           echo "Deleted ${deleted} intermediate Linux artifact(s); retained ${retained} failed-retrace fixture(s)."
+
+  pipe-gates:
+    name: MGPipe generators and hygiene gates
+    runs-on: ubuntu-latest
+    # Deliberately independent of build-linux: these are source-level gates, they take
+    # seconds, and a broken build must not hide a drifted interface.
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v6
+
+      # The seven generators all read MG_Pipe/*.def, so regenerating and diffing is what
+      # keeps the two interface tables, the wire records, the verify comparators, the
+      # PipeInputs field ids, the read-inventory coverage and the render-state member list
+      # from drifting apart from the catalogue. The generated files are committed
+      # deliberately: the build must not depend on python.
+      - name: Regenerate the MGPipe interface (G1-G7)
+        run: |
+          python3 scripts/gen_pipe.py
+          git diff --exit-code -- MobileGL/MG_Pipe/generated
+
+      # The generators' own negative controls: canned inputs that MUST trip each structural check
+      # (a field list that does not cover its struct's members, a verb set that is not the function
+      # table's). Regenerating and diffing above cannot see a check that silently stopped
+      # checking - a broken gate and a clean tree produce the same green.
+      - name: The MGPipe generators' checks can still fail
+        run: python3 scripts/gen_pipe.py --self-test
+
+      # The same question for the symbol tool the P1 gate is written in terms of.
+      - name: The symbol report's buckets and gates can still fail
+        run: python3 scripts/symbol_report.py --self-test
+
+      # Per-draw fprintf/printf instrumentation has repeatedly been committed by accident,
+      # once inside a mutex critical section. Nothing under these two trees prints to a
+      # stdio stream today - MGLOG_D compiles out in INFO builds and is the only channel
+      # they are allowed to use - so this gate starts with no exceptions, and any addition
+      # to it needs a reason in the pull request rather than a quiet whitelist entry. The
+      # alternation names every stdio spelling, not just the two that were committed:
+      # fprintf to either stream, printf, puts, and the iostream pair.
+      - name: No stdio instrumentation in MG_Backend or MG_State
+        run: |
+          if grep -rnE 'fprintf[[:space:]]*\((stderr|stdout)|(^|[^[:alnum:]_>.])printf[[:space:]]*\(|(^|[^[:alnum:]_>.:])puts[[:space:]]*\(|std::(cout|cerr)' \
+              MobileGL/MG_Backend MobileGL/MG_State; then
+            echo "::error::stdio instrumentation found; use MGLOG_D (compiled out in INFO builds)"
+            exit 1
+          fi
+          echo "no fprintf(stderr/stdout / printf( / puts( / std::cout|cerr under MobileGL/MG_Backend or MobileGL/MG_State"
+
+      # Informational: the frontend mutation surface an MGPipe aggregate generation has to
+      # cover. It becomes a gate in P2, when the mapping file exists to diff against
+      # (ROADMAP.md:18 puts the first mapping round in P2, not P1).
+      - name: MGPipe dirty-surface report
+        run: python3 scripts/gen_pipe_dirty_surface.py --summary
+
+      # Warning only for now: the disaggregation documents are still being written, and a
+      # lint that fails a rewrite in progress teaches people to ignore it. It becomes
+      # --strict when the documents settle.
+      - name: Documentation citation lint
+        run: |
+          shopt -s nullglob
+          documents=(docs/Disaggregated/*.md)
+          if [ ${#documents[@]} -eq 0 ]; then
+            echo "no disaggregation documents to check"
+            exit 0
+          fi
+          python3 scripts/check_doc_citations.py "${documents[@]}" || true

.gitmodules

@@ -34,3 +34,6 @@
 [submodule "include/ska"]
 	path = include/ska
 	url = https://github.com/MobileGL-Dev/flat_hash_map.git
+[submodule "3rdparty/flatbuffers"]
+	path = 3rdparty/flatbuffers
+	url = https://github.com/google/flatbuffers.git

CMakeLists.txt

@@ -14,6 +14,19 @@ option(MOBILEGL_ENABLE_TRACY      "Enable tracy for profiling"
 option(MOBILEGL_BUILD_TRACE_REPLAY "Build desktop apitrace replay runner"            OFF)
 option(MOBILEGL_TRACE_ANGLE_VARIANTS "Enable signed trace-APK ANGLE variant loading" OFF)
 option(MOBILEGL_IOS               "Build MobileGL for iOS instead of macOS when APPLE is set" OFF)
+# The disaggregated (two-process) shape. OFF is the shipping default and OFF
+# must stay byte-comparable to a tree without MG_Remote at all: nothing under
+# MobileGL/MG_Remote/ is compiled, no include path is added, and no library is
+# linked, so `nm --defined-only libMobileGL.so | grep -i MG_Remote` is empty.
+# That emptiness is one of the two byte-level equalities the plan's validation
+# gates keep (section 10.3).
+option(MOBILEGL_BUILD_DISAGGREGATED "Build the MG_Remote transport layer (two-process shape)" OFF)
+option(MOBILEGL_BUILD_SERVER_SPIKE "Build the P0 spike-A MobileGLServer delivery-chain executable (Android only)" OFF)
+# The PipeInputs strangler (ARCHITECTURE.md 9.2). OFF is the pull build and must stay
+# byte-identical to a tree without either option: MGB_CTX is the live GLContext, no
+# MGPipe/PipeInputs source is compiled, every MGP_FILL is ((void)0).
+option(MOBILEGL_PIPE_PUSH "Backends read frontend state through the MGPipe PipeInputs block instead of MG_State::pGLContext (ARCHITECTURE.md 9.2 phase A)" OFF)
+option(MOBILEGL_PIPE_VERIFY "Compile SnapshotFromGLContext() and the G4 per-verb shadow comparator; implies MOBILEGL_PIPE_PUSH; never shipped" OFF)
 set(MOBILEGL_LOG_ACTIVE_LEVEL "MOBILEGL_LOG_LEVEL_INFO" CACHE STRING "MobileGL active log level macro")
 set(MOBILEGL_VULKAN_LIBRARY "" CACHE FILEPATH "Vulkan loader/MoltenVK library to link for iOS builds")
 
@@ -238,6 +251,8 @@ set(SOURCE_FILES
 
     MobileGL/MG_Util/Metrics/BufferMetrics.cpp
 
+    MobileGL/MG_Util/Metrics/PipeStats.cpp
+
     MobileGL/MG_Util/Converters/GLToStr/GLEnumConverter.cpp
     MobileGL/MG_Util/Converters/EGLToStr/EGLEnumConverter.cpp
     MobileGL/MG_Util/Converters/MGToStr/DataTypeConverter.cpp
@@ -285,6 +300,7 @@ set(SOURCE_FILES
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/PackDoubleVertexInputsPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/FlattenXfbInterfaceBlocksPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/UniquifyIoBlockNamesPass.cpp
+    MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/StripIoBlockLocationsPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/SplitArrayVertexInputsPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/RebaseInstanceIndexPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/ZeroBaseVertexPass.cpp
@@ -306,6 +322,7 @@ set(SOURCE_FILES
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/LegalizeFragmentOutputIndexPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/LegalizeResourceArrayIndexPass.cpp
     MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/FlattenAtomicCounterBlockPass.cpp
+    MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/DemotePointSizePass.cpp
 
     MobileGL/MG_Util/BackendLoaders/OpenGL/Loader.cpp
     MobileGL/MG_Util/BackendLoaders/Vulkan/Loader.cpp
@@ -313,6 +330,7 @@ set(SOURCE_FILES
     MobileGL/MG_Util/SelfTest/DriverBugProbes.cpp
     MobileGL/MG_Util/SelfTest/DriverPost.cpp
     MobileGL/MG_Util/SelfTest/DriverPostIterationRPWitness.cpp
+    MobileGL/MG_Util/SelfTest/PrimitivesGeneratedNoXfbProbe.cpp
 
     MobileGL/MG_Util/Texture/PixelStoreProcessor.cpp
     MobileGL/MG_Util/Texture/TextureFormatProcessor.cpp
@@ -414,6 +432,65 @@ set(SOURCE_FILES
     MobileGL/MG_State/GLState/RenderbufferState/RenderbufferState.cpp
 )
 
+# ---------------------------------------------------------------------------
+# MG_Remote (disaggregated transport). Everything below is gated: with the
+# option OFF not one file here is compiled and no include path is added.
+# ---------------------------------------------------------------------------
+
+# FlatBuffers is a submodule and its runtime is header-only. Guard both ways:
+# a checkout without the submodule must configure and build, just without the
+# disaggregated shape, rather than fail with a missing-header error a hundred
+# lines later. Note this only checks for the RUNTIME headers - flatc is never
+# built here (see scripts/gen_protocol.py).
+if (MOBILEGL_BUILD_DISAGGREGATED AND
+    NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/flatbuffers/include/flatbuffers/flatbuffers.h")
+    message(WARNING
+        "MOBILEGL_BUILD_DISAGGREGATED=ON but 3rdparty/flatbuffers/include is missing. "
+        "Run `git submodule update --init 3rdparty/flatbuffers`. Building without the "
+        "disaggregated shape for this configure; the cached ON takes effect once the "
+        "submodule is present.")
+    # A NORMAL variable, deliberately not `CACHE BOOL ... FORCE`: forcing OFF into the cache
+    # made the plain re-configure after `git submodule update` stay OFF with no message at
+    # all. Shadowing the cache entry for this configure only keeps the operator's ON where it
+    # was, so the next configure - with the submodule there - honours it.
+    set(MOBILEGL_BUILD_DISAGGREGATED OFF)
+endif()
+
+# MOBILEGL_PIPE_VERIFY implies MOBILEGL_PIPE_PUSH: the comparator compares the pushed block
+# against a snapshot, so there has to be a pushed block. A normal variable, not a forced
+# cache write, for the same reason as the disaggregated fallback above.
+if (MOBILEGL_PIPE_VERIFY AND NOT MOBILEGL_PIPE_PUSH)
+    message(STATUS "MobileGL: MOBILEGL_PIPE_VERIFY=ON forces MOBILEGL_PIPE_PUSH ON for this configure")
+    set(MOBILEGL_PIPE_PUSH ON)
+endif()
+
+if (MOBILEGL_PIPE_PUSH)
+    message(STATUS "MobileGL: PipeInputs push ON, appending the MGPipe fill sources")
+    list(APPEND SOURCE_FILES
+        MobileGL/MG_Backend/MGPipe/PipeInputs.cpp
+        MobileGL/MG_Impl/Pipe/PipeFill.cpp
+    )
+endif()
+
+if (MOBILEGL_BUILD_DISAGGREGATED)
+    message(STATUS "MobileGL: disaggregated transport ON, appending MG_Remote sources")
+    list(APPEND SOURCE_FILES
+        MobileGL/MG_Remote/Transport/Ring.cpp
+        MobileGL/MG_Remote/Transport/Doorbell.cpp
+        MobileGL/MG_Remote/Transport/ShmSegment.cpp
+        # Both platform halves are listed unconditionally and each is empty on
+        # the other OS, so neither can rot behind an `if (WIN32)` nobody
+        # configures.
+        MobileGL/MG_Remote/Transport/ShmSegmentPosix.cpp
+        MobileGL/MG_Remote/Transport/ShmSegmentWin32.cpp
+        MobileGL/MG_Remote/Transport/FdPassing.cpp
+        MobileGL/MG_Remote/Transport/InProcessTransport.cpp
+        # Keeps MG_Util/Debug/Log.h - and through it the GL frontend's
+        # umbrella header - out of the header-only wire code (WireLog.h).
+        MobileGL/MG_Remote/Transport/WireLog.cpp
+    )
+endif()
+
 if (APPLE AND NOT MOBILEGL_IOS)
     list(APPEND SOURCE_FILES
         MobileGL/MG_Impl/CGLImpl/CGLImpl.cpp
@@ -464,11 +541,26 @@ set(MOBILEGL_COMPILE_DEF
         -DASIO_NO_DEPRECATED
 )
 
+if (MOBILEGL_BUILD_DISAGGREGATED)
+    list(APPEND MOBILEGL_COMPILE_DEF -DMOBILEGL_BUILD_DISAGGREGATED=1)
+endif()
+
+if (MOBILEGL_PIPE_PUSH)
+    list(APPEND MOBILEGL_COMPILE_DEF -DMOBILEGL_PIPE_PUSH=1)
+endif()
+if (MOBILEGL_PIPE_VERIFY)
+    list(APPEND MOBILEGL_COMPILE_DEF -DMOBILEGL_PIPE_VERIFY=1)
+endif()
+
 message(STATUS "MOBILEGL_COMPILE_DEF=${MOBILEGL_COMPILE_DEF}")
 
 set(MOBILEGL_INCLUDE_DIR
         ${CMAKE_SOURCE_DIR}/include
         ${CMAKE_SOURCE_DIR}/MobileGL
+        # The MGPipe boundary headers. They are reachable as <MG_Pipe/MGPipe.h> through the
+        # line above too; this entry lets the client, the backends and MG_Remote spell them
+        # as <MGPipe.h> once MG_Pipe stops being a leaf of the frontend tree.
+        ${CMAKE_SOURCE_DIR}/MobileGL/MG_Pipe
         ${spirv-tools_SOURCE_DIR}
         ${spirv-tools_SOURCE_DIR}/include
         ${spirv-tools_BINARY_DIR}
@@ -479,6 +571,13 @@ set(MOBILEGL_INCLUDE_DIR
         ${CMAKE_SOURCE_DIR}/3rdparty/asio/include
 )
 
+if (MOBILEGL_BUILD_DISAGGREGATED)
+    # Header-only runtime: an include path, no add_subdirectory, no link
+    # target, and above all no flatc in the build graph. protocol_generated.h
+    # is committed and regenerated by scripts/gen_protocol.py.
+    list(APPEND MOBILEGL_INCLUDE_DIR ${CMAKE_SOURCE_DIR}/3rdparty/flatbuffers/include)
+endif()
+
 add_library(${CMAKE_PROJECT_NAME} SHARED
     ${SOURCE_FILES}
 )
@@ -695,3 +794,43 @@ endif()
 if (ANDROID AND MOBILEGL_BUILD_INTEGRATION_TEST)
     add_subdirectory(MobileGL/MG_IntegrationTest)
 endif()
+
+# ---------------------------------------------------------------------------
+# P0 spike A: the Android delivery chain for a second native executable.
+#
+# The disaggregated design needs a server process on Android (PLAN-B.md §8.1,
+# inheriting PLAN.md §11.1-§11.6). An APK's only exec-able install location is
+# lib/<abi>/, and the packager only puts a file there if it is named lib*.so -
+# so a second executable has to be built with an .so name and exec'd out of
+# getApplicationInfo().nativeLibraryDir. This target is the stub that proves the
+# chain end to end: it is packaged like a library, exec'd from the app's own
+# untrusted_app process, and writes a marker the parent reads back.
+#
+# Off by default and ANDROID-only, so no shipping configuration builds it. The
+# trace flavour of the plugin APK turns it on (android-plugin/build.gradle).
+# ---------------------------------------------------------------------------
+if (ANDROID AND MOBILEGL_BUILD_SERVER_SPIKE)
+    add_executable(MobileGLServer
+        ${CMAKE_CURRENT_SOURCE_DIR}/tools/spikes/server_stub/main.cpp)
+
+    # An executable that is named like a shared library still has to be a real
+    # PIE executable: Android has refused non-PIE executables since API 21, and
+    # the name alone does not change what the loader demands of the file.
+    set_target_properties(MobileGLServer PROPERTIES
+        PREFIX "lib"
+        SUFFIX ".so"
+        OUTPUT_NAME "MobileGLServer"
+        POSITION_INDEPENDENT_CODE ON)
+    target_compile_options(MobileGLServer PRIVATE -fPIE)
+    target_link_options(MobileGLServer PRIVATE -pie)
+
+    # AGP packages what the external native build drops into the per-ABI output
+    # directory, and it selects by the .so extension. CMake puts executables in
+    # CMAKE_RUNTIME_OUTPUT_DIRECTORY, which is not the directory AGP hands to
+    # CMAKE_LIBRARY_OUTPUT_DIRECTORY, so point this target's runtime output at
+    # the library directory when the generator gave us one.
+    if (CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+        set_target_properties(MobileGLServer PROPERTIES
+            RUNTIME_OUTPUT_DIRECTORY "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}")
+    endif()
+endif()

MobileGL/Config.h

@@ -69,34 +69,34 @@ namespace MobileGL::MG_Config {
     struct FeaturesTable {
         // MOBILEGL_DISABLE_TIMERQUERY: do not advertise or use GPU timer queries.
         Bool DisableTimerQuery = false;
-        // MOBILEGL_ENABLE_GLES_TEXTURE_VIEW: advertise GL_ARB_texture_view on DirectGLES when
+        // MOBILEGL_ESPRYT_ENABLE_TEXTURE_VIEW: advertise GL_ARB_texture_view on DirectGLES when
         // the host ES driver has EXT/OES_texture_view. Off by default: the host extension is
         // present on Adreno 830 and the functional half of KHR-GL4{2,3}.texture_view still fails
         // there, because the view's ES internalformat is normalized independently of the storage
         // it aliases (see BackendObject_DirectGLES::BuildAdvertisedExtensions). The flag exists
         // so that work can be done without editing the gate.
-        Bool EnableGlesTextureView = false;
+        Bool EsprytEnableTextureView = false;
         // MOBILEGL_ENABLE_SPIRV_VALIDATION: validate generated and transformed SPIR-V.
         // Disabled by default because validation is a diagnostics-only cost.
         Bool EnableSpirvValidation = false;
-        // MOBILEGL_USE_ANGLE: load ANGLE EGL/GLES libraries.
-        Bool UseAngle = false;
+        // MOBILEGL_ESPRYT_USE_ANGLE: load ANGLE EGL/GLES libraries.
+        Bool EsprytUseAngle = false;
 #if defined(MOBILEGL_TRACE_ANGLE_VARIANTS)
         // MOBILEGL_TRACE_ANGLE_VARIANT: signed trace-APK ANGLE build short hash.
         String TraceAngleVariant;
 #endif
-        // MOBILEGL_DISABLE_SUBGROUP: force-disable Vulkan shader subgroup support,
+        // MOBILEGL_MAGMA_DISABLE_SUBGROUP: force-disable Vulkan shader subgroup support,
         // including the opt-in emulated compute path below.
-        Bool DisableSubgroup = false;
+        Bool MagmaDisableSubgroup = false;
         // MOBILEGL_MAGMA_EMULATE_SUBGROUP: implement GL_KHR_shader_subgroup's compute
         // stage on a 32-lane VIRTUAL subgroup lowered to workgroup-shared memory
         // (ShaderTranspiler::EmulateSubgroupsPass). Strictly a last resort: it only ever
         // engages when this flag is set AND the device has no native subgroup support at
         // all - a device with real subgroup operations always uses them natively,
         // whatever their width (the known iterationRP defect is patched by
-        // FixIterationRPSubgroupScratch below instead). Off by default.
+        // MagmaFixIterationRPSubgroupScratch below instead). Off by default.
         Bool MagmaEmulateSubgroup = false;
-        // MOBILEGL_FIX_ITERATIONRP_SUBGROUP_SCRATCH: patch iterationRP's own bug - the
+        // MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH: patch iterationRP's own bug - the
         // pack declares `shared vec2 prefixSumCache[32]` for a 512-invocation exposure
         // reduction and indexes it by gl_SubgroupID, so any device with sub-16-lane
         // subgroups (8-lane lavapipe -> 64 subgroups) writes shared memory out of
@@ -106,12 +106,12 @@ namespace MobileGL::MG_Config {
         // so every other shader passes through byte-identical - as does iterationRP
         // itself on >= 16-lane devices. Auto is ON; ForceOff replays the pack's bug
         // verbatim.
-        QuirkOverride FixIterationRPSubgroupScratch = QuirkOverride::Auto;
-        // MOBILEGL_ITERATIONRP_FIX_BARRIER: repair Program 203's missing workgroup
+        QuirkOverride MagmaFixIterationRPSubgroupScratch = QuirkOverride::Auto;
+        // MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER: repair Program 203's missing workgroup
         // rendezvous between its two reductions over prefixSumCache. Off by default and
         // fingerprint-gated by FixIterationRPBarrierPass when enabled.
-        Bool IterationRPFixBarrier = false;
-        // MOBILEGL_DERIVE_NUM_SUBGROUPS: replace compute gl_NumSubgroups loads with
+        Bool MagmaIterationRPFixBarrier = false;
+        // MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS: replace compute gl_NumSubgroups loads with
         // ceil(workgroup invocations / gl_SubgroupSize) on the NATIVE subgroup path
         // (ShaderTranspiler::DeriveNumSubgroupsPass). Auto is ON: GL requires
         // gl_SubgroupID < gl_NumSubgroups, Adreno's builtin reports 1 while the same
@@ -119,7 +119,7 @@ namespace MobileGL::MG_Config {
         // whenever the pipeline can request REQUIRE_FULL_SUBGROUPS (which the renderer
         // does whenever local_size_x is a multiple of the native width). ForceOff returns
         // to the raw driver builtin.
-        QuirkOverride DeriveNumSubgroups = QuirkOverride::Auto;
+        QuirkOverride MagmaDeriveNumSubgroups = QuirkOverride::Auto;
         // MOBILEGL_ADVERTISE_FP64: add GL_ARB_gpu_shader_fp64 to the advertised extension
         // string. `double` in a shader always WORKS - it is narrowed to 32 bits before any
         // module reaches a backend (ShaderTranspiler::DemoteFloat64Pass) - but the extension
@@ -132,16 +132,39 @@ namespace MobileGL::MG_Config {
         Bool MagmaR11G11B10FFallback = false;
         // MOBILEGL_MAGMA_FRAMESINFLIGHT: requested Magma frames in flight, defaulting to 3.
         Uint32 MagmaFramesInFlight = 3;
-        // MOBILEGL_AVOID_SAMPLER_MIPMAP_MIN_FILTER: avoid mipmap min filters in samplers,
+        // MOBILEGL_ESPRYT_AVOID_SAMPLER_MIPMAP_MIN_FILTER: avoid mipmap min filters in samplers,
         // resolves certain rendering bugs on ANGLE + llvmpipe.
-        Bool AvoidSamplerMipmapMinFilter = false;
-        // MOBILEGL_AVOID_EXPLICIT_LOD_BIAS: leave an already-explicit LOD argument alone when
+        Bool EsprytAvoidSamplerMipmapMinFilter = false;
+        // MOBILEGL_ESPRYT_AVOID_EXPLICIT_LOD_BIAS: leave an already-explicit LOD argument alone when
         // emulating GL_TEXTURE_LOD_BIAS, instead of adding the bias uniform to it. Injecting
         // the uniform turns a compile-time-constant LOD into a runtime expression, which
         // sends ANGLE + llvmpipe down a mip-selection path that dereferences a NULL
         // descriptor and kills the process. Deviates from spec (Vulkan adds the bias to
         // OpImageSampleExplicitLod), so it is an avoidance for that stack only.
-        Bool AvoidExplicitLodBias = false;
+        Bool EsprytAvoidExplicitLodBias = false;
+        // MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS: emit a tessellation/geometry program's
+        // inter-stage interface blocks WITHOUT their layout(location=) qualifier, letting ES
+        // match them by block name and member sequence instead. The Mali ES driver delivers
+        // nothing at all through a located block once a tessellation or geometry stage is in
+        // the pipeline; the driver POST measures that and turns this on by itself, so Auto is
+        // the right setting everywhere. ForceOn exists so the emulation can be exercised on a
+        // healthy driver - which is what the integration lane does, since llvmpipe and
+        // lavapipe carry a located block correctly and would otherwise never run this code -
+        // and ForceOff is the negative control. See StripIoBlockLocationsPass.
+        QuirkOverride EsprytUnlocatedIoBlocks = QuirkOverride::Auto;
+        // MOBILEGL_POINT_SIZE_DEMOTION: demote gl_PointSize out of tessellation/geometry
+        // stages into an ordinary varying (ShaderCompiler::
+        // DemoteTessellationGeometryPointSizeForProgram) instead of declining such programs
+        // on a device that advertises neither EXT/OES_tessellation_point_size /
+        // geometry_point_size (DirectGLES) nor shaderTessellationAndGeometryPointSize
+        // (DirectVulkan). Auto arms it exactly where the detection says the capability is
+        // absent, which is the right setting everywhere. ForceOn exists so the demotion can
+        // be exercised on a healthy driver - llvmpipe and lavapipe host the built-in
+        // natively and would otherwise never run this code, which is what the pinned
+        // integration lane uses - and ForceOff restores the plain declines (escape hatch /
+        // negative control). Cross-backend by design: the demotion runs in the shared
+        // phase-B chain, so one switch covers both. See DemotePointSizePass.
+        QuirkOverride PointSizeDemotion = QuirkOverride::Auto;
         // MOBILEGL_COHERENT_AS_FLUSH: app-compat for engines (e.g. Flywheel) that write
         // GPU-read data through persistent GL_MAP_FLUSH_EXPLICIT_BIT maps they never
         // flush. Persistent FLUSH_EXPLICIT map requests are rewritten to coherent
@@ -151,15 +174,38 @@ namespace MobileGL::MG_Config {
         Bool CoherentAsFlush = false;
         // MOBILEGL_TRACE_SKIP_AUTODESTROY: skip teardown in the ELF destructor (Init.cpp).
         Bool TraceSkipAutodestroy = false;
-        // MOBILEGL_DISABLE_UBO_RING: force the DirectGLES global-UBO upload back to the
+        // MOBILEGL_ESPRYT_DISABLE_UBO_RING: force the DirectGLES global-UBO upload back to the
         // per-draw glBufferSubData path instead of the persistent-mapped ring allocator
         // (negative control / driver-bug escape hatch).
-        Bool DisableUboRing = false;
-        // MOBILEGL_DISABLE_UNPACK_RING: force DirectGLES texture uploads back to
+        Bool EsprytDisableUboRing = false;
+        // MOBILEGL_ESPRYT_DISABLE_UNPACK_RING: force DirectGLES texture uploads back to
         // glTexSubImage from the client pointer instead of staging them through the
         // persistent-mapped unpack-PBO ring (negative control / driver-bug escape
         // hatch).
-        Bool DisableUnpackRing = false;
+        Bool EsprytDisableUnpackRing = false;
+        // MOBILEGL_ESPRYT_DISABLE_UPLOAD_RING: force DirectGLES app buffer updates
+        // (glBufferSubData / map flushes) back to the immediate driver upload instead
+        // of queueing them for the staged-copy flush through the persistent-mapped
+        // upload ring (negative control / driver-bug escape hatch; the immediate
+        // upload stalls on drivers that resolve the WAR hazard on the CPU, e.g. Mali).
+        Bool EsprytDisableUploadRing = false;
+        // MOBILEGL_ESPRYT_DISABLE_INVALIDATE_FLUSH: skip the glMapBufferRange(WRITE |
+        // INVALIDATE_RANGE) tier of the DirectGLES pending-range flush and go straight
+        // to the upload ring's staged glCopyBufferSubData (negative control / escape
+        // hatch for a driver whose range-invalidating map misbehaves). The map tier is
+        // what keeps a partial write into a large in-flight buffer priced by the RANGE:
+        // on Mali both the immediate glBufferSubData and a staged copy into a busy
+        // mutable store ghost the whole destination on the CPU.
+        Bool EsprytDisableInvalidateFlush = false;
+        // MOBILEGL_DISABLE_LARGE_BUFFER_ADOPTION: keep mesh-arena-sized buffer stores
+        // (>= 16MiB) on the CPU-shadow model instead of backing them with the backend's
+        // persistently+coherently mapped storage at definition time (negative control /
+        // escape hatch). Frontend-scoped: it engages only where the active backend
+        // provides AcquirePersistentMap. With adoption on, an app SubData into a busy
+        // 128MB arena is a plain memcpy into GPU-visible memory; every driver-mediated
+        // route for the same write stalls the thread or ghost-copies the whole arena on
+        // this class of Mali driver, and the arena stops costing its size again in RAM.
+        Bool DisableLargeBufferAdoption = false;
         // MOBILEGL_ESPRYT_FORCE_DS_READBACK_EMULATION: make DirectGLES skip the native ES
         // depth/stencil reads and always go through the shader-sampling emulation. Core GL
         // ES has no depth or stencil readback, but some drivers accept it anyway (Mesa does,
@@ -180,10 +226,10 @@ namespace MobileGL::MG_Config {
         // gl_FragDepth writers, and fully color-masked attachments are exempt (see
         // PipelineFactory::ShouldSuppressDepthWrite). Auto detects Qualcomm.
         QuirkOverride MagmaDisableBlendedDepthWriteQuirk = QuirkOverride::Auto;
-        // MOBILEGL_DISABLE_ROBUST_BUFFER_ACCESS: leave the Vulkan robustBufferAccess device
+        // MOBILEGL_MAGMA_DISABLE_ROBUST_BUFFER_ACCESS: leave the Vulkan robustBufferAccess device
         // feature off. It is enabled by default to match GL's defined out-of-range fetch
         // behavior; this escape hatch exists to measure or dodge its GPU cost on a device.
-        Bool DisableRobustBufferAccess = false;
+        Bool MagmaDisableRobustBufferAccess = false;
         // MOBILEGL_MAGMA_MULTIDRAW_MODE: preferred DirectVulkan multi-draw dispatch tier
         // ("ext" | "indirect" | "unroll", see MultiDrawMode). Clamped to device support;
         // unset picks the best supported tier.
@@ -224,7 +270,7 @@ namespace MobileGL::MG_Config {
         // miscompiled shader: if a device ever renders differently with the cache
         // on, one run with this falsy says so.
         QuirkOverride ShaderTranslationCache = QuirkOverride::Auto;
-        // MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION: DirectGLES' gl_ViewportIndex routing
+        // MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION: DirectGLES' gl_ViewportIndex routing
         // emulation - the builtin becomes a flat varying, the fragment stage gets a
         // per-pass gate, and a routed draw is REPLAYED once per distinct viewport state
         // with the real glViewport/glScissor/glDepthRangef set for it. Auto is ON, and
@@ -236,7 +282,100 @@ namespace MobileGL::MG_Config {
         // the pre-emulation path, extension passthrough where it exists and
         // LowerViewportIndexPass' demote-to-a-plain-global where it does not - and is
         // the negative control the emulation is measured against.
-        QuirkOverride ViewportArrayEmulation = QuirkOverride::Auto;
+        QuirkOverride EsprytViewportArrayEmulation = QuirkOverride::Auto;
+        // MOBILEGL_ESPRYT_WIDEN_PACKED16_STORAGE: DirectGLES stores GL_RGB565/GL_RGB5(A1)/GL_RGBA4
+        // images as 8-bit-per-channel ES storage (GL_RGB8/GL_RGBA8) instead of the driver's
+        // native 16-bit packed formats. Auto defers to a POST driver-bug probe
+        // (SelfTest::CopyImageMirrorsPacked16FieldOrder): some Mali drivers store SOME
+        // packed16 allocations with a MIRRORED field order (allocation-scoped and
+        // shape/context dependent - the failing 30x30x12 GL_TEXTURE_2D_ARRAYs are mirrored
+        // at every level), so glCopyImageSubData - a raw texel-block move - lands R/G/B/A
+        // reversed whenever exactly one endpoint sits in a mirrored allocation
+        // (KHR-GL4x.copy_image.functional rgb5/rgb5_a1/rgba4 x every *2d_array* pair).
+        // With no 16-bit packed ES image left there is no field order to disagree about; the
+        // client word still round-trips exactly, because the canonical shadow is already
+        // UNorm8 and an n-bit field encodes to UNorm8 and back losslessly for n <= 8.
+        // ForceOn widens on any driver (the llvmpipe suites use it to exercise the widened
+        // path); ForceOff keeps the native narrow storage even where the probe fires - the
+        // negative control that replays the corruption. Costs 2x the memory of the affected
+        // formats where it engages, which is why Auto is probe-gated rather than always-on.
+        QuirkOverride EsprytWidenPacked16Storage = QuirkOverride::Auto;
+        // MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE: DirectVulkan's GL_PRIMITIVES_GENERATED
+        // reroute for draws made while transform feedback is INACTIVE. The stream query
+        // (VK_QUERY_TYPE_TRANSFORM_FEEDBACK_STREAM_EXT primitivesNeeded) is defined to count
+        // them, but a Mali driver - and Mesa lavapipe - answers 0 unless a capture span is
+        // open, which is exactly the shape the CTS uses to measure the tessellator, so ~29
+        // tessellation tests per tree size a capture buffer from the 0 and die on the
+        // zero-length map. Auto defers to a device probe at renderer bring-up
+        // (SelfTest::RunPrimitivesGeneratedNoXfbProbe), which measures two substitutes on
+        // the same capture-less draws and arms the best proven one: the dedicated
+        // VK_EXT_primitives_generated_query (exact semantics by definition; lavapipe passes
+        // it, rasterizer discard included), else a clipping-invocations pipeline-statistics
+        // pool (see the verdict vocabulary for its rasterizer-discard split). ForceOn pins
+        // the reroute structurally wherever a pool can exist (the arming-observable lane,
+        // immune to the probe's verdict moving), and ForceOff is the negative control that
+        // replays the driver's silence.
+        QuirkOverride MagmaPrimGenQueryReroute = QuirkOverride::Auto;
+        // --- MGPipe (the disaggregation plan's explicit frontend/backend boundary) ---
+        // MOBILEGL_PIPE_PUSH: per-subsystem bitmask selecting which state the frontend
+        // PUSHES over MGPipe instead of leaving the backend to pull it out of GLContext.
+        // 0 - the default and the only shipped value until the migration lands - is "pull
+        // everything", i.e. exactly today's behaviour. One bit of it also turns OFF
+        // client-side content addressing of CSOs, which is the negative control the CSO
+        // design is measured against. Accepts decimal or 0x-prefixed hex.
+        Uint64 PipePush = 0;
+        // MOBILEGL_PIPE_VERIFY: per-draw, per-FIELD shadow comparison of the pushed state
+        // against a snapshot taken from GLContext the old way, printing the first field
+        // that differs and the draw serial. Roughly 5-10x slower and never shipped; it is
+        // the semantic gate that replaces byte identity, and it catches the dangerous
+        // direction - a dirty bit that fires too RARELY - which no purity gate can see.
+        Bool PipeVerify = false;
+#if MOBILEGL_PIPE_PUSH
+        // The three knobs of the MOBILEGL_PIPE_VERIFY build (P1 brief D2). Compiled only
+        // under MOBILEGL_PIPE_PUSH so the pull build's FeaturesTable does not change size.
+        // MOBILEGL_PIPE_VERIFY_FATAL: the first divergence aborts (default). 0 logs and
+        // counts instead, for triage and for the lane that must survive to read its own
+        // log. Tri-state parse like PipeLegacyMemos: only an explicit falsy value turns it
+        // off.
+        Bool PipeVerifyFatal = true;
+        // MOBILEGL_PIPE_VERIFY_CORRUPT: a field name from kMGPipeInputFieldNames[]; the
+        // comparator perturbs that field in the SNAPSHOT arm before the entry compare, so a
+        // green verify run goes red naming it (negative control A). Unknown name is
+        // Fatal{PipeVerifyBadKnob}.
+        String PipeVerifyCorrupt;
+        // MOBILEGL_PIPE_POISON_OMIT: <Verb>:<FieldName>; the filler skips the STAMP (not
+        // the value) of that field for that verb, an omission indistinguishable from a
+        // forgotten FillPoints.def row, so that verb's read of it is
+        // Fatal{UnmigratedPipeInput} (negative control B). Unknown name is
+        // Fatal{PipeVerifyBadKnob}.
+        String PipePoisonOmit;
+#endif
+        // MOBILEGL_PIPE_STATS: dump the boundary counters (bytes, calls, roundtrips,
+        // texture pulls, upload shapes, residual-block bytes, index mirror bytes).
+        Bool PipeStats = false;
+        // MOBILEGL_PIPE_LEGACY_MEMOS: keep the pre-handle registries and TwinLookupMemos
+        // alive so the first handle waves have a real old-versus-new arm to be compared
+        // against. ON by default for the whole migration window, deleted with the pull
+        // path itself.
+        Bool PipeLegacyMemos = true;
+        // MOBILEGL_PIPE_TEXEL_RETAIN_MB: LRU budget for texels retained against a
+        // server-initiated texture re-send. Default 0, i.e. OFF: MipmapStorage already
+        // holds a complete CPU shadow, so this cache buys latency, never correctness.
+        Uint32 PipeTexelRetainMb = 0;
+        // MOBILEGL_PIPE_INDEX_MIRROR_MB: budget for the server-side index host mirror,
+        // which is what lets primitive-restart rewriting and multi-draw flattening stay on
+        // the server without shipping index bytes per draw. Over budget it degrades to
+        // per-draw staging, counted separately in the stats.
+        Uint32 PipeIndexMirrorMb = 64;
+        // MOBILEGL_PIPE_STATS_PERIOD: frames per boundary-counter summary line. 120 is the
+        // steady-state cadence; the device retrace harness never reaches the teardown dump
+        // and a trimmed fixture (create-indirect) is shorter than 120 frames, so a run that
+        // needs its numbers at all sets this low enough to land at least one window.
+        Uint32 PipeStatsPeriod = 120;
+        // MOBILEGL_PIPE_STATS_FILE: where the boundary counters' teardown JSON dump goes.
+        // Empty (the default) means no dump; the per-120-frame summary line still goes to
+        // the log whenever PipeStats is on, so a device run needs no writable path.
+        String PipeStatsFile;
     };
     extern FeaturesTable Features;
 } // namespace MobileGL::MG_Config

MobileGL/ConfigLoader.cpp

@@ -159,37 +159,74 @@ namespace MobileGL::MG_ConfigLoader {
         return static_cast<Uint32>(parsedValue);
     }
 
+    // Same contract as QueryEnvUint32, over 64 bits and accepting an explicit 0x prefix: the
+    // one consumer is a subsystem BITMASK, and a bitmask written in decimal is unreadable.
+    // Decimal otherwise - never strtoull's base 0, whose "leading zero means octal" rule
+    // silently read MOBILEGL_PIPE_PUSH=010 as 8 - and a '-' anywhere is rejected rather than
+    // wrapped, which strtoull would otherwise do without complaint (-1 -> every bit set).
+    inline Uint64 QueryEnvUint64(const String& key, Uint64 defaultValue) {
+        auto it = acceptedEnvVariablesMap->find(key);
+        if (it == acceptedEnvVariablesMap->end()) {
+            return defaultValue;
+        }
+
+        const String& value = it->second;
+        const char* text = value.c_str();
+        int base = 10;
+        if (value.size() > 2 && text[0] == '0' && (text[1] == 'x' || text[1] == 'X')) {
+            text += 2;
+            base = 16;
+        }
+        char* parseEnd = nullptr;
+        errno = 0;
+        const bool negative = value.find('-') != String::npos;
+        const unsigned long long parsedValue = negative ? 0 : std::strtoull(text, &parseEnd, base);
+        if (negative || parseEnd == text || *parseEnd != '\0' || errno == ERANGE) {
+            MGLOG_W("Config: Ignoring invalid env variable %s='%s'; expected a non-negative integer "
+                    "(decimal, or 0x-prefixed hexadecimal), using default %llu",
+                    key.c_str(), value.c_str(), static_cast<unsigned long long>(defaultValue));
+            return defaultValue;
+        }
+
+        return static_cast<Uint64>(parsedValue);
+    }
+
     inline void InitFeatures() {
         auto& features = MG_Config::Features;
         features.DisableTimerQuery = QueryEnvFlag("MOBILEGL_DISABLE_TIMERQUERY");
-        features.EnableGlesTextureView = QueryEnvFlag("MOBILEGL_ENABLE_GLES_TEXTURE_VIEW");
+        features.EsprytEnableTextureView = QueryEnvFlag("MOBILEGL_ESPRYT_ENABLE_TEXTURE_VIEW");
         features.EnableSpirvValidation = QueryEnvFlag("MOBILEGL_ENABLE_SPIRV_VALIDATION");
-        features.UseAngle = QueryEnvFlag("MOBILEGL_USE_ANGLE");
+        features.EsprytUseAngle = QueryEnvFlag("MOBILEGL_ESPRYT_USE_ANGLE");
 #if defined(MOBILEGL_TRACE_ANGLE_VARIANTS)
         QueryEnvVariable("MOBILEGL_TRACE_ANGLE_VARIANT", features.TraceAngleVariant, "");
 #endif
-        features.DisableSubgroup = QueryEnvFlag("MOBILEGL_DISABLE_SUBGROUP");
+        features.MagmaDisableSubgroup = QueryEnvFlag("MOBILEGL_MAGMA_DISABLE_SUBGROUP");
         features.MagmaEmulateSubgroup = QueryEnvFlag("MOBILEGL_MAGMA_EMULATE_SUBGROUP");
-        features.FixIterationRPSubgroupScratch =
-            QueryEnvQuirkOverride("MOBILEGL_FIX_ITERATIONRP_SUBGROUP_SCRATCH");
-        features.IterationRPFixBarrier = QueryEnvFlag("MOBILEGL_ITERATIONRP_FIX_BARRIER");
-        features.DeriveNumSubgroups = QueryEnvQuirkOverride("MOBILEGL_DERIVE_NUM_SUBGROUPS");
+        features.MagmaFixIterationRPSubgroupScratch =
+            QueryEnvQuirkOverride("MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH");
+        features.MagmaIterationRPFixBarrier = QueryEnvFlag("MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER");
+        features.MagmaDeriveNumSubgroups = QueryEnvQuirkOverride("MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS");
         features.AdvertiseFp64 = QueryEnvFlag("MOBILEGL_ADVERTISE_FP64");
         features.MagmaR11G11B10FFallback = QueryEnvFlag("MOBILEGL_MAGMA_R11G11B10F_FALLBACK");
         features.MagmaFramesInFlight = QueryEnvUint32("MOBILEGL_MAGMA_FRAMESINFLIGHT", 3, 1, 64);
-        features.AvoidSamplerMipmapMinFilter =
-            QueryEnvFlag("MOBILEGL_AVOID_SAMPLER_MIPMAP_MIN_FILTER");
-        features.AvoidExplicitLodBias = QueryEnvFlag("MOBILEGL_AVOID_EXPLICIT_LOD_BIAS");
+        features.EsprytAvoidSamplerMipmapMinFilter =
+            QueryEnvFlag("MOBILEGL_ESPRYT_AVOID_SAMPLER_MIPMAP_MIN_FILTER");
+        features.EsprytAvoidExplicitLodBias = QueryEnvFlag("MOBILEGL_ESPRYT_AVOID_EXPLICIT_LOD_BIAS");
+        features.EsprytUnlocatedIoBlocks = QueryEnvQuirkOverride("MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS");
+        features.PointSizeDemotion = QueryEnvQuirkOverride("MOBILEGL_POINT_SIZE_DEMOTION");
         features.CoherentAsFlush = QueryEnvFlag("MOBILEGL_COHERENT_AS_FLUSH");
         features.TraceSkipAutodestroy = QueryEnvFlag("MOBILEGL_TRACE_SKIP_AUTODESTROY");
-        features.DisableUboRing = QueryEnvFlag("MOBILEGL_DISABLE_UBO_RING");
-        features.DisableUnpackRing = QueryEnvFlag("MOBILEGL_DISABLE_UNPACK_RING");
+        features.EsprytDisableUboRing = QueryEnvFlag("MOBILEGL_ESPRYT_DISABLE_UBO_RING");
+        features.EsprytDisableUnpackRing = QueryEnvFlag("MOBILEGL_ESPRYT_DISABLE_UNPACK_RING");
+        features.EsprytDisableUploadRing = QueryEnvFlag("MOBILEGL_ESPRYT_DISABLE_UPLOAD_RING");
+        features.EsprytDisableInvalidateFlush = QueryEnvFlag("MOBILEGL_ESPRYT_DISABLE_INVALIDATE_FLUSH");
+        features.DisableLargeBufferAdoption = QueryEnvFlag("MOBILEGL_DISABLE_LARGE_BUFFER_ADOPTION");
         features.EsprytForceDepthStencilReadbackEmulation =
             QueryEnvFlag("MOBILEGL_ESPRYT_FORCE_DS_READBACK_EMULATION");
         features.RelaxedSemantics = QueryEnvFlag("MOBILEGL_RELAXED_SEMANTICS");
         features.MagmaDisableBlendedDepthWriteQuirk =
             QueryEnvQuirkOverride("MOBILEGL_MAGMA_DISABLE_BLENDED_DEPTH_WRITE");
-        features.DisableRobustBufferAccess = QueryEnvFlag("MOBILEGL_DISABLE_ROBUST_BUFFER_ACCESS");
+        features.MagmaDisableRobustBufferAccess = QueryEnvFlag("MOBILEGL_MAGMA_DISABLE_ROBUST_BUFFER_ACCESS");
         features.MagmaMultiDrawMode = QueryEnvMultiDrawMode("MOBILEGL_MAGMA_MULTIDRAW_MODE");
         features.EsprytMultiDrawMode = QueryEnvGLESMultiDrawMode("MOBILEGL_ESPRYT_MULTIDRAW_MODE");
         features.AsyncShaderCompile = QueryEnvQuirkOverride("MOBILEGL_ASYNC_SHADER_COMPILE");
@@ -197,8 +234,33 @@ namespace MobileGL::MG_ConfigLoader {
         features.AsyncOptimisticShaderStatus =
             QueryEnvQuirkOverride("MOBILEGL_ASYNC_OPTIMISTIC_SHADER_STATUS");
         features.ShaderTranslationCache = QueryEnvQuirkOverride("MOBILEGL_SHADER_CACHE");
-        features.ViewportArrayEmulation =
-            QueryEnvQuirkOverride("MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION");
+        features.EsprytViewportArrayEmulation =
+            QueryEnvQuirkOverride("MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION");
+        features.EsprytWidenPacked16Storage =
+            QueryEnvQuirkOverride("MOBILEGL_ESPRYT_WIDEN_PACKED16_STORAGE");
+        features.MagmaPrimGenQueryReroute = QueryEnvQuirkOverride("MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE");
+        // MGPipe. Nothing here needs adding to an allow-list: InitializeAcceptedEnvVariables
+        // accepts every MOBILEGL_ / LIBGL_ prefixed variable in the environment, so a name
+        // that starts with MOBILEGL_ is visible to these queries by construction.
+        features.PipePush = QueryEnvUint64("MOBILEGL_PIPE_PUSH", 0);
+        features.PipeVerify = QueryEnvFlag("MOBILEGL_PIPE_VERIFY");
+#if MOBILEGL_PIPE_PUSH
+        // Defaults ON: read as a tri-state so only an explicitly falsy value turns it off.
+        features.PipeVerifyFatal =
+            QueryEnvQuirkOverride("MOBILEGL_PIPE_VERIFY_FATAL") != MG_Config::QuirkOverride::ForceOff;
+        QueryEnvVariable("MOBILEGL_PIPE_VERIFY_CORRUPT", features.PipeVerifyCorrupt, "");
+        QueryEnvVariable("MOBILEGL_PIPE_POISON_OMIT", features.PipePoisonOmit, "");
+#endif
+        features.PipeStats = QueryEnvFlag("MOBILEGL_PIPE_STATS");
+        // Defaults ON, so the flag has to be read as a tri-state rather than as a plain
+        // truthy check: unset must keep the memos, and only an explicitly falsy value may
+        // drop them.
+        features.PipeLegacyMemos =
+            QueryEnvQuirkOverride("MOBILEGL_PIPE_LEGACY_MEMOS") != MG_Config::QuirkOverride::ForceOff;
+        features.PipeTexelRetainMb = QueryEnvUint32("MOBILEGL_PIPE_TEXEL_RETAIN_MB", 0, 0, 4096);
+        features.PipeIndexMirrorMb = QueryEnvUint32("MOBILEGL_PIPE_INDEX_MIRROR_MB", 64, 0, 4096);
+        features.PipeStatsPeriod = QueryEnvUint32("MOBILEGL_PIPE_STATS_PERIOD", 120, 1, 1000000);
+        QueryEnvVariable("MOBILEGL_PIPE_STATS_FILE", features.PipeStatsFile, "");
     }
 
     inline void InitBackendType() {

MobileGL/Init.cpp

@@ -17,6 +17,7 @@
 #include <MG_Impl/GLImpl/Sync/GL_Sync.h>
 #include <MG_Impl/GLImpl/Query/GL_Query.h>
 #include <MG_Util/Async/ShaderCompilePool.h>
+#include <MG_Util/Metrics/PipeStats.h>
 #include <MG_Util/ShaderTranspiler/ShaderCompiler.h>
 #include <MG_State/GLState/ProgramState/ProgramTranslationCache.h>
 #include <MG_Util/ShaderTranspiler/TranslationCache.h>
@@ -42,6 +43,11 @@ namespace MobileGL {
             if (logLifecycle) {
                 MGLOG_I("MobileGL closing...");
             }
+            // Before any subsystem the counters name goes away, and before the last frame's
+            // numbers can be lost: emits the final summary line and, when
+            // MOBILEGL_PIPE_STATS_FILE is set, the JSON dump. A no-op when the counters are
+            // off, and idempotent.
+            MG_Util::PipeStats::Shutdown();
             // First, before anything else is torn down. In-flight compile/link jobs own
             // their own inputs and are safe against everything below EXCEPT glslang's
             // process globals and the TShader/TProgram objects hanging off pGLContext,
@@ -102,6 +108,10 @@ namespace MobileGL {
         MGLOG_I("Initializing MobileGL...");
         MG_ConfigLoader::Init();
         MGLOG_I("Config loaded");
+        // Immediately after the config load and before anything can count: the MGPipe
+        // boundary counters latch their enable flag here, so every counting site in the
+        // two backends is a load of an already-settled global for the rest of the run.
+        MG_Util::PipeStats::Init();
         MG_State::Init();
         MGLOG_D("MG_State initialized");
         MG_Backend::Init();

MobileGL/MG_Backend/BackendObject.h

@@ -192,9 +192,23 @@ namespace MobileGL {
             void (*MemoryBarrierByRegion)(GLbitfield barriers);
             void (*BindImageTexture)(GLuint unit, GLuint texture, GLint level, GLboolean layered, GLint layer,
                                      GLenum access, GLenum format);
+            // The ONLY indexed query that is genuinely a backend one, and only for the pnames
+            // MG_Impl/GLImpl/Getter/GL_Getter.cpp does not already own. Every indexed pname that
+            // names FRONTEND state - the indexed buffer bindings, the per-unit texture/sampler
+            // bindings, the image-unit bindings, the viewport rectangles, the indexed capabilities
+            // - is answered in GL_Getter::GetIntegeri_v and never reaches this entry; the
+            // 64-bit and float/double widths are derived there from the same answer, which is why
+            // no GetInteger64i_v/GetFloati_v/GetDoublei_v table entry exists. In practice this
+            // leaves GL_MAX_COMPUTE_WORK_GROUP_COUNT / _SIZE (also asked directly by
+            // MG_Util/ShaderTranspiler/CompileEnv.cpp) plus whatever pname the frontend has no
+            // case for at all.
             void (*GetIntegeri_v)(GLenum target, GLuint index, GLint* data);
-            void (*GetInteger64i_v)(GLenum target, GLuint index, GLint64* data);
-            void (*GetProgramiv)(GLuint program, GLenum pname, GLint* params);
+            // There is deliberately NO GetProgramiv entry: glGetProgramiv describes the program
+            // the APPLICATION wrote - link status, the transform-feedback mode, the compute local
+            // size - all of which are frontend link artifacts on ProgramObject, and
+            // MG_Impl/GLImpl/Program/GL_Program.cpp answers every one of them from there. Asking a
+            // backend would mean asking about a DIFFERENT program (a SPIRV-Cross-generated ESSL
+            // one, or a SPIR-V module), in a namespace the application never sees.
             // The GL program interface (glGetProgramInterfaceiv / glGetProgramResource*) is NOT
             // a backend query: it describes the program the application wrote, in the
             // application's namespace, which neither backend program is in. It is answered
@@ -364,6 +378,19 @@ namespace MobileGL {
             Int MaxFragmentShaderStorageBlocks = 8;
             Int MaxComputeUniformBlocks = 12;
             Int MaxComputeWorkGroupInvocations = 128;
+            // GL_MAX_COMPUTE_WORK_GROUP_COUNT / GL_MAX_COMPUTE_WORK_GROUP_SIZE, one value per
+            // axis. These six, with the invocations limit above, are the only indexed limits a
+            // backend genuinely OWNS - the device answers them (glGetIntegeri_v on DirectGLES,
+            // VkPhysicalDeviceLimits::maxComputeWorkGroupCount/Size on DirectVulkan) - and so
+            // the only ones that survive the retirement of the GetIntegeri_v table entry: they
+            // cross the MGPipe boundary inside MGPCaps, by inclusion of this struct (plan B
+            // section 4.4.1). Every other indexed pname names frontend state. RAW driver
+            // answers, like the invocations limit: GL_Getter and the compile environment floor
+            // them at the shared MIN_COMPUTE_WORK_GROUP_* minimums themselves. The defaults are
+            // the GL 4.3 core minimums (table 23.60) and describe the no-backend case, as
+            // MaxClipDistances' does.
+            Int MaxComputeWorkGroupCount[3] = {65535, 65535, 65535};
+            Int MaxComputeWorkGroupSize[3] = {1024, 1024, 64};
             Int MaxShaderStorageBufferBindings = 8;
             Int MaxTextureBufferSize = 65536;
             // GL_TEXTURE_BUFFER_OFFSET_ALIGNMENT; 1 means the offset is unconstrained.
@@ -389,6 +416,19 @@ namespace MobileGL {
             // where there is no device to be honest about and BuildTBuiltInResource still has to
             // hand glslang a workable gl_MaxClipDistances.
             Int MaxClipDistances = 8;
+            // GL_MAX_CULL_DISTANCES and GL_MAX_COMBINED_CLIP_AND_CULL_DISTANCES, under exactly
+            // the contract stated for MaxClipDistances above: ZERO IS A LEGAL ANSWER and a
+            // backend that cannot host a cull distance MUST report it. The failure this prevents
+            // is worse than the clip one, because cull distance discards the whole primitive:
+            // glslang bounds gl_CullDistance[i] against maxCullDistances and expands
+            // gl_MaxCullDistances from it, SPIRV-Cross then emits
+            // `#extension GL_EXT_clip_cull_distance : require` into the ESSL, and a host driver
+            // without that extension rejects the program in an info log nobody surfaces. These
+            // used to be bare 8s inside BuildTBuiltInResource with no backend consulted at all.
+            // The DEFAULTS are the GL 4.5 core minimums for the same reason MaxClipDistances'
+            // is: they describe the no-backend case (standalone compiles, unit tests).
+            Int MaxCullDistances = 8;
+            Int MaxCombinedClipAndCullDistances = 8;
             Int MaxViewports = 16;
             // GL_LAYER_PROVOKING_VERTEX / GL_VIEWPORT_INDEX_PROVOKING_VERTEX: which vertex of a
             // primitive supplies gl_Layer and gl_ViewportIndex. GL 4.6 table 23.65 makes
@@ -482,6 +522,24 @@ namespace MobileGL {
             // halves (PackDoubleVertexInputsPass and VertexInputStateFactory::ToVkVertexFormat)
             // still see one consistent world.
             Bool SupportsFloat64VertexAttributes = false;
+            // Whether a TESSELLATION stage of this backend may access gl_PointSize - i.e.
+            // whether a module declaring OpCapability TessellationPointSize can reach the
+            // driver at all. DirectVulkan sets both this and the geometry twin from the one
+            // shaderTessellationAndGeometryPointSize feature; DirectGLES sets them
+            // independently from the EXT/OES_tessellation_point_size /
+            // geometry_point_size extension pairs (PointSizeTier), which really do come
+            // separately. When absent, ProgramSpirvTask demotes the built-in to an ordinary
+            // varying program-wide (ShaderCompiler::
+            // DemoteTessellationGeometryPointSizeForProgram); MOBILEGL_POINT_SIZE_DEMOTION
+            // overrides the detection in either direction at backend init.
+            //
+            // Defaults TRUE, deliberately against the house "assume absent" rule: false
+            // ARMS a rewrite, so the conservative no-backend answer (standalone compiles,
+            // unit tests) is the one that leaves modules untouched. A backend that never
+            // sets it gets standard modules and, at worst, the old honest declines.
+            Bool SupportsTessellationPointSize = true;
+            // The geometry-stage twin (OpCapability GeometryPointSize).
+            Bool SupportsGeometryPointSize = true;
             SizeT MaxShaderStorageBlockSize = 128 * 1024 * 1024;
             Uint32 SubgroupSize = 0;
             Uint32 SubgroupSupportedStages = 0;

MobileGL/MG_Backend/DirectGLES/BackendObject_DirectGLES.cpp

@@ -307,6 +307,23 @@ namespace MobileGL::MG_Backend::DirectGLES {
             return capabilities.MaxColorTextureSamples;
         }
 
+        // The RENDERBUFFER twin, and it is a different set of pnames on purpose.
+        // GL_MAX_{COLOR,DEPTH}_TEXTURE_SAMPLES bound multisample TEXTURES; a renderbuffer is
+        // bounded by GL_MAX_SAMPLES (GL 4.6 core 9.2.4), with GL_MAX_INTEGER_SAMPLES for the
+        // integer formats. Using the texture ceilings here - which is what the renderbuffer probe
+        // did - is not merely untidy: the two texture pnames are ES 3.1 state, so on an ES 3.0
+        // context the loader's rejected-probe clamp leaves them at 1 (see the multisample clamps
+        // in the GLES loader) and the walk below would never run past one sample, recording {1}
+        // for EVERY colour format while GL_MAX_SAMPLES - ES 3.0 core, so genuinely answered -
+        // reports 4. Once the frontend validates against this list, that would reject every
+        // multisample renderbuffer on such a context.
+        Int GetGLESRenderbufferFormatMaxSamples(const MG_External::GLESCapabilities& capabilities,
+                                                GLenum imageFormat) {
+            const Bool isInteger = imageFormat == GL_RED_INTEGER || imageFormat == GL_RG_INTEGER ||
+                                   imageFormat == GL_RGB_INTEGER || imageFormat == GL_RGBA_INTEGER;
+            return isInteger ? capabilities.MaxIntegerSamples : capabilities.MaxSamples;
+        }
+
         Bool ProbeFramebufferCompletenessForTexture(const MG_External::GLESFunctionsTable& gl, TextureTarget target,
                                                     GLuint texture, TextureInternalFormat format) {
             GLuint framebuffer = 0;
@@ -717,7 +734,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
                         AddFullFormatCaps(cache, renderbufferTargetIndex, formatIndex,
                                           GetRenderbufferFeatureCaps(logicalFormat));
                         const Int maxSamples =
-                            GetGLESFormatMaxSamples(capabilities, logicalFormat, nativeInfo.ImageFormat);
+                            GetGLESRenderbufferFormatMaxSamples(capabilities, nativeInfo.ImageFormat);
                         cache.SampleCounts[renderbufferTargetIndex][formatIndex] =
                             ProbeRenderbufferSampleCounts(gl, nativeInfo.InternalFormat, logicalFormat, maxSamples);
                     } else {
@@ -731,7 +748,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
                         LogGLESFormatCaveat(logicalFormat, renderbufferTargetIndex, renderbufferFallbackInfo);
                     }
                     const Int maxSamples =
-                        GetGLESFormatMaxSamples(capabilities, logicalFormat, renderbufferFallbackInfo.ImageFormat);
+                        GetGLESRenderbufferFormatMaxSamples(capabilities, renderbufferFallbackInfo.ImageFormat);
                     cache.SampleCounts[renderbufferTargetIndex][formatIndex] = ProbeRenderbufferSampleCounts(
                         gl, renderbufferFallbackInfo.InternalFormat, logicalFormat, maxSamples);
                 }
@@ -749,7 +766,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
                 .ExtraVendor = Nullopt,              // Extra vendor
                 .RendererGLInfo =
                     {
-                        .TargetGLVersion = {4, 3, 0},   // GL target version
+                        .TargetGLVersion = {4, 6, 0},   // GL target version
                         .TargetGLSLVersion = {4, 6, 0}, // Target Shading Language Version
                         // Baseline advertisement (no runtime capabilities yet); reconciled once
                         // the ES capabilities exist, see UpdateAdvertisedCapabilityExtensions.
@@ -995,10 +1012,11 @@ namespace MobileGL::MG_Backend::DirectGLES {
                                                   Bool textureViewSupported, Bool cubeMapArraySupported) {
         Vector<GLExtension> extensions = {
             // The version tokens have to reach the version the backend actually claims:
-            // TargetGLVersion is {4,3,0}, and a list that stopped at OpenGL40 told an
+            // TargetGLVersion is {4,6,0}, and a list that stopped at OpenGL40 told an
             // application feature-detecting off these tokens the opposite of what
             // GL_MAJOR_VERSION / GL_MINOR_VERSION told it.
             V_OpenGL30, V_OpenGL31, V_OpenGL32, V_OpenGL33, V_OpenGL40, V_OpenGL41, V_OpenGL42, V_OpenGL43,
+            V_OpenGL44, V_OpenGL45, V_OpenGL46,
             E_GL_ARB_draw_buffers_blend,
             E_GL_ARB_compute_shader, E_GL_ARB_shader_storage_buffer_object, E_GL_ARB_shader_image_load_store,
             E_GL_ARB_clear_buffer_object, E_GL_ARB_program_interface_query, E_GL_ARB_framebuffer_object, E_GL_EXT_framebuffer_object,
@@ -1180,8 +1198,8 @@ namespace MobileGL::MG_Backend::DirectGLES {
         //
         // Until that reconciliation exists, advertising here would be the same lie the comment
         // above refuses to tell, just with an extra prerequisite met. Set
-        // MOBILEGL_ENABLE_GLES_TEXTURE_VIEW=1 to re-enable it for that work.
-        if (textureViewSupported && MG_Config::Features.EnableGlesTextureView) {
+        // MOBILEGL_ESPRYT_ENABLE_TEXTURE_VIEW=1 to re-enable it for that work.
+        if (textureViewSupported && MG_Config::Features.EsprytEnableTextureView) {
             extensions.push_back(E_GL_ARB_texture_view);
         }
         // Only advertised when the host ES driver actually filters anisotropically: the sampler
@@ -1237,8 +1255,6 @@ namespace MobileGL::MG_Backend::DirectGLES {
             funcsTable.GL.MemoryBarrierByRegion = MemoryBarrierByRegion;
             funcsTable.GL.BindImageTexture = BindImageTexture;
             funcsTable.GL.GetIntegeri_v = GetIntegeri_v;
-            funcsTable.GL.GetInteger64i_v = GetInteger64i_v;
-            funcsTable.GL.GetProgramiv = GetProgramiv;
             funcsTable.GL.ShaderStorageBlockBinding = ShaderStorageBlockBinding;
             funcsTable.GL.Clear = Clear;
             funcsTable.GL.ClearBufferfi = ClearBufferfi;
@@ -1399,6 +1415,13 @@ namespace MobileGL::MG_Backend::DirectGLES {
             clampStageStorageBlocks(m_GLESCapabilities.MaxFragmentShaderStorageBlocks);
         m_dynamicParameters.MaxComputeUniformBlocks = m_GLESCapabilities.MaxComputeUniformBlocks;
         m_dynamicParameters.MaxComputeWorkGroupInvocations = m_GLESCapabilities.MaxComputeWorkGroupInvocations;
+        // The six per-axis compute limits: the driver's raw glGetIntegeri_v answers, the same
+        // numbers GLFunctionsTable::GetIntegeri_v forwards live. Carried here so that MGPCaps has
+        // them once the table entry retires (plan B section 4.4.1); GL_Getter floors them.
+        for (SizeT axis = 0; axis < 3; ++axis) {
+            m_dynamicParameters.MaxComputeWorkGroupCount[axis] = m_GLESCapabilities.MaxComputeWorkGroupCount[axis];
+            m_dynamicParameters.MaxComputeWorkGroupSize[axis] = m_GLESCapabilities.MaxComputeWorkGroupSize[axis];
+        }
         // (MaxShaderStorageBufferBindings is assigned above, before the per-stage clamp reads it.)
         // This is the number glGetIntegerv(GL_MAX_TEXTURE_BUFFER_SIZE) hands the application, and
         // on a host without buffer textures it is knowingly a floor MobileGL cannot honour rather
@@ -1461,9 +1484,44 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // Follows the line above, and must: OpenGL ES has no double-precision vertex format and no
         // fp64 type to consume one with, so a 64-bit vertex attribute has nowhere to land here.
         m_dynamicParameters.SupportsFloat64VertexAttributes = false;
+        // Whether a tessellation / geometry stage's ESSL may name gl_PointSize at all: the two
+        // extension pairs the loader probed, independently, because they really do come
+        // separately. False arms the shared phase-B demotion
+        // (ShaderCompiler::DemoteTessellationGeometryPointSizeForProgram), whose ESSL then
+        // never names the built-in in those stages and needs no extension.
+        // MOBILEGL_POINT_SIZE_DEMOTION=1 pretends both are absent so the demotion can be
+        // exercised on a healthy driver (the pinned integration lane); =0 restores the
+        // detected answer's declines.
+        m_dynamicParameters.SupportsTessellationPointSize =
+            m_GLESCapabilities.TessellationPointSizeSupport !=
+            MG_External::GLESCapabilities::PointSizeTier::None;
+        m_dynamicParameters.SupportsGeometryPointSize =
+            m_GLESCapabilities.GeometryPointSizeSupport !=
+            MG_External::GLESCapabilities::PointSizeTier::None;
+        switch (MG_Config::Features.PointSizeDemotion) {
+        case MG_Config::QuirkOverride::ForceOn:
+            MGLOG_I("DirectGLES: MOBILEGL_POINT_SIZE_DEMOTION=1 - treating tessellation/geometry "
+                    "gl_PointSize as unhosted so the demotion runs on this driver");
+            m_dynamicParameters.SupportsTessellationPointSize = false;
+            m_dynamicParameters.SupportsGeometryPointSize = false;
+            break;
+        case MG_Config::QuirkOverride::ForceOff:
+            MGLOG_I("DirectGLES: MOBILEGL_POINT_SIZE_DEMOTION=0 - keeping the built-in and the "
+                    "plain declines regardless of the driver's extensions");
+            m_dynamicParameters.SupportsTessellationPointSize = true;
+            m_dynamicParameters.SupportsGeometryPointSize = true;
+            break;
+        case MG_Config::QuirkOverride::Auto:
+            break;
+        }
         m_dynamicParameters.MaxDrawBuffers = m_GLESCapabilities.MaxDrawBuffers;
         m_dynamicParameters.MaxColorAttachments = m_GLESCapabilities.MaxColorAttachments;
         m_dynamicParameters.MaxClipDistances = m_GLESCapabilities.MaxClipDistances;
+        // The loader already gated both on GL_EXT_clip_cull_distance and left 0 without it, which
+        // is the answer that keeps glslang from accepting a gl_CullDistance the ESSL compiler
+        // would reject.
+        m_dynamicParameters.MaxCullDistances = m_GLESCapabilities.MaxCullDistances;
+        m_dynamicParameters.MaxCombinedClipAndCullDistances = m_GLESCapabilities.MaxCombinedClipAndCullDistances;
         m_dynamicParameters.MaxViewports = m_GLESCapabilities.MaxViewports;
         // Whatever the driver said about which vertex supplies gl_Layer, and GL_UNDEFINED_VERTEX
         // for gl_ViewportIndex on every driver without GL_OES_viewport_array - which is both test

MobileGL/MG_Backend/DirectGLES/DirectGLES.h

@@ -92,8 +92,6 @@ namespace MobileGL::MG_Backend::DirectGLES {
     void BindImageTexture(GLuint unit, GLuint texture, GLint level, GLboolean layered, GLint layer, GLenum access,
                           GLenum format);
     void GetIntegeri_v(GLenum target, GLuint index, GLint* data);
-    void GetInteger64i_v(GLenum target, GLuint index, GLint64* data);
-    void GetProgramiv(GLuint program, GLenum pname, GLint* params);
     void ShaderStorageBlockBinding(GLuint program, const GLchar* storageBlockName, GLuint storageBlockBinding);
     Bool InitWindowSurface(NativeWindowType window);
     Bool InitPbufferSurface(EGLint width, EGLint height);

MobileGL/MG_Backend/DirectGLES/Managers.h

@@ -102,9 +102,98 @@ namespace MobileGL::MG_Backend::DirectGLES {
     // Brings the whole draw-relevant frontend state onto the native ES context and binds
     // the program; every GL draw entry point calls it exactly once before issuing draws.
     void PrepareForDraw(DrawSyncFlags syncBits);
-    // GLES core supports only GL_PRIMITIVE_RESTART_FIXED_INDEX. Throws when the app enabled
-    // the arbitrary GL_PRIMITIVE_RESTART with a non-fixed index for this index type.
-    void CheckPrimitiveRestartSupported(GLenum indexType);
+    // What an indexed draw has to do about primitive restart before it can be issued.
+    //
+    // Desktop GL restarts on an application-chosen index (glPrimitiveRestartIndex under
+    // GL_PRIMITIVE_RESTART); GLES core restarts only on the all-ones value of the index type
+    // (GL_PRIMITIVE_RESTART_FIXED_INDEX), which the render-state push enables for BOTH caps.
+    // That leaves three cases, and the difference between the last two is not cosmetic - one
+    // adds restarts, the other has to take away restarts the driver would otherwise make.
+    enum class RestartSubstitutionKind : Uint8 {
+        // Nothing to do: restart is off, the fixed-index cap is on, or the application's
+        // restart index already IS the type's all-ones value. The overwhelmingly common answer.
+        None,
+        // The application's index is representable in this index type and differs from the
+        // all-ones value: the index DATA has to be rewritten so the driver restarts where the
+        // application asked.
+        RewriteIndices,
+        // The application's index cannot be held by this index type at all. GL 4.6 core 10.3.6
+        // compares the fetched index, zero-extended, against the full 32-bit
+        // PRIMITIVE_RESTART_INDEX, so no index can match and the draw restarts NOWHERE - but the
+        // render-state push has already enabled the driver's fixed-index restart, so the
+        // all-ones value has to be un-restarted for the duration of the draw.
+        SuppressRestart,
+    };
+    RestartSubstitutionKind ResolveRestartSubstitution(GLenum indexType);
+
+    // Turns the driver's fixed-index restart off for one draw and back on afterwards, for the
+    // SuppressRestart case above. Separate from the substitution below because the multi-draw
+    // tiers need it on its own: they rewrite the index stream themselves and only ever need the
+    // cap half. Inert for every other kind, and it never touches the render-state shadow - it
+    // puts the driver back exactly where SyncRenderState left it.
+    class ScopedSuppressedPrimitiveRestart {
+    public:
+        explicit ScopedSuppressedPrimitiveRestart(RestartSubstitutionKind kind);
+        ~ScopedSuppressedPrimitiveRestart();
+        ScopedSuppressedPrimitiveRestart(const ScopedSuppressedPrimitiveRestart&) = delete;
+        ScopedSuppressedPrimitiveRestart& operator=(const ScopedSuppressedPrimitiveRestart&) = delete;
+
+    private:
+        Bool m_suppressed = false;
+    };
+
+    // Swaps in a scratch element array buffer holding a copy of the index data in which the
+    // application's restart index has been replaced by the value GLES restarts on. Inert
+    // (and free) unless ResolveRestartSubstitution asks for it. The swap lives for the
+    // object's lifetime, so it covers every pass of a viewport-routed draw, and the previous
+    // GL_ELEMENT_ARRAY_BUFFER name is restored on destruction - which matters beyond tidiness,
+    // because the VAO twin memoises that it already synced that binding.
+    //
+    // The copy may be WIDER than the source (see IndexType): when the source already contains
+    // the type's all-ones value as an ordinary vertex index, that value cannot double as the
+    // restart sentinel, and widening is the only way to keep both meanings. Callers must
+    // therefore take the index type from this object, not from their own argument.
+    class ScopedRestartIndexSubstitution {
+    public:
+        // count/indices describe the draw's index range when the CPU knows it. Pass
+        // count == 0 for an indirect draw, whose count lives in GPU memory: the whole bound
+        // element array buffer is rewritten instead, so every element keeps its position and
+        // a GPU-resident firstIndex - an ELEMENT index, so it survives widening too - still
+        // addresses the index it named.
+        ScopedRestartIndexSubstitution(GLenum indexType, GLsizei count, const void* indices);
+        ~ScopedRestartIndexSubstitution();
+        ScopedRestartIndexSubstitution(const ScopedRestartIndexSubstitution&) = delete;
+        ScopedRestartIndexSubstitution& operator=(const ScopedRestartIndexSubstitution&) = delete;
+
+        // False only when a substitution was needed and could not be made. The draw must
+        // then be skipped: issuing it would let the driver silently drop every restart and
+        // weld the primitives on either side together, which is worse than drawing nothing.
+        Bool DrawIsValid() const { return m_valid; }
+        // The element-array offset (or client pointer) the draw must use. Identical to what
+        // was passed in unless a substitution was made.
+        const void* Indices() const { return m_indices; }
+        // The index type the draw must be issued with. Identical to the constructor's unless
+        // the copy had to be widened to keep an all-ones vertex index distinguishable from the
+        // restart sentinel.
+        GLenum IndexType() const { return m_indexType; }
+
+    private:
+        // Declared before m_capOverride so it is initialised first (members initialise in
+        // declaration order): the whole decision is made once, and both the cap override and the
+        // constructor body read the same answer.
+        RestartSubstitutionKind m_kind = RestartSubstitutionKind::None;
+        ScopedSuppressedPrimitiveRestart m_capOverride;
+        const void* m_indices = nullptr;
+        GLenum m_indexType = 0;
+        Uint m_previousBinding = 0;
+        Bool m_substituted = false;
+        Bool m_valid = true;
+    };
+
+    // Drops the scratch element array buffer the substitution above stages through. Like
+    // MultiDrawImpl's scratch names it is abandoned rather than deleted: the name belongs to
+    // the dead ES context, and deleting it would target whatever its successor handed out.
+    void OnRestartSubstitutionContextDestroyed();
     // Feed the current program's gl_BaseInstance / gl_DrawID / gl_BaseVertex emulation
     // uniforms. All are no-ops when the program does not read the corresponding builtin.
     void SetCurrentBaseInstance(Uint32 baseInstance);
@@ -141,7 +230,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
     // still holding what glViewport/glScissor/glDepthRange broadcast to all sixteen - collapses
     // to a single pass with an all-ones gate mask, i.e. one draw and no behaviour change at all.
     //
-    // Whether emulation runs. Off only under MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION falsy, which
+    // Whether emulation runs. Off only under MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION falsy, which
     // restores the pre-emulation path as a negative control.
     Bool ViewportArrayEmulationEnabled();
     // Whether ANY program built in this process has come out with a viewport gate. Sticky once
@@ -372,6 +461,16 @@ namespace MobileGL::MG_Backend::DirectGLES {
             // the owning thread replaying them: guard both fields with pendingMutex.
             Bool pendingRespecify = false;
             VecRange1D pendingRanges;
+            // App bytes for an ADOPTED store, awaiting their GPU-ordered landing (ring
+            // stage + glCopyBufferSubData at the next sync; see
+            // BufferBackendOps::ResidentSubData). The frontend keeps such writes out of
+            // the coherent mapping - an in-place host write tears the in-flight frames
+            // still reading the old bytes. Guarded by pendingMutex like pendingRanges.
+            struct PendingResidentWrite {
+                SizeT offset = 0;
+                Vector<Uint8> bytes;
+            };
+            Vector<PendingResidentWrite> pendingResidentWrites;
             std::mutex pendingMutex;
             // Buffer-mutation epoch (see CurrentBufferMutationEpoch) at which this
             // resource last probed IsBufferDrawClean == true, 0 = never (epochs start
@@ -455,12 +554,21 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // BackendVertexArrayObject::SyncToBackend.
         extern Uint64 g_bufferBackendIdGeneration;
         // Redundant-bind cache for INDEXED buffer bindings (glBindBufferBase/Range on
-        // GL_UNIFORM_BUFFER / GL_SHADER_STORAGE_BUFFER): skips the GL call when the
-        // (id, range) already at that index matches, like the array-buffer/texture/
-        // sampler caches already do. Invalidated on MakeCurrent (context may reset).
+        // GL_UNIFORM_BUFFER / GL_SHADER_STORAGE_BUFFER / GL_TRANSFORM_FEEDBACK_BUFFER):
+        // skips the GL call when the (id, range) already at that index matches, like the
+        // array-buffer/texture/sampler caches already do. Invalidated on MakeCurrent
+        // (context may reset).
+        // Binds the transform feedback capture points [0, bufferCount) from the frontend
+        // state, and touches nothing else - in particular it never binds a zero the
+        // application did not ask for. See the definition for why that matters on Mali.
+        void SyncTransformFeedbackBindingPoints(SizeT bufferCount);
         void BindBufferBaseCached(GLenum glTarget, Uint index, Uint id);
         void BindBufferRangeCached(GLenum glTarget, Uint index, Uint id, GLintptr offset, GLsizeiptr size);
         void InvalidateIndexedBufferBindingCache();
+        // The transform feedback capture points are per-transform-feedback-OBJECT state, so
+        // every glBindTransformFeedback swaps all of them under the shadow above. XfbImpl
+        // calls this on each bind/delete.
+        void InvalidateTransformFeedbackBindingShadows();
         // Re-issues the GL_ATOMIC_COUNTER_BUFFER binding points a program's shaders declare as
         // GL_SHADER_STORAGE_BUFFER bindings at the reserved slots the transpiled ESSL was built
         // against (BackendProgramObjectImpl::GetAtomicCounterBindings /
@@ -529,7 +637,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // which is what to watch if this ring ever shows up in an RSS regression: it
         // grows on demand from 4 MiB and is capped, not unbounded.
         //
-        // False when the feature is disabled (MOBILEGL_DISABLE_UNPACK_RING),
+        // False when the feature is disabled (MOBILEGL_ESPRYT_DISABLE_UNPACK_RING),
         // EXT_buffer_storage / fences are missing, the ES context is not current, or
         // ring creation already failed under this context. Callers then upload from
         // the client pointer exactly as before.
@@ -544,6 +652,23 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // Largest single staging request the ring can ever satisfy.
         SizeT UnpackRingMaxBytes();
         void UnpackRingOnPresent();
+
+        // --- Buffer upload ring ---------------------------------------------------
+        // The same persistent-mapped bump allocator, staging APP BUFFER UPDATES
+        // (glBufferSubData / non-persistent map flushes) whose destination store may
+        // still be referenced by in-flight GPU work. Mali resolves that WAR hazard by
+        // BLOCKING the calling glBufferSubData (osup_sync_object_wait) until every
+        // referencing job retires - Minecraft 26.3 rewrites its chunk-section and
+        // dynamic-transform UBOs and streams chunk meshes with per-frame SubData, and
+        // each such call serialized against the whole GPU queue (~1 fps while chunks
+        // stream in, and again on every camera pan). App SubData ranges are queued on
+        // the resource instead (the frontend shadow already holds the bytes) and
+        // draw-time sync drains them: bytes staged into this ring, then one
+        // glCopyBufferSubData per merged range - the copy is ordered on the GPU
+        // timeline, so the hazard costs no CPU wait. Reclamation contract identical
+        // to the other two rings. MOBILEGL_ESPRYT_DISABLE_UPLOAD_RING restores the
+        // historical immediate-upload path (negative control / escape hatch).
+        void UploadRingOnPresent();
     } // namespace BufferImpl
 
     namespace VertexArrayImpl {
@@ -961,7 +1086,14 @@ namespace MobileGL::MG_Backend::DirectGLES {
             Uint16 m_syncedShapeParamsVersion = 0;
             SamplerParameters m_cacheSamplerParameters;
             UintVec2 m_cacheLodRange = {0, 1000};
+            // All three representations plus the form, because none of them alone identifies the
+            // border colour the driver texture is holding: two integer borders can share one float
+            // (anything differing above 2^24), and a Float -> Int transition can leave every number
+            // unchanged while still needing a different driver entry point.
             FloatVec4 m_cacheBorderColor = {0.0f, 0.0f, 0.0f, 0.0f};
+            IntVec4 m_cacheBorderColorI = {0, 0, 0, 0};
+            UintVec4 m_cacheBorderColorUI = {0, 0, 0, 0};
+            BorderColorForm m_cacheBorderColorForm = BorderColorForm::Float;
             Vec4<TextureSwizzleParam> m_cacheSwizzleParams = {TextureSwizzleParam::Red, TextureSwizzleParam::Green,
                                                               TextureSwizzleParam::Blue, TextureSwizzleParam::Alpha};
             // GL_DEPTH_STENCIL_TEXTURE_MODE. GL_DEPTH_COMPONENT is the GL and ES default, so a
@@ -1447,6 +1579,17 @@ namespace MobileGL::MG_Backend::DirectGLES {
             Int GetPassthroughTessControlPatchVertices() const {
                 return m_passthroughTessControlPatchVertices;
             }
+            // GL_PATCH_DEFAULT_{OUTER,INNER}_LEVEL the same synthesized stage was built with, for
+            // the same reason: ES has neither the state nor an entry point to forward it to, so
+            // glPatchParameterfv's values are compiled in as literals and a program built with one
+            // set is stale for another. Meaningless (and never read) when the patch-vertices field
+            // above is -1, which is the gate the draw path tests first.
+            const FloatVec4& GetPassthroughTessControlOuterLevel() const {
+                return m_passthroughTessControlOuterLevel;
+            }
+            const FloatVec2& GetPassthroughTessControlInnerLevel() const {
+                return m_passthroughTessControlInnerLevel;
+            }
 
             Bool HasGlobalUboBlock() const { return m_globalUboBackendBlockIndex >= 0; }
             const Vector<Int>& GetUniformBlockBackendIndices() const { return m_uniformBlockBackendIndices; }
@@ -1517,6 +1660,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
                                       const UnorderedMap<String, Int>& storageBlockBindingOverrides,
                                       const std::map<String, String>& inputBlockRenames,
                                       const std::map<String, String>& outputBlockRenames,
+                                      Bool stripInputBlockLocations, Bool stripOutputBlockLocations,
                                       Int atomicCounterEsslBindingTop, Bool enableSpirvValidation,
                                       String& outSource,
                                       std::set<String>& outFlattenedXfbBlockNames,
@@ -1547,6 +1691,10 @@ namespace MobileGL::MG_Backend::DirectGLES {
             // all); otherwise the GL_PATCH_VERTICES the synthesized pass-through stage was built
             // with. See GetPassthroughTessControlPatchVertices.
             Int m_passthroughTessControlPatchVertices = -1;
+            // The default tessellation levels baked into that same stage. Only meaningful while
+            // the field above is not -1.
+            FloatVec4 m_passthroughTessControlOuterLevel = FloatVec4(1.0f, 1.0f, 1.0f, 1.0f);
+            FloatVec2 m_passthroughTessControlInnerLevel = FloatVec2(1.0f, 1.0f);
             Bool m_isInitialized = false;
             Bool m_backendProgramUsable = false;
             // Set by SyncToBackend every time it relinks the driver program, cleared by the

MobileGL/MG_Backend/DirectGLES/MultiDraw.cpp

@@ -9,6 +9,8 @@
 #include "MultiDraw.h"
 #include "Managers.h"
 #include <MG_State/GLState/Core.h>
+#include <MG_Pipe/PipeInputsSwitch.h>
+#include <MG_Util/Metrics/PipeStats.h>
 #include <cstring>
 #include <limits>
 
@@ -29,21 +31,26 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
             }
         }
 
-        // The all-ones value of an index type, which is what GL restarts on once
-        // primitive restart is in play. CheckPrimitiveRestartSupported has already
-        // rejected the arbitrary-index form of GL_PRIMITIVE_RESTART, so an enabled
-        // restart always restarts here and nowhere else.
+        // The index value this batch restarts on, compared at 32 bits against the zero-extended
+        // source index. Normally the all-ones value of the source type, which is what
+        // GL_PRIMITIVE_RESTART_FIXED_INDEX and GLES both restart on; with desktop
+        // GL_PRIMITIVE_RESTART it is instead whatever glPrimitiveRestartIndex named. The rebased
+        // tier turns whichever it is into 0xFFFFFFFF in its widened stream, which is what the
+        // driver restarts on.
+        //
+        // No truncation, deliberately, and the same rule ResolveRestartSubstitution applies: a
+        // restart index the source type cannot hold simply matches nothing, so returning it
+        // verbatim is already "this batch restarts nowhere".
         Uint32 RestartSentinelFor(GLenum type) {
-            switch (type) {
-            case GL_UNSIGNED_BYTE: return 0xFFu;
-            case GL_UNSIGNED_SHORT: return 0xFFFFu;
-            default: return 0xFFFFFFFFu;
+            if (ResolveRestartSubstitution(type) != RestartSubstitutionKind::None) {
+                return MGB_CTX->GetPrimitiveRestartIndex();
             }
+            return MG_Util::FixedRestartIndexForGLType(type);
         }
 
         Bool RestartActive() {
-            return MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::PrimitiveRestart) ||
-                   MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::PrimitiveRestartFixedIndex);
+            return MGB_CTX->IsCapabilityEnabled(CapabilityInput::PrimitiveRestart) ||
+                   MGB_CTX->IsCapabilityEnabled(CapabilityInput::PrimitiveRestartFixedIndex);
         }
 
         // Vertices per primitive for the modes whose sub-draws may be concatenated into a
@@ -78,7 +85,7 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
 
         Uint BoundDrawIndirectBufferId() {
             const auto& indirect =
-                MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
+                MGB_CTX->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
             if (!indirect) return 0;
             const auto* resource = BufferImpl::EnsureBufferResource(indirect);
             return resource ? resource->id : 0;
@@ -86,7 +93,7 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
 
         const SharedPtr<MG_State::GLState::BufferObject>& BoundIndexBuffer() {
             static const SharedPtr<MG_State::GLState::BufferObject> none;
-            const auto& vao = MG_State::pGLContext->GetBoundVertexArray();
+            const auto& vao = MGB_CTX->GetBoundVertexArray();
             if (!vao) return none;
             return vao->GetIndexBufferBindingSlot().GetBoundObject();
         }
@@ -151,7 +158,10 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
         // are bound as storage blocks. Respecifies rather than sub-updates: glBufferData
         // orphans the previous store, so the upload never waits on a dispatch still reading
         // the old contents out of the same name.
-        Bool UploadScratch(ScratchBuffer& buffer, SizeT bytes, const void* data) {
+        // statsClass: which MGPipe byte population these bytes belong to. Counted here
+        // rather than at the four call sites so a new tier cannot forget it.
+        Bool UploadScratch(ScratchBuffer& buffer, SizeT bytes, const void* data,
+                           MG_Util::PipeStats::ByteClass statsClass) {
             if (bytes == 0) return true;
             if (!EnsureScratchName(buffer)) return false;
             BufferImpl::BindBufferId(BufferImpl::TempBufferTarget, buffer.id);
@@ -164,6 +174,9 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
             buffer.cursor = 0;
             if (data) {
                 g_GLESFuncs.glBufferSubData(BufferImpl::TempBufferTarget, 0, static_cast<GLsizeiptr>(bytes), data);
+                if (MG_Util::PipeStats::Enabled()) {
+                    MG_Util::PipeStats::AddBytes(statsClass, static_cast<Uint64>(bytes));
+                }
             }
             return true;
         }
@@ -178,7 +191,8 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
         constexpr SizeT kRingAlignment = 16; // >= 4, so both command and uint32-index offsets stay legal
         constexpr SizeT kMinRingBytes = 1u << 16;
 
-        Bool UploadScratchRing(ScratchBuffer& buffer, SizeT bytes, const void* data, SizeT& outOffset) {
+        Bool UploadScratchRing(ScratchBuffer& buffer, SizeT bytes, const void* data,
+                               MG_Util::PipeStats::ByteClass statsClass, SizeT& outOffset) {
             outOffset = 0;
             if (bytes == 0) return true;
             if (!EnsureScratchName(buffer)) return false;
@@ -202,6 +216,9 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
             if (data) {
                 g_GLESFuncs.glBufferSubData(BufferImpl::TempBufferTarget, static_cast<GLintptr>(outOffset),
                                             static_cast<GLsizeiptr>(bytes), data);
+                if (MG_Util::PipeStats::Enabled()) {
+                    MG_Util::PipeStats::AddBytes(statsClass, static_cast<Uint64>(bytes));
+                }
             }
             buffer.cursor += aligned;
             return true;
@@ -275,10 +292,20 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
         // its remaining feasibility checks inside its implementation, where the data it
         // has to walk is already in hand.
         GLESMultiDrawMode ResolveTierForBatch(Bool programReadsDrawID, Bool perSubDrawBaseVertex,
-                                              Bool hasIndexBuffer) {
+                                              Bool hasIndexBuffer, Bool arbitraryRestart) {
             ResolveTierOnce();
             GLESMultiDrawMode tier = g_resolvedTier;
 
+            // Desktop GL_PRIMITIVE_RESTART restarts on an application-chosen index; the driver
+            // only ever restarts on the all-ones value. Every tier but the rebased one hands
+            // the application's own index data to the driver, which would then see no restarts
+            // at all and weld the primitives together. The rebased tier is the one that
+            // REWRITES the stream, and RestartSentinelFor already tells it which value to
+            // translate, so it is the only tier this batch can take.
+            if (arbitraryRestart) {
+                return GLESMultiDrawMode::DrawElements;
+            }
+
             // Batched tiers issue one driver entry for the whole batch, so the emulated
             // gl_DrawID uniform can only hold one value across every sub-draw. A program
             // that reads gl_DrawID gets an unrolled tier, which feeds each sub-draw its
@@ -402,7 +429,8 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
 
             const SizeT commandBytes = g_commandStaging.size() * sizeof(DrawElementsIndirectCommand);
             SizeT commandBase = 0;
-            if (!UploadScratchRing(g_indirectCommands, commandBytes, g_commandStaging.data(), commandBase)) {
+            if (!UploadScratchRing(g_indirectCommands, commandBytes, g_commandStaging.data(),
+                                   MG_Util::PipeStats::ByteClass::StageIndirectCmd, commandBase)) {
                 return false;
             }
 
@@ -488,6 +516,16 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
 
             const Bool restartActive = RestartActive();
             const Uint32 restartSentinel = RestartSentinelFor(type);
+            // Widening to GL_UNSIGNED_INT gives a UBYTE/USHORT source a sentinel it can never
+            // spell, so those batches are lossless. A UINT source that already uses 0xFFFFFFFF as
+            // a real vertex index while restarting on a different one is the one shape 32 bits
+            // cannot express - the same corner the single-draw substitution reports.
+            if (restartActive && indexSize == 4 && restartSentinel != 0xFFFFFFFFu) {
+                MGLOG_E_ONCE("GL_PRIMITIVE_RESTART with restart index %u over GL_UNSIGNED_INT multi-draw indices: "
+                             "any index that is already 0xFFFFFFFF will restart too, because the rewritten stream "
+                             "has no wider sentinel to move to.",
+                             restartSentinel);
+            }
             g_indexStaging.resize(total);
             SizeT cursor = 0;
             for (GLsizei i = 0; i < drawcount; ++i) {
@@ -507,7 +545,8 @@ namespace MobileGL::MG_Backend::DirectGLES::MultiDrawImpl {
             }
 
             SizeT indexBase = 0;
-            if (!UploadScratchRing(g_rebasedIndices, total * sizeof(Uint32), g_indexStaging.data(), indexBase)) {
+            if (!UploadScratchRing(g_rebasedIndices, total * sizeof(Uint32), g_indexStaging.data(),
+                                   MG_Util::PipeStats::ByteClass::StageIndexClient, indexBase)) {
                 return false;
             }
 
@@ -712,10 +751,16 @@ void main() {
             if (total == 0) return; // nothing to draw; the ordinary tiers no-op just as well
 
             if (!EnsureComputeProgram()) return;
-            if (!UploadScratch(g_drawInfo, g_drawInfoStaging.size() * sizeof(Uint32), g_drawInfoStaging.data())) {
+            if (!UploadScratch(g_drawInfo, g_drawInfoStaging.size() * sizeof(Uint32), g_drawInfoStaging.data(),
+                               MG_Util::PipeStats::ByteClass::StageIndirectCmd)) {
+                return;
+            }
+            // data == nullptr: pure respecify, the compute pass writes the contents, so no
+            // host bytes cross here and nothing is counted.
+            if (!UploadScratch(g_flattenedIndices, total * sizeof(Uint32), nullptr,
+                               MG_Util::PipeStats::ByteClass::StageIndexClient)) {
                 return;
             }
-            if (!UploadScratch(g_flattenedIndices, total * sizeof(Uint32), nullptr)) return;
 
             BufferImpl::BindBufferBaseCached(GL_SHADER_STORAGE_BUFFER, 0, sourceResource->id);
             BufferImpl::BindBufferBaseCached(GL_SHADER_STORAGE_BUFFER, 1, g_drawInfo.id);
@@ -852,8 +897,14 @@ void main() {
     void DrawElementsBatch(GLenum mode, const GLsizei* count, GLenum type, const GLvoid* const* indices,
                            GLsizei drawcount, const GLint* basevertex) {
         if (drawcount <= 0 || !count || !indices) return;
-        // State-independent and possibly throwing, so it runs before any GL work.
-        CheckPrimitiveRestartSupported(type);
+        // Read before any GL work, because it decides the tier below: a desktop restart index
+        // the driver does not know about can only be honoured by the tier that rewrites the
+        // index stream (see ResolveTierForBatch). A restart index this index type cannot hold
+        // needs no rewrite at all - nothing can match it - but it does need the driver's own
+        // fixed-index restart held off for the batch, which is what the scope below does.
+        const RestartSubstitutionKind restartKind = ResolveRestartSubstitution(type);
+        const Bool arbitraryRestart = restartKind == RestartSubstitutionKind::RewriteIndices;
+        const ScopedSuppressedPrimitiveRestart restartCapOverride(restartKind);
 
         const Bool hasIndexBuffer = BoundIndexBuffer() != nullptr;
 
@@ -889,7 +940,8 @@ void main() {
         // the tier choice and the per-sub-draw feeds use those, not the guess above.
         const Bool feedDrawID = CurrentProgramReadsDrawID();
         const Bool feedBaseVertex = basevertex != nullptr && CurrentProgramReadsBaseVertex();
-        const GLESMultiDrawMode tier = ResolveTierForBatch(feedDrawID, feedBaseVertex, hasIndexBuffer);
+        const GLESMultiDrawMode tier =
+            ResolveTierForBatch(feedDrawID, feedBaseVertex, hasIndexBuffer, arbitraryRestart);
 
         Bool drawn = false;
         switch (tier) {
@@ -921,8 +973,10 @@ void main() {
         // Every tier above may decline a batch whose shape it cannot express. The two
         // below are the floor: a base-vertex replay where the driver has one, and the
         // rewritten index stream where it does not. Both are safe for any batch these
-        // entry points can receive.
-        if (!drawn) {
+        // entry points can receive - except that the base-vertex replay hands the
+        // application's own indices to the driver, which cannot restart on a desktop
+        // restart index, so that batch has only the rewriting floor.
+        if (!drawn && !arbitraryRestart) {
             drawn = RunBaseVertexLoop(mode, count, type, indices, drawcount, basevertex, feedDrawID, feedBaseVertex);
         }
         if (!drawn) {

MobileGL/MG_Backend/DirectGLES/Utils.cpp

@@ -11,10 +11,13 @@
 #include "Managers.h"
 #include "MG_Backend/BackendObjects.h"
 #include "MG_Util/Converters/GLToMG/FramebufferEnumConverter.h"
+#include "MG_Util/SelfTest/DriverBugProbes.h"
 #include "MG_Util/Texture/TextureFormatProcessor.h"
 #include "MG_Util/ShaderTranspiler/ShaderCompiler.h"
+#include <Config.h>
 
 #include <MG_State/GLState/Core.h>
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include <MG_Util/BackendLoaders/OpenGL/Loader.h>
 #include <MG_Util/Converters/GLToStr/GLEnumConverter.h>
 #include <MG_Util/Converters/MGToGL/TextureEnumConverter.h>
@@ -26,6 +29,7 @@
 #include <cmath>
 #include <cctype>
 #include <cstring>
+#include <format>
 #include <regex>
 
 namespace MobileGL::MG_Backend::DirectGLES {
@@ -124,6 +128,14 @@ namespace MobileGL::MG_Backend::DirectGLES {
                     requestedInternalFormat,
                     TextureImpl::GetRenderTargetNormalizeOptions(g_GLESCapabilities, targetIndex));
             }
+            // Outside the caveat branch on purpose: the driver CAN create the native narrow
+            // storage - the capability probes say so - it just cannot be trusted as a raw-copy
+            // endpoint. Texture and renderbuffer targets both come through here, which is what
+            // keeps a renderbuffer -> texture copy of these formats same-ES-format when the
+            // widening engages.
+            if (TextureImpl::UsesWidenedPacked16NormStorage(internalFormat)) {
+                options |= PixelFormatNormalizeOptionBit::WidenPacked16Norm;
+            }
             NormalizePixelFormat(requestedInternalFormat, options, outInternalFormat, outFormat, outType);
         }
     } // namespace
@@ -181,6 +193,36 @@ namespace MobileGL::MG_Backend::DirectGLES {
             return options;
         }
 
+        Bool UsesWidenedPacked16NormStorage(TextureInternalFormat internalFormat) {
+            switch (internalFormat) {
+            // TextureInternalFormat::RGB5 is both GL_RGB5 and GL_RGB565 - the GL-to-MG
+            // converter folds the two spellings onto one logical format.
+            case TextureInternalFormat::RGB5:
+            case TextureInternalFormat::RGB5A1:
+            case TextureInternalFormat::RGBA4:
+                break;
+            default:
+                return false;
+            }
+            switch (MG_Config::Features.EsprytWidenPacked16Storage) {
+            case MG_Config::QuirkOverride::ForceOn:
+                return true;
+            case MG_Config::QuirkOverride::ForceOff:
+                return false;
+            case MG_Config::QuirkOverride::Auto:
+                break;
+            }
+            // Behind the backend gate on purpose: the memoized probe latches its first answer
+            // for the whole process, and before the backend is up the GL function table may
+            // not be resolved yet - a probe run then would latch "cannot tell" as "clean"
+            // forever. Once the backend exists, the first narrow-format image this process
+            // creates runs the probe on a live context.
+            if (pActiveBackendObject == nullptr) {
+                return false;
+            }
+            return MG_Util::SelfTest::CopyImageMirrorsPacked16FieldOrder(g_GLESFuncs);
+        }
+
         void GenerateTextureFormatInfo(TextureInternalFormat internalFormat, GLenum* outInternalFormat,
                                        GLenum* outFormat, GLenum* outType, TextureTarget target) {
 #ifdef TRACY_ENABLE
@@ -712,6 +754,47 @@ namespace MobileGL::MG_Backend::DirectGLES {
             return glslCode;
         }
 
+        const char* PointSizeExtensionName(MG_External::GLESCapabilities::PointSizeTier tier, Bool tessellation) {
+            using Tier = MG_External::GLESCapabilities::PointSizeTier;
+            switch (tier) {
+                case Tier::ExtensionEXT:
+                    return tessellation ? "GL_EXT_tessellation_point_size" : "GL_EXT_geometry_point_size";
+                case Tier::ExtensionOES:
+                    return tessellation ? "GL_OES_tessellation_point_size" : "GL_OES_geometry_point_size";
+                default:
+                    return nullptr;
+            }
+        }
+
+        String RequestPointSizeExtension(String glslCode, const char* extensionName) {
+#ifdef TRACY_ENABLE
+            ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
+#endif
+            // The gl_ViewportIndex story, one built-in over: ESSL 320 makes the tessellation and
+            // geometry STAGES core but leaves gl_PointSize out of their gl_PerVertex entirely,
+            // and SPIRV-Cross - which only ever sees a SPIR-V BuiltIn PointSize decoration -
+            // prints the identifier with no directive behind it. Same hard rule as the two
+            // neighbours: never emitted speculatively, because `#extension` on a name the driver
+            // does not advertise is a compile error of its own.
+            if (extensionName == nullptr || glslCode.find(extensionName) != String::npos) {
+                return glslCode;
+            }
+            const String directive = String("#extension ") + extensionName + " : require\n";
+            // Right after the #version line, the one position that must stay first;
+            // ForceSupporterOutput's scan for the LAST #extension directive still finds
+            // whichever one that ends up being.
+            const SizeT versionPos = glslCode.find("#version");
+            if (versionPos == String::npos) {
+                return directive + glslCode;
+            }
+            const SizeT lineEnd = glslCode.find('\n', versionPos);
+            if (lineEnd == String::npos) {
+                return glslCode + "\n" + directive;
+            }
+            glslCode.insert(lineEnd + 1, directive);
+            return glslCode;
+        }
+
         String BakeImageFormatQualifiers(String glslCode,
                                          const UnorderedMap<String, String>& esslFormatByUniformName) {
 #ifdef TRACY_ENABLE
@@ -836,7 +919,9 @@ namespace MobileGL::MG_Backend::DirectGLES {
 
         String BuildPassthroughTessControlEssl(const Uint esslVersion, const Uint patchVertices,
                                                const String& inPerVertexMembers,
-                                               const String& outPerVertexMembers) {
+                                               const String& outPerVertexMembers,
+                                               const FloatVec4& defaultOuterLevel,
+                                               const FloatVec2& defaultInnerLevel) {
 #ifdef TRACY_ENABLE
             ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
@@ -866,12 +951,14 @@ namespace MobileGL::MG_Backend::DirectGLES {
             // was declined before this was ever called (ModuleReadsLocatedInput), and gl_PointSize
             // from a tessellation stage is a separate capability on both targets.
             source += "    gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;\n";
-            source += "    gl_TessLevelOuter[0] = 1.0;\n";
-            source += "    gl_TessLevelOuter[1] = 1.0;\n";
-            source += "    gl_TessLevelOuter[2] = 1.0;\n";
-            source += "    gl_TessLevelOuter[3] = 1.0;\n";
-            source += "    gl_TessLevelInner[0] = 1.0;\n";
-            source += "    gl_TessLevelInner[1] = 1.0;\n";
+            for (Uint i = 0; i < 4; ++i) {
+                source += "    gl_TessLevelOuter[" + std::to_string(i) +
+                          "] = " + MG_Util::ShaderTranspiler::TessellationLevelLiteral(defaultOuterLevel[i]) + ";\n";
+            }
+            for (Uint i = 0; i < 2; ++i) {
+                source += "    gl_TessLevelInner[" + std::to_string(i) +
+                          "] = " + MG_Util::ShaderTranspiler::TessellationLevelLiteral(defaultInnerLevel[i]) + ";\n";
+            }
             source += "}\n";
             return source;
         }
@@ -2208,11 +2295,11 @@ namespace MobileGL::MG_Backend::DirectGLES {
         static Bool StoreClientRows(SizeT dstPixelBytes, SizeT swapGroupSize, GLsizei width, GLsizei sliceHeight,
                                     GLsizei sliceCount, void* pixels, Bool applyPackImageParams, FillRow&& fillRow) {
             const auto& pixelPackBufferObject =
-                MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
+                MGB_CTX->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
 
             // Destination layout is computed from the client-side PACK parameters; only the actual pixel
             // rows are written so skip regions of the destination stay untouched.
-            const auto packParams = MG_State::pGLContext->GetPixelStoreParameters(false);
+            const auto packParams = MGB_CTX->GetPixelStoreParameters(false);
             const SizeT rowPixels = static_cast<SizeT>(packParams.RowLength > 0 ? packParams.RowLength : width);
             const SizeT dstRowStride = AlignReadbackRow(rowPixels * dstPixelBytes, packParams.Alignment);
             const SizeT imageRows =

MobileGL/MG_Backend/DirectGLES/Utils.h

@@ -46,6 +46,15 @@ namespace MobileGL::MG_Backend::DirectGLES {
         Flags<PixelFormatNormalizeOptionBit> GetRenderTargetNormalizeOptions(
             const MG_External::GLESCapabilities& capabilities, SizeT targetIndex);
 
+        // Whether this format's ES storage is widened to 8-bit-per-channel because the
+        // driver stores some packed16 allocations with a mirrored field order
+        // (PixelFormatNormalizeOptionBit::WidenPacked16Norm). True only for
+        // GL_RGB565/GL_RGB5(_A1)/GL_RGBA4, and only where the POST probe measured the
+        // divergence (or MOBILEGL_ESPRYT_WIDEN_PACKED16_STORAGE forces it). The transfer paths
+        // consult it too: the packed-norm re-upload leg must stand down when the ES storage
+        // is no longer 16-bit packed.
+        Bool UsesWidenedPacked16NormStorage(TextureInternalFormat internalFormat);
+
         void GenerateTextureFormatInfo(TextureInternalFormat internalFormat, GLenum* outInternalFormat,
                                        GLenum* outFormat, GLenum* outType,
                                        TextureTarget target = TextureTarget::Unknown);
@@ -273,6 +282,22 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // error, so this is never emitted speculatively. A no-op when not needed or already
         // present.
         String RequestViewportArrayExtension(String glslCode, Bool needed);
+        // Adds `#extension <extensionName> : require` when a TESSELLATION or GEOMETRY stage's
+        // emitted ESSL names gl_PointSize. Desktop GL has that built-in in gl_PerVertex for every
+        // vertex-processing stage; ESSL does NOT have it in those two at any version - not even
+        // 320, where the stages themselves are core - until EXT/OES_tessellation_point_size resp.
+        // EXT/OES_geometry_point_size is requested. SPIRV-Cross prints the identifier bare and
+        // asks for nothing, exactly as it does for gl_ViewportIndex, so without this the stage
+        // fails to compile with "`gl_PointSize' undeclared" and the WHOLE program is replaced by
+        // program 0 - the draw renders nothing and any transform-feedback capture it was carrying
+        // is rejected outright. `extensionName` is the caller's answer, nullptr when the driver
+        // advertises neither spelling, because requesting an unadvertised extension is itself a
+        // compile error. A no-op when nullptr or already present.
+        String RequestPointSizeExtension(String glslCode, const char* extensionName);
+        // The extension name RequestPointSizeExtension should be given for `tier`, or nullptr for
+        // PointSizeTier::None. `tessellation` picks the tessellation spellings over the geometry
+        // ones; the two extensions are separate and neither implies the other.
+        const char* PointSizeExtensionName(MG_External::GLESCapabilities::PointSizeTier tier, Bool tessellation);
         // Writes a format layout qualifier into the image declarations named in
         // `esslFormatByUniformName` that still have none. The completion half of the image-format
         // bake, and ONLY that: the SPIR-V pass (BakeImageFormatsPass) is what normally puts the
@@ -368,11 +393,11 @@ namespace MobileGL::MG_Backend::DirectGLES {
         //
         // All four outer levels and both inner levels are written unconditionally: writing a
         // level the evaluation stage's domain does not use is legal and ignored, and it saves
-        // this from having to know the domain. They are literal 1.0 because that is the GL
-        // default and glPatchParameterfv - their only setter - is a stub in this frontend
-        // (MG_Impl/GLImpl/Exporting/Definitions.cpp). Implementing that entry point means making
-        // the levels a parameter here AND part of what makes a built program stale, exactly as
-        // PATCH_VERTICES already is; the two must move together, so they are named together.
+        // this from having to know the domain. They are the GL_PATCH_DEFAULT_OUTER_LEVEL /
+        // GL_PATCH_DEFAULT_INNER_LEVEL state, baked in as literals - ES has no such state and no
+        // glPatchParameterfv to forward to, so compiling them in is the only way to honour them.
+        // That makes them part of what a built program is stale against, exactly as PATCH_VERTICES
+        // is: see the staleness clause in DirectGLES.cpp's SyncCurrentProgram, which compares both.
         //
         // The same stage, for the same reason, that DirectVulkan synthesizes in
         // ProgramFactory::BuildPassthroughTessControlSource - Vulkan likewise requires both
@@ -382,7 +407,9 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // VkShaderModule against a driver shader object.
         String BuildPassthroughTessControlEssl(Uint esslVersion, Uint patchVertices,
                                                const String& inPerVertexMembers,
-                                               const String& outPerVertexMembers);
+                                               const String& outPerVertexMembers,
+                                               const FloatVec4& defaultOuterLevel,
+                                               const FloatVec2& defaultInnerLevel);
         // Prefix of the writeonly half a read+write image uniform is split into (see
         // SplitReadWriteImageUniforms); the suffix is the image's own (already access-tagged) name.
         constexpr const char* IMAGE_WRITE_ALIAS_PREFIX = "mg_imageWrite_";
@@ -505,7 +532,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // avoidExplicitLodBias leaves lookups that already carry an explicit LOD untouched,
         // so their constant level stays constant; only the implicit-LOD forms take the bias.
         // Off by default and only ever set on ANGLE + llvmpipe, where injecting the uniform
-        // into a constant LOD crashes the driver (MOBILEGL_AVOID_EXPLICIT_LOD_BIAS).
+        // into a constant LOD crashes the driver (MOBILEGL_ESPRYT_AVOID_EXPLICIT_LOD_BIAS).
         String EmulateTextureLodBias(const String& glslCode, Bool avoidExplicitLodBias = false);
     } // namespace PrgramImpl
 

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.cpp

@@ -12,6 +12,7 @@
 #include "SubgroupSupportPolicy.h"
 #include "MG_State/GLState/FramebufferState/FramebufferObject.h"
 #include "MG_State/GLState/Core.h"
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include "MG_State/GLState/TextureState/TextureState.h"
 #include "MG_Util/Classifiers/TextureEnumClassifier.h"
 #include "MG_Util/Converters/MGToGL/TextureEnumConverter.h"
@@ -385,8 +386,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
         UpdateDynamicBackendParameters();
         UpdateAdvertisedExtensions();
-        if (MG_State::pGLContext) {
-            MG_State::pGLContext->InvalidateCompileEnv();
+        if (MGB_CTX_LIVE) {
+            MGB_CTX->InvalidateCompileEnv();
         }
         PopulateFormatCapabilities(physicalDevice.handle, vkGetPhysicalDeviceFormatProperties, m_vulkanCaps,
                                    MutableFormatCapabilities());
@@ -500,7 +501,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             .RendererName = "Magma",
             .BackendName = "Direct (Vulkan)",
             .ExtraVendor = Nullopt,
-            .RendererGLInfo = {.TargetGLVersion = {4, 3, 0},
+            .RendererGLInfo = {.TargetGLVersion = {4, 6, 0},
                                .TargetGLSLVersion = {4, 6, 0},
                                // Baseline advertisement (no runtime-gated capabilities); a live
                                // backend reconciles its copy in UpdateAdvertisedExtensions.
@@ -516,10 +517,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                   Bool cubeMapArraySupported) {
         Vector<GLExtension> extensions = {
             // The version tokens have to reach the version the backend actually claims:
-            // TargetGLVersion is {4,3,0}, and a list that stopped at OpenGL40 told an
+            // TargetGLVersion is {4,6,0}, and a list that stopped at OpenGL40 told an
             // application feature-detecting off these tokens the opposite of what
             // GL_MAJOR_VERSION / GL_MINOR_VERSION told it.
             V_OpenGL30, V_OpenGL31, V_OpenGL32, V_OpenGL33, V_OpenGL40, V_OpenGL41, V_OpenGL42, V_OpenGL43,
+            V_OpenGL44, V_OpenGL45, V_OpenGL46,
             E_GL_ARB_draw_buffers_blend,
             E_GL_ARB_compute_shader, E_GL_ARB_shader_storage_buffer_object, E_GL_ARB_shader_image_load_store,
             E_GL_ARB_clear_buffer_object, E_GL_ARB_program_interface_query, E_GL_ARB_framebuffer_object, E_GL_ARB_draw_indirect,
@@ -623,7 +625,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (nonZeroIndirectBaseInstanceSupported) {
             extensions.push_back(E_GL_ARB_base_instance);
         }
-        if (shaderSubgroupSupported && !MG_Config::Features.DisableSubgroup) {
+        if (shaderSubgroupSupported && !MG_Config::Features.MagmaDisableSubgroup) {
             extensions.push_back(E_GL_KHR_shader_subgroup);
         }
         // GL_KHR_parallel_shader_compile is MobileGL's own capability, not the Vulkan
@@ -739,8 +741,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             funcsTable.GL.MemoryBarrierByRegion = MemoryBarrierByRegion;
             funcsTable.GL.BindImageTexture = BindImageTexture;
             funcsTable.GL.GetIntegeri_v = GetIntegeri_v;
-            funcsTable.GL.GetInteger64i_v = GetInteger64i_v;
-            funcsTable.GL.GetProgramiv = GetProgramiv;
             funcsTable.GL.ShaderStorageBlockBinding = ShaderStorageBlockBinding;
             funcsTable.GL.FenceSync = FenceSync;
             funcsTable.GL.ClientWaitSync = ClientWaitSync;
@@ -784,8 +784,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_vulkanCaps = capabilities;
         UpdateDynamicBackendParameters();
         UpdateAdvertisedExtensions();
-        if (MG_State::pGLContext) {
-            MG_State::pGLContext->InvalidateCompileEnv();
+        if (MGB_CTX_LIVE) {
+            MGB_CTX->InvalidateCompileEnv();
         }
         MutableFormatCapabilities().Clear();
     }
@@ -938,6 +938,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             clampLimit("GL_MAX_COMPUTE_UNIFORM_BLOCKS", m_vulkanCaps.MaxComputeUniformBlocks,
                        kMaxAdvertisedBufferBlocks);
         m_dynamicParameters.MaxComputeWorkGroupInvocations = m_vulkanCaps.MaxComputeWorkGroupInvocations;
+        // The six per-axis compute limits, from the same VkPhysicalDeviceLimits fields
+        // GLFunctionsTable::GetIntegeri_v (DirectVulkan.cpp) reads live. Carried here so that
+        // MGPCaps has them once the table entry retires (plan B section 4.4.1); GL_Getter floors
+        // them. Not clamped: unlike the block counts these are not amounts an application
+        // allocates, and the frontend already raises them to the GL minimum.
+        for (SizeT axis = 0; axis < 3; ++axis) {
+            m_dynamicParameters.MaxComputeWorkGroupCount[axis] = m_vulkanCaps.MaxComputeWorkGroupCount[axis];
+            m_dynamicParameters.MaxComputeWorkGroupSize[axis] = m_vulkanCaps.MaxComputeWorkGroupSize[axis];
+        }
         m_dynamicParameters.MaxShaderStorageBufferBindings =
             clampLimit("GL_MAX_SHADER_STORAGE_BUFFER_BINDINGS", m_vulkanCaps.MaxShaderStorageBufferBindings,
                        kMaxAdvertisedBufferBlocks);
@@ -1005,6 +1014,19 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // it the limit describes a capacity no shader may use, so report none.
         m_dynamicParameters.MaxClipDistances =
             m_vulkanCaps.SupportsShaderClipDistance ? std::max(m_vulkanCaps.MaxClipDistances, 0) : 0;
+        // The cull pair, gated on its own feature. shaderCullDistance is separate from
+        // shaderClipDistance and VulkanRenderer enables it independently, so it gets its own
+        // gate rather than riding on the clip one.
+        m_dynamicParameters.MaxCullDistances =
+            m_vulkanCaps.SupportsShaderCullDistance ? std::max(m_vulkanCaps.MaxCullDistances, 0) : 0;
+        // GL 4.6 core 11.1.3.10: the combined limit is at least as large as either half. A device
+        // with only one of the two features must not report a combined capacity that implies the
+        // other, so the gate is "either feature" and the value never drops below what is enabled.
+        m_dynamicParameters.MaxCombinedClipAndCullDistances =
+            (m_vulkanCaps.SupportsShaderClipDistance || m_vulkanCaps.SupportsShaderCullDistance)
+                ? std::max({m_vulkanCaps.MaxCombinedClipAndCullDistances, m_dynamicParameters.MaxClipDistances,
+                            m_dynamicParameters.MaxCullDistances})
+                : 0;
         m_dynamicParameters.MaxViewports = m_vulkanCaps.MaxViewports;
         // Assigned explicitly rather than left to the struct's defaults, like every other
         // parameter here, so a second fill cannot inherit a stale value. GL_UNDEFINED_VERTEX is
@@ -1067,6 +1089,31 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // report VK_FALSE, so on every real mobile device this is false and the demotion runs
         // exactly as it always has.
         m_dynamicParameters.SupportsShaderFloat64 = m_vulkanCaps.SupportsShaderFloat64;
+        // shaderTessellationAndGeometryPointSize, both stage families from the one feature.
+        // False arms the shared phase-B point-size demotion, whose modules then carry no
+        // TessellationPointSize/GeometryPointSize capability and build without the feature.
+        // MOBILEGL_POINT_SIZE_DEMOTION=1 pretends it is absent so the demotion can be
+        // exercised on a healthy driver (lavapipe advertises the feature); =0 restores the
+        // detected answer's declines.
+        {
+            Bool supportsStagePointSize = m_vulkanCaps.SupportsTessellationAndGeometryPointSize;
+            switch (MG_Config::Features.PointSizeDemotion) {
+            case MG_Config::QuirkOverride::ForceOn:
+                MGLOG_I("DirectVulkan: MOBILEGL_POINT_SIZE_DEMOTION=1 - treating tessellation/geometry "
+                        "gl_PointSize as unhosted so the demotion runs on this driver");
+                supportsStagePointSize = false;
+                break;
+            case MG_Config::QuirkOverride::ForceOff:
+                MGLOG_I("DirectVulkan: MOBILEGL_POINT_SIZE_DEMOTION=0 - keeping the built-in and the "
+                        "plain declines regardless of the device feature");
+                supportsStagePointSize = true;
+                break;
+            case MG_Config::QuirkOverride::Auto:
+                break;
+            }
+            m_dynamicParameters.SupportsTessellationPointSize = supportsStagePointSize;
+            m_dynamicParameters.SupportsGeometryPointSize = supportsStagePointSize;
+        }
         // Never, on any device, and DELIBERATELY NOT COUPLED to the line above even though it
         // once tracked the same feature. It used to, because a `dvec` input needed Float64 to
         // exist in the module at all; a 64-bit vertex FETCH was already impossible

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.h

@@ -70,7 +70,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     const RendererInfo& GetRendererIdentity();
 
     // The full OpenGL extension list Magma advertises (glGetString(GL_EXTENSIONS)) for
-    // a device with the given raw capabilities. The MOBILEGL_DISABLE_SUBGROUP and
+    // a device with the given raw capabilities. The MOBILEGL_MAGMA_DISABLE_SUBGROUP and
     // MOBILEGL_DISABLE_TIMERQUERY escape hatches are applied inside, so callers pass
     // the detected device support (passing an already-gated value is harmless).
     Vector<GLExtension> BuildAdvertisedExtensions(Bool shaderSubgroupSupported, Bool timerQueriesSupported,

MobileGL/MG_Backend/DirectVulkan/DirectVulkan.cpp

@@ -10,9 +10,11 @@
 #include "DirectVulkanResourceState.h"
 #include "MG_Backend/BackendObjects.h"
 #include "MG_State/GLState/Core.h"
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include "MG_State/GLState/ErrorState/ErrorInfo.h"
 #include "MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.h"
 #include "MG_Util/Converters/GLToMG/TextureEnumConverter.h"
+#include "MG_Util/Metrics/PipeStats.h"
 #include "MG_Util/Metrics/TextureMetrics.h"
 #include "MG_Util/Miscellany/IndexGenerator.h"
 #include <atomic>
@@ -77,7 +79,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             Uint32 blockBindingVersion = 0;
             Vector<StorageBlockResource> storageBlocks;
             Vector<BufferVariableResource> bufferVariables;
-            GLint computeWorkGroupSize[3] = {1, 1, 1};
         };
 
         struct DrawElementsIndirectCommand {
@@ -208,16 +209,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             }
 
             for (auto& module : modules) {
-                for (Uint32 entryIndex = 0; entryIndex < module.entry_point_count; ++entryIndex) {
-                    const auto& entryPoint = module.entry_points[entryIndex];
-                    if ((entryPoint.shader_stage & SPV_REFLECT_SHADER_STAGE_COMPUTE_BIT) == 0) {
-                        continue;
-                    }
-                    cache.computeWorkGroupSize[0] = static_cast<GLint>(std::max<Uint32>(entryPoint.local_size.x, 1));
-                    cache.computeWorkGroupSize[1] = static_cast<GLint>(std::max<Uint32>(entryPoint.local_size.y, 1));
-                    cache.computeWorkGroupSize[2] = static_cast<GLint>(std::max<Uint32>(entryPoint.local_size.z, 1));
-                }
-
                 uint32_t bindingCount = 0;
                 SpvReflectResult result = spvReflectEnumerateDescriptorBindings(&module, &bindingCount, nullptr);
                 if (result != SPV_REFLECT_RESULT_SUCCESS || bindingCount == 0) {
@@ -277,15 +268,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
 
         MG_State::GLState::ProgramObject* TryGetDirectVulkanProgram(GLuint program) {
-            if (!MG_State::pGLContext->ValidateProgramName(program)) {
+            if (!MGB_CTX->ValidateProgramName(program)) {
                 return nullptr;
             }
-            auto& programObject = MG_State::pGLContext->GetProgramObject(program);
+            auto& programObject = MGB_CTX->GetProgramObject(program);
             return programObject.get();
         }
 
         const Uint8* ResolveIndirectCommandBytes(const void* indirect, SizeT requiredBytes, const char* label) {
-            auto drawBuffer = MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
+            auto drawBuffer = MGB_CTX->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
             if (drawBuffer) {
                 drawBuffer->SyncPersistentMappedRange();
                 const SizeT commandOffset = reinterpret_cast<SizeT>(indirect);
@@ -344,64 +335,64 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     void ClearBufferfi(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearBufferfi called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearBufferfi called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearBufferfi called with null GL context");
         pVulkanRenderer->ClearBufferfi(buffer, drawbuffer, depth, stencil);
     }
 
     void ClearBufferfv(GLenum buffer, GLint drawbuffer, const GLfloat* value) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearBufferfv called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearBufferfv called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearBufferfv called with null GL context");
         pVulkanRenderer->ClearBufferfv(buffer, drawbuffer, value);
     }
 
     void ClearBufferuiv(GLenum buffer, GLint drawbuffer, const GLuint* value) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearBufferuiv called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearBufferuiv called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearBufferuiv called with null GL context");
         pVulkanRenderer->ClearBufferuiv(buffer, drawbuffer, value);
     }
 
     void ClearBufferiv(GLenum buffer, GLint drawbuffer, const GLint* value) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearBufferiv called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearBufferiv called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearBufferiv called with null GL context");
         pVulkanRenderer->ClearBufferiv(buffer, drawbuffer, value);
     }
 
     void ClearNamedFramebufferfv(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer,
                                  GLint drawbuffer, const GLfloat* value) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearNamedFramebufferfv called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearNamedFramebufferfv called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearNamedFramebufferfv called with null GL context");
         pVulkanRenderer->ClearNamedFramebufferfv(framebuffer, buffer, drawbuffer, value);
     }
 
     void ClearNamedFramebufferiv(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer,
                                  GLint drawbuffer, const GLint* value) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearNamedFramebufferiv called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearNamedFramebufferiv called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearNamedFramebufferiv called with null GL context");
         pVulkanRenderer->ClearNamedFramebufferiv(framebuffer, buffer, drawbuffer, value);
     }
 
     void ClearNamedFramebufferuiv(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer,
                                   GLint drawbuffer, const GLuint* value) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearNamedFramebufferuiv called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearNamedFramebufferuiv called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearNamedFramebufferuiv called with null GL context");
         pVulkanRenderer->ClearNamedFramebufferuiv(framebuffer, buffer, drawbuffer, value);
     }
 
     void ClearNamedFramebufferfi(const SharedPtr<MG_State::GLState::FramebufferObject>& framebuffer, GLenum buffer,
                                  GLint drawbuffer, GLfloat depth, GLint stencil) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ClearNamedFramebufferfi called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ClearNamedFramebufferfi called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ClearNamedFramebufferfi called with null GL context");
         pVulkanRenderer->ClearNamedFramebufferfi(framebuffer, buffer, drawbuffer, depth, stencil);
     }
 
     void MultiDrawElementsIndirect(GLenum mode, GLenum type, const void* indirect, GLsizei drawcount, GLsizei stride) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawElementsIndirect called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawElementsIndirect called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawElementsIndirect called with null GL context");
         pVulkanRenderer->MultiDrawElementsIndirect(mode, type, indirect, drawcount, stride);
     }
     void MultiDrawArraysIndirect(GLenum mode, const void* indirect, GLsizei drawcount, GLsizei stride) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawArraysIndirect called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawArraysIndirect called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawArraysIndirect called with null GL context");
 
         if (drawcount <= 0) {
             return;
@@ -409,7 +400,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         // With a bound GL_DRAW_INDIRECT_BUFFER the command parameters may be GPU-written
         // (e.g. by a compute shader), so consume them natively on the GPU.
-        auto drawBuffer = MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
+        auto drawBuffer = MGB_CTX->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
         if (drawBuffer) {
             pVulkanRenderer->MultiDrawArraysIndirect(mode, indirect, drawcount, stride);
             return;
@@ -452,13 +443,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void MultiDrawElementsIndirectCount(GLenum mode, GLenum type, const void* indirect, GLintptr drawcount,
                                         GLsizei maxdrawcount, GLsizei stride) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawElementsIndirectCount called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawElementsIndirectCount called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawElementsIndirectCount called with null GL context");
         pVulkanRenderer->MultiDrawElementsIndirectCount(mode, type, indirect, drawcount, maxdrawcount, stride);
     }
     void MultiDrawArraysIndirectCount(GLenum mode, const void* indirect, GLintptr drawcount,
                                       GLsizei maxdrawcount, GLsizei stride) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawArraysIndirectCount called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawArraysIndirectCount called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawArraysIndirectCount called with null GL context");
 
         if (maxdrawcount <= 0) {
             return;
@@ -472,7 +463,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return;
         }
 
-        auto parameterBuffer = MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::Parameter).GetBoundObject();
+        auto parameterBuffer = MGB_CTX->GetBufferBindingSlot(BufferTarget::Parameter).GetBoundObject();
         if (!parameterBuffer || drawcount < 0 || static_cast<SizeT>(drawcount) + sizeof(Uint32) > parameterBuffer->GetSize()) {
             MGLOG_E_ONCE("MultiDrawArraysIndirectCount skipped: invalid GL_PARAMETER_BUFFER binding or range");
             return;
@@ -503,7 +494,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void DrawElementsInstancedBaseVertexBaseInstance(GLenum mode, GLsizei count, GLenum type, const void* indices,
                                                      GLsizei instancecount, GLint basevertex, GLuint baseinstance) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawElementsInstancedBaseVertexBaseInstance called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawElementsInstancedBaseVertexBaseInstance called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawElementsInstancedBaseVertexBaseInstance called with null GL context");
 
         DrawIndexedCmd payload{};
         payload.mode = mode;
@@ -530,7 +521,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     }
     void DrawElementsIndirect(GLenum mode, GLenum type, const void* indirect) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawElementsIndirect called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawElementsIndirect called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawElementsIndirect called with null GL context");
 
         const SizeT indexSize = MG_Util::GetGLTypeSize(type);
         if (indexSize == 0) {
@@ -540,7 +531,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         // With a bound GL_DRAW_INDIRECT_BUFFER the command parameters may be GPU-written
         // (e.g. by a compute shader), so consume them natively on the GPU.
-        auto drawBuffer = MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
+        auto drawBuffer = MGB_CTX->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
         if (drawBuffer) {
             pVulkanRenderer->MultiDrawElementsIndirect(mode, type, indirect, 1, 0);
             return;
@@ -574,7 +565,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void DrawArraysInstancedBaseInstance(GLenum mode, GLint first, GLsizei count, GLsizei instancecount,
                                          GLuint baseinstance) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawArraysInstancedBaseInstance called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawArraysInstancedBaseInstance called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawArraysInstancedBaseInstance called with null GL context");
 
         DrawCmd payload{};
         payload.mode = mode;
@@ -589,11 +580,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     }
     void DrawArraysIndirect(GLenum mode, const void* indirect) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawArraysIndirect called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawArraysIndirect called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawArraysIndirect called with null GL context");
 
         // With a bound GL_DRAW_INDIRECT_BUFFER the command parameters may be GPU-written
         // (e.g. by a compute shader), so consume them natively on the GPU.
-        auto drawBuffer = MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
+        auto drawBuffer = MGB_CTX->GetBufferBindingSlot(BufferTarget::DrawIndirect).GetBoundObject();
         if (drawBuffer) {
             pVulkanRenderer->MultiDrawArraysIndirect(mode, indirect, 1, 0);
             return;
@@ -623,13 +614,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void CopyTexImage2D(GLenum target, GLint level, GLenum internalformat, GLint x, GLint y, GLsizei width,
                         GLsizei height, GLint border) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::CopyTexImage2D called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::CopyTexImage2D called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::CopyTexImage2D called with null GL context");
         pVulkanRenderer->CopyTexSubImage2D(target, level, 0, 0, x, y, width, height);
     }
     void CopyTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint x, GLint y, GLsizei width,
                            GLsizei height) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::CopyTexSubImage2D called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::CopyTexSubImage2D called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::CopyTexSubImage2D called with null GL context");
         pVulkanRenderer->CopyTexSubImage2D(target, level, xoffset, yoffset, x, y, width, height);
     }
     void CopyImageSubData(const CopyImageEndpoint& src,
@@ -638,32 +629,32 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                           GLenum dstTarget, GLint dstLevel, GLint dstX, GLint dstY, GLint dstZ,
                           GLsizei srcWidth, GLsizei srcHeight, GLsizei srcDepth) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::CopyImageSubData called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::CopyImageSubData called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::CopyImageSubData called with null GL context");
         pVulkanRenderer->CopyImageSubData(src, srcTarget, srcLevel, srcX, srcY, srcZ,
                                           dst, dstTarget, dstLevel, dstX, dstY, dstZ,
                                           srcWidth, srcHeight, srcDepth);
     }
     void GenerateMipmap(GLenum target) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::GenerateMipmap called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::GenerateMipmap called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::GenerateMipmap called with null GL context");
         pVulkanRenderer->GenerateMipmap(target);
     }
 
     void DispatchCompute(GLuint numGroupsX, GLuint numGroupsY, GLuint numGroupsZ) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DispatchCompute called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DispatchCompute called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DispatchCompute called with null GL context");
         pVulkanRenderer->DispatchCompute(numGroupsX, numGroupsY, numGroupsZ);
     }
 
     void DispatchComputeIndirect(GLintptr indirect) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DispatchComputeIndirect called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DispatchComputeIndirect called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DispatchComputeIndirect called with null GL context");
         pVulkanRenderer->DispatchComputeIndirect(indirect);
     }
 
     void MemoryBarrier(GLbitfield barriers) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MemoryBarrier called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MemoryBarrier called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MemoryBarrier called with null GL context");
         pVulkanRenderer->MemoryBarrier(barriers);
     }
 
@@ -682,130 +673,40 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         (void)format;
     }
 
+    // The two compute limits are the only indexed pnames a backend genuinely owns: they come
+    // from the physical device, and MG_Impl/GLImpl/Getter/GL_Getter.cpp asks for them here so it
+    // can raise the answer to the GL required minimum. The same six numbers are carried in
+    // DynamicBackendParameters::MaxComputeWorkGroupCount/Size (filled at capability init from
+    // the same limits), which is their MGPCaps carrier once this entry retires - the
+    // AdvertisedLimitsScenario pins the two against each other. Every other indexed pname names FRONTEND
+    // state (the indexed buffer bindings, the per-unit texture/sampler bindings, the image-unit
+    // bindings, the viewport rectangles, the indexed capabilities) and is answered there before
+    // the table is consulted, so the arms this function used to carry for
+    // GL_SHADER_STORAGE_BUFFER_* and GL_IMAGE_BINDING_* were unreachable duplicates - and not
+    // even faithful ones: the frontend reports the range glBindBufferRange was ASKED for,
+    // verbatim, while these clamped it to the buffer's current storage.
     void GetIntegeri_v(GLenum target, GLuint index, GLint* data) {
         if (!data) return;
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::GetIntegeri_v called with null VulkanRenderer");
+        if (index >= 3) {
+            *data = 0;
+            return;
+        }
         switch (target) {
         case GL_MAX_COMPUTE_WORK_GROUP_COUNT:
-            if (index >= 3) {
-                *data = 0;
-                return;
-            }
             *data = static_cast<GLint>(
                 pVulkanRenderer->GetPhysicalDevice().properties.limits.maxComputeWorkGroupCount[index]);
             return;
         case GL_MAX_COMPUTE_WORK_GROUP_SIZE:
-            if (index >= 3) {
-                *data = 0;
-                return;
-            }
             *data = static_cast<GLint>(
                 pVulkanRenderer->GetPhysicalDevice().properties.limits.maxComputeWorkGroupSize[index]);
             return;
-        case GL_SHADER_STORAGE_BUFFER_BINDING: {
-            auto& point = MG_State::pGLContext->GetBufferBindingPoint(BufferTarget::ShaderStorage, index);
-            auto& obj = point.GetBoundObject();
-            *data = obj ? static_cast<GLint>(obj->GetExternalIndex()) : 0;
-            return;
-        }
-        case GL_SHADER_STORAGE_BUFFER_START: {
-            auto& point = MG_State::pGLContext->GetBufferBindingPoint(BufferTarget::ShaderStorage, index);
-            *data = static_cast<GLint>(point.GetRange().start);
-            return;
-        }
-        case GL_SHADER_STORAGE_BUFFER_SIZE: {
-            auto& point = MG_State::pGLContext->GetBufferBindingPoint(BufferTarget::ShaderStorage, index);
-            auto& obj = point.GetBoundObject();
-            if (!obj) {
-                *data = 0;
-                return;
-            }
-            const auto& range = point.GetRange();
-            const auto start = std::min(range.start, obj->GetSize());
-            const auto end = std::min(range.end, obj->GetSize());
-            *data = static_cast<GLint>(end - start);
-            return;
-        }
-        case GL_IMAGE_BINDING_NAME:
-        case GL_IMAGE_BINDING_LEVEL:
-        case GL_IMAGE_BINDING_LAYERED:
-        case GL_IMAGE_BINDING_LAYER:
-        case GL_IMAGE_BINDING_ACCESS:
-        case GL_IMAGE_BINDING_FORMAT: {
-            if (index >= MG_State::GLState::TextureState::MAX_TEXTURE_IMAGE_UNITS) {
-                *data = 0;
-                return;
-            }
-            auto& imageBinding = MG_State::pGLContext->GetImageTextureBinding(static_cast<Int>(index));
-            if (target == GL_IMAGE_BINDING_NAME) {
-                *data = imageBinding.Texture ? static_cast<GLint>(imageBinding.Texture->GetExternalIndex()) : 0;
-            } else if (target == GL_IMAGE_BINDING_LEVEL) {
-                *data = imageBinding.Level;
-            } else if (target == GL_IMAGE_BINDING_LAYERED) {
-                *data = imageBinding.Layered;
-            } else if (target == GL_IMAGE_BINDING_LAYER) {
-                *data = imageBinding.Layer;
-            } else if (target == GL_IMAGE_BINDING_ACCESS) {
-                *data = static_cast<GLint>(imageBinding.Access);
-            } else {
-                *data = static_cast<GLint>(imageBinding.Format);
-            }
-            return;
-        }
         default:
             *data = 0;
             return;
         }
     }
 
-    void GetInteger64i_v(GLenum target, GLuint index, GLint64* data) {
-        if (!data) return;
-        switch (target) {
-        case GL_SHADER_STORAGE_BUFFER_START: {
-            auto& point = MG_State::pGLContext->GetBufferBindingPoint(BufferTarget::ShaderStorage, index);
-            *data = static_cast<GLint64>(point.GetRange().start);
-            return;
-        }
-        case GL_SHADER_STORAGE_BUFFER_SIZE: {
-            auto& point = MG_State::pGLContext->GetBufferBindingPoint(BufferTarget::ShaderStorage, index);
-            auto& obj = point.GetBoundObject();
-            if (!obj) {
-                *data = 0;
-                return;
-            }
-            const auto& range = point.GetRange();
-            const auto start = std::min(range.start, obj->GetSize());
-            const auto end = std::min(range.end, obj->GetSize());
-            *data = static_cast<GLint64>(end - start);
-            return;
-        }
-        default:
-            *data = 0;
-            return;
-        }
-    }
-
-    void GetProgramiv(GLuint program, GLenum pname, GLint* params) {
-        if (!params) return;
-        auto* programObject = TryGetDirectVulkanProgram(program);
-        if (!programObject) {
-            params[0] = 0;
-            return;
-        }
-        switch (pname) {
-        case GL_COMPUTE_WORK_GROUP_SIZE: {
-            auto& cache = GetProgramResourceCache(*programObject);
-            params[0] = cache.computeWorkGroupSize[0];
-            params[1] = cache.computeWorkGroupSize[1];
-            params[2] = cache.computeWorkGroupSize[2];
-            return;
-        }
-        default:
-            params[0] = 0;
-            return;
-        }
-    }
-
     void ShaderStorageBlockBinding(GLuint program, const GLchar* storageBlockName, GLuint storageBlockBinding) {
         auto* programObject = TryGetDirectVulkanProgram(program);
         if (!programObject || storageBlockName == nullptr) return;
@@ -813,7 +714,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             ? pActiveBackendObject->GetDynamicParameters().MaxShaderStorageBufferBindings
             : 0;
         if (storageBlockBinding >= static_cast<GLuint>(maxBindings)) {
-            MG_State::pGLContext->RecordError(
+            MGB_CTX->RecordError(
                 ErrorCode::InvalidValue,
                 MakeUnique<GenericErrorInfo>("DirectVulkan", __func__, "Shader storage binding is out of range."));
             return;
@@ -838,24 +739,24 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     }
     void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::ReadPixels called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::ReadPixels called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::ReadPixels called with null GL context");
         pVulkanRenderer->ReadPixels(x, y, width, height, format, type, pixels);
     }
     void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::GetTexImage called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::GetTexImage called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::GetTexImage called with null GL context");
         pVulkanRenderer->GetTexImage(target, level, format, type, pixels);
     }
     void GetTextureImage(const SharedPtr<MG_State::GLState::ITextureObject>& texture, TextureUploadTarget uploadTarget,
                          GLint level, GLenum format, GLenum type, GLsizei bufSize, GLvoid* pixels) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::GetTextureImage called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::GetTextureImage called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::GetTextureImage called with null GL context");
         pVulkanRenderer->GetTextureImage(texture, uploadTarget, level, format, type, bufSize, pixels);
     }
 
     void Clear(GLbitfield mask) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::Clear called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::Clear called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::Clear called with null GL context");
         pVulkanRenderer->Clear(mask);
     }
 
@@ -883,7 +784,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return false;
         }
         const Uint8* indexBytes = nullptr;
-        const auto& vao = *MG_State::pGLContext->GetBoundVertexArray();
+        const auto& vao = *MGB_CTX->GetBoundVertexArray();
         const auto& indexBufferShared = vao.GetIndexBufferBindingSlot().GetBoundObject();
         if (indexBufferShared != nullptr) {
             const SizeT offset = reinterpret_cast<SizeT>(indices);
@@ -914,7 +815,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     void DrawArrays(GLenum mode, GLint first, GLsizei count) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawArrays called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawArrays called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawArrays called with null GL context");
 
         if (mode == GL_LINE_LOOP) {
             if (count < 2) {
@@ -939,7 +840,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     void DrawElements(GLenum mode, GLsizei count, GLenum type, const void* indices) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawElements called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawElements called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawElements called with null GL context");
 
         if (mode == GL_LINE_LOOP) {
             Vector<Uint32> closedIndices;
@@ -962,7 +863,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     void MultiDrawArrays(GLenum mode, const GLint* first, const GLsizei* count, GLsizei drawcount) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawArrays called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawArrays called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawArrays called with null GL context");
         if (drawcount <= 0) {
             return;
         }
@@ -1007,7 +908,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // MultiDrawIndexedCmd left the client-memory shape addressing a view whose byte
         // offset is a hardcoded 0, so UploadAndBindIndexBuffer saw a null client pointer,
         // declined the whole batch and painted nothing.)
-        const auto& vao = *MG_State::pGLContext->GetBoundVertexArray();
+        const auto& vao = *MGB_CTX->GetBoundVertexArray();
         if (vao.GetIndexBufferBindingSlot().GetBoundObject() == nullptr) {
             for (GLsizei i = 0; i < drawcount; ++i) {
                 if (count[i] <= 0) {
@@ -1068,13 +969,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void MultiDrawElements(GLenum mode, const GLsizei* count, GLenum type, const GLvoid* const* indices,
                            GLsizei drawcount) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawElements called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawElements called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawElements called with null GL context");
         MultiDrawElementsImpl(mode, count, type, indices, drawcount, nullptr);
     }
 
     void DrawElementsBaseVertex(GLenum mode, GLsizei count, GLenum type, const GLvoid* indices, GLint basevertex) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawElementsBaseVertex called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawElementsBaseVertex called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::DrawElementsBaseVertex called with null GL context");
         if (mode == GL_LINE_LOOP) {
             Vector<Uint32> closedIndices;
             if (BuildClosedLineLoopIndices(count, type, indices, closedIndices)) {
@@ -1098,14 +999,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void MultiDrawElementsBaseVertex(GLenum mode, const GLsizei* count, GLenum type, const GLvoid* const* indices,
                                      GLsizei drawcount, const GLint* basevertex) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::MultiDrawElementsBaseVertex called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::MultiDrawElementsBaseVertex called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::MultiDrawElementsBaseVertex called with null GL context");
         MultiDrawElementsImpl(mode, count, type, indices, drawcount, basevertex);
     }
 
     void BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1,
                          GLint dstY1, GLbitfield mask, GLenum filter) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::BlitFramebuffer called with null VulkanRenderer");
-        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::BlitFramebuffer called with null GL context");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "DirectVulkan::BlitFramebuffer called with null GL context");
         pVulkanRenderer->BlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
     }
 
@@ -1206,6 +1107,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             SharedPtr<VkTimerQueryManager::TimestampRecord> end;
             // Kind::Occlusion - pool slots recorded between Begin/End; summed at result time.
             Vector<Uint32> occlusionSlots;
+            // Kind::XfbGenerated - reroute-pool slots for the span's XFB-INACTIVE
+            // draws, where the renderer's reroute is armed (the affected driver's
+            // stream query counts nothing without an open capture; see
+            // VulkanRenderer::BeginXfbQueryForDraw). Summed alongside the stream
+            // slots above, which keep the span's XFB-active draws.
+            Vector<Uint32> rerouteSlots;
             // Renderer generation the records were written under (see
             // g_rendererGeneration). A stale generation resolves as available
             // with a final zero result: the records' pool indices and frame
@@ -1215,11 +1122,19 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // stale queries are always safe to delete.
             Uint64 rendererGeneration = 0;
             // Kind::XfbGenerated - the frontend's paused-draw primitive counter when the
-            // query began. VK_QUERY_TYPE_TRANSFORM_FEEDBACK_STREAM_EXT counts only what the
-            // capture saw, so a draw made while the span was paused is invisible to it -
-            // but GL_PRIMITIVES_GENERATED counts what the last vertex processing stage
-            // emitted regardless. The delta closes that gap at result time.
+            // query began. On the affected drivers VK_QUERY_TYPE_TRANSFORM_FEEDBACK_STREAM_EXT
+            // counts only what the capture saw, so a draw made while the span was paused is
+            // invisible to it - but GL_PRIMITIVES_GENERATED counts what the last vertex
+            // processing stage emitted regardless. The delta closes that gap at result time.
             Uint64 pausedPrimitiveSnapshot = 0;
+            // ...unless the GPU already counted those paused draws when the span opened -
+            // through the reroute pool (VulkanRenderer::BeginXfbQueryForDraw reroutes every
+            // draw with no open capture, paused ones included) or, where the probe measured
+            // the stream query as counting capture-less draws, through the stream slot the
+            // paused draw still takes. Adding the CPU delta on top would count them twice,
+            // and the CPU counter is the weaker source anyway: only 3 of the ~15 draw entry
+            // points write it and it answers 0 for GL_PATCHES.
+            Bool pausedPrimitivesCountedByGpu = false;
         };
     } // namespace
 
@@ -1313,13 +1228,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (query->kind == VulkanTimerQuery::Kind::XfbWritten ||
             query->kind == VulkanTimerQuery::Kind::XfbGenerated) {
             Uint64 primitives = 0;
-            if (!pVulkanRenderer->ResolveXfbQueryResult(query->occlusionSlots,
+            if (!pVulkanRenderer->ResolveXfbQueryResult(query->occlusionSlots, query->rerouteSlots,
                                                         query->kind == VulkanTimerQuery::Kind::XfbGenerated,
                                                         primitives)) {
                 return false;
             }
-            if (query->kind == VulkanTimerQuery::Kind::XfbGenerated && MG_State::pGLContext != nullptr) {
-                primitives += MG_State::pGLContext->GetTransformFeedbackPausedPrimitiveCounter() -
+            if (query->kind == VulkanTimerQuery::Kind::XfbGenerated &&
+                !query->pausedPrimitivesCountedByGpu && MGB_CTX_LIVE) {
+                primitives += MGB_CTX->GetTransformFeedbackPausedPrimitiveCounter() -
                               query->pausedPrimitiveSnapshot;
             }
             *outNanoseconds = primitives;
@@ -1366,7 +1282,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         query->kind = generated ? VulkanTimerQuery::Kind::XfbGenerated : VulkanTimerQuery::Kind::XfbWritten;
         query->rendererGeneration = GetRendererGeneration();
         query->pausedPrimitiveSnapshot =
-            MG_State::pGLContext ? MG_State::pGLContext->GetTransformFeedbackPausedPrimitiveCounter() : 0;
+            MGB_CTX_LIVE ? MGB_CTX->GetTransformFeedbackPausedPrimitiveCounter() : 0;
+        // Read AFTER StartXfbQueryCapture, which is where a failed reroute-pool creation
+        // disarms: the answer is then what this span will actually do for every draw.
+        query->pausedPrimitivesCountedByGpu = generated && pVulkanRenderer->ArePausedDrawsGpuCounted();
         return query;
     }
 
@@ -1377,7 +1296,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return;
         }
         pVulkanRenderer->StopXfbQueryCapture(
-            query->kind == VulkanTimerQuery::Kind::XfbGenerated ? 1u : 0u, query->occlusionSlots);
+            query->kind == VulkanTimerQuery::Kind::XfbGenerated ? 1u : 0u, query->occlusionSlots,
+            query->rerouteSlots);
     }
 
     BackendQueryHandle BeginOcclusionQuery() {
@@ -1411,5 +1331,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void Present() {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::Present called with null VulkanRenderer");
         pVulkanRenderer->Present();
+        // THE frame boundary for the MGPipe counters, at the backend entry point rather
+        // than inside VulkanRenderer::Present: that function has an early return for the
+        // no-usable-swapchain case, and a suspended frame is still a frame the counters
+        // must close.
+        if (MG_Util::PipeStats::Enabled()) {
+            MG_Util::PipeStats::OnPresent();
+        }
     }
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/DirectVulkan.h

@@ -95,8 +95,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     void BindImageTexture(GLuint unit, GLuint texture, GLint level, GLboolean layered, GLint layer, GLenum access,
                           GLenum format);
     void GetIntegeri_v(GLenum target, GLuint index, GLint* data);
-    void GetInteger64i_v(GLenum target, GLuint index, GLint64* data);
-    void GetProgramiv(GLuint program, GLenum pname, GLint* params);
     void ShaderStorageBlockBinding(GLuint program, const GLchar* storageBlockName, GLuint storageBlockBinding);
     void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels);
     void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels);

MobileGL/MG_Backend/DirectVulkan/Renderer/PipelineFactory.cpp

@@ -201,11 +201,16 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.renderPass, sizeof(payload.renderPass)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.colorAttachmentCount, sizeof(payload.colorAttachmentCount)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.rasterizationSamples, sizeof(payload.rasterizationSamples)));
+        XXHASH_VERIFY(XXH64_update(m_hashState, &payload.sampleShadingEnable, sizeof(payload.sampleShadingEnable)));
+        XXHASH_VERIFY(XXH64_update(m_hashState, &payload.minSampleShading, sizeof(payload.minSampleShading)));
+        XXHASH_VERIFY(XXH64_update(m_hashState, &payload.sampleMask, sizeof(payload.sampleMask)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.subpass, sizeof(payload.subpass)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.topology, sizeof(payload.topology)));
         XXHASH_VERIFY(
             XXH64_update(m_hashState, &payload.primitiveRestartEnable, sizeof(payload.primitiveRestartEnable)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.patchControlPoints, sizeof(payload.patchControlPoints)));
+        XXHASH_VERIFY(XXH64_update(m_hashState, &payload.passthroughTessControlKey,
+                                   sizeof(payload.passthroughTessControlKey)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.viewportCount, sizeof(payload.viewportCount)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.polygonMode, sizeof(payload.polygonMode)));
         XXHASH_VERIFY(XXH64_update(m_hashState, &payload.cullMode, sizeof(payload.cullMode)));
@@ -435,6 +440,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         VkPipelineMultisampleStateCreateInfo ms{VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO};
         ms.rasterizationSamples = payload.rasterizationSamples;
+        ms.sampleShadingEnable = payload.sampleShadingEnable ? VK_TRUE : VK_FALSE;
+        // Ignored by Vulkan unless sampleShadingEnable is set, but written unconditionally so the
+        // struct's bytes match the hash the payload was keyed by.
+        ms.minSampleShading = payload.minSampleShading;
+        // GL_SAMPLE_MASK / glSampleMaski. Left at nullptr - which Vulkan reads as all-ones - until
+        // now, so glSampleMaski was a silent no-op on this backend while DirectGLES forwarded it.
+        // The pointer has to outlive the vkCreateGraphicsPipelines call, which the payload does.
+        ms.pSampleMask = payload.sampleMask;
 
         VkPipelineDepthStencilStateCreateInfo depthStencil{VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO};
         depthStencil.depthTestEnable = payload.depthTestEnable ? VK_TRUE : VK_FALSE;

MobileGL/MG_Backend/DirectVulkan/Renderer/PipelineFactory.h

@@ -37,11 +37,39 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             VkRenderPass renderPass = VK_NULL_HANDLE;
             Uint32 colorAttachmentCount = 1;
             VkSampleCountFlagBits rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;
+            // glEnable(GL_SAMPLE_SHADING) + glMinSampleShading, which Vulkan bakes into the
+            // pipeline rather than exposing as dynamic state - so both are part of the pipeline's
+            // identity and both are hashed. The renderer leaves the enable false unless the
+            // device's sampleRateShading feature was enabled
+            // (VUID-VkPipelineMultisampleStateCreateInfo-sampleShadingEnable-00784).
+            Bool sampleShadingEnable = false;
+            Float minSampleShading = 0.0f;
+            // glEnable(GL_SAMPLE_MASK) + glSampleMaski, the fixed-function coverage mask, already
+            // reduced to what GL says this draw gets (VulkanRenderer::ResolveEffectiveSampleMask:
+            // all-ones unless the target is genuinely multisampled). Pipeline state like the two
+            // above - Vulkan has no dynamic sample mask before VK_EXT_extended_dynamic_state3 -
+            // so it is hashed with them, and all-ones has to keep producing the pipeline a null
+            // pSampleMask always did.
+            //
+            // TWO words, though GL only ever fills the first. GL_MAX_SAMPLE_MASK_WORDS is clamped
+            // to 1 on both backends, so glSampleMaski writes index 0 and nothing else - but the
+            // count Vulkan READS is ceil(rasterizationSamples / 32), which is 2 on a 64-sample
+            // target, and GetAdvertisedMaxSamples does not cap the driver's sample count. A
+            // single Uint32 here let such a pipeline read one word past the member (the next
+            // struct field). The second word is all-ones: full coverage for samples 32..63, which
+            // is the only honest answer when GL has no state describing them.
+            Uint32 sampleMask[2] = {0xffffffffu, 0xffffffffu};
             Uint32 subpass = 0;
             VkPrimitiveTopology topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
             Bool primitiveRestartEnable = false;
             // GL_PATCH_VERTICES; only read for a PATCH_LIST topology.
             Uint32 patchControlPoints = 3;
+            // ProgramFactory::ComputePassthroughTessControlKey of the synthesized pass-through
+            // tessellation control stage below, or 0 when this pipeline has none. Hashed, because
+            // the levels glPatchParameterfv set are compiled INTO that module and are not a
+            // function of the program or of patchControlPoints - see the note on
+            // passthroughTessControlStage.
+            Uint64 passthroughTessControlKey = 0;
             // How many of ARB_viewport_array's viewports this pipeline rasterizes into. 1 for
             // every program that never assigns gl_ViewportIndex, which is all of them outside the
             // conformance suite - the wide shape costs a longer vkCmdSetViewport/Scissor per state
@@ -87,8 +115,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // renderer could not build one, and CreatePipeline refuses the pipeline - the same
             // refusal it applies when `stages` itself is half-tessellated.
             //
-            // NOT hashed: it is a pure function of the program and of patchControlPoints, both
-            // of which ComputeHash already mixes in.
+            // NOT hashed directly: it is a pure function of the program, of patchControlPoints and
+            // of the default tessellation levels - the first two of which ComputeHash already
+            // mixes in, and the third of which arrives through passthroughTessControlKey above.
             VkPipelineShaderStageCreateInfo passthroughTessControlStage{};
             const VkPipelineVertexInputStateCreateInfo* vertexInputState = nullptr;
             // Diagnostic only; may be null. Read solely from the pipeline-creation failure path.

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.cpp

@@ -13,7 +13,10 @@
 #include "MG_Util/ShaderTranspiler/SpvcSession.h"
 #include "MG_Util/ShaderTranspiler/Types.h"
 #include <algorithm>
+#include <bit>
+#include <cmath>
 #include <cstring>
+#include <format>
 #include <map>
 #include <utility>
 #include <spirv-tools/libspirv.h>
@@ -74,6 +77,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             }
         };
 
+        // Where a gl_PerVertex built-in output lives, resolved from the module's annotations.
+        // Named for gl_Position because the clip-space fixup is what it was written for, and it
+        // is still the only shape that pass accepts - but the transform-feedback capture pass
+        // resolves gl_PointSize through the same struct, in which case `vectorTypeId` /
+        // `vectorPtrTypeId` hold the SCALAR float type and its Output pointer rather than a vec4.
         struct PositionTargetInfo {
             Uint32 variableId = 0;
             Uint32 vectorTypeId = 0;
@@ -99,6 +107,23 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return true;
         }
 
+        // gl_PointSize's counterpart to IsVec4Float32. The two are the only shapes any
+        // gl_PerVertex member this file resolves can have, and each resolver takes whichever
+        // one its built-in is declared with, so a mismatched type declines rather than
+        // producing a mirror the driver would reject.
+        Bool IsFloat32Scalar(spvtools::opt::IRContext* context, Uint32 typeId, Uint32* outFloatTypeId) {
+            auto* floatInst = context->get_def_use_mgr()->GetDef(typeId);
+            if (!floatInst || floatInst->opcode() != spv::Op::OpTypeFloat) return false;
+            if (floatInst->GetSingleWordInOperand(0) != 32) return false;
+
+            if (outFloatTypeId) *outFloatTypeId = typeId;
+            return true;
+        }
+
+        // Which of the two shapes above a resolver should accept. A plain function pointer
+        // rather than a std::function: every call site is one of the two free functions.
+        using BuiltInTypeCheckFn = Bool (*)(spvtools::opt::IRContext*, Uint32, Uint32*);
+
         spvc_basetype MapReflectInterfaceToSpvcBasetype(const SpvReflectInterfaceVariable& variable) {
             if (variable.type_description == nullptr) {
                 return SPVC_BASETYPE_UNKNOWN;
@@ -378,9 +403,33 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return used;
         }
 
-        void ValidateTransformedSpirv(const Vector<Uint>& spirv, ShaderStage shaderStage, Uint programExternalIndex) {
+        // What a failed validation says, for a caller that wants to put it in its own message.
+        struct SpirvValidationFailure {
+            String message;
+            Int result = 0;
+            SizeT index = 0;
+        };
+
+        // Returns whether the module validates. The result used to be discarded everywhere: the
+        // call was DEBUG-or-env gated and only logged, so an invalid module produced by a backend
+        // transform went straight to vkCreateShaderModule. That is not a survivable outcome on
+        // this hardware - Mali r54 SIGSEGVs building the pipeline instead of returning an error,
+        // the same "not a validating entry point" behaviour PipelineFactory already documents for
+        // vkCreateGraphicsPipelines - so the callers that feed the driver now act on it.
+        //
+        // This function does NOT log the failure at E any more. It used to, unlatched, on the
+        // stated grounds that "reaching here already requires the validation switch to be armed,
+        // which bounds the volume" - and that premise died when the two GetOrCreateProgram call
+        // sites became unconditional: MGLOG_E is live at the production INFO level, and Log.h's
+        // own rule is that anything at W or E on a repeatable path must be latched or demoted.
+        // The failure text now travels back through `outFailure` so the LATCHED call-site
+        // messages carry the VUID instead of an unlatched inner one repeating it; what stays here
+        // is the D-level detail and the process-wide counter the test lanes assert on.
+        Bool ValidateTransformedSpirv(const Vector<Uint>& spirv, ShaderStage shaderStage, Uint programExternalIndex,
+                                      SpirvValidationFailure* outFailure = nullptr) {
+            if (outFailure != nullptr) *outFailure = {};
             if (spirv.empty()) {
-                return;
+                return true;
             }
 
             spv_const_binary_t binary = {spirv.data(), spirv.size()};
@@ -402,18 +451,24 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             spv_diagnostic diagnostic = nullptr;
             const spv_result_t result = spvValidateWithOptions(context, options, &binary, &diagnostic);
             if (result != SPV_SUCCESS) {
-                // MGLOG_E, unlatched: reaching here already requires the validation switch to
-                // be armed, which bounds the volume, and each VUID names a different defect.
-                // (Parked at MGLOG_I until the Log.h level ordering was fixed, when E was
-                // compiled out of every INFO build.) The latch is what a test harness asserts on.
+                const char* message =
+                    diagnostic != nullptr && diagnostic->error != nullptr ? diagnostic->error : "<null>";
+                const SizeT index = diagnostic != nullptr ? diagnostic->position.index : 0;
+                // The test-lane signal (ShaderCompiler.h documents harnesses snapshotting it and
+                // asserting on the delta). Bumped for every failed validation, including one a
+                // caller goes on to recover from: a transform that produced an invalid module is
+                // a real defect whether or not this run survived it.
                 MG_Util::ShaderTranspiler::ShaderCompiler::NoteSpirvValidationFailure();
-                MGLOG_E(
+                if (outFailure != nullptr) {
+                    *outFailure = {String(message), static_cast<Int>(result), index};
+                }
+                MGLOG_D(
                     "ProgramFactory::ValidateTransformedSpirv: validation failed for stage=%d program=%u result=%d index=%zu msg=%s",
                     static_cast<Int>(shaderStage),
                     programExternalIndex,
                     static_cast<Int>(result),
-                    diagnostic != nullptr ? diagnostic->position.index : 0,
-                    diagnostic != nullptr && diagnostic->error != nullptr ? diagnostic->error : "<null>");
+                    index,
+                    message);
             }
             MOBILEGL_ASSERT(
                 result == SPV_SUCCESS,
@@ -429,6 +484,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             spvDiagnosticDestroy(diagnostic);
             spvValidatorOptionsDestroy(options);
             spvContextDestroy(context);
+            return result == SPV_SUCCESS;
         }
 
         void ReflectStageInterfaceVariable(const SpvReflectInterfaceVariable& variable,
@@ -740,8 +796,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             }
         }
 
-        Bool ResolveDirectPositionTarget(spvtools::opt::IRContext* context, Uint32 variableId,
-                                         PositionTargetInfo* outTarget) {
+        Bool ResolveDirectBuiltInTarget(spvtools::opt::IRContext* context, Uint32 variableId,
+                                        BuiltInTypeCheckFn typeCheck, PositionTargetInfo* outTarget) {
             auto* varInst = context->get_def_use_mgr()->GetDef(variableId);
             if (!varInst || varInst->opcode() != spv::Op::OpVariable) return false;
             if (varInst->GetSingleWordInOperand(0) != static_cast<Uint32>(spv::StorageClass::Output)) return false;
@@ -753,7 +809,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             PositionTargetInfo target{};
             target.variableId = variableId;
             target.vectorTypeId = ptrTypeInst->GetSingleWordInOperand(1);
-            if (!IsVec4Float32(context, target.vectorTypeId, &target.floatTypeId)) return false;
+            if (!typeCheck(context, target.vectorTypeId, &target.floatTypeId)) return false;
             target.vectorPtrTypeId = varInst->type_id();
             target.isMember = false;
 
@@ -768,15 +824,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return context->get_type_mgr()->GetTypeInstruction(&ptrType);
         }
 
-        Bool ResolveMemberPositionTarget(spvtools::opt::IRContext* context, Uint32 structTypeId, Uint32 memberIndex,
-                                         PositionTargetInfo* outTarget) {
+        Bool ResolveMemberBuiltInTarget(spvtools::opt::IRContext* context, Uint32 structTypeId, Uint32 memberIndex,
+                                        BuiltInTypeCheckFn typeCheck, PositionTargetInfo* outTarget) {
             auto* structInst = context->get_def_use_mgr()->GetDef(structTypeId);
             if (!structInst || structInst->opcode() != spv::Op::OpTypeStruct) return false;
             if (memberIndex >= structInst->NumInOperands()) return false;
 
             const Uint32 vectorTypeId = structInst->GetSingleWordInOperand(memberIndex);
             Uint32 floatTypeId = 0;
-            if (!IsVec4Float32(context, vectorTypeId, &floatTypeId)) return false;
+            if (!typeCheck(context, vectorTypeId, &floatTypeId)) return false;
 
             const Uint32 vectorPtrTypeId = FindOutputVectorPointerTypeId(context, vectorTypeId);
             if (vectorPtrTypeId == 0) return false;
@@ -804,27 +860,130 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return false;
         }
 
-        Bool FindPositionTarget(spvtools::opt::IRContext* context, PositionTargetInfo* outTarget) {
+        // The OUTPUT variable (or gl_PerVertex member) carrying `builtIn`, if the module
+        // declares one of the expected type. Annotations are the search space deliberately:
+        // they survive the link-time sanitize chain's interface delisting, which is the whole
+        // reason EnsureEntryPointInterface exists.
+        Bool FindBuiltInTarget(spvtools::opt::IRContext* context, spv::BuiltIn builtIn,
+                               BuiltInTypeCheckFn typeCheck, PositionTargetInfo* outTarget) {
             Vector<Pair<Uint32, Uint32>> memberCandidates;
             constexpr auto kDecorationBuiltIn = static_cast<Uint32>(spv::Decoration::BuiltIn);
-            constexpr auto kBuiltInPosition = static_cast<Uint32>(spv::BuiltIn::Position);
+            const auto wantedBuiltIn = static_cast<Uint32>(builtIn);
 
             for (auto& inst : context->module()->annotations()) {
                 if (inst.opcode() == spv::Op::OpDecorate) {
                     if (inst.NumInOperands() < 3) continue;
                     if (inst.GetSingleWordInOperand(1) != kDecorationBuiltIn) continue;
-                    if (inst.GetSingleWordInOperand(2) != kBuiltInPosition) continue;
-                    if (ResolveDirectPositionTarget(context, inst.GetSingleWordInOperand(0), outTarget)) return true;
+                    if (inst.GetSingleWordInOperand(2) != wantedBuiltIn) continue;
+                    if (ResolveDirectBuiltInTarget(context, inst.GetSingleWordInOperand(0), typeCheck, outTarget)) {
+                        return true;
+                    }
                 } else if (inst.opcode() == spv::Op::OpMemberDecorate) {
                     if (inst.NumInOperands() < 4) continue;
                     if (inst.GetSingleWordInOperand(2) != kDecorationBuiltIn) continue;
-                    if (inst.GetSingleWordInOperand(3) != kBuiltInPosition) continue;
+                    if (inst.GetSingleWordInOperand(3) != wantedBuiltIn) continue;
                     memberCandidates.emplace_back(inst.GetSingleWordInOperand(0), inst.GetSingleWordInOperand(1));
                 }
             }
 
             for (const auto& [structTypeId, memberIndex] : memberCandidates) {
-                if (ResolveMemberPositionTarget(context, structTypeId, memberIndex, outTarget)) return true;
+                if (ResolveMemberBuiltInTarget(context, structTypeId, memberIndex, typeCheck, outTarget)) return true;
+            }
+            return false;
+        }
+
+        Bool FindPositionTarget(spvtools::opt::IRContext* context, PositionTargetInfo* outTarget) {
+            return FindBuiltInTarget(context, spv::BuiltIn::Position, IsVec4Float32, outTarget);
+        }
+
+        // Put `variableId` back on `entryPoint`'s interface list if it is not already there.
+        //
+        // SPIR-V requires every Input/Output global an entry point statically uses to be listed on
+        // its OpEntryPoint, and spirv-val enforces it ("Interface variable id <N> is used by entry
+        // point 'main' id <M>, but is not listed as an interface"). The link-time sanitize chain
+        // DELISTS a variable nothing referenced yet - ShaderCompiler::SanitizeAndOptimizeBinary
+        // runs CreateAggressiveDCEPass(false), which may never delete an Output, followed by
+        // CreateRemoveUnusedInterfaceVariablesPass, which rebuilds the operand list from the
+        // variables actually referenced. A TES that redeclares `out gl_PerVertex { vec4
+        // gl_Position; }` and never writes it therefore reaches the backend with the OpVariable
+        // and its BuiltIn Position decoration intact and its interface slot gone. Any pass that
+        // then injects a reference has to put the slot back, or it hands the driver a module no
+        // validator accepts - and Mali r54 answers that with a SIGSEGV inside pipeline creation
+        // rather than an error return.
+        //
+        // No SPIR-V version gate here, unlike GlFragCoordYFlipPass's identical call for its
+        // injected PRIVATE global: Input and Output belong on the interface in every version,
+        // and only 1.4 widened it to the other storage classes.
+        Bool EnsureEntryPointInterface(spvtools::opt::IRContext* context, spvtools::opt::Instruction& entryPoint,
+                                       Uint32 variableId) {
+            // In-operands: 0 = execution model, 1 = entry function id, 2 = name, 3.. = interface.
+            constexpr Uint32 kFirstInterfaceOperand = 3;
+            if (variableId == 0) return false;
+            for (Uint32 operand = kFirstInterfaceOperand; operand < entryPoint.NumInOperands(); ++operand) {
+                if (entryPoint.GetSingleWordInOperand(operand) == variableId) return false;
+            }
+            entryPoint.AddOperand({SPV_OPERAND_TYPE_ID, {variableId}});
+            context->AnalyzeUses(&entryPoint);
+            return true;
+        }
+
+        // Is `pointerId` the position target itself, or an access chain rooted at it?
+        Bool PointerReachesPositionTarget(spvtools::opt::IRContext* context, Uint32 pointerId,
+                                          const PositionTargetInfo& target) {
+            auto* defUse = context->get_def_use_mgr();
+            for (Uint32 current = pointerId; current != 0;) {
+                if (current == target.variableId) return true;
+                const auto* inst = defUse->GetDef(current);
+                if (inst == nullptr) return false;
+                switch (inst->opcode()) {
+                case spv::Op::OpAccessChain:
+                case spv::Op::OpInBoundsAccessChain:
+                case spv::Op::OpPtrAccessChain:
+                case spv::Op::OpInBoundsPtrAccessChain:
+                case spv::Op::OpCopyObject:
+                    current = inst->GetSingleWordInOperand(0);
+                    break;
+                default:
+                    return false;
+                }
+            }
+            return false;
+        }
+
+        // Does anything in the module write the position target?
+        //
+        // Deliberately conservative - it answers "assume yes" for every shape it cannot read
+        // exactly, because a false "no" would silently drop the clip-space fixup from a shader
+        // that does write gl_Position, while a false "yes" only reinstates the behaviour this
+        // pass has always had. Scans every function rather than just the entry point's: a shader
+        // that assigns gl_Position inside a helper is still a shader that writes it, and passing
+        // the pointer to a call is a write as far as this can tell.
+        Bool ModuleWritesPositionTarget(spvtools::opt::IRContext* context, const PositionTargetInfo& target) {
+            for (auto& function : *context->module()) {
+                for (auto& block : function) {
+                    for (const auto& inst : block) {
+                        switch (inst.opcode()) {
+                        case spv::Op::OpStore:
+                        case spv::Op::OpCopyMemory:
+                        case spv::Op::OpCopyMemorySized:
+                            if (PointerReachesPositionTarget(context, inst.GetSingleWordInOperand(0), target)) {
+                                return true;
+                            }
+                            break;
+                        case spv::Op::OpFunctionCall:
+                            // In-operand 0 is the callee; the rest are arguments.
+                            for (Uint32 argument = 1; argument < inst.NumInOperands(); ++argument) {
+                                if (PointerReachesPositionTarget(context, inst.GetSingleWordInOperand(argument),
+                                                                 target)) {
+                                    return true;
+                                }
+                            }
+                            break;
+                        default:
+                            break;
+                        }
+                    }
+                }
             }
             return false;
         }
@@ -911,6 +1070,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 PositionTargetInfo target{};
                 if (!FindPositionTarget(context(), &target)) return Status::SuccessWithoutChange;
 
+                // Nothing to remap in a Position the shader never writes. Declining is not just
+                // an optimisation: the fixup is load-modify-store, so on an unwritten Position it
+                // converts "undefined, never written" into "written with whatever the load
+                // returned", and the store is a reference to a variable the link-time sanitize
+                // chain has already delisted from the entry-point interface. glslang emits the
+                // OpVariable for every DECLARED interface block, so a redeclared-but-unwritten
+                // `out gl_PerVertex` is a shape real shaders have.
+                if (!ModuleWritesPositionTarget(context(), target)) {
+                    MGLOG_D("gl-to-vulkan-position-fix: the shader never writes gl_Position; leaving it alone");
+                    return Status::SuccessWithoutChange;
+                }
+
                 auto* floatType = context()->get_type_mgr()->GetType(target.floatTypeId);
                 if (!floatType) return Status::SuccessWithoutChange;
 
@@ -942,6 +1113,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                     auto* function = context()->GetFunction(entryPoint.GetSingleWordInOperand(1));
                     if (!function) continue;
 
+                    Bool modifiedThisEntryPoint = false;
                     for (auto& bb : *function) {
                         for (auto instIter = bb.begin(); instIter != bb.end(); ++instIter) {
                             auto* inst = &*instIter;
@@ -950,10 +1122,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                 (model != spv::ExecutionModel::Geometry && inst->opcode() == spv::Op::OpReturn);
                             if (!needsFixup) continue;
 
-                            modified |= InsertPositionFixup(context(), inst, target, halfConstId, doYFlip, doZRemap,
-                                                             doSurfaceRotate90, doSurfaceRotate180, doSurfaceRotate270);
+                            modifiedThisEntryPoint |=
+                                InsertPositionFixup(context(), inst, target, halfConstId, doYFlip, doZRemap,
+                                                    doSurfaceRotate90, doSurfaceRotate180, doSurfaceRotate270);
                         }
                     }
+                    // Per entry point, and only for one this pass actually injected into: the
+                    // injected load/store is a static use of the position variable, so the
+                    // variable has to be on THIS entry point's interface list.
+                    if (modifiedThisEntryPoint) {
+                        EnsureEntryPointInterface(context(), entryPoint, target.variableId);
+                    }
+                    modified |= modifiedThisEntryPoint;
                 }
 
                 if (!modified) return Status::SuccessWithoutChange;
@@ -1232,6 +1412,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 Bool needsPositionMirror = false;
                 Uint32 positionBufferIndex = 0;
                 Uint32 positionOffset = 0;
+                // gl_PointSize is a gl_PerVertex MEMBER, never a variable of its own, so the
+                // debug-name lookup below can never resolve it - it used to fall through to
+                // "no SPIR-V variable named 'gl_PointSize'" and leave the frontend's reserved
+                // slot unwritten, or, when it was the only capture, leave the module with no
+                // Xfb execution mode at all and the whole span declined.
+                Bool needsPointSizeMirror = false;
+                Uint32 pointSizeBufferIndex = 0;
+                Uint32 pointSizeOffset = 0;
                 for (const auto& varying : m_varyings) {
                     if (varying.name == "gl_Position") {
                         needsPositionMirror = true;
@@ -1239,6 +1427,28 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                         positionOffset = varying.offsetBytes;
                         continue;
                     }
+                    if (varying.name == "gl_PointSize") {
+                        // A demoted module (ShaderCompiler::
+                        // DemoteTessellationGeometryPointSizeForProgram) no longer ACCESSES the
+                        // built-in member - the value lives in the carrier variable the demotion
+                        // named - so the capture binds to the carrier directly. The mirror below
+                        // must not run for it: reading the now-unwritten member would capture
+                        // garbage, and the read itself is the capability access the demotion
+                        // exists to remove. Detected off the module's own debug names, so a
+                        // composite built from another program's stage answers for the module it
+                        // actually contains.
+                        const auto carrierIt = idsByName.find(
+                            MG_Util::ShaderTranspiler::ShaderCompiler::POINT_SIZE_CAPTURE_CARRIER_NAME);
+                        if (carrierIt != idsByName.end()) {
+                            decorateForXfb(carrierIt->second, varying.bufferIndex, varying.offsetBytes);
+                            modified = true;
+                            continue;
+                        }
+                        needsPointSizeMirror = true;
+                        pointSizeBufferIndex = varying.bufferIndex;
+                        pointSizeOffset = varying.offsetBytes;
+                        continue;
+                    }
                     if (varying.blockMemberIndex >= 0) {
                         // glslang names the block's instance variable and its struct type
                         // separately; an anonymous instance leaves only the type named, so
@@ -1303,8 +1513,16 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 }
 
                 if (needsPositionMirror) {
-                    modified |= MirrorPositionForCapture(entryFunctionId, *entryPoint, positionBufferIndex,
-                                                         positionOffset, decorateForXfb);
+                    modified |= MirrorPerVertexBuiltInForCapture(entryFunctionId, *entryPoint,
+                                                                 spv::BuiltIn::Position, IsVec4Float32,
+                                                                 "gl_Position", positionBufferIndex, positionOffset,
+                                                                 decorateForXfb);
+                }
+                if (needsPointSizeMirror) {
+                    modified |= MirrorPerVertexBuiltInForCapture(entryFunctionId, *entryPoint,
+                                                                 spv::BuiltIn::PointSize, IsFloat32Scalar,
+                                                                 "gl_PointSize", pointSizeBufferIndex,
+                                                                 pointSizeOffset, decorateForXfb);
                 }
 
                 if (!modified) return Status::SuccessWithoutChange;
@@ -1344,19 +1562,28 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 return 0;
             }
 
+            // gl_Position and gl_PointSize are captured the same way and differ only in which
+            // built-in is looked up and what type it has, so one injector serves both. Anything
+            // else in gl_PerVertex would need its own type check before it could be added here.
             template <typename DecorateFn>
-            Bool MirrorPositionForCapture(Uint32 entryFunctionId, spvtools::opt::Instruction& entryPoint,
-                                          Uint32 bufferIndex, Uint32 offsetBytes, const DecorateFn& decorateForXfb) {
+            Bool MirrorPerVertexBuiltInForCapture(Uint32 entryFunctionId, spvtools::opt::Instruction& entryPoint,
+                                                  spv::BuiltIn builtIn, BuiltInTypeCheckFn typeCheck,
+                                                  const char* glslName, Uint32 bufferIndex, Uint32 offsetBytes,
+                                                  const DecorateFn& decorateForXfb) {
                 const Uint32 entryPointModel = entryPoint.GetSingleWordInOperand(0);
                 using namespace spvtools::opt;
                 PositionTargetInfo target{};
-                if (!FindPositionTarget(context(), &target)) {
-                    MGLOG_E("XfbCaptureDecoratePass: gl_Position capture requested but no position output found");
+                if (!FindBuiltInTarget(context(), builtIn, typeCheck, &target)) {
+                    MGLOG_E("XfbCaptureDecoratePass: %s capture requested but no such output found", glslName);
                     return false;
                 }
                 if (!target.isMember) {
-                    // Standalone gl_Position variable: decorate it directly.
+                    // Standalone built-in variable: decorate it directly. It still has to be
+                    // on the interface - a transform-feedback decoration on a variable the entry
+                    // point does not list captures nothing, and the sanitize chain delists an
+                    // unwritten one (see EnsureEntryPointInterface).
                     decorateForXfb(target.variableId, bufferIndex, offsetBytes);
+                    EnsureEntryPointInterface(context(), entryPoint, target.variableId);
                     return true;
                 }
 
@@ -1410,6 +1637,16 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                         injected = true;
                     }
                 }
+                // The mirror was listed on the entry point above, but the loop just added a READ
+                // of the SOURCE block through an access chain, and the interface rule covers
+                // reads exactly as it covers writes. A built-in capture on a shader whose
+                // block the sanitize chain delisted - a TES that redeclares `out gl_PerVertex`
+                // and never writes it, which is what the tessellation_control_to_tessellation_
+                // evaluation.gl_MaxPatchVertices_Position_PointSize bodies do - produced an
+                // invalid module here for the same reason the position fixup did.
+                if (injected) {
+                    EnsureEntryPointInterface(context(), entryPoint, target.variableId);
+                }
                 return injected;
             }
 
@@ -3233,11 +3470,21 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // `spirv` and `moduleSpirvs` for any program attached to after it linked.
         const Vector<ShaderStage> stages = program.GetLinkedShaderStages();
         auto& spirv = program.GetGeneratedSpirv();
+        if (program.PointSizeDemoted()) {
+            // THE ARMING SIGNAL, INFO on purpose and latched: the integration lane that pins
+            // MOBILEGL_POINT_SIZE_DEMOTION=1 asserts on exactly this line, because every
+            // rendering assertion above it stays green on a healthy driver whether the
+            // demotion ran or was silently disarmed. See PointSizeDemotionScenario.
+            MGLOG_I_ONCE("DirectVulkan is building programs whose tessellation/geometry gl_PointSize was "
+                         "demoted to an ordinary varying, because this device cannot host the built-in "
+                         "in those stages.");
+        }
         Vector<Vector<Uint>> moduleSpirvs(spirv.size());
         const Bool enableSpirvValidation = program.GetSpirvValidationEnabled();
-        if (enableSpirvValidation) {
-            MG_Util::ShaderTranspiler::ShaderCompiler::PrepareSpirvValidation();
-        }
+        // Unconditional now: the two ValidateTransformedSpirv calls below run in every build,
+        // not only when the switch is armed, so the validator's static tables have to be pinned
+        // against process exit in every build too.
+        MG_Util::ShaderTranspiler::ShaderCompiler::PrepareSpirvValidation();
 
         const ShaderStage fixupStage = PickClipFixupStage(stages);
 
@@ -3261,6 +3508,46 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                     }
                 }
                 TransformSpirvForVulkanPositionFix(*fixupInput, moduleSpirvs[i], flags);
+                // These two passes INJECT references - a store for the clip fixup, an access
+                // chain and a load for the gl_Position capture mirror - and a reference to a
+                // variable the link-time sanitize chain delisted from the entry-point interface
+                // is invalid SPIR-V that Mali r54 turns into a SIGSEGV inside pipeline creation
+                // rather than an error return. EnsureEntryPointInterface keeps them honest; this
+                // is the backstop.
+                //
+                // The fallback UNWINDS ONE PASS AT A TIME, which matters because the two passes
+                // are not equally optional. Rewinding straight to `spv` would also throw away the
+                // XfbBuffer/XfbStride/Offset decorations, the TransformFeedback capability and the
+                // Xfb execution mode - while the renderer decides to call
+                // vkCmdBeginTransformFeedbackEXT purely from GL state and never looks at the
+                // module. That ships a pipeline whose last pre-rasterization stage has no Xfb mode
+                // into a transform-feedback span, violating
+                // VUID-vkCmdBeginTransformFeedbackEXT-None-04128 on exactly the driver class this
+                // guard exists for. So: try the post-XFB, pre-clip-fixup module first, which keeps
+                // capture working and costs only the clip-space remap.
+                //
+                // Once per program on a cache miss, and only for the single stage that carries the
+                // fixups - not per draw and not per module.
+                SpirvValidationFailure fixupFailure{};
+                if (!ValidateTransformedSpirv(moduleSpirvs[i], stages[i], program.GetExternalIndex(),
+                                              &fixupFailure)) {
+                    SpirvValidationFailure xfbFailure{};
+                    if (fixupInput != &spv &&
+                        ValidateTransformedSpirv(*fixupInput, stages[i], program.GetExternalIndex(), &xfbFailure)) {
+                        MGLOG_E_ONCE("ProgramFactory: the clip fixup produced an invalid module for program %u "
+                                     "stage %d (%s); keeping the capture-decorated one, so this program draws "
+                                     "without the clip-space remap",
+                                     program.GetExternalIndex(), static_cast<Int>(stages[i]),
+                                     fixupFailure.message.c_str());
+                        moduleSpirvs[i] = *fixupInput;
+                    } else {
+                        MGLOG_E_ONCE("ProgramFactory: the clip/XFB fixups produced an invalid module for program %u "
+                                     "stage %d (%s); keeping the untransformed one",
+                                     program.GetExternalIndex(), static_cast<Int>(stages[i]),
+                                     fixupFailure.message.c_str());
+                        moduleSpirvs[i] = spv;
+                    }
+                }
             } else {
                 moduleSpirvs[i] = spv;
             }
@@ -3469,15 +3756,63 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             auto& moduleSpv = moduleSpirvs[i];
             if (moduleSpv.empty()) continue;
 
-#if MOBILEGL_LOG_ACTIVE_LEVEL <= MOBILEGL_LOG_LEVEL_DEBUG
-            ValidateTransformedSpirv(moduleSpv, stages[i], program.GetExternalIndex());
-#else
-            // Final module the driver receives; also checked in the INFO-level CI/test
-            // lanes, where the DEBUG gate above is compiled out.
-            if (enableSpirvValidation) {
-                ValidateTransformedSpirv(moduleSpv, stages[i], program.GetExternalIndex());
+            // Last look at the exact bytes the driver receives, in EVERY build rather than only
+            // in DEBUG or with MOBILEGL_ENABLE_SPIRV_VALIDATION armed. This one only reports:
+            // by here the descriptor bindings have been remapped and the layout about to be
+            // reflected describes the remapped module, so there is no module left that is both
+            // valid and consistent with it to fall back to. The recovery lives one step earlier,
+            // at the clip/XFB fixups (see the revert there) - which is where a transform can
+            // introduce a reference to a delisted interface variable, the failure this whole
+            // guard exists for. Anything that reaches this line names itself in the log of a
+            // shipping build instead of dying anonymously inside the driver.
+            SpirvValidationFailure finalFailure{};
+            if (!ValidateTransformedSpirv(moduleSpv, stages[i], program.GetExternalIndex(), &finalFailure)) {
+                MGLOG_E_ONCE("ProgramFactory: handing vkCreateShaderModule an INVALID module for program %u stage %d - "
+                             "a backend transform after the clip/XFB fixups broke it (%s)",
+                             program.GetExternalIndex(), static_cast<Int>(stages[i]),
+                             finalFailure.message.c_str());
+            }
+
+            // Does the stage the driver will treat as the last pre-rasterization one actually
+            // carry Xfb? Asked of the FINAL bytes, so it answers for whatever the whole transform
+            // chain produced - a rewound clip/XFB backstop, a capture pass that resolved no
+            // varying and changed nothing, anything later that might strip it. The renderer picks
+            // its capture commands from GL state alone and would otherwise open a span against a
+            // pipeline that cannot feed it.
+            if (stages[i] == fixupStage && (flags & ProgramFactory::CompileOptionBit::XfbCapture) &&
+                program.GetTransformFeedbackVaryingCount() > 0 &&
+                !MG_Util::ShaderTranspiler::ShaderCompiler::ModuleDeclaresTransformFeedback(moduleSpv)) {
+                MGLOG_E_ONCE("ProgramFactory: program %u was built as a transform-feedback capture variant but its "
+                             "stage %d carries no Xfb execution mode; its capture spans will be declined rather "
+                             "than recorded against a pipeline that cannot feed them",
+                             program.GetExternalIndex(), static_cast<Int>(stages[i]));
+                entry.xfbCaptureDeclined = true;
+            }
+
+            // Does this stage need a device feature the device did not give us? Asked ONLY when
+            // the feature is off, so a device that has it - the common case - pays nothing: the
+            // whole test is short-circuited before the module is parsed.
+            //
+            // gl_PointSize is an ordinary per-vertex output in desktop GL and any
+            // vertex-processing stage may write it, but Vulkan puts the built-in behind
+            // shaderTessellationAndGeometryPointSize in the tessellation and geometry stages
+            // (VUID-RuntimeSpirv-PointSize-06439). glslang emits TessellationPointSize /
+            // GeometryPointSize from the application's own access, so this program is legal GL
+            // that this device cannot run - the same shape the DirectGLES arm reports when a
+            // driver advertises neither EXT nor OES point-size extension, and it deserves the
+            // same named message rather than a pipeline the driver may fault on.
+            if (!m_tessellationAndGeometryPointSizeEnabled &&
+                (stages[i] == ShaderStage::TessControl || stages[i] == ShaderStage::TessEval ||
+                 stages[i] == ShaderStage::Geometry) &&
+                MG_Util::ShaderTranspiler::ShaderCompiler::ModuleDeclaresTessellationOrGeometryPointSize(
+                    moduleSpv)) {
+                MGLOG_E_ONCE("ProgramFactory: program %u stage %d accesses gl_PointSize, but this device does not "
+                             "support shaderTessellationAndGeometryPointSize; its draws are refused rather than "
+                             "built into a pipeline the driver may fault on. Point size from a non-vertex stage "
+                             "is not available on this device.",
+                             program.GetExternalIndex(), static_cast<Int>(stages[i]));
+                entry.pointSizeCapabilityUnsupported = true;
             }
-#endif
 
             VkShaderModuleCreateInfo smci{VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO};
             smci.codeSize = moduleSpv.size() * sizeof(Uint);
@@ -3594,18 +3929,136 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
     }
 
-    String ProgramFactory::BuildPassthroughTessControlSource(Uint32 patchVertices) {
+    Uint64 ProgramFactory::ComputePassthroughTessControlKey(Uint32 patchVertices,
+                                                            const FloatVec4& defaultOuterLevel,
+                                                            const FloatVec2& defaultInnerLevel,
+                                                            Uint32 perVertexMembers) {
+        // A plain 32-byte blob of exactly what the generator reads, hashed once. Deliberately over
+        // the RAW BITS rather than the values: two levels that compare unequal must key apart, and
+        // a NaN level - which glPatchParameterfv accepts - compares unequal to itself.
+        struct Blob {
+            Uint32 patchVertices;
+            Uint32 outerBits[4];
+            Uint32 innerBits[2];
+            Uint32 perVertexMembers;
+        } blob{};
+        blob.patchVertices = patchVertices;
+        for (Uint32 i = 0; i < 4; ++i) blob.outerBits[i] = std::bit_cast<Uint32>(defaultOuterLevel[i]);
+        for (Uint32 i = 0; i < 2; ++i) blob.innerBits[i] = std::bit_cast<Uint32>(defaultInnerLevel[i]);
+        blob.perVertexMembers = perVertexMembers;
+        return XXH64(&blob, sizeof(blob), 0);
+    }
+
+    // The member list a gl_PerVertex redeclaration must spell, derived from the mask. Order is
+    // glslang's declaration order and is load-bearing: a redeclaration whose members are the same
+    // set in a different order is a different block.
+    static String BuildPerVertexMemberDeclarations(Uint32 perVertexMembers) {
+        using Bit = ProgramFactory::PerVertexMemberBit;
+        String members;
+        if (perVertexMembers & static_cast<Uint32>(Bit::Position)) members += "    vec4 gl_Position;\n";
+        if (perVertexMembers & static_cast<Uint32>(Bit::PointSize)) members += "    float gl_PointSize;\n";
+        // Sized at one, not left unsized: an unsized built-in array in a redeclared block is
+        // implicitly sized by use, and this stage never indexes either distance array.
+        if (perVertexMembers & static_cast<Uint32>(Bit::ClipDistance)) members += "    float gl_ClipDistance[1];\n";
+        if (perVertexMembers & static_cast<Uint32>(Bit::CullDistance)) members += "    float gl_CullDistance[1];\n";
+        return members;
+    }
+
+    Uint32 ProgramFactory::ReflectPerVertexInputMembers(const Vector<Uint>& spirv) {
+        // Minimal, self-contained SPIR-V walk. SPIRV-Reflect is deliberately NOT used: for an
+        // array of interface blocks it reports built_in == -1 on the block and leaves every
+        // member's built_in at 0 (which is SpvBuiltInPosition), so a member walk through it reads
+        // "Position, Position, Position" - the same trap ReflectPassthroughTessControlNeed
+        // documents. The decorations below are unambiguous.
+        constexpr SizeT kHeaderWords = 5;
+        constexpr Uint32 kOpName = 5;
+        constexpr Uint32 kOpDecorate = 71;
+        constexpr Uint32 kOpMemberDecorate = 72;
+        constexpr Uint32 kOpTypeArray = 28;
+        constexpr Uint32 kOpTypePointer = 32;
+        constexpr Uint32 kOpVariable = 59;
+        constexpr Uint32 kDecorationBlock = 2;
+        constexpr Uint32 kDecorationBuiltIn = 11;
+        constexpr Uint32 kStorageClassInput = 1;
+        constexpr Uint32 kBuiltInPosition = 0;
+        constexpr Uint32 kBuiltInPointSize = 1;
+        constexpr Uint32 kBuiltInClipDistance = 3;
+        constexpr Uint32 kBuiltInCullDistance = 4;
+        (void)kOpName;
+
+        if (spirv.size() <= kHeaderWords) return 0;
+
+        UnorderedMap<Uint32, Uint32> arrayElementType;             // array id   -> element type id
+        UnorderedMap<Uint32, Pair<Uint32, Uint32>> pointerPointee; // pointer id -> (storage class, pointee)
+        UnorderedMap<Uint32, Uint32> structMembers;                // struct id  -> PerVertexMemberBit mask
+        std::set<Uint32> blockStructs;
+        Vector<Uint32> inputVariablePointerTypes;
+
+        for (SizeT i = kHeaderWords; i < spirv.size();) {
+            const Uint32 wordCount = spirv[i] >> 16;
+            const Uint32 opcode = spirv[i] & 0xFFFFu;
+            if (wordCount == 0 || i + wordCount > spirv.size()) break;
+            const Uint32* words = &spirv[i];
+            switch (opcode) {
+            case kOpTypeArray:
+                if (wordCount >= 4) arrayElementType[words[1]] = words[2];
+                break;
+            case kOpTypePointer:
+                if (wordCount >= 4) pointerPointee[words[1]] = {words[2], words[3]};
+                break;
+            case kOpVariable:
+                if (wordCount >= 4 && words[3] == kStorageClassInput) inputVariablePointerTypes.push_back(words[1]);
+                break;
+            case kOpDecorate:
+                if (wordCount >= 3 && words[2] == kDecorationBlock) blockStructs.insert(words[1]);
+                break;
+            case kOpMemberDecorate:
+                if (wordCount >= 5 && words[3] == kDecorationBuiltIn) {
+                    Uint32 bit = 0;
+                    switch (words[4]) {
+                    case kBuiltInPosition: bit = static_cast<Uint32>(PerVertexMemberBit::Position); break;
+                    case kBuiltInPointSize: bit = static_cast<Uint32>(PerVertexMemberBit::PointSize); break;
+                    case kBuiltInClipDistance: bit = static_cast<Uint32>(PerVertexMemberBit::ClipDistance); break;
+                    case kBuiltInCullDistance: bit = static_cast<Uint32>(PerVertexMemberBit::CullDistance); break;
+                    default: break;
+                    }
+                    structMembers[words[1]] |= bit;
+                }
+                break;
+            default:
+                break;
+            }
+            i += wordCount;
+        }
+
+        // The one Input variable whose type is an array of a Block-decorated struct IS gl_in;
+        // gl_TessCoord and friends are plain scalars/vectors and never match.
+        for (const Uint32 pointerType : inputVariablePointerTypes) {
+            const auto pointer = pointerPointee.find(pointerType);
+            if (pointer == pointerPointee.end()) continue;
+            const auto array = arrayElementType.find(pointer->second.second);
+            if (array == arrayElementType.end()) continue;
+            if (!blockStructs.contains(array->second)) continue;
+            const auto members = structMembers.find(array->second);
+            if (members == structMembers.end()) continue;
+            return members->second;
+        }
+        return 0;
+    }
+
+    String ProgramFactory::BuildPassthroughTessControlSource(Uint32 patchVertices,
+                                                             const FloatVec4& defaultOuterLevel,
+                                                             const FloatVec2& defaultInnerLevel,
+                                                             Uint32 perVertexMembers) {
         // The stage GL 4.6 core 11.2.2 describes when a program has an evaluation shader and no
         // control shader: "the input patch is passed through unmodified", the output patch has
         // as many vertices as the input one (PATCH_VERTICES), and the levels come from the
         // PATCH_DEFAULT_OUTER_LEVEL / PATCH_DEFAULT_INNER_LEVEL state.
         //
-        // Those two levels default to 1.0 and are baked here as literals because
-        // glPatchParameterfv - their only setter - is not implemented in this frontend (it is a
-        // stub in MG_Impl/GLImpl/Exporting/Definitions.cpp). Implementing that entry point means
-        // making the levels a parameter of this source AND of the cache key in
-        // GetOrCreatePassthroughTessControlStage; the two must move together, so they are named
-        // together here.
+        // Those two levels are baked in as literals - Vulkan has no equivalent dynamic state, so
+        // compiling them in is the only way to honour glPatchParameterfv. That makes them part of
+        // this module's identity: GetOrCreatePassthroughTessControlStage keys its cache on them,
+        // and PipelineFactory hashes them into the pipeline key. The three must move together.
         //
         // gl_out carries gl_Position and nothing else on purpose. The evaluation stage that
         // reads it was linked against the VERTEX stage directly, so its input gl_PerVertex holds
@@ -3619,60 +4072,104 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // this from having to know the domain.
         String source = "#version 450 core\n";
         source += "layout(vertices = " + std::to_string(patchVertices) + ") out;\n";
-        // gl_in and gl_out are redeclared to the exact gl_PerVertex the FRONTEND's linked programs
-        // carry - gl_Position, gl_PointSize, gl_ClipDistance[1], in that order - because Vulkan
-        // matches built-in interface blocks by their whole shape, and the two obvious spellings
-        // are both wrong:
+        // gl_in and gl_out are redeclared to the exact gl_PerVertex the NEIGHBOURING EVALUATION
+        // STAGE carries, because Vulkan matches built-in interface blocks by their whole shape,
+        // and the two obvious spellings are both wrong:
         //   * narrowing the block to gl_Position alone makes the evaluation stage read a patch of
         //     zeroes (degenerate triangles, nothing rasterized), and
-        //   * taking glslang's DEFAULT block for a standalone control stage yields FOUR members -
-        //     it appends gl_CullDistance - where a linked vertex+evaluation program has three.
-        // PassthroughTessControlTest.MatchesTheFrontendPerVertexBlock is the latch: it links a
-        // vertex+evaluation program through this same compiler and fails if the two shapes ever
-        // stop agreeing, rather than letting the mismatch show up as a black frame.
+        //   * taking glslang's DEFAULT block for a standalone control stage yields whatever THIS
+        //     source's #version implies, which is unrelated to the evaluation stage's.
         //
-        // Only gl_Position is written. gl_PointSize is declared but left alone deliberately:
-        // writing it from a tessellation stage requires the shaderTessellationAndGeometryPointSize
-        // feature, which this renderer does not enable, so a program whose evaluation stage reads
-        // gl_in[].gl_PointSize gets an undefined point size instead of the vertex stage's - a gap
-        // this trades for not making every tessellated pipeline depend on an optional feature.
-        source += "in gl_PerVertex {\n"
-                  "    vec4 gl_Position;\n"
-                  "    float gl_PointSize;\n"
-                  "    float gl_ClipDistance[1];\n"
-                  "} gl_in[gl_MaxPatchVertices];\n";
-        source += "out gl_PerVertex {\n"
-                  "    vec4 gl_Position;\n"
-                  "    float gl_PointSize;\n"
-                  "    float gl_ClipDistance[1];\n"
-                  "} gl_out[];\n";
+        // The member set is a PARAMETER rather than a constant, and that is the whole point: it
+        // was hardcoded to {gl_Position, gl_PointSize, gl_ClipDistance[1]}, which is the shape a
+        // program carries only below #version 450. glslang appends gl_CullDistance to the block
+        // from 450 upward, so every 450/460 program - and every ESSL program, which the source
+        // processor rewrites to "#version 460 core" - carried FOUR members against this stage's
+        // three and got the black-frame-no-error case described above. The mask comes from
+        // ReflectPerVertexInputMembers, read off the evaluation stage's own SPIR-V.
+        // PassthroughTessControlTest.MatchesTheFrontendPerVertexBlock is the latch, and it now
+        // links the program at both 430 and 460.
+        //
+        // Only gl_Position is written, and gl_PointSize is declared without being forwarded. That
+        // is a KNOWN GAP, not a design: GL 4.6 core 11.2.2 says the fixed-function pass-through
+        // hands the input patch to the evaluation stage unmodified, so an evaluation stage
+        // reading gl_in[].gl_PointSize should see the vertex stage's value and instead sees
+        // whatever this stage left in gl_out[] - which is nothing. A capture of it (the mirror in
+        // XfbCaptureDecoratePass) faithfully records that nothing.
+        //
+        // The reason this comment used to give - "the renderer does not enable
+        // shaderTessellationAndGeometryPointSize" - stopped being true when
+        // VulkanRenderer::CreateLogicalDeviceAndQueues started taking the feature wherever the
+        // device advertises it. Closing the gap is therefore possible now, but it is not free:
+        // the forwarding store has to be gated on that feature, because on a device without it
+        // the store is exactly the invalid usage the build-time refusal
+        // (VkProgramObject::pointSizeCapabilityUnsupported) exists to keep away from the driver -
+        // and this synthesized stage is not the application's, so refusing the program because
+        // MobileGL's own pass-through named a built-in would be the wrong trade. Nothing pins
+        // the shape either: every case in TessellationXfbCaptureScenario builds an explicit
+        // control stage, so a TES-without-TCS test has to come with the fix.
+        const String perVertexBody = BuildPerVertexMemberDeclarations(perVertexMembers);
+        source += "in gl_PerVertex {\n" + perVertexBody + "} gl_in[gl_MaxPatchVertices];\n";
+        source += "out gl_PerVertex {\n" + perVertexBody + "} gl_out[];\n";
         source += "void main() {\n";
         source += "    gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;\n";
-        source += "    gl_TessLevelOuter[0] = 1.0;\n";
-        source += "    gl_TessLevelOuter[1] = 1.0;\n";
-        source += "    gl_TessLevelOuter[2] = 1.0;\n";
-        source += "    gl_TessLevelOuter[3] = 1.0;\n";
-        source += "    gl_TessLevelInner[0] = 1.0;\n";
-        source += "    gl_TessLevelInner[1] = 1.0;\n";
+        for (Uint32 i = 0; i < 4; ++i) {
+            source += "    gl_TessLevelOuter[" + std::to_string(i) +
+                      "] = " + MG_Util::ShaderTranspiler::TessellationLevelLiteral(defaultOuterLevel[i]) + ";\n";
+        }
+        for (Uint32 i = 0; i < 2; ++i) {
+            source += "    gl_TessLevelInner[" + std::to_string(i) +
+                      "] = " + MG_Util::ShaderTranspiler::TessellationLevelLiteral(defaultInnerLevel[i]) + ";\n";
+        }
         source += "}\n";
         return source;
     }
 
-    VkPipelineShaderStageCreateInfo ProgramFactory::GetOrCreatePassthroughTessControlStage(Uint32 patchVertices) {
+    VkPipelineShaderStageCreateInfo ProgramFactory::GetOrCreatePassthroughTessControlStage(
+        Uint32 patchVertices, const FloatVec4& defaultOuterLevel, const FloatVec2& defaultInnerLevel,
+        Uint32 perVertexMembers) {
+        // Everything compiled into the stage, folded into one key. The patch size alone stopped
+        // being enough once glPatchParameterfv could change the levels: two modules that differ
+        // only in a baked-in level are different modules, and pipelines built from either may be
+        // alive at the same time. The gl_PerVertex member set joins it for the same reason - two
+        // programs at different GLSL versions need differently-shaped blocks.
+        const Uint64 key =
+            ComputePassthroughTessControlKey(patchVertices, defaultOuterLevel, defaultInnerLevel, perVertexMembers);
         // A cached VK_NULL_HANDLE is a remembered failure, not a miss: returning it keeps a
         // generator that cannot compile from re-running glslang on every draw.
-        const auto cached = m_passthroughTessControlStages.find(patchVertices);
+        const auto cached = m_passthroughTessControlStages.find(key);
         if (cached != m_passthroughTessControlStages.end()) {
             return cached->second;
         }
 
+        // The key stopped being bounded when the levels joined it: patchVertices alone could only
+        // take 32 values, but six unclamped application floats can take any number, and an
+        // application that ramps a level per frame would retain one VkShaderModule per frame for
+        // the lifetime of the device. Flushed wholesale rather than aged: a module is not
+        // referenced by the pipelines built from it (Vulkan copies what it needs at
+        // vkCreateGraphicsPipelines), everything here runs on the GL thread, and an application
+        // that can overflow this cap is already recompiling every frame - so the flush costs it
+        // nothing it was not paying anyway.
+        if (m_passthroughTessControlStages.size() >= kMaxPassthroughTessControlStages) {
+            MGLOG_D("ProgramFactory: flushing %zu pass-through tessellation control stages; the application has "
+                    "used more than %zu distinct (patch size, default level) combinations",
+                    m_passthroughTessControlStages.size(), kMaxPassthroughTessControlStages);
+            for (auto& entry : m_passthroughTessControlStages) {
+                if (entry.second.module != VK_NULL_HANDLE) {
+                    vkDestroyShaderModule(m_device, entry.second.module, nullptr);
+                }
+            }
+            m_passthroughTessControlStages.clear();
+        }
+
         VkPipelineShaderStageCreateInfo stage{VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO};
         stage.stage = VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT;
         stage.module = VK_NULL_HANDLE;
         stage.pName = "main";
 
         using namespace MG_Util::ShaderTranspiler;
-        const String source = BuildPassthroughTessControlSource(patchVertices);
+        const String source =
+            BuildPassthroughTessControlSource(patchVertices, defaultOuterLevel, defaultInnerLevel, perVertexMembers);
         // Same compile configuration as every other stage of every other program: this runs on
         // the GL thread (the draw path), so the live compile env is the right one, and flags=0
         // is the Vulkan-targeting form (CompileForOpenGL is what the GLES backend adds).
@@ -3686,7 +4183,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             MGLOG_E("ProgramFactory: could not compile the pass-through tessellation control stage for "
                     "patchVertices=%u; a program with an evaluation stage and no control stage cannot draw. %s",
                     patchVertices, compiled.error().log.c_str());
-            m_passthroughTessControlStages.emplace(patchVertices, stage);
+            m_passthroughTessControlStages.emplace(key, stage);
             return stage;
         }
 
@@ -3696,7 +4193,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (!linked) {
             MGLOG_E("ProgramFactory: could not link the pass-through tessellation control stage for "
                     "patchVertices=%u. %s", patchVertices, linked.error().log.c_str());
-            m_passthroughTessControlStages.emplace(patchVertices, stage);
+            m_passthroughTessControlStages.emplace(key, stage);
             return stage;
         }
 
@@ -3705,19 +4202,33 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (!binary || binary.value().empty() || binary.value().front().empty()) {
             MGLOG_E("ProgramFactory: could not generate SPIR-V for the pass-through tessellation control stage "
                     "for patchVertices=%u", patchVertices);
-            m_passthroughTessControlStages.emplace(patchVertices, stage);
+            m_passthroughTessControlStages.emplace(key, stage);
             return stage;
         }
 
         const Vector<Uint>& spirv = binary.value().front();
+        {
+            // Still switch-gated, unlike the two in GetOrCreateProgram: this stage is synthesized
+            // by MobileGL from a fixed template rather than transformed from application SPIR-V,
+            // so a failure here is a MobileGL bug to catch in a validating lane, not something a
+            // shipping build can be handed by an application. The message is latched all the same
+            // - the pass-through cache is keyed on patchVertices, so a broken template would
+            // otherwise re-report once per distinct patch size.
+            Bool validateThisOne = false;
 #if MOBILEGL_LOG_ACTIVE_LEVEL <= MOBILEGL_LOG_LEVEL_DEBUG
-        ValidateTransformedSpirv(spirv, ShaderStage::TessControl, 0);
+            validateThisOne = true;
 #else
-        if (m_enableSpirvValidation) {
-            MG_Util::ShaderTranspiler::ShaderCompiler::PrepareSpirvValidation();
-            ValidateTransformedSpirv(spirv, ShaderStage::TessControl, 0);
-        }
+            validateThisOne = m_enableSpirvValidation;
+            if (validateThisOne) MG_Util::ShaderTranspiler::ShaderCompiler::PrepareSpirvValidation();
 #endif
+            SpirvValidationFailure passthroughFailure{};
+            if (validateThisOne &&
+                !ValidateTransformedSpirv(spirv, ShaderStage::TessControl, 0, &passthroughFailure)) {
+                MGLOG_E_ONCE("ProgramFactory: the synthesized pass-through tessellation control stage for "
+                             "patchVertices=%u does not validate (%s)",
+                             patchVertices, passthroughFailure.message.c_str());
+            }
+        }
 
         VkShaderModuleCreateInfo smci{VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO};
         smci.codeSize = spirv.size() * sizeof(Uint);
@@ -3727,14 +4238,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (result != VK_SUCCESS) {
             MGLOG_E("ProgramFactory: vkCreateShaderModule failed (%d) for the pass-through tessellation control "
                     "stage for patchVertices=%u", static_cast<Int>(result), patchVertices);
-            m_passthroughTessControlStages.emplace(patchVertices, stage);
+            m_passthroughTessControlStages.emplace(key, stage);
             return stage;
         }
 
         stage.module = module;
         MGLOG_D("ProgramFactory: built the pass-through tessellation control stage for patchVertices=%u "
                 "(GL 4.6 11.2.2; Vulkan has no fixed-function equivalent)", patchVertices);
-        m_passthroughTessControlStages.emplace(patchVertices, stage);
+        m_passthroughTessControlStages.emplace(key, stage);
         return stage;
     }
 
@@ -3744,6 +4255,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VkProgramObject& entry) const {
         entry.needsPassthroughTessControl = false;
         entry.passthroughTessControlEmulatable = false;
+        entry.passthroughPerVertexMembers = 0;
 
         Bool hasTessEval = false;
         Bool hasTessControl = false;
@@ -3763,6 +4275,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (tessEvalModuleIndex >= spirv.size() || spirv[tessEvalModuleIndex].empty()) return;
         const auto& module = spirv[tessEvalModuleIndex];
 
+        // The shape the synthesized control stage has to redeclare. Read here because this is the
+        // only place that holds the evaluation stage's module; a zero mask means the walk found
+        // no input per-vertex block at all, in which case the pre-450 shape is the safe stand-in
+        // (it is what every program carried before gl_CullDistance joined the block).
+        const Uint32 perVertexMembers = ReflectPerVertexInputMembers(module);
+        entry.passthroughPerVertexMembers = perVertexMembers != 0 ? perVertexMembers : kDefaultPerVertexMembers;
+        if (perVertexMembers == 0) {
+            MGLOG_W("ProgramFactory: could not read the evaluation stage's gl_PerVertex block shape; the "
+                    "pass-through control stage falls back to the pre-450 three-member form");
+        }
+
         SpvReflectShaderModule reflectModule{};
         const SpvReflectResult createResult =
             spvReflectCreateShaderModule(module.size() * sizeof(Uint), module.data(), &reflectModule);

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.h

@@ -76,6 +76,23 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         using CompileOptionFlags = Flags<CompileOptionBit>;
         using HashType = Uint64;
 
+        // The gl_PerVertex members a pass-through tessellation control stage may have to carry,
+        // in the order glslang declares them - which is the order a redeclaration must use.
+        // Which of them exist is a function of the neighbouring stage's GLSL VERSION
+        // (gl_CullDistance joins the block at #version 450), so the mask is read off that
+        // stage's SPIR-V rather than assumed. See ReflectPerVertexInputMembers.
+        enum class PerVertexMemberBit : Uint32 {
+            Position = 1u << 0,
+            PointSize = 1u << 1,
+            ClipDistance = 1u << 2,
+            CullDistance = 1u << 3,
+        };
+        // What a program parsed below #version 450 carries, and the fallback when a module's
+        // block cannot be read.
+        static constexpr Uint32 kDefaultPerVertexMembers =
+            static_cast<Uint32>(PerVertexMemberBit::Position) | static_cast<Uint32>(PerVertexMemberBit::PointSize) |
+            static_cast<Uint32>(PerVertexMemberBit::ClipDistance);
+
         struct UpdateAfterBindLimits {
             Bool enabled = false;
             Uint32 maxPerStageSamplers = 0;
@@ -185,6 +202,32 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // tessellation stages are present or neither
             // (VUID-VkGraphicsPipelineCreateInfo-pStages-00730). So the draw path has to supply
             // the pass-through stage GL describes; see GetOrCreatePassthroughTessControlStage.
+            // True when this program was built AS a transform-feedback capture variant but its
+            // last pre-rasterization module does NOT carry the Xfb execution mode - so the
+            // renderer must decline the capture span instead of issuing
+            // vkCmdBeginTransformFeedbackEXT against it
+            // (VUID-vkCmdBeginTransformFeedbackEXT-None-04128).
+            //
+            // Two ways to get here, and neither is visible from GL state, which is all
+            // BeginXfbCaptureForDraw otherwise consults: the clip/XFB validation backstop had to
+            // rewind past the capture decoration, or XfbCaptureDecoratePass resolved none of the
+            // requested varyings and returned without changing anything (its own MGLOG_E path)
+            // while its runner still reported success. Both used to ship a non-Xfb module under
+            // an Xfb-flagged cache entry - the flag and the layout are part of the program cache
+            // key, so it was sticky for every later captured draw of the program, not a glitch.
+            Bool xfbCaptureDeclined = false;
+            // The program has a tessellation or geometry module declaring TessellationPointSize /
+            // GeometryPointSize on a device whose shaderTessellationAndGeometryPointSize feature
+            // is off, so a pipeline built from it is invalid usage
+            // (VUID-RuntimeSpirv-PointSize-06439). Its draws are refused in SetupDraw rather than
+            // handed to the driver - the same contract PipelineFactory's half-tessellated refusal
+            // implements one level up, and the counterpart of the DirectGLES arm that reports a
+            // driver with neither point-size extension by name.
+            //
+            // Sticky by construction, which is what makes ONE log line honest: the flag lives on
+            // the cache entry, so every later draw of the same program variant reads the same
+            // answer instead of re-deciding it.
+            Bool pointSizeCapabilityUnsupported = false;
             Bool needsPassthroughTessControl = false;
             // ...and the pass-through this renderer can synthesize carries gl_Position and
             // nothing else, so it is only correct when the evaluation stage's inputs are
@@ -194,6 +237,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // instead (PipelineFactory::CreatePipeline refuses the pipeline and the draw is
             // skipped). See ReflectPassthroughTessControlNeed.
             Bool passthroughTessControlEmulatable = false;
+            // Which gl_PerVertex members the evaluation stage's `in gl_PerVertex gl_in[]` block
+            // actually carries, as a PerVertexMemberBit mask read off its SPIR-V. The synthesized
+            // control stage has to redeclare the SAME shape: glslang appends gl_CullDistance to
+            // that block from #version 450 upward, so a 450/460 program - and every ESSL program,
+            // which the source processor rewrites to "#version 460 core" - carries four members
+            // where a 430 program carries three. A fixed three-member pass-through fed the
+            // evaluation stage a differently-shaped block, which is the black-frame-no-error case
+            // this whole family is written around.
+            Uint32 passthroughPerVertexMembers = 0;
             // Frame-boundary counter value of the last GetOrCreateProgram hit; drives
             // cache eviction (see OnFrameBoundary). Mutable: the draw snapshot's memoised
             // entry pointer re-stamps use through a const reference (StampProgramUse).
@@ -249,6 +301,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 writesViewportIndexBuiltin = other.writesViewportIndexBuiltin;
                 needsPassthroughTessControl = other.needsPassthroughTessControl;
                 passthroughTessControlEmulatable = other.passthroughTessControlEmulatable;
+                passthroughPerVertexMembers = other.passthroughPerVertexMembers;
                 lastUsedFrame = other.lastUsedFrame;
                 other.hash = 0;
                 other.descriptorSetLayout = VK_NULL_HANDLE;
@@ -267,6 +320,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 other.writesViewportIndexBuiltin = false;
                 other.needsPassthroughTessControl = false;
                 other.passthroughTessControlEmulatable = false;
+                other.passthroughPerVertexMembers = 0;
                 other.lastUsedFrame = 0;
             }
             VkProgramObject& operator=(VkProgramObject&& other) noexcept {
@@ -311,6 +365,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 writesViewportIndexBuiltin = other.writesViewportIndexBuiltin;
                 needsPassthroughTessControl = other.needsPassthroughTessControl;
                 passthroughTessControlEmulatable = other.passthroughTessControlEmulatable;
+                passthroughPerVertexMembers = other.passthroughPerVertexMembers;
                 lastUsedFrame = other.lastUsedFrame;
                 other.hash = 0;
                 other.descriptorSetLayout = VK_NULL_HANDLE;
@@ -329,6 +384,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 other.writesViewportIndexBuiltin = false;
                 other.needsPassthroughTessControl = false;
                 other.passthroughTessControlEmulatable = false;
+                other.passthroughPerVertexMembers = 0;
                 other.lastUsedFrame = 0;
                 return *this;
             }
@@ -396,12 +452,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         explicit ProgramFactory(VkDevice device, const VulkanRendererConfig& config, Uint32 maxBindings,
                                 Bool shaderDrawParametersEnabled,
                                 Bool unformattedFloatStorageImagesEnabled,
+                                Bool tessellationAndGeometryPointSizeEnabled,
                                 Bool enableSpirvValidation,
                                 UpdateAfterBindLimits updateAfterBindLimits,
                                 SubgroupLoweringPolicy subgroupPolicy)
             : m_device(device), m_maxBindings(maxBindings), m_config(config),
               m_shaderDrawParametersEnabled(shaderDrawParametersEnabled),
               m_unformattedFloatStorageImagesEnabled(unformattedFloatStorageImagesEnabled),
+              m_tessellationAndGeometryPointSizeEnabled(tessellationAndGeometryPointSizeEnabled),
               m_enableSpirvValidation(enableSpirvValidation),
               m_updateAfterBindLimits(updateAfterBindLimits),
               m_subgroupPolicy(subgroupPolicy) {
@@ -485,18 +543,40 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // the caller then has no control stage to inject, and CreatePipeline refuses the
         // pipeline rather than handing the driver a half-tessellated one.
         //
-        // Keyed on the patch size because GL takes the output patch size from PATCH_VERTICES,
-        // which is draw state, not link state - the CTS case that motivated this links at the
-        // default 3 and draws at 4. The pipeline cache already re-keys on patchControlPoints,
-        // so the module a pipeline was built with is part of that pipeline's identity.
-        // Compiling is bounded by the number of distinct patch sizes a program draws with
-        // (MAX_PATCH_VERTICES = 32 in the worst case, one or two in practice) and only ever
-        // happens for the rare program that has no control stage at all.
-        VkPipelineShaderStageCreateInfo GetOrCreatePassthroughTessControlStage(Uint32 patchVertices);
+        // Keyed on the patch size, the six default tessellation levels AND the gl_PerVertex
+        // member set, because all three decide what the generator emits. The size comes from
+        // PATCH_VERTICES and the levels from PATCH_DEFAULT_OUTER_LEVEL / PATCH_DEFAULT_INNER_LEVEL
+        // - draw state rather than link state, and the CTS case that motivated this links at the
+        // default 3 and draws at 4. The member set comes from the neighbouring evaluation stage's
+        // own SPIR-V, so two programs at different GLSL versions need different modules. The
+        // pipeline cache re-keys on the same inputs, so the module a pipeline was built with is
+        // part of that pipeline's identity. Compiling is bounded by the number of distinct
+        // (size, levels, members) combinations a program draws with - one or two in practice -
+        // and only ever happens for the rare program that has no control stage at all.
+        VkPipelineShaderStageCreateInfo GetOrCreatePassthroughTessControlStage(Uint32 patchVertices,
+                                                                              const FloatVec4& defaultOuterLevel,
+                                                                              const FloatVec2& defaultInnerLevel,
+                                                                              Uint32 perVertexMembers);
 
         // Source of the module above. Exposed for tests: the generated GLSL is the whole
         // contract with the evaluation stage, so it is worth pinning independently of a device.
-        static String BuildPassthroughTessControlSource(Uint32 patchVertices);
+        static String BuildPassthroughTessControlSource(Uint32 patchVertices, const FloatVec4& defaultOuterLevel,
+                                                        const FloatVec2& defaultInnerLevel, Uint32 perVertexMembers);
+
+        // The identity of one such module: everything the generator bakes in, folded into a
+        // 64-bit key over the raw bits (so -0.0 and +0.0 key apart, which is harmless, and NaN
+        // keys to itself, which is what matters). Shared with PipelineFactory, which mixes the
+        // same value into the pipeline hash so a pipeline can never be handed a module built for
+        // different levels or a different block shape.
+        static Uint64 ComputePassthroughTessControlKey(Uint32 patchVertices, const FloatVec4& defaultOuterLevel,
+                                                       const FloatVec2& defaultInnerLevel, Uint32 perVertexMembers);
+
+        // The PerVertexMemberBit mask of the INPUT per-vertex block a module declares, read
+        // straight out of its SPIR-V (OpMemberDecorate ... BuiltIn on the struct behind the one
+        // Input variable that is an array of a Block-decorated struct). Zero when the module has
+        // no such block. Exposed for tests, which is the only way to pin the shape agreement
+        // without a device.
+        static Uint32 ReflectPerVertexInputMembers(const Vector<Uint>& spirv);
 
     private:
         struct ProgramLookupCache {
@@ -539,6 +619,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // True only when the logical device enabled both
         // shaderStorageImageReadWithoutFormat and shaderStorageImageWriteWithoutFormat.
         Bool m_unformattedFloatStorageImagesEnabled = false;
+        // True when the logical device enabled shaderTessellationAndGeometryPointSize. When it is
+        // FALSE a program whose tessellation or geometry module declares TessellationPointSize /
+        // GeometryPointSize is refused at build time (see VkProgramObject::
+        // pointSizeCapabilityUnsupported) instead of being handed to the driver as invalid usage.
+        Bool m_tessellationAndGeometryPointSizeEnabled = false;
         // Startup snapshot used only by internally synthesized shader modules, which do not
         // originate from a ProgramLinkTask.
         Bool m_enableSpirvValidation = false;
@@ -556,11 +641,20 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // See GetCacheStructureEpoch(). Starts at 1 so a zero-initialized memo can never match.
         Uint64 m_cacheStructureEpoch = 1;
         IEvictionObserver* m_evictionObserver = nullptr;
-        // Pass-through tessellation control stages by input patch size. Never evicted: at most
-        // MAX_PATCH_VERTICES entries exist for the lifetime of the device, and every pipeline
-        // ever built from one keeps referencing its module. A failed build is cached as
+        // Pass-through tessellation control stages by the identity of what was compiled into
+        // them - the input patch size and the six default tessellation levels, folded into one
+        // 64-bit key by ComputePassthroughTessControlKey (the levels are float state, so the map
+        // cannot simply be keyed on the patch size any more). A failed build is cached as
         // VK_NULL_HANDLE so a broken generator costs one compile, not one per draw.
-        UnorderedMap<Uint32, VkPipelineShaderStageCreateInfo> m_passthroughTessControlStages;
+        //
+        // Hard-capped, because the key is application-controlled: glPatchParameterfv clamps
+        // nothing, so an application that recomputes a level per frame mints a new key per frame.
+        // Reaching the cap destroys every module and starts over (see the flush in
+        // GetOrCreatePassthroughTessControlStage); the cap is far above what any program that
+        // holds its levels still will ever need. The gl_PerVertex member set is in the key too
+        // and adds only a handful of values, so it does not move the cap in practice.
+        static constexpr SizeT kMaxPassthroughTessControlStages = 64;
+        UnorderedMap<Uint64, VkPipelineShaderStageCreateInfo> m_passthroughTessControlStages;
         static inline XXH64_state_t* m_hashState = XXH64_createState();
     };
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.cpp

@@ -10,6 +10,7 @@
 
 #include "MG_Backend/DirectVulkan/DirectVulkanResourceState.h"
 #include "MG_State/GLState/Core.h"
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include "MG_State/GLState/ProgramState/ProgramObject.h"
 #include "MG_State/GLState/TextureState/TextureObject1D.h"
 #include "MG_State/GLState/TextureState/TextureObject2D.h"
@@ -20,6 +21,7 @@
 #include "MG_Util/Converters/GLToMG/TextureEnumConverter.h"
 #include "MG_Util/Converters/MGToStr/FramebufferEnumConverter.h"
 #include "MG_Util/Converters/MGToVk/TextureEnumConverter.h"
+#include "MG_Util/Metrics/PipeStats.h"
 #include "MG_Util/Metrics/TextureMetrics.h"
 #include "MG_Util/ShaderTranspiler/Types.h"
 #include <Config.h>
@@ -37,6 +39,24 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // glGenTextures ever hands this out, and nothing looks a placeholder up by name - so the
         // id only has to stay clear of the application's, exactly like the sampled fallback's.
         constexpr Uint kUnboundStorageImageExternalIndex = 0xFFFFFF01u;
+        // The multisample sampled fallbacks: one per (target, numeric domain), because unlike the
+        // single-sampled fallback they cannot be reinterpreted into another domain at view time
+        // (see GetFallbackMultisampleTexture). Six reserved ids, contiguous from this base for the
+        // same reason as the two above - they must not collide with anything glGenTextures can
+        // hand out.
+        constexpr Uint kFallbackMultisampleExternalIndexBase = 0xFFFFFF02u;
+        constexpr Uint kFallbackMultisampleExternalIndexCount = 6u;
+
+        // MobileGL's own stand-in textures, by the reserved ids above. Nothing an application can
+        // do reaches one, so anything keyed on the GL object an application bound - image-unit
+        // aliasing above all - has to leave them alone.
+        Bool IsPlaceholderTexture(const MG_State::GLState::ITextureObject* texture) {
+            if (texture == nullptr) return false;
+            const Uint index = static_cast<Uint>(texture->GetExternalIndex());
+            return index == kFallbackTexture2DExternalIndex || index == kUnboundStorageImageExternalIndex ||
+                   (index >= kFallbackMultisampleExternalIndexBase &&
+                    index < kFallbackMultisampleExternalIndexBase + kFallbackMultisampleExternalIndexCount);
+        }
 
         // The R32 member of each numeric class. Every one of the three is a MANDATORY-support
         // format for uniform texel buffers, storage texel buffers and storage images alike
@@ -360,6 +380,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_textureManager = nullptr;
         m_samplerManager = nullptr;
         m_fallbackTexture2D.reset();
+        m_fallbackMultisampleTextures.clear();
     }
 
     void UniformManager::BeginFrame(Uint32 frameIndex) {
@@ -483,7 +504,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // alive through the draw via GL binding state. Only the fallback path needs a SharedPtr to
         // keep the fallback texture alive for the rest of this call.
         MG_State::GLState::ITextureObject* texture = ResolveSamplerTextureRaw(program, programObj, binding, element);
-        auto& textureUnit = MG_State::pGLContext->GetTextureUnitObject(unit);
+        auto& textureUnit = MGB_CTX->GetTextureUnitObject(unit);
         const auto& samplerOverride = textureUnit.GetSamplerObject();
         const auto preferredTarget = programObj.samplerTextureTargetByBinding[binding];
         SharedPtr<MG_State::GLState::ITextureObject> fallbackHolder;
@@ -496,7 +517,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             texture = nullptr;
         }
         if (texture == nullptr) {
-            fallbackHolder = GetFallbackTexture(preferredTarget);
+            // The binding's sampler class, read here rather than through the `numericDomain`
+            // local further down (it is declared after this point): the multisample placeholder
+            // has to be built in the class the shader will read it in.
+            fallbackHolder = GetFallbackTexture(preferredTarget, programObj.samplerNumericDomainByBinding[binding]);
             texture = fallbackHolder.get();
             if (texture == nullptr) {
                 MGLOG_E_ONCE("ResolveSamplerDescriptor: no fallback texture available for binding=%u ('%s') "
@@ -529,7 +553,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return false;
         }
         if (!IsValidSampledImageLayout(resource->layout)) {
-            auto drawFbo = MG_State::pGLContext->GetFramebufferBindingSlot(FramebufferTarget::Draw).GetBoundObject();
+            auto drawFbo = MGB_CTX->GetFramebufferBindingSlot(FramebufferTarget::Draw).GetBoundObject();
             FramebufferAttachmentType attachmentType = FramebufferAttachmentType::None;
             Int attachmentLevel = 0;
             if (drawFbo &&
@@ -756,7 +780,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 // filtering - which a single-level view can still have. Resolve the sampler exactly
                 // the way ResolveSamplerDescriptor does and bail if anisotropy would apply.
                 const Int unit = ResolveSamplerUnitIndex(program, location, binding);
-                const auto& samplerOverride = MG_State::pGLContext->GetTextureUnitObject(unit).GetSamplerObject();
+                const auto& samplerOverride = MGB_CTX->GetTextureUnitObject(unit).GetSamplerObject();
                 const auto* effectiveSampler =
                     samplerOverride ? samplerOverride.get() : texture->GetSamplerObject().get();
                 if (effectiveSampler == nullptr) return false;
@@ -786,7 +810,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                          const ProgramFactory::VkProgramObject& programObj, Uint32 binding,
                                                          SharedPtr<MG_State::GLState::ITextureObject>& outTexture) {
         outTexture.reset();
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveSamplerTexture: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveSamplerTexture: GL context is null");
         MOBILEGL_ASSERT(binding < programObj.samplerUniformLocationByBinding.size(),
                         "ResolveSamplerTexture: sampler location binding %u out of range", binding);
         MOBILEGL_ASSERT(binding < programObj.samplerTextureTargetByBinding.size(),
@@ -795,7 +819,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const Int location = programObj.samplerUniformLocationByBinding[binding];
         const Int unit = ResolveSamplerUnitIndex(program, location, binding);
 
-        auto& textureUnit = MG_State::pGLContext->GetTextureUnitObject(unit);
+        auto& textureUnit = MGB_CTX->GetTextureUnitObject(unit);
         const TextureTarget preferredTarget = programObj.samplerTextureTargetByBinding[binding];
         outTexture = textureUnit.GetBindingSlot(preferredTarget).GetBoundObject();
         // The slot always holds at least the target's default texture (name 0). While that
@@ -811,7 +835,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     MG_State::GLState::ITextureObject* UniformManager::ResolveSamplerTextureRaw(
         const MG_State::GLState::ProgramObject& program, const ProgramFactory::VkProgramObject& programObj,
         Uint32 binding, Uint32 element) {
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveSamplerTextureRaw: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveSamplerTextureRaw: GL context is null");
         MOBILEGL_ASSERT(binding < programObj.samplerUniformLocationByBinding.size(),
                         "ResolveSamplerTextureRaw: sampler location binding %u out of range", binding);
         MOBILEGL_ASSERT(binding < programObj.samplerTextureTargetByBinding.size(),
@@ -821,7 +845,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             ResolveDescriptorElementLocation(program, programObj.samplerUniformLocationByBinding[binding], element);
         const Int unit = ResolveSamplerUnitIndex(program, location, binding);
 
-        auto& textureUnit = MG_State::pGLContext->GetTextureUnitObject(unit);
+        auto& textureUnit = MGB_CTX->GetTextureUnitObject(unit);
         const TextureTarget preferredTarget = programObj.samplerTextureTargetByBinding[binding];
         // GetBoundObject() returns the SharedPtr by const ref; .get() reads the pointer without
         // touching the refcount (no atomic inc/dec per binding per draw).
@@ -966,7 +990,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                              VkBufferView& outBufferView) {
         outBufferView = VK_NULL_HANDLE;
         MOBILEGL_ASSERT(m_bufferManager != nullptr, "ResolveStorageTexelBufferDescriptor: buffer manager is null");
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveStorageTexelBufferDescriptor: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveStorageTexelBufferDescriptor: GL context is null");
         MOBILEGL_ASSERT(frameIndex < m_frames.size(),
                         "ResolveStorageTexelBufferDescriptor: frame index out of range");
         MOBILEGL_ASSERT(binding < programObj.samplerUniformLocationByBinding.size(),
@@ -990,7 +1014,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         MOBILEGL_ASSERT(binding < programObj.samplerNumericDomainByBinding.size(),
                         "ResolveStorageTexelBufferDescriptor: numeric domain binding %u out of range", binding);
 
-        auto& imageBinding = MG_State::pGLContext->GetImageTextureBinding(imageUnit);
+        auto& imageBinding = MGB_CTX->GetImageTextureBinding(imageUnit);
         const auto& texture = imageBinding.Texture;
         if (texture == nullptr) {
             // An image unit with no texture on it is legal GL (4.6 core 8.26): loads return zero
@@ -1126,7 +1150,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                         VkDescriptorBufferInfo& outBufferInfo) const {
         outBufferInfo = {};
         MOBILEGL_ASSERT(m_bufferManager != nullptr, "ResolveStorageBufferDescriptor: buffer manager is null");
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveStorageBufferDescriptor: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveStorageBufferDescriptor: GL context is null");
         MOBILEGL_ASSERT(binding < programObj.storageBlockIndexByBinding.size(),
                         "ResolveStorageBufferDescriptor: binding %u out of range", binding);
 
@@ -1163,12 +1187,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 ? static_cast<GLuint>(atomicCounterBinding)
                 : GetShaderStorageBlockBinding(program, static_cast<GLuint>(blockIndex)) + element;
         const Uint32 bindingPointCount =
-            static_cast<Uint32>(MG_State::pGLContext->GetBufferBindingPointCount(bufferTarget));
+            static_cast<Uint32>(MGB_CTX->GetBufferBindingPointCount(bufferTarget));
         MOBILEGL_ASSERT(frontendBinding < bindingPointCount,
                         "ResolveStorageBufferDescriptor: frontend binding %u out of range for block '%s'",
                         frontendBinding, blockName.c_str());
 
-        auto& bindingPoint = MG_State::pGLContext->GetBufferBindingPoint(bufferTarget, frontendBinding);
+        auto& bindingPoint = MGB_CTX->GetBufferBindingPoint(bufferTarget, frontendBinding);
         const auto& bufferObject = bindingPoint.GetBoundObject();
         if (bufferObject == nullptr) {
             // NOT an error, and above all not a reason to lose the draw. GL 4.6 core 7.8 lets a
@@ -1240,7 +1264,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                        VkDescriptorImageInfo& outImageInfo) const {
         outImageInfo = {};
         MOBILEGL_ASSERT(m_textureManager != nullptr, "ResolveStorageImageDescriptor: texture manager is null");
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveStorageImageDescriptor: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveStorageImageDescriptor: GL context is null");
         MOBILEGL_ASSERT(binding < programObj.samplerUniformLocationByBinding.size(),
                         "ResolveStorageImageDescriptor: binding %u out of range", binding);
 
@@ -1269,7 +1293,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return false;
         }
 
-        auto& imageBinding = MG_State::pGLContext->GetImageTextureBinding(imageUnit);
+        auto& imageBinding = MGB_CTX->GetImageTextureBinding(imageUnit);
         if (imageBinding.Texture == nullptr) {
             // Legal GL: an image unit with no texture bound makes loads return zero and discards
             // stores (4.6 core 8.26). It is not a reason to lose the draw, which is what returning
@@ -1367,18 +1391,30 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return outImageInfo.imageView != VK_NULL_HANDLE;
     }
 
-    SharedPtr<MG_State::GLState::ITextureObject> UniformManager::GetFallbackTexture(TextureTarget target) const {
-        // The fallback is a single-sampled 2D image, so it can only stand in for a sampler that
-        // would accept one. A multisample sampler in particular cannot: its descriptor demands a
-        // multisample view, and handing it this one is invalid Vulkan, not a degraded picture.
-        // Report that there is no fallback and let the caller decline the draw - aborting the
-        // process over an unbound sampler is never the right answer.
+    SharedPtr<MG_State::GLState::ITextureObject> UniformManager::GetFallbackTexture(
+        TextureTarget target, SamplerNumericDomain numericDomain) const {
+        // A multisample sampler cannot be served by the single-sampled 2D image below - its
+        // descriptor demands a multisample view - so it gets its own placeholder rather than no
+        // placeholder at all. Without one, ResolveSamplerDescriptor declined and
+        // BindProgramUniformBuffers dropped the WHOLE draw, which is how every
+        // sample_variables.*.samples_0 body failed: the CTS's resolve program declares both a
+        // sampler2D and a sampler2DMS and deliberately points the unused one at an empty texture
+        // unit, and at samples_0 the unused one is the sampler2DMS. GL says sampling an
+        // incomplete texture is undefined, not fatal, so the draw has to happen.
+        if (target == TextureTarget::Texture2DMultisample ||
+            target == TextureTarget::Texture2DMultisampleArray) {
+            return GetFallbackMultisampleTexture(target, numericDomain);
+        }
         if (target != TextureTarget::Texture2D && target != TextureTarget::TextureRectangle) {
             MGLOG_E_ONCE("UniformManager::GetFallbackTexture: no fallback exists for target=%d",
                     static_cast<Int>(target));
             return nullptr;
         }
 
+        // The single-sampled fallback stays domain-agnostic: it is storage-image capable, so its
+        // image carries VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT and ResolveSampledImageViewFormat can
+        // hand an integer sampler an R8G8B8A8_UINT view of these same RGBA8 texels. A multisample
+        // image can never carry that bit, which is why the arm above needs one object per domain.
         if (m_fallbackTexture2D == nullptr) {
             auto fallbackTexture = MakeShared<MG_State::GLState::TextureObject2D>(kFallbackTexture2DExternalIndex);
             fallbackTexture->SetInternalFormat(TextureInternalFormat::RGBA8);
@@ -1396,6 +1432,83 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return m_fallbackTexture2D;
     }
 
+    SharedPtr<MG_State::GLState::ITextureObject> UniformManager::GetFallbackMultisampleTexture(
+        TextureTarget target, SamplerNumericDomain numericDomain) const {
+        // ONE PLACEHOLDER PER NUMERIC DOMAIN, unlike the single-sampled fallback.
+        //
+        // A descriptor whose image format is in a different numeric class than the sampler that
+        // reads it needs a format-reinterpreting view, and building one needs
+        // VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT on the image. A multisample image can never have it:
+        // SyncTextureResource computes storageImageCapable as `!isMultisampleTexture && ...`, and
+        // the only other source of the bit is the sRGB twin, which RGBA8 is not. So an RGBA8
+        // placeholder handed to a usampler2DMS made GetOrCreateSampledImageView bail with "needs
+        // mutable image format", ResolveSamplerDescriptor return false, and the draw be dropped -
+        // the exact outcome the placeholder exists to prevent, just reached later. Matching the
+        // image's own format to the sampler's class instead means no reinterpreting view is
+        // needed at all.
+        const Bool arrayed = target == TextureTarget::Texture2DMultisampleArray;
+        TextureInternalFormat internalFormat = TextureInternalFormat::RGBA8;
+        Uint32 domainSlot = 0;
+        switch (numericDomain) {
+        case SamplerNumericDomain::SignedInteger:
+            internalFormat = TextureInternalFormat::RGBA8I;
+            domainSlot = 1;
+            break;
+        case SamplerNumericDomain::UnsignedInteger:
+            internalFormat = TextureInternalFormat::RGBA8UI;
+            domainSlot = 2;
+            break;
+        case SamplerNumericDomain::Float:
+        case SamplerNumericDomain::Unknown:
+        default:
+            // Unknown reads as float, matching PlaceholderFormatForNumericDomain's own default:
+            // a shader whose sampler class could not be reflected is far likelier to be a plain
+            // sampler2DMS than an integer one, and a float view is the only one buildable without
+            // the mutable bit anyway.
+            break;
+        }
+        const Uint32 key = (arrayed ? kFallbackMultisampleExternalIndexCount / 2 : 0u) + domainSlot;
+        auto cached = m_fallbackMultisampleTextures.find(key);
+        if (cached != m_fallbackMultisampleTextures.end()) {
+            return cached->second;
+        }
+
+        const TextureUploadTarget uploadTarget = arrayed ? TextureUploadTarget::Texture2DMultisampleArray
+                                                         : TextureUploadTarget::Texture2DMultisample;
+        const Uint externalIndex = kFallbackMultisampleExternalIndexBase + key;
+        SharedPtr<MG_State::GLState::TextureObjectMipmap> texture;
+        if (arrayed) {
+            texture = MakeShared<MG_State::GLState::TextureObject2DMultisampleArray>(externalIndex);
+        } else {
+            texture = MakeShared<MG_State::GLState::TextureObject2DMultisample>(externalIndex);
+        }
+        texture->SetInternalFormat(internalFormat);
+        // TWO samples, never one. VUID-RuntimeSpirv-samples-08726 forbids an OpTypeImage with
+        // MS = 1 from reading a VK_SAMPLE_COUNT_1_BIT image, which is exactly the hazard
+        // VkTextureManager::SyncTextureResource's one-sample floor exists to avoid; a placeholder
+        // that re-created it would be worse than none.
+        texture->SetSamples(2);
+        texture->SetFixedSampleLocations(true);
+        // No upload, and MarkStorageDirty(dirty = false) to say so: a multisample image cannot be
+        // written by a transfer at all - it deliberately carries no TRANSFER_DST usage - so unlike
+        // the 2D fallback this one cannot be given (0, 0, 0, 1) content. Its texels are undefined,
+        // which is precisely what GL 4.6 core 8.17 promises for a texelFetch on a multisample
+        // texture that is not complete. The point of the placeholder is that the DRAW happens.
+        texture->AllocateStorage(uploadTarget, 0, {.texelSize = {1, 1, 1}, .byteSize = 0});
+        texture->TruncateMipmapLevels(uploadTarget, 1);
+        texture->MarkStorageDirty(uploadTarget, 0, false);
+        // Worth knowing if it ever fires: an integer multisample format can legitimately support
+        // no count above one on a device (framebufferIntegerColorSampleCounts is allowed to be
+        // VK_SAMPLE_COUNT_1_BIT), and SyncTextureResource's round-down would then hand this
+        // placeholder a single-sampled image, which is the samples-08726 shape the SetSamples(2)
+        // above exists to avoid. It already warns from there; nothing better is available - a
+        // one-sample integer image is still a draw, and declining is the outcome this whole
+        // placeholder replaced.
+        MGLOG_D("UniformManager::GetFallbackMultisampleTexture: created placeholder target=%d domain=%d format=%d",
+                static_cast<Int>(target), static_cast<Int>(numericDomain), static_cast<Int>(internalFormat));
+        return m_fallbackMultisampleTextures.emplace(key, Move(texture)).first->second;
+    }
+
     VkBufferView UniformManager::AcquireUnboundTexelBufferView(VkFormat declaredFormat,
                                                                SamplerNumericDomain numericDomain, Bool storage) {
         MOBILEGL_ASSERT(m_bufferManager != nullptr, "AcquireUnboundTexelBufferView: buffer manager is null");
@@ -1536,7 +1649,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // Open-coded ResolveSamplerTextureRaw so the unit is resolved once for both the
         // texture and the sampler override - this runs per binding per full-path draw,
         // and program-alternating draw streams take the full path on every draw.
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveSampledBinding: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveSampledBinding: GL context is null");
         MOBILEGL_ASSERT(binding < programObj.samplerUniformLocationByBinding.size(),
                         "ResolveSampledBinding: sampler location binding %u out of range", binding);
         MOBILEGL_ASSERT(binding < programObj.samplerTextureTargetByBinding.size(),
@@ -1547,29 +1660,53 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return false;
         }
         const Int unit = ResolveSamplerUnitIndex(program, location, binding);
-        auto& textureUnit = MG_State::pGLContext->GetTextureUnitObject(unit);
+        auto& textureUnit = MGB_CTX->GetTextureUnitObject(unit);
         const TextureTarget preferredTarget = programObj.samplerTextureTargetByBinding[binding];
         MG_State::GLState::ITextureObject* texture =
             textureUnit.GetBindingSlot(preferredTarget).GetBoundObject().get();
+        // The sampler in effect, resolved BEFORE the completeness test below rather than after:
+        // GL's completeness rules are a property of (texture, sampler in effect), so the test
+        // cannot be asked without it.
+        const auto& samplerOverride = textureUnit.GetSamplerObject();
+        const MG_State::GLState::SamplerObject* effectiveSampler =
+            samplerOverride ? samplerOverride.get()
+                            : (texture != nullptr ? texture->GetSamplerObject().get() : nullptr);
         // Undefined default texture (name 0, no image) resolves as "unbound", exactly
         // like ResolveSamplerTextureRaw reports it.
         if (MG_State::GLState::IsUndefinedDefaultTexture(texture)) {
             texture = nullptr;
         }
+        // ...and so does a texture that fails the completeness rules for the filter in effect,
+        // because that is precisely what ResolveSamplerDescriptor does with it. The two used to
+        // disagree: this one asked only whether the default texture was UNDEFINED, so a default
+        // texture that had been given a base level but no mip chain - which is what the GL-CTS
+        // state reset between test cases leaves behind, and what any application that uploads to
+        // texture 0 has - stayed in the sampled set while the descriptor path swapped it for the
+        // fallback. SetupDraw then synced a texture no descriptor would use, the sync declined
+        // (GL calls it incomplete), and the null it returned was dereferenced one line later.
+        // Keeping the two predicates identical is the invariant; CollectSampledTextures exists to
+        // pre-sync exactly the textures the descriptors will hold.
+        if (MG_State::GLState::SamplesAsIncompleteTexture(texture, effectiveSampler)) {
+            texture = nullptr;
+        }
         if (texture == nullptr) {
             // ResolveSamplerDescriptor will substitute the fallback texture for this binding;
             // include it in the sampled set so the pre-render-pass sync/transition pass covers
             // its first use instead of leaving that work to happen inside an active pass.
-            if (preferredTarget != TextureTarget::Texture2D &&
-                preferredTarget != TextureTarget::TextureRectangle) {
+            // Ask GetFallbackTexture rather than re-listing the targets it serves: that list grew
+            // a multisample arm and the two must not drift apart.
+            texture = GetFallbackTexture(preferredTarget, programObj.samplerNumericDomainByBinding[binding]).get();
+            if (texture == nullptr) {
                 return false;
             }
-            texture = GetFallbackTexture(preferredTarget).get();
+            // The substitution changed the texture, so the "no override" arm of the effective
+            // sampler has to follow it to the fallback's own.
+            if (!samplerOverride) {
+                effectiveSampler = texture != nullptr ? texture->GetSamplerObject().get() : nullptr;
+            }
         }
-        const auto& samplerOverride = textureUnit.GetSamplerObject();
         outTexture = texture;
-        outSampler = samplerOverride ? samplerOverride.get()
-                                     : (texture != nullptr ? texture->GetSamplerObject().get() : nullptr);
+        outSampler = effectiveSampler;
         return true;
     }
 
@@ -1667,7 +1804,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const ProgramFactory::VkProgramObject& programObj,
         Vector<MG_State::GLState::ITextureObject*>& outTextures) const {
         outTextures.clear();
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr,
+        MOBILEGL_ASSERT(MGB_CTX_LIVE,
                         "CollectStorageImageTextures: GL context is null");
         // Same as the sampled walk: a declined program is refused at bind time, and its declined
         // binding has no uniform location to reach an image unit through.
@@ -1711,7 +1848,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                     return false;
                 }
 
-                auto* texture = MG_State::pGLContext->GetImageTextureBinding(imageUnit).Texture.get();
+                auto* texture = MGB_CTX->GetImageTextureBinding(imageUnit).Texture.get();
                 if (texture == nullptr) {
                     // ResolveStorageImageDescriptor will substitute the placeholder image for this
                     // binding; include it here for the same reason the sampled walk includes the
@@ -1749,7 +1886,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const ProgramFactory::VkProgramObject& programObj,
         Vector<SamplerImageFeedbackBinding>& outBindings) const {
         outBindings.clear();
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr,
+        MOBILEGL_ASSERT(MGB_CTX_LIVE,
                         "CollectSamplerImageFeedback: GL context is null");
         if (programObj.declinedDescriptors) return true;
 
@@ -1765,9 +1902,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 if (!ResolveSampledBinding(program, programObj, samplerBinding, samplerElement,
                                            sampledTexture, sampledSampler) ||
                     sampledTexture == nullptr || sampledSampler == nullptr ||
-                    MG_State::GLState::SamplesAsIncompleteTexture(sampledTexture, sampledSampler)) {
+                    IsPlaceholderTexture(sampledTexture)) {
                     // ResolveSamplerDescriptor uses a fallback in these cases, which cannot
-                    // alias the image-unit binding of the original texture.
+                    // alias the image-unit binding of the original texture. The unbound and
+                    // incomplete cases both arrive here AS that fallback now that
+                    // ResolveSampledBinding applies the completeness rule itself, so the test is
+                    // "is this one of ours" rather than a second completeness check.
                     continue;
                 }
                 // Multisample source images intentionally omit TRANSFER_SRC usage. Keep their existing
@@ -1796,7 +1936,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                         if (imageUnit < 0 || imageUnit >= MG_State::GLState::TextureState::MAX_TEXTURE_IMAGE_UNITS) {
                             return false;
                         }
-                        const auto& image = MG_State::pGLContext->GetImageTextureBinding(imageUnit);
+                        const auto& image = MGB_CTX->GetImageTextureBinding(imageUnit);
                         // A sampler view exposes all layers of its target; equal texture plus an
                         // overlapping mip therefore aliases the writable image subresource.
                         if (image.Texture.get() == sampledTexture &&
@@ -1826,7 +1966,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const void* outData = nullptr;
         VkDeviceSize outSize = 0;
 
-        MOBILEGL_ASSERT(MG_State::pGLContext != nullptr, "ResolveUniformBufferPayload: GL context is null");
+        MOBILEGL_ASSERT(MGB_CTX_LIVE, "ResolveUniformBufferPayload: GL context is null");
         MOBILEGL_ASSERT(binding < programObj.bindingKinds.size(),
                         "ResolveUniformBufferPayload: binding %u out of range", binding);
         MOBILEGL_ASSERT(programObj.bindingKinds[binding] == ProgramFactory::DescriptorBindingKind::UniformBufferDynamic,
@@ -1871,12 +2011,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         const Uint32 frontendBinding = program.GetUniformBlockBinding(static_cast<Uint32>(blockIndex));
         const Uint32 uniformBindingPointCount =
-            static_cast<Uint32>(MG_State::pGLContext->GetBufferBindingPointCount(BufferTarget::Uniform));
+            static_cast<Uint32>(MGB_CTX->GetBufferBindingPointCount(BufferTarget::Uniform));
         MOBILEGL_ASSERT(frontendBinding < uniformBindingPointCount,
                         "ResolveUniformBufferPayload: frontend UBO binding %u out of range for block '%s'",
                         frontendBinding, program.GetUniformBlockName(static_cast<Uint32>(blockIndex)).c_str());
 
-        auto& bindingPoint = MG_State::pGLContext->GetBufferBindingPoint(BufferTarget::Uniform, frontendBinding);
+        auto& bindingPoint = MGB_CTX->GetBufferBindingPoint(BufferTarget::Uniform, frontendBinding);
         const auto& bufferObject = bindingPoint.GetBoundObject();
         MOBILEGL_ASSERT(bufferObject != nullptr,
                         "ResolveUniformBufferPayload: no UBO bound at frontend binding %u for block '%s'",
@@ -1938,6 +2078,16 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 out.dynamicOffset = rangeStart;
             }
         }
+        if (MG_Util::PipeStats::Enabled() && !out.directBindable) {
+            // D-B8: the bytes Magma repacks into its own UBO ring, i.e. exactly the host
+            // payload a split build would have to ship with set_shader_buffers. Espryt binds
+            // the frontend buffer to the driver and contributes nothing here, which is why
+            // the class is named for the payload and not for the call. Counted AFTER the
+            // zero-copy direct-bind decision: a direct bind repacks nothing, and counting it
+            // here reported a copy that never happened.
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageUboNamed,
+                                         static_cast<Uint64>(outSize));
+        }
         return true;
     }
 
@@ -2145,6 +2295,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         outBuffer = slice.buffer;
         outRange = ubo.payloadSize;
         outDynamicOffset = static_cast<Uint32>(slice.offset);
+        if (isGlobalUbo && MG_Util::PipeStats::Enabled()) {
+            // Magma's half of stage-ubo-global, so the class means the same on both
+            // backends. The memo hit above returns before this, so a frame that reuses the
+            // slice correctly contributes nothing.
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageUboGlobal,
+                                         static_cast<Uint64>(ubo.payloadSize));
+        }
         if (isGlobalUbo) {
             m_globalUboMemo[m_globalUboMemoNext] =
                 GlobalUboSliceMemo{uboProgramLifetimeId, uboFrameSerial, uboContentVersion,

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.h

@@ -179,7 +179,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         static MG_State::GLState::ITextureObject* ResolveSamplerTextureRaw(
             const MG_State::GLState::ProgramObject& program,
             const ProgramFactory::VkProgramObject& programObj, Uint32 binding, Uint32 element);
-        SharedPtr<MG_State::GLState::ITextureObject> GetFallbackTexture(TextureTarget target) const;
+        // `numericDomain` is the sampler's class, and it matters only for the multisample arm -
+        // see GetFallbackMultisampleTexture for why the single-sampled fallback can ignore it.
+        SharedPtr<MG_State::GLState::ITextureObject> GetFallbackTexture(
+            TextureTarget target, SamplerNumericDomain numericDomain) const;
+        // The multisample arm of GetFallbackTexture. One object per (target, numeric domain) and
+        // no upload path: a multisample image cannot be written by a transfer, so its texels stay
+        // undefined - which is what GL promises for a texelFetch on an incomplete multisample
+        // texture - and it cannot carry MUTABLE_FORMAT, so its format has to match the sampler's
+        // class outright rather than being reinterpreted at view time.
+        SharedPtr<MG_State::GLState::ITextureObject> GetFallbackMultisampleTexture(
+            TextureTarget target, SamplerNumericDomain numericDomain) const;
         // ---- placeholders for UNBOUND image-backed descriptors -------------------------
         // GL lets a program declare `samplerBuffer`, `imageBuffer` or `image2D` and bind nothing
         // to the unit it names: the fetch is then undefined (GL 4.6 core 8.9 for an incomplete
@@ -293,6 +303,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VkTextureManager* m_textureManager = nullptr;
         VkSamplerManager* m_samplerManager = nullptr;
         mutable SharedPtr<MG_State::GLState::ITextureObject> m_fallbackTexture2D;
+        // Keyed by (arrayed, numeric domain); see GetFallbackMultisampleTexture. Lazily populated,
+        // never evicted - at most six tiny 1x1 images - and torn down with the manager.
+        mutable UnorderedMap<Uint32, SharedPtr<MG_State::GLState::ITextureObject>> m_fallbackMultisampleTextures;
         // See AcquireUnboundTexelBufferView / GetUnboundStorageImageTexture. Both are lazily
         // populated, never evicted (a program's declared formats are a fixed, tiny set) and torn
         // down with the manager. The texel views are keyed by format AND by storage-vs-sampled

MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateFactory.h

@@ -130,7 +130,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // stale memo.
         //
         // Drawn from a process-wide source, never a per-instance counter: the VAO
-        // memos outlive this factory (they live on pGLContext's VAOs, the renderer
+        // memos outlive this factory (they live on the frontend context's VAOs, the renderer
         // is destroyed and recreated on EGL surface release/re-create), so a fresh
         // factory restarting at a dead factory's epoch value would honor its
         // dangling entry pointers. The constructor takes a value strictly greater

MobileGL/MG_Backend/DirectVulkan/Renderer/VkBufferManager.cpp

@@ -10,6 +10,8 @@
 #include "../DirectVulkan.h"
 #include "VulkanRenderer.h"
 
+#include "MG_Util/Metrics/PipeStats.h"
+
 namespace MobileGL::MG_Backend::DirectVulkan {
     namespace {
         constexpr VmaAllocationCreateFlags kResidentBufferAllocationFlags =
@@ -229,8 +231,38 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     Bool VkBufferManager::UploadTransient(BufferKind kind, Uint32 frameIndex, const void* data,
                                           VkDeviceSize size, VkDeviceSize alignment, BufferSlice& outSlice) {
-        (void)kind;
-        return m_transientUploadArena.Upload(frameIndex, data, size, alignment, outSlice);
+        if (!m_transientUploadArena.Upload(frameIndex, data, size, alignment, outSlice)) {
+            return false;
+        }
+        if (MG_Util::PipeStats::Enabled()) {
+            // The single chokepoint for Magma's per-draw staging. Uniform is deliberately
+            // absent: its bytes are counted by the caller, which is the only place that
+            // knows whether the payload is the default block (stage-ubo-global) or a named
+            // one repacked into the ring (stage-ubo-named), and counting here as well would
+            // double every uniform byte.
+            switch (kind) {
+            case BufferKind::Vertex:
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageVertexClient,
+                                             static_cast<Uint64>(size));
+                break;
+            case BufferKind::Index:
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageIndexClient,
+                                             static_cast<Uint64>(size));
+                break;
+            case BufferKind::Indirect:
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageIndirectCmd,
+                                             static_cast<Uint64>(size));
+                break;
+            case BufferKind::TextureBuffer:
+            case BufferKind::ShaderStorage:
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer,
+                                             static_cast<Uint64>(size));
+                break;
+            case BufferKind::Uniform:
+                break;
+            }
+        }
+        return true;
     }
 
     Bool VkBufferManager::InitializeTransientArenas() {
@@ -339,6 +371,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             resource.pendingFullUpload = true;
             return false;
         }
+        if (MG_Util::PipeStats::Enabled()) {
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer, static_cast<Uint64>(size));
+        }
         resource.pendingFullUpload = false;
         return true;
     }
@@ -353,6 +388,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                            static_cast<VkDeviceSize>(size), 16, staging)) {
             return false;
         }
+        if (MG_Util::PipeStats::Enabled()) {
+            // The staging fill is the host copy; the vkCmdCopyBuffer below is the device
+            // half of the same bytes and is not counted twice.
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer, static_cast<Uint64>(size));
+        }
         VkCommandBuffer commandBuffer = m_copyProvider->AcquireBufferCopyCommandBuffer();
         if (commandBuffer == VK_NULL_HANDLE) {
             return false;
@@ -422,6 +462,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (!resource->buffer.Upload(bufferObject.MappedData(), size, 0)) {
             MGLOG_E_ONCE("VkBufferManager::OnRespecify: in-place upload failed");
             resource->pendingFullUpload = true;
+        } else if (MG_Util::PipeStats::Enabled()) {
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer, static_cast<Uint64>(size));
         }
     }
 
@@ -447,6 +489,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                          static_cast<VkDeviceSize>(size), static_cast<VkDeviceSize>(offset))) {
                 MGLOG_E_ONCE("VkBufferManager::OnSubData: host upload failed");
                 resource->pendingFullUpload = true;
+            } else if (MG_Util::PipeStats::Enabled()) {
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer,
+                                             static_cast<Uint64>(size));
             }
             return;
         }
@@ -484,6 +529,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                          static_cast<VkDeviceSize>(size), static_cast<VkDeviceSize>(offset))) {
                 MGLOG_E_ONCE("VkBufferManager::OnFlushMappedRange: host upload failed");
                 resource->pendingFullUpload = true;
+            } else if (MG_Util::PipeStats::Enabled()) {
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer,
+                                             static_cast<Uint64>(size));
             }
             return;
         }
@@ -554,6 +602,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const Uint8* seed = bufferObject.MappedData();
         if (seed != nullptr) {
             resource->buffer.Upload(seed, size, 0);
+            if (MG_Util::PipeStats::Enabled()) {
+                // The one-time seed of a persistent map. Everything the app writes AFTER
+                // this goes straight through the mapping and is persistent-map-push
+                // territory (unwired, D4/D-B4), not this class.
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer,
+                                             static_cast<Uint64>(size));
+            }
         }
         resource->persistentMapped = true;
         resource->pendingFullUpload = false;
@@ -602,6 +657,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 resource->usageFlags = 0;
                 return false;
             }
+            if (MG_Util::PipeStats::Enabled()) {
+                MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer,
+                                             static_cast<Uint64>(size));
+            }
             resource->pendingFullUpload = false;
         }
 
@@ -681,6 +740,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                            outSlice)) {
             return false;
         }
+        if (MG_Util::PipeStats::Enabled()) {
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageBuffer, static_cast<Uint64>(size));
+        }
         resource->transientSlice = outSlice;
         resource->transientFrameSerial = m_frameSerial;
         resource->transientChangeSerial = changeSerial;

MobileGL/MG_Backend/DirectVulkan/Renderer/VkClearManager.cpp

@@ -8,7 +8,12 @@
 
 #include "VkClearManager.h"
 
+// For the shared ResolveAttachmentLayerCount (and the ToVulkanLevelExtent it is built on): the
+// clear key's layer span has to be the same one the render pass builds its attachment view from.
+#include "VkTextureManager.h"
+
 #include "MG_State/GLState/Core.h"
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include "MG_Util/Converters/MGToStr/FramebufferEnumConverter.h"
 #include "MG_Util/Converters/MGToStr/TextureEnumConverter.h"
 
@@ -50,7 +55,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (payload.colorEncoding != ClearColorEncoding::Float) return;
         // With GL_FRAMEBUFFER_SRGB enabled GL performs the encoding itself, so the driver doing it
         // is exactly right and there is nothing to undo.
-        if (MG_State::pGLContext->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb)) return;
+        if (MGB_CTX->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb)) return;
         if (ResolveSrgbAttachmentWriteFormat(destinationFormat, false) == destinationFormat) return;
 
         // sRGB -> linear (GL 4.6 core 8.24), applied to the colour channels only: alpha is stored
@@ -100,13 +105,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return ResolveAttachmentBaseArrayLayer(uploadTarget);
     }
 
-    static Uint32 ResolveAttachmentLayerCount(
-        const MG_State::GLState::FramebufferAttachmentObject& attachment) {
-        if (attachment.IsLayered()) {
-            return static_cast<Uint32>(std::max(attachment.GetSize().z(), 1));
-        }
-        return 1u;
-    }
+    // ResolveAttachmentLayerCount used to be duplicated here, reading attachment.GetSize().z()
+    // raw - no ToVulkanLevelExtent remap for a 1D array, no six-faces arm for a cube map. That is
+    // not a cosmetic difference: the count below is not key-only, it is written straight into
+    // VkImageSubresourceRange::layerCount by MaterializePendingClearForTexture, which then POPS
+    // the entry - so a layered cube map's glClear reached one face and the other five were lost
+    // for good, while the very same queued clear cleared all six through the render pass's
+    // LOAD_OP_CLEAR. The helper now lives once, in VkTextureManager.h beside ToVulkanLevelExtent.
 
     static const MG_State::GLState::FramebufferAttachmentObject* GetClearableAttachment(
         const MG_State::GLState::FramebufferObject& drawFbo, FramebufferAttachmentType attachmentType) {

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.cpp

@@ -13,6 +13,7 @@
 #include "MG_Util/Converters/MGToStr/FramebufferEnumConverter.h"
 #include "MG_Util/Converters/MGToVk/TextureEnumConverter.h"
 #include "MG_Util/Metrics/TextureMetrics.h"
+#include <MG_Pipe/PipeInputsSwitch.h>
 
 namespace MobileGL::MG_Backend::DirectVulkan {
     static Bool TryResolveSampleCountFlagBits(Int requestedSamples, VkSampleCountFlagBits& outSampleCount) {
@@ -86,25 +87,39 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return ToStorageArrayLayer(texture, face);
     }
 
-    // The attachment's size is GL geometry, and GL_TEXTURE_1D_ARRAY keeps its layer count in the
-    // state-side HEIGHT rather than in z (see ToVulkanLevelExtent, which exists for exactly this
-    // remap). Reading z directly gave every layered 1D-array attachment layerCount = 1, so a
-    // geometry shader writing gl_Layer = 1..n had its output silently dropped and the parent's
-    // upper layers were never written at all.
-    static Uint32 ResolveAttachmentLayerCount(const MG_State::GLState::FramebufferAttachmentObject& attachment) {
-        if (attachment.IsLayered()) {
-            const auto& texture = attachment.GetTexture();
-            const TextureTarget target = texture != nullptr ? texture->GetTarget() : TextureTarget::Unknown;
-            return static_cast<Uint32>(std::max(ToVulkanLevelExtent(target, attachment.GetSize()).z(), 1));
-        }
-        return 1u;
-    }
+    // ResolveAttachmentLayerCount lives in VkTextureManager.h, beside ToVulkanLevelExtent, because
+    // VkClearManager needs the SAME answer: its pending-clear key's layerCount becomes a real
+    // VkImageSubresourceRange when a clear is materialised outside a render pass. See the header.
 
+    // VUID-VkFramebufferCreateInfo-flags-04113: every view handed to vkCreateFramebuffer must have
+    // been created as VK_IMAGE_VIEW_TYPE_2D or VK_IMAGE_VIEW_TYPE_2D_ARRAY. The image's OWN view
+    // type is not a legal answer for several of the targets GL can attach, and returning it
+    // unchanged is what took the process down on every layered 3D / cube-map-array attachment:
+    // a 3D view is refused outright by the layer-span guard in GetOrCreateAttachmentViewAtMipLevel
+    // (3D images have arrayLayers == 1) and a CUBE_ARRAY view is built happily and then rejected -
+    // or dereferenced - by the driver inside vkCreateFramebuffer.
+    //
+    // A 2D_ARRAY view is the legal spelling of all three: over a 2D-array-compatible 3D image its
+    // "layers" are the mip's z slices (VUID-VkImageViewCreateInfo-image-04970), and over a
+    // CUBE_COMPATIBLE 2D image - which is what both cube targets are - its layers are the faces.
+    //
+    // Knowingly NOT remapped: VK_IMAGE_VIEW_TYPE_1D / _1D_ARRAY, which 04113 also forbids. There is
+    // no legal alternative for them (a VK_IMAGE_TYPE_1D image admits no 2D-family view at all), so
+    // the only honest answer would be to decline the attachment - and every driver this has run on,
+    // lavapipe included, accepts them. Declining would turn working GL_TEXTURE_1D[_ARRAY] render
+    // targets into skipped draws to satisfy a VU nothing enforces. Left as-is, deliberately.
     static VkImageViewType ResolveAttachmentViewType(
         const MG_State::GLState::FramebufferAttachmentObject& attachment,
         const VkTextureManager::TextureResource& resource) {
         if (attachment.IsLayered()) {
-            return resource.viewType;
+            switch (resource.viewType) {
+            case VK_IMAGE_VIEW_TYPE_3D:
+            case VK_IMAGE_VIEW_TYPE_CUBE:
+            case VK_IMAGE_VIEW_TYPE_CUBE_ARRAY:
+                return VK_IMAGE_VIEW_TYPE_2D_ARRAY;
+            default:
+                return resource.viewType;
+            }
         }
         // A non-layered attachment names ONE layer, so the view over it is a plain 2D view whatever
         // the image's own view type is. The cube-face upload targets always meant this; a cube map
@@ -112,8 +127,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // a single layer is not a legal attachment. The CUBE arm is inert today - no frontend path
         // produces a non-layered cube attachment without a face upload target - and is kept for
         // symmetry with CUBE_ARRAY.
+        //
+        // 3D belongs in the same list and was missing from it, which is why the "per-slice
+        // attachment view is a 2D view whose array layer is the slice" branch in
+        // GetOrCreateAttachmentViewAtMipLevel was unreachable: glFramebufferTextureLayer on a
+        // GL_TEXTURE_3D asked for a 3D view (illegal as an attachment) whose span was then checked
+        // against arrayLayers == 1, so every slice above z = 0 came back VK_NULL_HANDLE.
         if (IsCubeMapFaceUploadTarget(attachment.GetTextureUploadTarget()) ||
-            resource.viewType == VK_IMAGE_VIEW_TYPE_CUBE_ARRAY || resource.viewType == VK_IMAGE_VIEW_TYPE_CUBE) {
+            resource.viewType == VK_IMAGE_VIEW_TYPE_CUBE_ARRAY || resource.viewType == VK_IMAGE_VIEW_TYPE_CUBE ||
+            resource.viewType == VK_IMAGE_VIEW_TYPE_3D) {
             return VK_IMAGE_VIEW_TYPE_2D;
         }
         return resource.viewType;
@@ -334,47 +356,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
 
         const auto internalFormat = renderbuffer->GetInternalFormat();
-        // Three-channel color formats widen to their RGBA twin exactly like textures do
-        // (VkTextureManager::ResolveTextureFormatInfo): blits/resolves between a
-        // renderbuffer and a texture of the same GL format then see one VkFormat.
-        const VkFormat format = [&]() -> VkFormat {
-            switch (internalFormat) {
-            case TextureInternalFormat::RGB:
-            case TextureInternalFormat::RGB8:
-            case TextureInternalFormat::R3G3B2:
-            case TextureInternalFormat::RGB4:
-            case TextureInternalFormat::RGB5:
-                return VK_FORMAT_R8G8B8A8_UNORM;
-            case TextureInternalFormat::SRGB8:
-                return VK_FORMAT_R8G8B8A8_SRGB;
-            case TextureInternalFormat::RGB8Snorm:
-                return VK_FORMAT_R8G8B8A8_SNORM;
-            case TextureInternalFormat::RGB10:
-            case TextureInternalFormat::RGB12:
-            case TextureInternalFormat::RGB16:
-                return VK_FORMAT_R16G16B16A16_UNORM;
-            case TextureInternalFormat::RGB16Snorm:
-                return VK_FORMAT_R16G16B16A16_SNORM;
-            case TextureInternalFormat::RGB16F:
-                return VK_FORMAT_R16G16B16A16_SFLOAT;
-            case TextureInternalFormat::RGB32F:
-                return VK_FORMAT_R32G32B32A32_SFLOAT;
-            case TextureInternalFormat::RGB8I:
-                return VK_FORMAT_R8G8B8A8_SINT;
-            case TextureInternalFormat::RGB8UI:
-                return VK_FORMAT_R8G8B8A8_UINT;
-            case TextureInternalFormat::RGB16I:
-                return VK_FORMAT_R16G16B16A16_SINT;
-            case TextureInternalFormat::RGB16UI:
-                return VK_FORMAT_R16G16B16A16_UINT;
-            case TextureInternalFormat::RGB32I:
-                return VK_FORMAT_R32G32B32A32_SINT;
-            case TextureInternalFormat::RGB32UI:
-                return VK_FORMAT_R32G32B32A32_UINT;
-            default:
-                return MG_Util::ConvertTextureInternalFormatToVkEnum(internalFormat);
-            }
-        }();
+        // ONE resolver, shared with textures (VkTextureManager::ResolveTextureFormatInfo), so a
+        // renderbuffer and a texture of the same GL format cannot disagree about their VkFormat.
+        // `expandRgbToRgba` / `componentByteCount` / `alphaBytes` describe how to reshape a SHADOW
+        // UPLOAD, and a renderbuffer has none, so only `.format` is taken.
+        //
+        // This used to be a hand-maintained second copy of that table, and it was missing exactly
+        // four rows: RGBA2 and RGBA12 fell through to ConvertTextureInternalFormatToVkEnum's
+        // VK_FORMAT_UNDEFINED (no image at all - bound as a draw buffer the attachment became
+        // VK_ATTACHMENT_UNUSED and every draw into it was dropped), while RGBA4 and RGB5A1 fell
+        // through to the 16-bit packed formats and then faced 32-bit R8G8B8A8_UNORM textures across
+        // a size-incompatible vkCmdCopyImage.
+        const VkFormat format = ResolveTextureFormatInfo(internalFormat).format;
         const VkImageAspectFlags aspect = ResolveImageAspectMaskForFormat(format);
         // Renderbuffers are never sampled (GL has no way to bind one to a sampler), so the
         // usage set is attachment + transfer: transfer covers readback (vkCmdCopyImageToBuffer),
@@ -618,7 +611,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // sRGB attachments switch between their sRGB and UNORM-twin views with this
         // capability (ResolveSrgbAttachmentWriteFormat), changing the render pass formats.
         const Bool framebufferSrgbEnabled =
-            MG_State::pGLContext->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb);
+            MGB_CTX->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb);
         XXHASH_VERIFY(XXH64_update(m_hashState, &framebufferSrgbEnabled, sizeof(framebufferSrgbEnabled)));
         auto& drawBuffers = fbo.GetDrawBuffers();
         XXHASH_VERIFY(XXH64_update(m_hashState, drawBuffers.data(), drawBuffers.size() * sizeof(drawBuffers[0])));
@@ -772,7 +765,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return XXH64_digest(m_hashState);
     }
 
-    RenderPassEntry& VkRenderPassManager::GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo,
+    RenderPassEntry* VkRenderPassManager::GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo,
                                                                 Uint32 swapchainImageIndex,
                                                                 Bool drawUsesDepthStencil) {
         // Resolve the default-FBO depth flavor (see the header comment): keep the
@@ -858,7 +851,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             auto activeIt = m_renderPasses.find(activeRenderPass->hash);
             if (activeIt != m_renderPasses.end()) {
                 activeIt->second.lastUsedFrame = m_frameCounter;
-                return activeIt->second;
+                return &activeIt->second;
             }
         }
 
@@ -882,13 +875,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             m_rpFastRenderPassHash = activeRenderPass->hash;
             m_rpFastHadDepthStencil = activeIt->second.hasDepthStencilAttachment;
             activeIt->second.lastUsedFrame = m_frameCounter;
-            return activeIt->second;
+            return &activeIt->second;
         }
         auto hash = ComputeHash(fbo, swapchainImageIndex, true, includeDefaultFboDepthStencil);
         auto it = m_renderPasses.find(hash);
         if (it != m_renderPasses.end()) {
             it->second.lastUsedFrame = m_frameCounter;
-            return it->second;
+            return &it->second;
         }
 
         Bool isDefaultFbo = fbo.IsDefaultFramebuffer();
@@ -970,7 +963,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
                     const VkImageLayout trackedRbLayout = rbResource->layout;
                     const Bool rbFramebufferSrgb =
-                        MG_State::pGLContext->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb);
+                        MGB_CTX->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb);
                     const VkFormat rbAttachmentFormat =
                         ResolveSrgbAttachmentWriteFormat(rbResource->format, rbFramebufferSrgb);
                     rbDesc.flags = 0;
@@ -1011,8 +1004,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                     textureResources.emplace_back(nullptr);
                     attachmentViews.emplace_back(rbAttachmentFormat != rbResource->format ? rbResource->unormTwinView
                                                                                           : rbResource->view);
-                    MOBILEGL_ASSERT(attachmentViews.back() != VK_NULL_HANDLE,
-                                    "GetOrCreateRenderPass: renderbuffer view missing at color attachment %d", i);
+                    if (attachmentViews.back() == VK_NULL_HANDLE) {
+                        MGLOG_E_ONCE("GetOrCreateRenderPass: renderbuffer %u has no usable view for color attachment "
+                                     "%u on FBO %u; declining the render pass",
+                                     renderbuffer->GetExternalIndex(), i, fbo.GetExternalIndex());
+                        return nullptr;
+                    }
 
                     colorAttachmentRefs[i].attachment = rbAttachmentIndex;
                     continue;
@@ -1100,12 +1097,19 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                         attachmentViews.emplace_back(swapchainViews[swapchainImageIndex]);
                     } else {
                         auto* textureResource = m_textureManager.SyncTextureAndGetDescriptor(*texture);
-                        MOBILEGL_ASSERT(textureResource,
-                                        "GetOrCreateRenderPass: SyncTextureAndGetDescriptor failed at color attachment %d", i);
+                        if (textureResource == nullptr) {
+                            // SyncTextureResource legitimately declines - an unsupported format,
+                            // sample count or image-flag combination, or a vkCreateImage the driver
+                            // refused. There is no image to attach, so there is no render pass.
+                            MGLOG_E_ONCE("GetOrCreateRenderPass: textureId=%d could not be backed for color "
+                                         "attachment %u on FBO %u; declining the render pass",
+                                         texture->GetExternalIndex(), i, fbo.GetExternalIndex());
+                            return nullptr;
+                        }
                         textureResources.emplace_back(textureResource);
                         desc.format = ResolveSrgbAttachmentWriteFormat(
                             textureResource->format,
-                            MG_State::pGLContext->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb));
+                            MGB_CTX->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb));
                         attachmentSampleCount = textureResource->sampleCount;
                         trackedColorLayout = textureResource->layout;
                         trackedAttachmentLayouts.emplace_back(TrackedAttachmentLayoutInfo {
@@ -1122,8 +1126,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                         attachmentViews.emplace_back(
                             m_textureManager.GetOrCreateAttachmentViewAtMipLevel(
                                 *texture, attachmentMipLevel, baseArrayLayer, layerCount, attachmentViewType));
-                        MOBILEGL_ASSERT(attachmentViews.back() != VK_NULL_HANDLE,
-                                        "GetOrCreateRenderPass: GetOrCreateAttachmentView failed at color attachment %d", i);
+                        if (attachmentViews.back() == VK_NULL_HANDLE) {
+                            MGLOG_E_ONCE("GetOrCreateRenderPass: no attachment view for textureId=%d mip=%u layers "
+                                         "[%u, %u) viewType=%d at color attachment %u on FBO %u; declining the "
+                                         "render pass",
+                                         texture->GetExternalIndex(), attachmentMipLevel, baseArrayLayer,
+                                         baseArrayLayer + layerCount, static_cast<Int>(attachmentViewType), i,
+                                         fbo.GetExternalIndex());
+                            return nullptr;
+                        }
                     }
                     desc.samples = attachmentSampleCount;
                     adoptRenderPassSampleCount(attachmentSampleCount, "color", texture->GetExternalIndex());
@@ -1216,8 +1227,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             } else if (selectedDepthStencilAttachment->IsTexture()) {
                 auto& texture = *selectedDepthStencilAttachment->GetTexture();
                 depthTextureResource = m_textureManager.SyncTextureAndGetDescriptor(texture);
-                MOBILEGL_ASSERT(depthTextureResource,
-                                "GetOrCreateRenderPass: SyncTextureAndGetDescriptor failed at depth attachment");
+                if (depthTextureResource == nullptr) {
+                    MGLOG_E_ONCE("GetOrCreateRenderPass: textureId=%d could not be backed for the depth/stencil "
+                                 "attachment of FBO %u; declining the render pass",
+                                 texture.GetExternalIndex(), fbo.GetExternalIndex());
+                    return nullptr;
+                }
                 trackedDepthLayout = depthTextureResource->layout;
                 depthAttachmentDescription.format = depthTextureResource->format;
                 depthAttachmentSampleCount = depthTextureResource->sampleCount;
@@ -1229,8 +1244,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             } else {
                 const auto& renderbuffer = selectedDepthStencilAttachment->GetRenderbuffer();
                 depthRenderbufferResource = GetOrCreateRenderbufferResource(renderbuffer);
-                MOBILEGL_ASSERT(depthRenderbufferResource,
-                                "GetOrCreateRenderPass: GetOrCreateRenderbufferResource failed at depth attachment");
+                if (depthRenderbufferResource == nullptr) {
+                    MGLOG_E_ONCE("GetOrCreateRenderPass: renderbuffer %u could not be backed for the depth/stencil "
+                                 "attachment of FBO %u; declining the render pass",
+                                 renderbuffer->GetExternalIndex(), fbo.GetExternalIndex());
+                    return nullptr;
+                }
                 trackedDepthLayout = depthRenderbufferResource->layout;
                 depthAttachmentDescription.format = depthRenderbufferResource->format;
                 depthAttachmentSampleCount = depthRenderbufferResource->sampleCount;
@@ -1304,8 +1323,14 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 attachmentViews.emplace_back(
                     m_textureManager.GetOrCreateAttachmentViewAtMipLevel(
                         texture, attachmentMipLevel, baseArrayLayer, layerCount, attachmentViewType));
-                MOBILEGL_ASSERT(attachmentViews.back() != VK_NULL_HANDLE,
-                                "GetOrCreateRenderPass: GetOrCreateAttachmentView failed at depth attachment");
+                if (attachmentViews.back() == VK_NULL_HANDLE) {
+                    MGLOG_E_ONCE("GetOrCreateRenderPass: no attachment view for textureId=%d mip=%u layers [%u, %u) "
+                                 "viewType=%d at the depth/stencil attachment of FBO %u; declining the render pass",
+                                 texture.GetExternalIndex(), attachmentMipLevel, baseArrayLayer,
+                                 baseArrayLayer + layerCount, static_cast<Int>(attachmentViewType),
+                                 fbo.GetExternalIndex());
+                    return nullptr;
+                }
                 if (width == 0 || height == 0) {
                     width = attachmentExtent.x();
                     height = attachmentExtent.y();
@@ -1327,6 +1352,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 });
                 textureResources.emplace_back(nullptr);
                 attachmentViews.emplace_back(depthRenderbufferResource->view);
+                if (attachmentViews.back() == VK_NULL_HANDLE) {
+                    MGLOG_E_ONCE("GetOrCreateRenderPass: renderbuffer %u has no usable view for the depth/stencil "
+                                 "attachment of FBO %u; declining the render pass",
+                                 renderbuffer->GetExternalIndex(), fbo.GetExternalIndex());
+                    return nullptr;
+                }
                 if (width == 0 || height == 0) {
                     width = attachmentExtent.x();
                     height = attachmentExtent.y();
@@ -1424,8 +1455,25 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         renderPassCreateInfo.dependencyCount = 2;
         renderPassCreateInfo.pDependencies = subpassDependencies;
 
+        // NOT VK_VERIFY. VkIncludes.h states the rule this function now lives by: VK_VERIFY is the
+        // INVARIANT check - a should-never-happen state, fatal-logged unlatched and trapped in a
+        // DEBUG build - and "a soft, recoverable failure must therefore NOT be routed through
+        // VK_VERIFY. Check the VkResult directly and report it with MGLOG_E_ONCE". A decline here
+        // is recoverable by construction: the caller drops the draw. Routing it through VK_VERIFY
+        // would have made the recovery dead code in a DEBUG build (the TRAP fires inside the macro,
+        // before the handle is ever examined) and, in an INFO build, printed an UNLATCHED fatal
+        // line on every draw for the life of the process - a decline caches nothing, so every
+        // later draw to the same framebuffer re-enters this path and fails again.
         VkRenderPass renderPass = VK_NULL_HANDLE;
-        VK_VERIFY(vkCreateRenderPass(m_device, &renderPassCreateInfo, nullptr, &renderPass));
+        const VkResult renderPassResult =
+            vkCreateRenderPass(m_device, &renderPassCreateInfo, nullptr, &renderPass);
+        if (renderPassResult != VK_SUCCESS || renderPass == VK_NULL_HANDLE) {
+            MGLOG_E_ONCE("GetOrCreateRenderPass: vkCreateRenderPass failed (%s, %d) for FBO %u; declining the "
+                         "render pass",
+                         VkResultToString(renderPassResult), static_cast<Int>(renderPassResult),
+                         fbo.GetExternalIndex());
+            return nullptr;
+        }
 
         // Framebuffer
         VkFramebufferCreateInfo framebufferCreateInfo;
@@ -1438,8 +1486,21 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         framebufferCreateInfo.width = width;
         framebufferCreateInfo.height = height;
         framebufferCreateInfo.layers = framebufferLayers;
+        // Direct VkResult check, for the same reason as vkCreateRenderPass above.
         VkFramebuffer framebuffer = VK_NULL_HANDLE;
-        VK_VERIFY(vkCreateFramebuffer(m_device, &framebufferCreateInfo, nullptr, &framebuffer));
+        const VkResult framebufferResult =
+            vkCreateFramebuffer(m_device, &framebufferCreateInfo, nullptr, &framebuffer);
+        if (framebufferResult != VK_SUCCESS || framebuffer == VK_NULL_HANDLE) {
+            // The render pass has no entry to own it yet, so it is destroyed here rather than
+            // leaked - RenderPassEntry's destructor is the only other thing that would.
+            MGLOG_E_ONCE("GetOrCreateRenderPass: vkCreateFramebuffer failed (%s, %d) for FBO %u (%dx%d, "
+                         "%u attachments, %u layers); declining the render pass",
+                         VkResultToString(framebufferResult), static_cast<Int>(framebufferResult),
+                         fbo.GetExternalIndex(), width, height,
+                         static_cast<Uint32>(attachmentViews.size()), framebufferLayers);
+            vkDestroyRenderPass(m_device, renderPass, nullptr);
+            return nullptr;
+        }
         IntVec2 extent = {width, height};
         RenderPassEntry renderPassEntry {
             hash,
@@ -1464,7 +1525,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 extent.y());
         auto [insertedIt, _] = m_renderPasses.emplace(hash, Move(renderPassEntry));
         insertedIt->second.lastUsedFrame = m_frameCounter;
-        return insertedIt->second;
+        return &insertedIt->second;
     }
 
     void VkRenderPassManager::OnPresent() {

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.h

@@ -243,9 +243,24 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // draw against a depth-less active pass resolves to a new (incompatible)
         // entry, which the caller's compatibility check turns into a pass split;
         // the new pass's depth loads DONT_CARE (content was undefined all along).
-        RenderPassEntry& GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo,
-                                               Uint32 swapchainImageIndex,
-                                               Bool drawUsesDepthStencil = true);
+        //
+        // Returns NULLPTR when this framebuffer cannot be represented as a Vulkan render pass at
+        // all - a texture the texture manager declined to back (an unsupported format or sample
+        // count), or an attachment view it cannot construct (a layer span the image has no room
+        // for, a 3D image whose format was refused 2D-array compatibility). This used to be
+        // unrepresentable: the function returned a reference, so the only thing the two fallible
+        // calls it builds on could do was trip a MOBILEGL_ASSERT - which is compiled out of every
+        // INFO build - and then dereference the null resource, or hand VK_NULL_HANDLE to
+        // vkCreateFramebuffer. That took the whole process down (51 lost CTS records over 21
+        // bodies, one runner restart each) where a declined draw is merely a wrong picture.
+        //
+        // EVERY caller must handle nullptr by dropping the operation, exactly as the draw path
+        // already drops a draw whose sampler descriptor could not be resolved
+        // (UniformManager::BindProgramUniformBuffers). The failure paths log MGLOG_E_ONCE
+        // themselves, so a caller needs no message of its own.
+        [[nodiscard]] RenderPassEntry* GetOrCreateRenderPass(const MG_State::GLState::FramebufferObject& fbo,
+                                                             Uint32 swapchainImageIndex,
+                                                             Bool drawUsesDepthStencil = true);
         void QueueRenderbufferClear(GLbitfield mask, const ClearFramebufferPayload& clearPayload,
                                     const MG_State::GLState::FramebufferObject& drawFbo);
         void QueueRenderbufferClear(const ClearAttachmentPayload& clearPayload,

MobileGL/MG_Backend/DirectVulkan/Renderer/VkSamplerManager.cpp

@@ -21,6 +21,156 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                    sampler.GetWrapR() == SamplerWrapMode::ClampToBorder;
         }
 
+        // The numeric domain the texture is SAMPLED in. Vulkan splits VkBorderColor into a float
+        // family and an integer family and requires the sampler's choice to match the image view's
+        // format (a float border on an integer view, or the reverse, is undefined) - so the domain
+        // comes from the TEXTURE, while the value comes from whichever GL entry point wrote it.
+        enum class BorderColorDomain {
+            Float,
+            SignedInteger,
+            UnsignedInteger
+        };
+
+        BorderColorDomain ResolveBorderColorDomain(TextureInternalFormat format) {
+            switch (format) {
+            case TextureInternalFormat::R8I:
+            case TextureInternalFormat::R16I:
+            case TextureInternalFormat::R32I:
+            case TextureInternalFormat::RG8I:
+            case TextureInternalFormat::RG16I:
+            case TextureInternalFormat::RG32I:
+            case TextureInternalFormat::RGB8I:
+            case TextureInternalFormat::RGB16I:
+            case TextureInternalFormat::RGB32I:
+            case TextureInternalFormat::RGBA8I:
+            case TextureInternalFormat::RGBA16I:
+            case TextureInternalFormat::RGBA32I:
+                return BorderColorDomain::SignedInteger;
+            case TextureInternalFormat::R8UI:
+            case TextureInternalFormat::R16UI:
+            case TextureInternalFormat::R32UI:
+            case TextureInternalFormat::RG8UI:
+            case TextureInternalFormat::RG16UI:
+            case TextureInternalFormat::RG32UI:
+            case TextureInternalFormat::RGB8UI:
+            case TextureInternalFormat::RGB16UI:
+            case TextureInternalFormat::RGB32UI:
+            case TextureInternalFormat::RGBA8UI:
+            case TextureInternalFormat::RGBA16UI:
+            case TextureInternalFormat::RGBA32UI:
+            case TextureInternalFormat::RGB10A2UI:
+                return BorderColorDomain::UnsignedInteger;
+            default:
+                return BorderColorDomain::Float;
+            }
+        }
+
+        Bool IsSignedNormalizedFormat(TextureInternalFormat format) {
+            switch (format) {
+            case TextureInternalFormat::R8Snorm:
+            case TextureInternalFormat::R16Snorm:
+            case TextureInternalFormat::RG8Snorm:
+            case TextureInternalFormat::RG16Snorm:
+            case TextureInternalFormat::RGB8Snorm:
+            case TextureInternalFormat::RGB16Snorm:
+            case TextureInternalFormat::RGBA8Snorm:
+            case TextureInternalFormat::RGBA16Snorm:
+                return true;
+            default:
+                return false;
+            }
+        }
+
+        // GL 4.6 core 8.14.2: "The border values are clamped before they are used, according to the
+        // format in which texture components are stored. For signed and unsigned normalized
+        // fixed-point formats, border values are clamped to [-1,1] and [0,1] respectively. For
+        // floating-point and integer formats, border values are clamped to the representable range of
+        // the format." Every clause of that sentence is a real case here - the clamp is not just the
+        // normalized one.
+        //
+        // Only the 32-bit float formats are genuinely unclamped: every finite float is representable
+        // in them. Half-float has a finite maximum, and the two packed "float" formats are UNSIGNED,
+        // so a negative border on them must come back as 0 rather than as a negative number the
+        // driver delivers verbatim through VK_BORDER_COLOR_FLOAT_CUSTOM_EXT.
+        struct FloatBorderRange {
+            Bool clamped = true;
+            Float minValue = 0.0f;
+            Float maxValue = 1.0f;
+        };
+
+        FloatBorderRange ResolveFloatBorderRange(TextureInternalFormat format, Bool isSignedNormalized) {
+            switch (format) {
+            case TextureInternalFormat::R32F:
+            case TextureInternalFormat::RG32F:
+            case TextureInternalFormat::RGB32F:
+            case TextureInternalFormat::RGBA32F:
+                return {false, 0.0f, 0.0f};
+            case TextureInternalFormat::R16F:
+            case TextureInternalFormat::RG16F:
+            case TextureInternalFormat::RGB16F:
+            case TextureInternalFormat::RGBA16F:
+                return {true, -65504.0f, 65504.0f};
+            // Unsigned packed floats: no sign bit at all. 65024 is the largest 11-bit float; the
+            // 10-bit blue channel tops out lower (64512) and RGB9E5 higher (65408), but the bound
+            // that matters for correctness is the lower one, and a single conservative upper bound
+            // costs nothing a real border colour will ever notice.
+            case TextureInternalFormat::R11FG11FB10F:
+                return {true, 0.0f, 64512.0f};
+            case TextureInternalFormat::RGB9E5:
+                return {true, 0.0f, 65408.0f};
+            default:
+                return {true, isSignedNormalized ? -1.0f : 0.0f, 1.0f};
+            }
+        }
+
+        // Per-component representable range of an integer texture format, as Int64 so that the whole
+        // signed and unsigned 32-bit ranges are expressible in one type and the clamp can be written
+        // once for both domains. Alpha is carried separately because RGB10_A2UI is the one format
+        // whose alpha is narrower than its colour channels.
+        struct IntegerBorderRange {
+            Int64 rgbMin = 0;
+            Int64 rgbMax = 0;
+            Int64 alphaMin = 0;
+            Int64 alphaMax = 0;
+        };
+
+        IntegerBorderRange ResolveIntegerBorderRange(TextureInternalFormat format) {
+            const auto uniform = [](Int64 low, Int64 high) { return IntegerBorderRange{low, high, low, high}; };
+            switch (format) {
+            case TextureInternalFormat::R8I:
+            case TextureInternalFormat::RG8I:
+            case TextureInternalFormat::RGB8I:
+            case TextureInternalFormat::RGBA8I:
+                return uniform(-128, 127);
+            case TextureInternalFormat::R16I:
+            case TextureInternalFormat::RG16I:
+            case TextureInternalFormat::RGB16I:
+            case TextureInternalFormat::RGBA16I:
+                return uniform(-32768, 32767);
+            case TextureInternalFormat::R8UI:
+            case TextureInternalFormat::RG8UI:
+            case TextureInternalFormat::RGB8UI:
+            case TextureInternalFormat::RGBA8UI:
+                return uniform(0, 255);
+            case TextureInternalFormat::R16UI:
+            case TextureInternalFormat::RG16UI:
+            case TextureInternalFormat::RGB16UI:
+            case TextureInternalFormat::RGBA16UI:
+                return uniform(0, 65535);
+            case TextureInternalFormat::R32UI:
+            case TextureInternalFormat::RG32UI:
+            case TextureInternalFormat::RGB32UI:
+            case TextureInternalFormat::RGBA32UI:
+                return uniform(0, 4294967295LL);
+            case TextureInternalFormat::RGB10A2UI:
+                return {0, 1023, 0, 3};
+            default:
+                // The signed 32-bit formats, and anything unexpected: the full int32 range, i.e. a
+                // clamp that cannot alter a value the GL entry points could have carried.
+                return uniform(-2147483648LL, 2147483647LL);
+            }
+        }
+
         Bool IsDepthTextureFormat(TextureInternalFormat format) {
             switch (format) {
             case TextureInternalFormat::DepthComponent:
@@ -72,6 +222,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_config = initInfo.config;
         m_samplerAnisotropySupported = initInfo.samplerAnisotropySupported;
         m_maxSamplerAnisotropy = std::max(initInfo.maxSamplerAnisotropy, 1.0f);
+        m_customBorderColorSupported = initInfo.customBorderColorSupported;
+        m_maxCustomBorderColorSamplers = initInfo.maxCustomBorderColorSamplers;
+        m_customBorderColorSamplerCount = 0;
         MOBILEGL_ASSERT(m_device != VK_NULL_HANDLE && m_config != nullptr,
                         "VkSamplerManager::Initialize failed: invalid initialization info");
         return true;
@@ -102,6 +255,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_device = VK_NULL_HANDLE;
         m_config = nullptr;
         m_frameBoundaryCounter = 0;
+        m_customBorderColorSupported = false;
+        m_maxCustomBorderColorSamplers = 0;
+        m_customBorderColorSamplerCount = 0;
     }
 
     void VkSamplerManager::OnFrameBoundary() {
@@ -123,6 +279,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 if (m_device != VK_NULL_HANDLE && entry.handle != VK_NULL_HANDLE) {
                     vkDestroySampler(m_device, entry.handle, nullptr);
                 }
+                if (entry.usesCustomBorderColor && m_customBorderColorSamplerCount > 0) {
+                    --m_customBorderColorSamplerCount;
+                }
                 it = m_samplers.erase(it);
             } else {
                 ++it;
@@ -131,8 +290,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     }
 
     Uint64 VkSamplerManager::BuildSamplerKey(const MG_State::GLState::SamplerObject& sampler,
-                                             const MG_State::GLState::ITextureObject& texture,
-                                             Bool forceNearestFiltering, Bool singleLevelView) const {
+                                             Bool forceNearestFiltering, Bool singleLevelView,
+                                             const ResolvedBorderColor& borderColor) const {
         MOBILEGL_ASSERT(m_config != nullptr, "VkSamplerManager::BuildSamplerKey: m_config is null");
         XXHASH_VERIFY(XXH64_reset(m_hashState, m_config->CacheVersion));
 
@@ -166,8 +325,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         XXHASH_VERIFY(XXH64_update(m_hashState, &compareMode, sizeof(compareMode)));
         const auto compareFunc = sampler.GetSamplerCompareFunc();
         XXHASH_VERIFY(XXH64_update(m_hashState, &compareFunc, sizeof(compareFunc)));
-        const auto borderColor = ResolveVkBorderColor(sampler, texture);
-        XXHASH_VERIFY(XXH64_update(m_hashState, &borderColor, sizeof(borderColor)));
+        // The resolved enum AND, when it is one of the *_CUSTOM_EXT values, the sixteen bytes of the
+        // colour itself: two samplers that differ only in a custom border colour carry the same enum
+        // and would otherwise collide onto whichever one was created first.
+        XXHASH_VERIFY(XXH64_update(m_hashState, &borderColor.color, sizeof(borderColor.color)));
+        if (borderColor.isCustom) {
+            XXHASH_VERIFY(XXH64_update(m_hashState, &borderColor.customValue, sizeof(borderColor.customValue)));
+        }
         return XXH64_digest(m_hashState);
     }
 
@@ -183,7 +347,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // allocation for a genuinely single-level image) and faults the GPU - the same failure
         // the default-framebuffer blit shader had to work around with an explicit-LOD sample.
         const Bool singleLevelView = viewLevelCount == 1;
-        const Uint64 key = BuildSamplerKey(sampler, texture, forceNearestFiltering, singleLevelView);
+        // Resolved once and used for both the key and the create-info; see ResolvedBorderColor.
+        const ResolvedBorderColor borderColor = ResolveBorderColor(sampler, texture);
+        const Uint64 key = BuildSamplerKey(sampler, forceNearestFiltering, singleLevelView, borderColor);
         auto it = m_samplers.find(key);
         if (it != m_samplers.end()) {
             it->second.lastUsedFrameBoundary = m_frameBoundaryCounter;
@@ -211,9 +377,21 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // Must match BuildSamplerKey's resolution exactly.
         samplerInfo.maxLod = ResolveSingleLevelMaxLod(sampler, singleLevelView);
         samplerInfo.minLod = ResolveEffectiveMinLod(sampler, samplerInfo.maxLod);
-        samplerInfo.borderColor = ResolveVkBorderColor(sampler, texture);
+        samplerInfo.borderColor = borderColor.color;
         samplerInfo.unnormalizedCoordinates = VK_FALSE;
 
+        // VK_EXT_custom_border_color. `format` stays UNDEFINED, which is legal only because
+        // customBorderColorWithoutFormat was required alongside customBorderColors at device
+        // creation - a GL sampler object has no idea which texture it will be paired with.
+        VkSamplerCustomBorderColorCreateInfoEXT customBorderColorInfo{};
+        if (borderColor.isCustom) {
+            customBorderColorInfo.sType = VK_STRUCTURE_TYPE_SAMPLER_CUSTOM_BORDER_COLOR_CREATE_INFO_EXT;
+            customBorderColorInfo.customBorderColor = borderColor.customValue;
+            customBorderColorInfo.format = VK_FORMAT_UNDEFINED;
+            customBorderColorInfo.pNext = samplerInfo.pNext;
+            samplerInfo.pNext = &customBorderColorInfo;
+        }
+
         VkSampler vkSampler = VK_NULL_HANDLE;
         VK_VERIFY(vkCreateSampler(m_device, &samplerInfo, nullptr, &vkSampler), "vkCreateSampler(texture)");
 
@@ -222,6 +400,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         entry.externalIndex = sampler.GetExternalIndex();
         entry.version = sampler.GetVersion();
         entry.lastUsedFrameBoundary = m_frameBoundaryCounter;
+        entry.usesCustomBorderColor = borderColor.isCustom;
+        if (entry.usesCustomBorderColor) {
+            ++m_customBorderColorSamplerCount;
+        }
         m_samplers[key] = entry;
         return vkSampler;
     }
@@ -281,39 +463,148 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
     }
 
-    VkBorderColor VkSamplerManager::ResolveVkBorderColor(const MG_State::GLState::SamplerObject& sampler,
-                                                         const MG_State::GLState::ITextureObject& texture) {
+    VkSamplerManager::ResolvedBorderColor VkSamplerManager::ResolveBorderColor(
+        const MG_State::GLState::SamplerObject& sampler, const MG_State::GLState::ITextureObject& texture) const {
+        ResolvedBorderColor resolved{};
         if (!UsesBorderColor(sampler)) {
-            return VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK;
+            return resolved; // FLOAT_TRANSPARENT_BLACK, never sampled
         }
 
         // Border colour is sampler state: a bound sampler object supplies its own, and a texture
         // with none reaches the very same value through the sampler object it owns.
-        const auto& borderColor = sampler.GetBorderColor();
-        const Bool isDepthTexture = IsDepthTextureFormat(texture.GetFormat());
+        const auto format = texture.GetFormat();
+        const auto domain = ResolveBorderColorDomain(format);
+        const Bool canUseCustom = m_customBorderColorSupported && m_maxCustomBorderColorSamplers > 0 &&
+                                  m_customBorderColorSamplerCount < m_maxCustomBorderColorSamplers;
 
-        if (isDepthTexture) {
+        if (domain != BorderColorDomain::Float) {
+            // An integer image view REQUIRES an integer border colour, whatever the value is - even
+            // (0,0,0,1). The value itself is whichever integer form the application wrote; a float
+            // border on an integer texture is nonsense GL leaves undefined, so the derived integer
+            // representation (a plain cast) is as good an answer as any.
+            //
+            // Clamped to the format's representable range FIRST, per GL 4.6 core 8.14.2, and read
+            // through Int64 so the whole signed and unsigned 32-bit ranges are expressible at once.
+            //
+            // Which representation to start from is the TEXTURE's domain, not the entry-point form
+            // the application used. GL 4.6 core 8.10 stores an "I"-form border colour unmodified with
+            // an integer internal data type and does not define a sign conversion between the two
+            // integer forms, so the stored bits are reinterpreted in the sampled format's own
+            // signedness. Measured, not assumed: a border of -1 written with glTexParameterIiv
+            // against a GL_R8UI texture samples as 255 on the ES driver, i.e. as 0xFFFFFFFF clamped
+            // to the format's maximum - see the IntegerBorderColorScenario case that pins it. Picking
+            // the representation by the FORM instead would answer 0 here, which is a defensible
+            // reading of the same spec text but puts DirectVulkan at odds with DirectGLES - and
+            // DirectGLES cannot deviate, it forwards the value to the driver verbatim. Cross-backend
+            // agreement decides it.
+            const auto range = ResolveIntegerBorderRange(format);
+            const auto& borderColorI = sampler.GetBorderColorI();
+            const auto& borderColorUI = sampler.GetBorderColorUI();
+            const Bool startFromUnsigned = domain == BorderColorDomain::UnsignedInteger;
+            Int64 clamped[4];
+            for (SizeT channel = 0; channel < 4; ++channel) {
+                const Int64 raw = startFromUnsigned ? static_cast<Int64>(borderColorUI[channel])
+                                                    : static_cast<Int64>(borderColorI[channel]);
+                const Int64 low = channel == 3 ? range.alphaMin : range.rgbMin;
+                const Int64 high = channel == 3 ? range.alphaMax : range.rgbMax;
+                clamped[channel] = std::clamp(raw, low, high);
+            }
+
+            // Matched against the CLAMPED value, so a border the format cannot hold still lands on
+            // the palette entry it clamps to rather than missing every one of them.
+            const Bool allZeroRgb = clamped[0] == 0 && clamped[1] == 0 && clamped[2] == 0;
+            if (allZeroRgb && clamped[3] == 0) {
+                resolved.color = VK_BORDER_COLOR_INT_TRANSPARENT_BLACK;
+                return resolved;
+            }
+            if (allZeroRgb && clamped[3] == 1) {
+                resolved.color = VK_BORDER_COLOR_INT_OPAQUE_BLACK;
+                return resolved;
+            }
+            if (clamped[0] == 1 && clamped[1] == 1 && clamped[2] == 1 && clamped[3] == 1) {
+                resolved.color = VK_BORDER_COLOR_INT_OPAQUE_WHITE;
+                return resolved;
+            }
+            if (canUseCustom) {
+                resolved.color = VK_BORDER_COLOR_INT_CUSTOM_EXT;
+                resolved.isCustom = true;
+                for (SizeT channel = 0; channel < 4; ++channel) {
+                    if (domain == BorderColorDomain::UnsignedInteger) {
+                        resolved.customValue.uint32[channel] = static_cast<Uint32>(clamped[channel]);
+                    } else {
+                        resolved.customValue.int32[channel] = static_cast<Int32>(clamped[channel]);
+                    }
+                }
+                return resolved;
+            }
+            // No custom colour available: pick the nearest of the three integer palette entries
+            // rather than always answering transparent black, which is what turned an integer border
+            // of (-1,-1,-1,-1) into 0 and broke the CTS's clamped-texel detection outright.
+            const Bool opaque = clamped[3] != 0;
+            const Bool bright = clamped[0] != 0 || clamped[1] != 0 || clamped[2] != 0;
+            resolved.color = !opaque ? VK_BORDER_COLOR_INT_TRANSPARENT_BLACK
+                                     : (bright ? VK_BORDER_COLOR_INT_OPAQUE_WHITE : VK_BORDER_COLOR_INT_OPAQUE_BLACK);
+            return resolved;
+        }
+
+        // Float domain. GL 4.6 core 8.14.2/8.23: the border colour is interpreted in the texture's
+        // format, so it is clamped to that format's representable range first. Without the clamp the
+        // CTS's border of (255,255,255,255) on a GL_RGBA8 texture matched none of the palette entries
+        // and fell through to transparent black - every border texel sampled 0 where the test wanted
+        // 255. The range is per format class, not just the normalized [0,1] / [-1,1] pair: only the
+        // 32-bit float formats are unclamped.
+        FloatVec4 borderColor = sampler.GetBorderColor();
+        if (const auto range = ResolveFloatBorderRange(format, IsSignedNormalizedFormat(format)); range.clamped) {
+            borderColor = FloatVec4(std::clamp(borderColor.x(), range.minValue, range.maxValue),
+                                    std::clamp(borderColor.y(), range.minValue, range.maxValue),
+                                    std::clamp(borderColor.z(), range.minValue, range.maxValue),
+                                    std::clamp(borderColor.w(), range.minValue, range.maxValue));
+        }
+
+        // A depth texture samples one component, so only x decides - and its alpha reads as 1.
+        if (IsDepthTextureFormat(format)) {
             if (NearlyEqual(borderColor.x(), 1.0f)) {
-                return VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
+                resolved.color = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
+                return resolved;
             }
             if (NearlyEqual(borderColor.x(), 0.0f)) {
-                return VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK;
+                resolved.color = VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK;
+                return resolved;
             }
         }
 
         const Bool rgbZero = NearlyEqual(borderColor.x(), 0.0f) && NearlyEqual(borderColor.y(), 0.0f) &&
                              NearlyEqual(borderColor.z(), 0.0f);
         if (rgbZero && NearlyEqual(borderColor.w(), 0.0f)) {
-            return VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK;
+            resolved.color = VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK;
+            return resolved;
         }
         if (rgbZero && NearlyEqual(borderColor.w(), 1.0f)) {
-            return VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK;
+            resolved.color = VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK;
+            return resolved;
         }
         if (NearlyEqual(borderColor.x(), 1.0f) && NearlyEqual(borderColor.y(), 1.0f) &&
             NearlyEqual(borderColor.z(), 1.0f) && NearlyEqual(borderColor.w(), 1.0f)) {
-            return VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
+            resolved.color = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
+            return resolved;
         }
 
-        return VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK;
+        if (canUseCustom) {
+            resolved.color = VK_BORDER_COLOR_FLOAT_CUSTOM_EXT;
+            resolved.isCustom = true;
+            resolved.customValue.float32[0] = borderColor.x();
+            resolved.customValue.float32[1] = borderColor.y();
+            resolved.customValue.float32[2] = borderColor.z();
+            resolved.customValue.float32[3] = borderColor.w();
+            return resolved;
+        }
+
+        // Nearest of the three float palette entries. Transparent black stays the answer for a
+        // transparent border, which is what the old unconditional fallback got right by accident.
+        const Bool opaque = borderColor.w() >= 0.5f;
+        const Bool bright = (borderColor.x() + borderColor.y() + borderColor.z()) >= 1.5f;
+        resolved.color = !opaque ? VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK
+                                 : (bright ? VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE : VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK);
+        return resolved;
     }
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/VkSamplerManager.h

@@ -28,6 +28,13 @@ public:
         Bool samplerAnisotropySupported = false;
         // VkPhysicalDeviceLimits::maxSamplerAnisotropy.
         Float maxSamplerAnisotropy = 1.0f;
+        // VK_EXT_custom_border_color was enabled with BOTH customBorderColors and
+        // customBorderColorWithoutFormat; see VulkanRenderer::m_customBorderColorFeatureEnabled.
+        Bool customBorderColorSupported = false;
+        // VkPhysicalDeviceCustomBorderColorPropertiesEXT::maxCustomBorderColorSamplers. A hard device
+        // limit on how many LIVE samplers may carry a custom border colour, so the cache counts them
+        // and falls back to the snapped predefined value once it is reached.
+        Uint32 maxCustomBorderColorSamplers = 0;
     };
 
     Bool Initialize(const InitInfo& initInfo);
@@ -52,6 +59,21 @@ public:
     // boundaries.
     void OnFrameBoundary();
 
+    // What GL_TEXTURE_BORDER_COLOR resolves to for one (sampler, texture) pair. `color` is always a
+    // legal VkBorderColor; when `isCustom` it is one of the *_CUSTOM_EXT values and `customValue`
+    // carries the actual components in a VkSamplerCustomBorderColorCreateInfoEXT.
+    //
+    // Resolved ONCE per GetOrCreateSampler call and threaded into both the cache key and the
+    // create-info, so the two cannot disagree - the same discipline the resolved anisotropy needs,
+    // and here it also makes the maxCustomBorderColorSamplers fallback deterministic: whether a
+    // custom colour was affordable is decided before the key is built, not twice with a budget
+    // change in between.
+    struct ResolvedBorderColor {
+        VkBorderColor color = VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK;
+        VkClearColorValue customValue{};
+        Bool isCustom = false;
+    };
+
 private:
     struct SamplerCacheEntry {
         VkSampler handle = VK_NULL_HANDLE;
@@ -60,17 +82,18 @@ private:
         // Frame boundary of the last cache hit; entries idle past the
         // OnFrameBoundary retirement age have their VkSampler destroyed.
         Uint64 lastUsedFrameBoundary = 0;
+        // Counted against maxCustomBorderColorSamplers for as long as this entry lives.
+        Bool usesCustomBorderColor = false;
     };
 
-    Uint64 BuildSamplerKey(const MG_State::GLState::SamplerObject& sampler,
-                           const MG_State::GLState::ITextureObject& texture,
-                           Bool forceNearestFiltering, Bool singleLevelView) const;
+    Uint64 BuildSamplerKey(const MG_State::GLState::SamplerObject& sampler, Bool forceNearestFiltering,
+                           Bool singleLevelView, const ResolvedBorderColor& borderColor) const;
     static VkFilter ToVkFilter(SamplerFilterMode mode);
     static VkSamplerMipmapMode ToVkMipmapMode(SamplerMipmapMode mode);
     static VkSamplerAddressMode ToVkAddressMode(SamplerWrapMode mode);
     static VkCompareOp ToVkCompareOp(SamplerCompareFunc func);
-    static VkBorderColor ResolveVkBorderColor(const MG_State::GLState::SamplerObject& sampler,
-                                              const MG_State::GLState::ITextureObject& texture);
+    ResolvedBorderColor ResolveBorderColor(const MG_State::GLState::SamplerObject& sampler,
+                                           const MG_State::GLState::ITextureObject& texture) const;
     // The anisotropy Vulkan will actually apply: 1.0 (i.e. disabled) unless the feature is on and
     // the sampler filters linearly both ways, otherwise the GL request clamped to the device limit.
     // GL happily carries GL_TEXTURE_MAX_ANISOTROPY on a NEAREST sampler (Blaze3D's blocks do exactly
@@ -82,6 +105,12 @@ private:
     const VulkanRendererConfig* m_config = nullptr;
     Bool m_samplerAnisotropySupported = false;
     Float m_maxSamplerAnisotropy = 1.0f;
+    Bool m_customBorderColorSupported = false;
+    Uint32 m_maxCustomBorderColorSamplers = 0;
+    // Live cache entries carrying a custom border colour. Kept in step with the entries themselves
+    // in exactly the three places one can appear or disappear: creation, the OnFrameBoundary sweep,
+    // and Shutdown.
+    Uint32 m_customBorderColorSamplerCount = 0;
     UnorderedMap<Uint64, SamplerCacheEntry> m_samplers;
     // Monotonic frame-boundary counter (bumped in OnFrameBoundary) for cache aging.
     Uint64 m_frameBoundaryCounter = 0;

MobileGL/MG_Backend/DirectVulkan/Renderer/VkTextureManager.cpp

@@ -11,8 +11,10 @@
 #include "ProgramFactory.h"
 
 #include "MG_State/GLState/Core.h"
+#include <MG_Pipe/PipeInputsSwitch.h>
 #include "MG_Util/Converters/MGToStr/TextureEnumConverter.h"
 #include "MG_Util/Converters/MGToVk/TextureEnumConverter.h"
+#include "MG_Util/Metrics/PipeStats.h"
 
 #include <Config.h>
 #include <algorithm>
@@ -46,13 +48,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return mipLevelCount;
     }
 
-    struct TextureFormatInfo {
-        VkFormat format = VK_FORMAT_UNDEFINED;
-        Bool expandRgbToRgba = false;
-        Uint32 componentByteCount = 0;
-        Array<Uint8, 4> alphaBytes = {0, 0, 0, 0};
-    };
-
     struct TextureShapeInfo {
         VkImageType imageType = VK_IMAGE_TYPE_2D;
         VkImageViewType viewType = VK_IMAGE_VIEW_TYPE_2D;
@@ -380,7 +375,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         return true;
     }
 
-    static TextureFormatInfo ResolveTextureFormatInfo(TextureInternalFormat format) {
+    TextureFormatInfo ResolveTextureFormatInfo(TextureInternalFormat format) {
         switch (format) {
         case TextureInternalFormat::RGB:
         case TextureInternalFormat::RGB8:
@@ -812,7 +807,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // sampled-texture sync scan the entire alive-texture map per draw.
             if (aliveIt == m_aliveObjects.end()) {
                 WeakPtr<MG_State::GLState::ITextureObject> aliveTexture;
-                const auto& liveTexture = MG_State::pGLContext->GetTextureObject(texture.GetExternalIndex());
+                const auto& liveTexture = MGB_CTX->GetTextureObject(texture.GetExternalIndex());
                 if (liveTexture && liveTexture.get() == &texture) {
                     aliveTexture = liveTexture;
                 } else {
@@ -921,18 +916,28 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (mipLevel >= resource->mipLevels) {
             return VK_NULL_HANDLE;
         }
-        // A 3D image has arrayLayers == 1 and keeps its GL layers on the z axis, so a per-slice
-        // attachment view is a 2D view whose "array layer" is the slice - legal only on a
-        // 2D-array-compatible image (VUID-VkImageViewCreateInfo-image-04970), which
-        // SyncTextureResource asks for and may have had refused per format.
-        if (resource->viewType == VK_IMAGE_VIEW_TYPE_3D && viewType == VK_IMAGE_VIEW_TYPE_2D) {
+        // A 3D image has arrayLayers == 1 and keeps its GL layers on the z axis, so an attachment
+        // view over it addresses SLICES through baseArrayLayer/layerCount: one slice for a
+        // non-layered attachment (a 2D view) and the whole span for a layered one (a 2D_ARRAY view,
+        // which is what a layered GL_TEXTURE_3D attachment plus a gl_Layer-writing geometry shader
+        // means). BOTH spellings are legal only on a 2D-array-compatible image
+        // (VUID-VkImageViewCreateInfo-image-04970 / -06723), which SyncTextureResource asks for and
+        // may have had refused per format.
+        //
+        // The span is validated against the MIP's slice count, never against arrayLayers: a 3D
+        // image's arrayLayers is 1 by construction, so measuring a layered span against it rejected
+        // every layered 3D attachment - the null view that used to reach vkCreateFramebuffer.
+        if (resource->viewType == VK_IMAGE_VIEW_TYPE_3D &&
+            (viewType == VK_IMAGE_VIEW_TYPE_2D || viewType == VK_IMAGE_VIEW_TYPE_2D_ARRAY)) {
             const Uint32 sliceCount = std::max(resource->depth >> mipLevel, 1u);
             if ((resource->imageCreateFlags & VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT) == 0 ||
                 layerCount == 0 || baseArrayLayer >= sliceCount || baseArrayLayer + layerCount > sliceCount) {
-                MGLOG_D("%s: cannot name slice span [%u, %u) of 3D textureId=%d (mip %u has %u slices, "
-                        "2D-array-compatible=%d)",
+                // Not an error line: the render-pass builder turns the null view into one
+                // MGLOG_E_ONCE and a skipped draw, which is the level this belongs at.
+                MGLOG_D("%s: cannot name slice span [%u, %u) of 3D textureId=%d as viewType=%d (mip %u has %u "
+                        "slices, 2D-array-compatible=%d)",
                         __func__, baseArrayLayer, baseArrayLayer + layerCount, texture.GetExternalIndex(),
-                        mipLevel, sliceCount,
+                        static_cast<Int>(viewType), mipLevel, sliceCount,
                         (int)((resource->imageCreateFlags & VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT) != 0));
                 return VK_NULL_HANDLE;
             }
@@ -945,7 +950,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
 
         const Bool framebufferSrgbEnabled =
-            MG_State::pGLContext->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb);
+            MGB_CTX->IsCapabilityEnabled(MobileGL::CapabilityInput::FramebufferSrgb);
         const VkFormat baseAttachmentFormat =
             viewFormatOverride != VK_FORMAT_UNDEFINED ? viewFormatOverride : resource->format;
         const VkFormat attachmentFormat =
@@ -2173,12 +2178,16 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             }
             if (imageFormatResult != VK_SUCCESS && !isMultisampleTexture &&
                 (imageInfo.flags & VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT) != 0) {
-                // Losing 2D-array compatibility only costs per-slice framebuffer attachment for this
-                // format; failing creation would lose the texture entirely. Remembered so later syncs
-                // neither reprobe nor flag-mismatch against this image and recreate it.
+                // Losing 2D-array compatibility only costs framebuffer attachment of this format's
+                // 3D images - per-slice AND layered, since both are spelled as a 2D-family view over
+                // the z axis; failing creation would lose the texture entirely. Recorded here (the
+                // per-format set below) so later syncs neither reprobe nor flag-mismatch against this
+                // image and recreate it, and so GetOrCreateAttachmentViewAtMipLevel declines rather
+                // than handing back a view that cannot exist - the render-pass builder then turns
+                // that decline into a skipped draw instead of a null VkImageView in pAttachments.
                 MGLOG_W_ONCE("%s: VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT is unsupported for format=%d "
-                        "textureId=%d; creating without it (per-slice framebuffer attachment will be "
-                        "unavailable for it)",
+                        "textureId=%d; creating without it (per-slice and layered framebuffer "
+                        "attachment of 3D textures in this format will be unavailable)",
                         __func__, static_cast<Int>(format), texture.GetExternalIndex());
                 m_2dArrayCompatibleUnsupported.insert(format);
                 imageInfo.flags &= ~VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT;
@@ -3143,6 +3152,32 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             packBox(dst, item.regionLo, item.regionSize);
         }
 
+        if (MG_Util::PipeStats::Enabled()) {
+            // Same shape split as Espryt's: one union box per item, or one job per rect of
+            // a refined rect list. The box/rect decision is invisible to SSIM and is what
+            // the +6 ms/frame Mali cliff of section 7.3 was, so it is counted apart from
+            // the bytes.
+            Uint64 boxEmissions = 0;
+            Uint64 rectEmissions = 0;
+            Uint64 jobs = 0;
+            for (const auto& item : uploadItems) {
+                if (item.rects.empty()) {
+                    ++boxEmissions;
+                    jobs += isCombinedDepthStencil ? 2u : 1u;
+                } else {
+                    ++rectEmissions;
+                    jobs += static_cast<Uint64>(item.rects.size());
+                }
+            }
+            MG_Util::PipeStats::AddBytes(MG_Util::PipeStats::ByteClass::StageTexture,
+                                         static_cast<Uint64>(stagingSize));
+            MG_Util::PipeStats::AddCalls(MG_Util::PipeStats::CallClass::TextureUploadEmissions,
+                                         static_cast<Uint64>(uploadItems.size()));
+            MG_Util::PipeStats::AddCalls(MG_Util::PipeStats::CallClass::TextureUploadBoxEmissions, boxEmissions);
+            MG_Util::PipeStats::AddCalls(MG_Util::PipeStats::CallClass::TextureUploadRectEmissions, rectEmissions);
+            MG_Util::PipeStats::AddCalls(MG_Util::PipeStats::CallClass::TextureUploadJobs, jobs);
+        }
+
         const VkImageAspectFlags aspectMask = GetAspectMaskForFormat(outResource.format);
         VkPipelineStageFlags uploadSrcStageMask = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
         VkAccessFlags uploadSrcAccessMask = 0;

MobileGL/MG_Backend/DirectVulkan/Renderer/VkTextureManager.h

@@ -10,8 +10,10 @@
 
 #include "../VkIncludes.h"
 #include <Includes.h>
+#include <MG_State/GLState/FramebufferState/FramebufferObject.h>
 #include <MG_State/GLState/TextureState/TextureObject.h>
 #include <vk_mem_alloc.h>
+#include <algorithm>
 #include <unordered_map>
 #include <unordered_set>
 
@@ -22,6 +24,31 @@ class ITextureObject;
 namespace MobileGL::MG_Backend::DirectVulkan {
 enum class SamplerNumericDomain : Uint8;
 
+// What VkFormat a GL internal format is BACKED with, and how a shadow upload has to be reshaped to
+// fit it. This is not the same question as "is there an exact VkFormat for this GL format", which is
+// what ConvertTextureInternalFormatToVkEnum answers: several GL formats have no Vulkan twin at all
+// (RGBA2, RGBA12) and several three-channel ones are deliberately widened to their four-channel twin
+// because Vulkan devices rarely support the 3-channel layouts.
+//
+// SHARED, and it must stay the only answer to that question. A renderbuffer and a texture of the
+// same GL format have to resolve to the SAME VkFormat or every blit, resolve and glCopyImageSubData
+// between them crosses a size-incompatible pair, which vkCmdCopyImage leaves undefined
+// (VUID-vkCmdCopyImage-srcImage-01548). The renderbuffer path used to carry a hand-maintained second
+// copy of this table that was missing four rows - RGBA2, RGBA4, RGB5A1 and RGBA12 - so those four
+// renderbuffer formats either got no image at all or a 16-bit-packed one facing a 32-bit texture.
+struct TextureFormatInfo {
+    VkFormat format = VK_FORMAT_UNDEFINED;
+    // The GL format has three channels and is carried in a four-channel image; a shadow upload has
+    // to be expanded, inserting `alphaBytes` after every `componentByteCount * 3` source bytes.
+    Bool expandRgbToRgba = false;
+    Uint32 componentByteCount = 0;
+    Array<Uint8, 4> alphaBytes = {0, 0, 0, 0};
+};
+
+// Callers that only need the backing VkFormat (a renderbuffer has no shadow upload to reshape) take
+// `.format` and ignore the rest.
+TextureFormatInfo ResolveTextureFormatInfo(TextureInternalFormat format);
+
 // A GL 1D-ARRAY level keeps its LAYER COUNT in the state-side HEIGHT: that is what
 // glTexImage2D(GL_TEXTURE_1D_ARRAY, width, layers) means, and the frontend records the level
 // as {width, layers, 1} (see GL_Texture.cpp's AllocateStorage and the completeness walk in
@@ -41,6 +68,37 @@ inline IntVec3 ToVulkanLevelExtent(TextureTarget stateTarget, const IntVec3& glT
     return glTexelSize;
 }
 
+// How many Vulkan array layers (or, for a 3D image, z slices) a GL framebuffer attachment spans.
+//
+// THE ONE COPY, deliberately. This used to exist twice - privately in VkRenderPassManager.cpp and
+// again in VkClearManager.cpp - and the two are not independent: the render pass builds the
+// attachment view and VkFramebufferCreateInfo::layers from one, while the CLEAR key built from the
+// other is written verbatim into VkImageSubresourceRange::layerCount when a queued glClear is
+// materialised outside a render pass (MaterializePendingClearForTexture). They are two consumers
+// of the same GL clear, so any disagreement means the same glClear produces two different pictures
+// depending only on which path happens to consume it first - and the materialise path then POPS
+// the entry, so the other one never runs. Fixing one copy and leaving the other is exactly how
+// that split gets introduced; keep them the same function.
+//
+// Two shapes make this more than `size.z()`:
+//   * GL_TEXTURE_1D_ARRAY keeps its layer count in the state-side HEIGHT (see ToVulkanLevelExtent
+//     just above), so z reads 1 and every layer above the first was silently dropped.
+//   * GL_TEXTURE_CUBE_MAP is attached layered as its REPRESENTATIVE upload target, the +X face
+//     (ResolveRepresentableFramebufferTextureUploadTarget), and one face's level size has z = 1 -
+//     but a layered cube attachment names all six faces (GL 4.6 core 9.2.8), which are the image's
+//     six array layers. A cube ARRAY needs no such arm: its representative target carries 6n in z.
+inline Uint32 ResolveAttachmentLayerCount(const MG_State::GLState::FramebufferAttachmentObject& attachment) {
+    if (!attachment.IsLayered()) {
+        return 1u;
+    }
+    const auto& texture = attachment.GetTexture();
+    const TextureTarget target = texture != nullptr ? texture->GetTarget() : TextureTarget::Unknown;
+    if (target == TextureTarget::TextureCubeMap) {
+        return 6u;
+    }
+    return static_cast<Uint32>(std::max(ToVulkanLevelExtent(target, attachment.GetSize()).z(), 1));
+}
+
 // A GL framebuffer attachment's level/layer, and a GL image unit's, are relative to the texture
 // the application NAMED. When that texture was created by glTextureView (ARB_texture_view) they
 // are relative to the VIEW, and have to be shifted into the storage image's numbering before they

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -24,6 +24,7 @@
 #include "MG_Util/Math/VectorTypes.h"
 #include <Includes.h>
 #include <MG_Backend/BackendObject.h>
+#include <MG_Util/SelfTest/PrimitivesGeneratedNoXfbProbe.h>
 #include <vk_mem_alloc.h>
 
 #include "../VkIncludes.h"
@@ -563,7 +564,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // Native subgroup topology, queried at device creation for the compute-module
         // subgroup repairs (SubgroupSupportPolicy.h) and the REQUIRE_FULL_SUBGROUPS
         // stage flag; 0 / false when the device has no usable compute subgroups or
-        // MOBILEGL_DISABLE_SUBGROUP forced them off.
+        // MOBILEGL_MAGMA_DISABLE_SUBGROUP forced them off.
         Uint32 m_nativeSubgroupSize = 0;
         Bool m_nativeSubgroupSupported = false;
         Bool m_computeFullSubgroupsFeatureEnabled = false;
@@ -584,6 +585,30 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // needs no feature). Both cached at device creation and drive a hard-fail-at-draw when absent.
         Bool m_dualSrcBlendFeatureEnabled = false;
         Bool m_primitiveTopologyListRestartFeatureEnabled = false;
+        // shaderTessellationAndGeometryPointSize gates the PointSize built-in in a tessellation
+        // or geometry stage, which desktop GL treats as an ordinary per-vertex output (writable,
+        // and capturable by name through transform feedback). Cached at device creation and
+        // handed to ProgramFactory, which refuses a program whose tessellation or geometry module
+        // declares the matching SPIR-V capability while this is false - SetupDraw then skips its
+        // draws (VkProgramObject::pointSizeCapabilityUnsupported) rather than building a pipeline
+        // that is invalid usage.
+        Bool m_tessellationAndGeometryPointSizeFeatureEnabled = false;
+        // VK_EXT_custom_border_color. Vulkan's four predefined VkBorderColor values cover only
+        // transparent/opaque black and opaque white; GL_TEXTURE_BORDER_COLOR is an arbitrary vec4 (or
+        // an arbitrary ivec4/uvec4 through the "I" entry points). Without this extension a border
+        // colour outside the palette has to be snapped to the nearest predefined one. Both features
+        // are required together: customBorderColorWithoutFormat is what lets a sampler carry a custom
+        // colour without naming the image format it will be paired with, which GL's sampler objects
+        // cannot know. maxCustomBorderColorSamplers is a real device limit, so the sampler cache has
+        // to be able to fall back to the snapped value once it is reached.
+        Bool m_customBorderColorFeatureEnabled = false;
+        Uint32 m_maxCustomBorderColorSamplers = 0;
+        // sampleRateShading gates VkPipelineMultisampleStateCreateInfo::sampleShadingEnable, i.e.
+        // glEnable(GL_SAMPLE_SHADING) + glMinSampleShading. Unlike dualSrcBlend this does NOT
+        // hard-fail the draw when absent: sample shading is a rate hint, and every sample-rate
+        // pipeline is still correct (just not per-sample) at the default rate - so the enable is
+        // dropped and the draw proceeds, which is what a GL implementation with SAMPLES=1 does too.
+        Bool m_sampleRateShadingFeatureEnabled = false;
         // multiViewport gates rasterizing into more than one of ARB_viewport_array's 16 viewports
         // (gl_ViewportIndex). m_maxRasterizableViewports is min(MAX_VIEWPORTS, device limit), or 1
         // when the feature is off, and is the viewportCount a gl_ViewportIndex-writing pipeline
@@ -650,8 +675,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // per object: one group of four slots each, handed out on first use.
         static constexpr SizeT kXfbCounterObjectSlots = 16;
         VkBufferObject m_xfbCounterBuffer;
-        UnorderedMap<Uint, Uint32> m_xfbCounterSlotByObject;
-        Uint32 m_xfbNextCounterSlot = 0;
+        // Which transform feedback object owns each slot group, by the frontend's never-reused
+        // lifetime id (0 = the slot is free). This used to be an UnorderedMap keyed on the GL
+        // NAME, which is recycled by glGenTransformFeedbacks: a deleted-and-recreated object
+        // inherited the dead one's slot, and since nothing ever removed an entry the map also
+        // grew for the life of the context. A fixed table cannot do either: a group is taken over
+        // only from an owner with no OPEN span (see CurrentXfbCounterSlot), so an object whose
+        // counters can still be resumed never loses them, and a dead object's group comes back.
+        Array<Uint64, kXfbCounterObjectSlots> m_xfbCounterSlotOwner{};
+        // Tie-break among reclaimable groups only; never on its own, because the paused span the
+        // groups exist for is by construction the least recently used one.
+        Array<Uint64, kXfbCounterObjectSlots> m_xfbCounterSlotLastUse{};
+        Uint64 m_xfbCounterSlotUseSerial = 0;
         // Set for a slot once a captured draw has been recorded into its span; selects
         // counter-buffer resume on the next captured draw of the same span.
         Array<Bool, kXfbCounterObjectSlots> m_xfbCountersValid{};
@@ -693,15 +728,74 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Vector<Uint32> m_xfbQueryActiveSlots[2];
         Bool m_xfbQuerySlotOpen = false;
         Uint32 m_xfbQueryOpenSlot = 0;
+        // GL_PRIMITIVES_GENERATED reroute for draws made while transform feedback is
+        // INACTIVE. The stream pool's primitivesNeeded is defined to count those draws
+        // too, but a Mali driver (and Mesa lavapipe) answers 0 unless a capture span
+        // is open (the CTS's tessellator-measuring shape). Where the bring-up probe
+        // finds that defect with a working control - or
+        // MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE forces it - such draws accumulate the
+        // GENERATED count through this pool instead, whose type the arming picks:
+        // VK_QUERY_TYPE_PRIMITIVES_GENERATED_EXT where the device hosts the dedicated
+        // query with its rasterizer-discard feature (exact semantics by definition -
+        // the extension exists because GL needs this count without a capture), else a
+        // VK_QUERY_TYPE_PIPELINE_STATISTICS pool over clipping-stage invocations (one
+        // per primitive reaching primitive clipping - after every vertex processing
+        // stage, before rasterizer discard - which is the same set).
+        // XFB-ACTIVE draws keep the stream slot (exact today, and WRITTEN needs it);
+        // every draw with no open capture - a PAUSED span's draws included - takes a
+        // reroute slot, and the span then ignores the frontend's CPU paused-primitive
+        // counter rather than adding it on top (see IsPrimGenRerouteArmed): that
+        // counter is written by only 3 of the ~15 draw entry points and answers 0 for
+        // GL_PATCHES, so it cannot price the draws this reroute exists to repair. One
+        // GL query span may therefore hold slots of both pools.
+        Bool m_pipelineStatisticsQueryFeatureEnabled = false;
+        // VK_EXT_primitives_generated_query: base feature, and the
+        // ...WithRasterizerDiscard feature without which a discarding draw inside the
+        // query is invalid usage (so the reroute never picks the dedicated pool on a
+        // base-only device - GL applications toggle discard freely).
+        Bool m_primitivesGeneratedQueryFeatureEnabled = false;
+        Bool m_primitivesGeneratedQueryDiscardFeatureEnabled = false;
+        // tessellationShader was enabled at device creation (it is taken whenever the
+        // device advertises it); gates the probe's PATCHES shape.
+        Bool m_tessellationShaderFeatureEnabled = false;
+        MG_Util::SelfTest::PrimGenRerouteKind m_primGenRerouteKind =
+            MG_Util::SelfTest::PrimGenRerouteKind::None;
+        // The bring-up probe measured this device's stream query as counting draws made
+        // with no capture span open (the StreamCounts verdict) - so it counts the
+        // PAUSED-span ones too, through the stream slot they take when nothing is
+        // rerouted. Only the probe can know this, so it stays false wherever the probe
+        // is not consulted (the forced arms), which keeps those lanes' accounting as it
+        // was.
+        Bool m_primGenStreamCountsXfbInactiveDraws = false;
+        VkQueryPool m_primGenReroutePool = VK_NULL_HANDLE;
+        Uint32 m_primGenRerouteSlotCursor = 0;
+        Vector<Uint32> m_primGenRerouteActiveSlots;
+        Bool m_primGenRerouteSlotOpen = false;
+        Uint32 m_primGenRerouteOpenSlot = 0;
+        // Runs the bring-up probe (memoized per process) and decides
+        // m_primGenRerouteKind. Called at the end of device creation: it records on
+        // m_graphicsQueue, which nothing else is using yet.
+        void ArmPrimGenReroute();
 
     public:
+        // Whether a GENERATED span opened now will have the draws made while the GL
+        // span is PAUSED counted on the GPU - through the reroute pool, which takes
+        // every draw with no open capture, or (where the reroute is not armed because
+        // the stream query was measured to count capture-less draws) through the stream
+        // slot such a draw still takes. The frontend's CPU paused-primitive counter
+        // must not be added on top of either: it would double count, and it cannot
+        // price the draws that matter anyway - only 3 of the ~15 draw entry points
+        // write it and it answers 0 for GL_PATCHES. Read once per span, after
+        // StartXfbQueryCapture (whose pool creation may disarm the reroute).
+        Bool ArePausedDrawsGpuCounted() const;
         // kind: 0 = PRIMITIVES_WRITTEN, 1 = PRIMITIVES_GENERATED.
         Bool StartXfbQueryCapture(Uint32 kind);
-        void StopXfbQueryCapture(Uint32 kind, Vector<Uint32>& outSlots);
-        Bool ResolveXfbQueryResult(const Vector<Uint32>& slots, Bool wantGenerated, Uint64& outPrimitives);
+        void StopXfbQueryCapture(Uint32 kind, Vector<Uint32>& outSlots, Vector<Uint32>& outRerouteSlots);
+        Bool ResolveXfbQueryResult(const Vector<Uint32>& slots, const Vector<Uint32>& rerouteSlots,
+                                   Bool wantGenerated, Uint64& outPrimitives);
 
     private:
-        void BeginXfbQueryForDraw(VkCommandBuffer commandBuffer);
+        void BeginXfbQueryForDraw(VkCommandBuffer commandBuffer, Bool xfbActive);
         void EndXfbQueryForDraw(VkCommandBuffer commandBuffer);
 
         VkCommandPool m_commandPool = VK_NULL_HANDLE;
@@ -733,6 +827,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // values the memo already holds.
             Uint64 pipelineStateHash = 0;
             ProgramFactory::CompileOptionFlags transformFlags = {};
+            // Baked into the pipeline (PipelineFactory::ComputeHash mixes it), and NOT derivable
+            // from anything else in this key: it depends on whether the draw is indexed and on the
+            // index type, neither of which the mode/program/state hashes carry. Without it an
+            // indexed and a non-indexed draw over the same program and state collide on one entry
+            // and the second one gets the first one's restart setting.
+            Bool primitiveRestartEnable = false;
             VkPipeline pipeline = VK_NULL_HANDLE;
         };
         static constexpr Uint32 kPipelineMemoSize = 8;
@@ -746,9 +846,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // version: the version is monotonic and bumps on every pipeline-state
         // change, so an unchanged (version, colorAttachmentCount) proves the state
         // bytes are unchanged and the hash can be reused without re-reading them.
-        Uint64 ComputePipelineStateHash(Uint32 colorAttachmentCount) const;
+        Uint64 ComputePipelineStateHash(Uint32 colorAttachmentCount,
+                                        VkSampleCountFlagBits rasterizationSamples) const;
+        // The effective GL_SAMPLE_MASK word for a draw at this rasterization sample count; see
+        // the definition for the GL-vs-Vulkan rule it reconciles. Shared by the pipeline payload
+        // and the pipeline-state memo word so the two cannot disagree.
+        Uint32 ResolveEffectiveSampleMask(VkSampleCountFlagBits rasterizationSamples) const;
         Uint m_pipelineStateHashVersion = 0;
         Uint32 m_pipelineStateHashColorCount = 0;
+        // The sample count the cached hash was computed at. A pipeline-state input now depends on
+        // it (the effective sample mask), so a draw that changes only the target's sample count
+        // has to recompute rather than reuse.
+        VkSampleCountFlagBits m_pipelineStateHashSampleCount = VK_SAMPLE_COUNT_1_BIT;
         Uint64 m_pipelineStateHash = 0;
         Bool m_pipelineStateHashValid = false;
         // GetShaderTransformFlags memo. NOT pure in the pre-transform alone: the
@@ -790,7 +899,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // Skip the per-draw CollectSampledTextures walk (~5% of the render thread) when the sampled
         // texture SET is provably unchanged from the previous draw: same program (lifetime id +
         // backend-state version, which covers sampler-uniform reassignment / relink) and transform
-        // flags, and no texture bind/unbind/delete since (GetTextureBindGeneration). On a hit,
+        // flags, no texture bind/unbind/delete since (GetTextureBindGeneration), and nothing that
+        // moves a texture's shape or a sampler's parameters since (GetSamplingResolutionGeneration
+        // - membership depends on mipmap-completeness, which both of those decide). On a hit,
         // m_sampledTexturesScratch still holds the previous draw's list and steps 2-4 (feedback /
         // layout probe / transition) re-run on it, so layout correctness is unaffected - only the GL
         // walk is skipped. The program lifetime id (never reused, unlike the GL name) and the
@@ -801,6 +912,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Uint32 m_lastSampledSetProgramVersion = 0;
         ProgramFactory::CompileOptionFlags m_lastSampledSetTransformFlags = {};
         Uint64 m_lastSampledSetBindGeneration = 0;
+        Uint64 m_lastSampledSetSamplingGeneration = 0;
+        // Set from the draw's resolved VkProgramObject on both the full and the fast setup paths;
+        // read by BeginXfbCaptureForDraw, which has only GL state otherwise. See
+        // VkProgramObject::xfbCaptureDeclined.
+        Bool m_currentDrawXfbCaptureDeclined = false;
 
         // Memo for the per-draw explicit-LOD-0 eligibility probe
         // (ProgramSamplesOnlySingleLevelTextures): same key family as the
@@ -865,6 +981,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             Uint64 bindGeneration = 0;
             Uint32 baseTransformFlags = 0;
             Uint32 resolvedTransformFlags = 0;
+            // What ResolvePrimitiveRestartEnable answered for the draw this snapshot was taken
+            // from, i.e. what its pipeline's primitiveRestartEnable was built with. `aspects`
+            // already separates indexed from non-indexed draws, but not one index TYPE from
+            // another, and a restart index that fits GL_UNSIGNED_INT but not GL_UNSIGNED_SHORT
+            // makes those two draws want different pipelines.
+            Bool primitiveRestartEnable = false;
             Uint64 renderPassHash = 0;
             Uint32 imageIndex = 0;
             Uint64 textureEraseEpoch = 0;
@@ -893,6 +1015,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // probe the pipeline memo after a state change without re-fetching the
             // render-pass entry (the pass itself is pinned by renderPassHash above).
             Uint32 renderPassColorCount = 0;
+            // Pinned with the colour count and for the same reason: the fast path recomputes the
+            // pipeline-state value hash from the snapshot, and that hash reads the sample count.
+            VkSampleCountFlagBits renderPassSampleCount = VK_SAMPLE_COUNT_1_BIT;
             VkPipeline pipeline = VK_NULL_HANDLE;
             // layoutHash of the snapshotting draw's vertex-input state. The pipeline and
             // the vertex-input pre-flight depend on the VAO only through this (plus the
@@ -1168,13 +1293,23 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void CreateSwapchain();
         void CreateCommandPool();
 
+        // Whether THIS draw's primitive stream restarts, and therefore what
+        // VkPipelineInputAssemblyStateCreateInfo::primitiveRestartEnable must be. Resolved by the
+        // caller because it needs two facts a pipeline cannot see: whether the draw is indexed at
+        // all (GL primitive restart acts on the index stream, so it is a no-op for glDrawArrays),
+        // and the index TYPE (an application restart index that does not fit the type matches no
+        // index, so that draw restarts nowhere - see UploadAndBindIndexBuffer).
+        Bool ResolvePrimitiveRestartEnable(Flags<DrawSetupAspect> aspects,
+                                           const IndexBufferView* pIndexBufferView) const;
+
         VkPipeline GetOrCreatePipeline(
             GLenum mode,
             const MG_State::GLState::ProgramObject& program,
             const ProgramFactory::VkProgramObject& programObj,
             ProgramFactory::CompileOptionFlags transformFlags,
             const MG_State::GLState::VertexArrayObject& vao,
-            const RenderPassEntry& renderPassEntry);
+            const RenderPassEntry& renderPassEntry,
+            Bool primitiveRestartEnable);
         VkPipeline GetOrCreateComputePipeline(const ProgramFactory::VkProgramObject& programObj);
         void DestroyComputePipelines();
         // Takes the frame rather than a command buffer: a first-time storage-usage upgrade has to
@@ -1241,13 +1376,25 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                    GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
                                                    GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
                                                    GLenum filter);
-        // Clears one z slice of a VK_IMAGE_TYPE_3D colour image. See the call site in
-        // MaterializePendingClearForTexture for why a transfer clear cannot do this.
+        // Clears one layer of a colour image through a throwaway render pass whose entire content
+        // is its LOAD_OP_CLEAR. Two callers, both of which a transfer clear cannot serve: a z
+        // slice of a VK_IMAGE_TYPE_3D image (vkCmdClearColorImage cannot name one), and a
+        // MULTISAMPLE image (which carries no TRANSFER_DST usage at all). `finalLayout` is the
+        // layout the caller already tracks for the whole image, so this never has to touch
+        // resource->layout.
         Bool ClearDepthSliceWithRenderPass(VkCommandBuffer commandBuffer,
                                            MG_State::GLState::ITextureObject& texture, Uint32 mipLevel,
-                                           Uint32 depthSlice, const VkClearValue& clearValue);
+                                           Uint32 depthSlice, const VkClearValue& clearValue,
+                                           VkImageLayout finalLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
         Bool MaterializePendingClearForTexture(VkCommandBuffer commandBuffer,
                                                MG_State::GLState::ITextureObject& texture);
+        // The multisample arm of the above. Split out rather than branched inline because it
+        // shares none of the transfer path: a multisample image carries no TRANSFER_DST usage, so
+        // neither the TRANSFER_DST transition nor vkCmdClearColorImage is legal on one.
+        Bool MaterializeMultisamplePendingClear(VkCommandBuffer commandBuffer,
+                                                MG_State::GLState::ITextureObject& texture,
+                                                VkTextureManager::TextureResource& resource,
+                                                const Vector<PendingClearEntry>& pendingClears);
         Bool MaterializePendingClearForRenderbuffer(
             VkCommandBuffer commandBuffer,
             const SharedPtr<MG_State::GLState::RenderbufferObject>& renderbuffer);

MobileGL/MG_Backend/DirectVulkan/SubgroupSupportPolicy.h

@@ -39,18 +39,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     inline Bool ShouldEmulateSubgroups(const Bool nativeSubgroupSupported) {
         return MG_Config::Features.MagmaEmulateSubgroup && !nativeSubgroupSupported &&
-               !MG_Config::Features.DisableSubgroup;
+               !MG_Config::Features.MagmaDisableSubgroup;
     }
 
     inline Bool ShouldFixIterationRPSubgroupScratch() {
         // Auto is ON: the patch is fingerprint-gated to iterationRP's reduction and
         // grows one under-declared array; every other module passes through untouched.
-        return MG_Config::Features.FixIterationRPSubgroupScratch !=
+        return MG_Config::Features.MagmaFixIterationRPSubgroupScratch !=
                MG_Config::QuirkOverride::ForceOff;
     }
 
     inline Bool ShouldFixIterationRPBarrier() {
-        return MG_Config::Features.IterationRPFixBarrier;
+        return MG_Config::Features.MagmaIterationRPFixBarrier;
     }
 
     inline Bool ShouldDeriveNumSubgroups() {
@@ -58,6 +58,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // contract to hold, and the derived ceil() value is the one the renderer can pin
         // with REQUIRE_FULL_SUBGROUPS - the driver builtin is the value with no
         // cross-driver guarantee (Adreno returns 1 for an 8-subgroup dispatch).
-        return MG_Config::Features.DeriveNumSubgroups != MG_Config::QuirkOverride::ForceOff;
+        return MG_Config::Features.MagmaDeriveNumSubgroups != MG_Config::QuirkOverride::ForceOff;
     }
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/MGPipe/PipeInputs.cpp

@@ -0,0 +1,179 @@
+// MobileGL - MobileGL/MG_Backend/MGPipe/PipeInputs.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+// The backend-side half of the PipeInputs block: the poison Fatal with its verb name, the
+// name lookups the runtime knobs need, and - in a verify build - the per-field equality,
+// the entry comparator and the corruption injector. Compiled only under MOBILEGL_PIPE_PUSH
+// (CMakeLists.txt appends it to SOURCE_FILES there), so the pull build never sees it. Spells
+// no MG_State global: everything that reads the live context lives in MG_Impl/Pipe/PipeFill.cpp.
+#include <MG_Backend/MGPipe/PipeInputs.h>
+
+#include <cstdint>
+#include <cstring>
+
+namespace MobileGL::MG_Pipe {
+    const char* MGPipeVerbName(MGPipeVerb verb) {
+        const auto index = static_cast<SizeT>(verb);
+        return index < kMGPipeVerbCount ? kMGPipeVerbNames[index] : "<none>";
+    }
+
+    [[noreturn]] void MGPipeInputPoisonFatalForVerb(MGPipeInputField field, MGPipeVerb verb) {
+        MGPipeInputPoisonFatal(field, MGPipeVerbName(verb));
+    }
+
+    Optional<MGPipeInputField> MGPipeFindInputField(const char* name) {
+        if (name == nullptr) return std::nullopt;
+        for (SizeT i = 0; i < kMGPipeInputFieldCount; ++i) {
+            if (std::strcmp(kMGPipeInputFieldNames[i], name) == 0) return static_cast<MGPipeInputField>(i);
+        }
+        return std::nullopt;
+    }
+
+    Optional<MGPipeVerb> MGPipeFindVerb(const char* name) {
+        if (name == nullptr) return std::nullopt;
+        for (SizeT i = 0; i < kMGPipeVerbCount; ++i) {
+            if (std::strcmp(kMGPipeVerbNames[i], name) == 0) return static_cast<MGPipeVerb>(i);
+        }
+        return std::nullopt;
+    }
+
+#if MOBILEGL_PIPE_VERIFY
+    namespace {
+        using CurrentVertexAttributeValue = PipeInputs::CurrentVertexAttributeValue;
+
+        // Every overload is declared up front: the array overloads recurse into their element
+        // type, and a call inside a template only sees what was declared before the template.
+        template <class T>
+        Bool StorageEqual(const T& a, const T& b);
+        template <class T>
+        Bool StorageEqual(T* const& a, T* const& b);
+        template <class T>
+        Bool StorageEqual(const SharedPtr<T>& a, const SharedPtr<T>& b);
+        template <class T, SizeT N>
+        Bool StorageEqual(const T (&a)[N], const T (&b)[N]);
+        Bool StorageEqual(const PipeInputs::IndexedCapabilities& a, const PipeInputs::IndexedCapabilities& b);
+        Bool StorageEqual(const CurrentVertexAttributeValue& a, const CurrentVertexAttributeValue& b);
+        template <class T>
+        void CorruptStorage(T& v);
+        template <class T>
+        void CorruptStorage(T*& p);
+        template <class T>
+        void CorruptStorage(SharedPtr<T>& p);
+        template <class T, SizeT N>
+        void CorruptStorage(T (&a)[N]);
+        void CorruptStorage(PipeInputs::IndexedCapabilities& c);
+        void CorruptStorage(CurrentVertexAttributeValue& v);
+
+        // ---- equality over one field's storage ----
+        // O-class storage compares by identity: a raw pointer into the context, or the object a
+        // SharedPtr owns. Everything else goes through G4's MGPipeFieldEqual, recursing through
+        // C arrays element-wise.
+        template <class T>
+        Bool StorageEqual(T* const& a, T* const& b) {
+            return a == b;
+        }
+        template <class T>
+        Bool StorageEqual(const SharedPtr<T>& a, const SharedPtr<T>& b) {
+            return a.get() == b.get();
+        }
+        template <class T, SizeT N>
+        Bool StorageEqual(const T (&a)[N], const T (&b)[N]) {
+            for (SizeT i = 0; i < N; ++i) {
+                if (!StorageEqual(a[i], b[i])) return false;
+            }
+            return true;
+        }
+        Bool StorageEqual(const PipeInputs::IndexedCapabilities& a, const PipeInputs::IndexedCapabilities& b) {
+            return StorageEqual(a.Blend, b.Blend) && StorageEqual(a.ScissorTest, b.ScissorTest);
+        }
+        // Three scalar arrays and nothing else (Core.h), so a bitwise compare has no padding to
+        // false-differ on and keeps a NaN float attribute equal to itself. The size assertion is
+        // what turns a fourth member into a build break rather than a blind spot.
+        Bool StorageEqual(const CurrentVertexAttributeValue& a, const CurrentVertexAttributeValue& b) {
+            static_assert(sizeof(CurrentVertexAttributeValue) == 3 * 4 * 4,
+                          "CurrentVertexAttributeValue grew a member; update the comparator");
+            return std::memcmp(&a, &b, sizeof(CurrentVertexAttributeValue)) == 0;
+        }
+        template <class T>
+        Bool StorageEqual(const T& a, const T& b) {
+            return MGPipeFieldEqual(a, b);
+        }
+
+        // ---- corruption of one field's storage ----
+        // Every shape is perturbed in a way the comparator above must see: a Bool flips, a
+        // scalar or enum moves by one, a pointer's low bits are flipped (never dereferenced:
+        // the snapshot is only ever compared), a SharedPtr becomes an aliasing pointer to a
+        // flipped address with no control block, an array corrupts its first element, and any
+        // other struct has its first byte XOR'ed with 0x5A.
+        template <class T>
+        T* FlipPointer(T* p) {
+            return reinterpret_cast<T*>(reinterpret_cast<std::uintptr_t>(p) ^ 0x5A);
+        }
+        template <class T>
+        void CorruptStorage(T*& p) {
+            p = FlipPointer(p);
+        }
+        template <class T>
+        void CorruptStorage(SharedPtr<T>& p) {
+            p = SharedPtr<T>(SharedPtr<T>(), FlipPointer(p.get()));
+        }
+        template <class T, SizeT N>
+        void CorruptStorage(T (&a)[N]) {
+            CorruptStorage(a[0]);
+        }
+        void CorruptStorage(PipeInputs::IndexedCapabilities& c) {
+            CorruptStorage(c.Blend);
+        }
+        void CorruptStorage(CurrentVertexAttributeValue& v) {
+            v.floatValue[0] += 1.f;
+        }
+        template <class T>
+        void CorruptStorage(T& v) {
+            if constexpr (std::is_same_v<T, Bool>) {
+                v = !v;
+            } else if constexpr (std::is_enum_v<T>) {
+                v = static_cast<T>(static_cast<std::underlying_type_t<T>>(v) + 1);
+            } else if constexpr (std::is_arithmetic_v<T>) {
+                v = static_cast<T>(v + 1);
+            } else {
+                static_assert(std::is_trivially_copyable_v<T>, "PipeInputs storage must be trivially copyable");
+                unsigned char first = 0;
+                std::memcpy(&first, &v, 1);
+                first ^= 0x5A;
+                std::memcpy(&v, &first, 1);
+            }
+        }
+    } // namespace
+
+    Bool MGPipeInputsFieldEqual(MGPipeInputField field, const PipeInputs& a, const PipeInputs& b) {
+        // A forwarded field has no storage and is equal by definition; VisitStorage answers
+        // false for it, hence the explicit sticky test first.
+        if (kMGPipeInputFieldSticky[static_cast<SizeT>(field)]) return true;
+        return PipeInputs::VisitStorage(field, a, b, [](const auto& x, const auto& y) { return StorageEqual(x, y); });
+    }
+
+    Bool MGPipeVerifyInputs(const PipeInputs& pushed, const PipeInputs& snapshot, const MGPipeFieldMask& mask,
+                            MGPipeInputField* outField) {
+        for (SizeT i = 0; i < kMGPipeInputFieldCount; ++i) {
+            const auto field = static_cast<MGPipeInputField>(i);
+            if (!MGPipeFieldMaskHas(mask, field)) continue;
+            if (MGPipeInputsFieldEqual(field, pushed, snapshot)) continue;
+            if (outField != nullptr) *outField = field;
+            return false;
+        }
+        return true;
+    }
+
+    Bool MGPipeApplyVerifyCorruption(PipeInputs& snapshot, MGPipeInputField field) {
+        return PipeInputs::VisitStorage(field, snapshot, snapshot, [](auto& x, auto&) {
+            CorruptStorage(x);
+            return true;
+        });
+    }
+#endif // MOBILEGL_PIPE_VERIFY
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Backend/MGPipe/PipeInputs.h

@@ -0,0 +1,714 @@
+// MobileGL - MobileGL/MG_Backend/MGPipe/PipeInputs.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <MG_Pipe/MGPipe.h>
+// The frontend types the accessors return. Allowed here: P13 keeps this include for the
+// verify arm (ARCHITECTURE.md 9.5). This header spells no MG_State global - every read of
+// the live context happens on the client side, in MG_Impl/Pipe/PipeFill.cpp.
+#include <MG_State/GLState/Core.h>
+
+// MOBILEGL_PIPE_POISON: the per-verb generation stamps and the read-side
+// Fatal{UnmigratedPipeInput} check. Derived here, once. The repository's debug gate is
+// MOBILEGL_LOG_ACTIVE_LEVEL <= MOBILEGL_LOG_LEVEL_DEBUG (Defines.h); the verify CI build is
+// Release/INFO with MOBILEGL_BUILD_DISAGGREGATED=OFF, so the third arm is what arms the poison
+// there without dragging MG_Remote in.
+#if MOBILEGL_PIPE_PUSH && (MOBILEGL_LOG_ACTIVE_LEVEL <= MOBILEGL_LOG_LEVEL_DEBUG || MOBILEGL_BUILD_DISAGGREGATED || \
+                           MOBILEGL_PIPE_VERIFY)
+#define MOBILEGL_PIPE_POISON 1
+#else
+#define MOBILEGL_PIPE_POISON 0
+#endif
+
+namespace MobileGL::MG_Pipe {
+    // PipeInputs.cpp. The poison Fatal with the verb's name ("<none>" before the first
+    // verb): MGLOG_F + std::abort(), live at every log level on purpose - this is not
+    // MOBILEGL_ASSERT, which is inert in INFO builds.
+    [[noreturn]] void MGPipeInputPoisonFatalForVerb(MGPipeInputField field, MGPipeVerb verb);
+    // kMGPipeVerbNames[verb], or "<none>" for kVerbCount (no verb has been filled yet).
+    const char* MGPipeVerbName(MGPipeVerb verb);
+    // Name lookups for the runtime knobs (MOBILEGL_PIPE_VERIFY_CORRUPT names a field,
+    // MOBILEGL_PIPE_POISON_OMIT a Verb:Field pair). Empty on an unknown name.
+    Optional<MGPipeInputField> MGPipeFindInputField(const char* name);
+    Optional<MGPipeVerb> MGPipeFindVerb(const char* name);
+
+    // The read-side poison check, on every non-forwarded accessor. Under MOBILEGL_PIPE_POISON
+    // a read of a field whose stamp is older than the current verb serial is
+    // Fatal{UnmigratedPipeInput, "Field@Verb"}; otherwise the accessor is a plain load.
+#if MOBILEGL_PIPE_POISON
+#define MGP_INPUT_CHECK(Field)                                                                                         \
+    do {                                                                                                               \
+        if (!::MobileGL::MG_Pipe::MGPipeInputFieldIsFresh(m_filled, (Field))) {                                        \
+            ::MobileGL::MG_Pipe::MGPipeInputPoisonFatalForVerb((Field), m_currentVerb);                                \
+        }                                                                                                              \
+    } while (0)
+#else
+#define MGP_INPUT_CHECK(Field) ((void)0)
+#endif
+    // The compare-at-read hook of the MOBILEGL_PIPE_VERIFY comparator (P1 brief D8), defined
+    // in MG_Impl/Pipe/PipeFill.cpp: re-reads the field from the live context and compares it
+    // against the stored value, and reports the FIRST divergence as
+    // Fatal{PipeVerifyDiffer, "Field@Verb", verb=<serial>, where=read} (the indices go in a
+    // preceding MGLOG_E). Only the live block (gPipeInputs) is verified; a snapshot's own
+    // accessors are plain loads. Off in every other build.
+    struct PipeInputs;
+#if MOBILEGL_PIPE_VERIFY
+    void MGPipeVerifyReadHook(const PipeInputs& self, MGPipeInputField field, Uint index0, Uint index1);
+#define MGP_INPUT_VERIFY_READ(Field, Index0, Index1)                                                                   \
+    ::MobileGL::MG_Pipe::MGPipeVerifyReadHook(*this, (Field), static_cast<Uint>(Index0), static_cast<Uint>(Index1))
+#else
+#define MGP_INPUT_VERIFY_READ(Field, Index0, Index1) ((void)0)
+#endif
+
+    // The V/O storage of every field that has storage, by field id. The seven F-class
+    // (forwarded) fields have none. PipeInputs::VisitStorage dispatches on this list, which
+    // is what keeps the comparator and the corruption injector one function each instead of
+    // two sixty-way switches.
+    // clang-format off
+#define MGP_INPUT_STORAGE_LIST(X)                                                    \
+    X(GetActiveTextureUnit,                        m_activeTextureUnit)              \
+    X(GetBlendColor,                               m_blendColor)                     \
+    X(GetBlendEquationIndexed,                     m_blendEquation)                  \
+    X(GetBlendFuncIndexed,                         m_blendFunc)                      \
+    X(GetBoundTransformFeedbackName,               m_boundTransformFeedbackName)     \
+    X(GetBoundVertexArray,                         m_boundVertexArray)               \
+    X(GetBufferBindingSlot,                        m_bufferBindingSlot)              \
+    X(GetBufferBindingPoint,                       m_bufferBindingPointBase)         \
+    X(GetTouchedBufferBindingPointCount,           m_touchedBindingPointCount)       \
+    X(GetClampReadColor,                           m_clampReadColor)                 \
+    X(GetClearColor,                               m_clearColor)                     \
+    X(GetClearDepth,                               m_clearDepth)                     \
+    X(GetClearStencil,                             m_clearStencil)                   \
+    X(GetColorMaskIndexed,                         m_colorMask)                      \
+    X(GetCullFaceMode,                             m_cullFaceMode)                   \
+    X(GetCurrentVertexAttribute,                   m_currentVertexAttribute)         \
+    X(GetDepthFunc,                                m_depthFunc)                      \
+    X(GetDepthMask,                                m_depthMask)                      \
+    X(GetDepthRangeIndexed,                        m_depthRange)                     \
+    X(GetFramebufferBindingSlot,                   m_framebufferBindingSlot)         \
+    X(GetImageTextureBinding,                      m_imageTextureBindingBase)        \
+    X(GetLineWidth,                                m_lineWidth)                      \
+    X(GetLogicOp,                                  m_logicOp)                        \
+    X(GetMaxTouchedTextureUnit,                    m_maxTouchedTextureUnit)          \
+    X(GetMinSampleShadingValue,                    m_minSampleShadingValue)          \
+    X(GetPatchDefaultInnerLevel,                   m_patchDefaultInnerLevel)         \
+    X(GetPatchDefaultOuterLevel,                   m_patchDefaultOuterLevel)         \
+    X(GetPatchVertices,                            m_patchVertices)                  \
+    X(GetPipelineStateVersion,                     m_pipelineStateVersion)           \
+    X(GetPixelStoreParameters,                     m_pixelStore)                     \
+    X(GetPolygonModeFront,                         m_polygonModeFront)               \
+    X(GetPolygonOffsetFactor,                      m_polygonOffsetFactor)            \
+    X(GetPolygonOffsetUnits,                       m_polygonOffsetUnits)             \
+    X(GetPrimitiveRestartIndex,                    m_primitiveRestartIndex)          \
+    X(GetProgramForDispatch,                       m_programForDispatch)             \
+    X(GetProgramForDraw,                           m_programForDraw)                 \
+    X(GetProvokingVertexMode,                      m_provokingVertexMode)            \
+    X(GetRenderStateParameters,                    m_renderState)                    \
+    X(GetRenderStateParametersVersion,             m_renderStateParametersVersion)   \
+    X(GetSamplingResolutionGeneration,             m_samplingResolutionGeneration)   \
+    X(GetScissorBox,                               m_scissorBox)                     \
+    X(GetStencilState,                             m_stencil)                        \
+    X(GetTextureBindGeneration,                    m_textureBindGeneration)          \
+    X(GetTextureContextId,                         m_textureContextId)               \
+    X(GetTextureUnitObject,                        m_textureUnitBase)                \
+    X(GetTransformFeedbackCapturedVertices,        m_transformFeedbackCapturedVertices) \
+    X(GetTransformFeedbackGeneration,              m_transformFeedbackGeneration)    \
+    X(GetTransformFeedbackPausedPrimitiveCounter,  m_transformFeedbackPausedPrimitiveCounter) \
+    X(GetTransformFeedbackProgram,                 m_transformFeedbackProgram)       \
+    X(GetViewport,                                 m_viewport)                       \
+    X(GetViewportIndexed,                          m_viewportIndexed)                \
+    X(IsCapabilityEnabled,                         m_capability)                     \
+    X(IsCapabilityEnabledIndexed,                  m_capabilityIndexed)              \
+    X(IsTransformFeedbackActive,                   m_transformFeedbackActive)        \
+    X(IsTransformFeedbackPaused,                   m_transformFeedbackPaused)        \
+    X(GetBoundTransformFeedbackLifetimeId,         m_boundTransformFeedbackLifetimeId)
+    // clang-format on
+
+    // The seven F-class fields, for the arithmetic below and for the sticky table's proof.
+    // The forwarded set IS the sticky set (PipeFields.def marks the same seven rows F and
+    // sticky), so an eighth sticky row without a forwarder is refused here, not by a test.
+    inline constexpr SizeT kMGPipeForwardedFieldCount = 7;
+    static_assert(kMGPipeForwardedFieldCount == kMGPipeInputStickyFieldCount,
+                  "the forwarded (F-class) fields and the sticky fields of PipeFields.def are the same seven rows");
+
+    // The block the backends read instead of GLContext (ARCHITECTURE.md 9.2 phase A, P1 brief
+    // D4). One struct, three storage classes, and every accessor keeps the NAME, PARAMETERS
+    // and RETURN TYPE of its GLContext counterpart (MG_State/GLState/Core.h) so the strangler
+    // sed is type-neutral:
+    //
+    //   V (value)            copied out of GLContext at fill time by calling the same accessor;
+    //                        no derivation logic is re-implemented here, which is what keeps the
+    //                        copy semantically identical by construction.
+    //   O (object reference) a SharedPtr copy, or a raw pointer to the live GLContext-owned
+    //                        slot/array for the accessors that return a non-const reference into
+    //                        the context. Identity is what phase C turns into a handle.
+    //   F (forwarded)        argument-keyed lookups and reverse-channel calls, defined out of
+    //                        line in MG_Impl/Pipe/PipeFill.cpp (the client side, where the live
+    //                        context may be spelled). Sticky: stamped once by the first fill that
+    //                        sees a live context.
+    //
+    // Every non-forwarded accessor is MGP_INPUT_CHECK (poison) -> MGP_INPUT_VERIFY_READ
+    // (compare-at-read) -> the storage. Both macros expand to nothing when their switch is
+    // off, so a plain MOBILEGL_PIPE_PUSH build's accessor is a load.
+    struct PipeInputs {
+        using GLContext = MG_State::GLState::GLContext;
+        using BufferObject = MG_State::GLState::BufferObject;
+        using BufferTarget = ::MobileGL::BufferTarget;
+        using FramebufferObject = MG_State::GLState::FramebufferObject;
+        using FramebufferTarget = ::MobileGL::FramebufferTarget;
+        using VertexArrayObject = MG_State::GLState::VertexArrayObject;
+        using ProgramObject = MG_State::GLState::ProgramObject;
+        using ITextureObject = MG_State::GLState::ITextureObject;
+        using TextureUnit = MG_State::GLState::TextureUnit;
+        using ImageTextureBinding = MG_State::GLState::ImageTextureBinding;
+        using CurrentVertexAttributeValue = MG_State::GLState::CurrentVertexAttributeValue;
+
+        static constexpr SizeT kBufferTargetCount = static_cast<SizeT>(BufferTarget::BufferTargetCount);
+        static constexpr SizeT kFramebufferTargetCount = static_cast<SizeT>(FramebufferTarget::FramebufferTargetCount);
+        static constexpr SizeT kCapabilityCount = static_cast<SizeT>(CapabilityInput::CapabilityInputCount);
+        static constexpr SizeT kMaxViewports = RenderStateParameters::MAX_VIEWPORTS;
+        static constexpr SizeT kMaxVertexAttribs = VertexArrayObject::MAX_VERTEX_ATTRIBS;
+        static constexpr SizeT kStencilFaceCount = static_cast<SizeT>(StencilFace::StencilFaceCount);
+
+        // IsCapabilityEnabledIndexed's two indexed capabilities, the only ones GLContext keeps
+        // indexed state for (RenderState::IsCapabilityEnabledIndexed).
+        struct IndexedCapabilities {
+            Bool Blend[kMGMaxDrawBuffers];
+            Bool ScissorTest[kMaxViewports];
+        };
+
+        // ---- identity / liveness (not fields) ----
+        // Whether a live GLContext exists. Forwarded (PipeFill.cpp): under push MGB_CTX_LIVE
+        // must be true as soon as a context exists, fill or no fill, which is what today's
+        // null-context guards test.
+        Bool IsLive() const;
+        // The live GLContext's address at the last fill; serves MGB_CTX_IDENTITY.
+        const void* ContextIdentity() const { return m_contextIdentity; }
+        // The verb of the last fill, kVerbCount before the first one.
+        MGPipeVerb CurrentVerb() const { return m_currentVerb; }
+#if MOBILEGL_PIPE_POISON
+        const MGPipeFilledState& FilledState() const { return m_filled; }
+#endif
+
+        // ---- V: values ----
+        Int GetActiveTextureUnit() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetActiveTextureUnit);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetActiveTextureUnit, 0, 0);
+            return m_activeTextureUnit;
+        }
+        const FloatVec4& GetBlendColor() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBlendColor);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBlendColor, 0, 0);
+            return m_blendColor;
+        }
+        void GetBlendEquationIndexed(Uint index, BlendEquation& color, BlendEquation& alpha) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBlendEquationIndexed);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBlendEquationIndexed, index, 0);
+            if (index >= kMGMaxDrawBuffers) {
+                MOBILEGL_ASSERT(false, "Blend equation index out of range: %u", index);
+                return;
+            }
+            color = m_blendEquation[index][0];
+            alpha = m_blendEquation[index][1];
+        }
+        void GetBlendFuncIndexed(Uint index, BlendFactor& srcRGB, BlendFactor& dstRGB, BlendFactor& srcAlpha,
+                                 BlendFactor& dstAlpha) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBlendFuncIndexed);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBlendFuncIndexed, index, 0);
+            if (index >= kMGMaxDrawBuffers) {
+                MOBILEGL_ASSERT(false, "Blend func index out of range: %u", index);
+                return;
+            }
+            srcRGB = m_blendFunc[index][0];
+            dstRGB = m_blendFunc[index][1];
+            srcAlpha = m_blendFunc[index][2];
+            dstAlpha = m_blendFunc[index][3];
+        }
+        // Dead field: filled, read by no backend since the D21 XFB counter-slot rekey; kept so
+        // the vendored inventory row keeps its mapping (Coverage.def).
+        Uint GetBoundTransformFeedbackName() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBoundTransformFeedbackName);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBoundTransformFeedbackName, 0, 0);
+            return m_boundTransformFeedbackName;
+        }
+        SizeT GetTouchedBufferBindingPointCount(BufferTarget target) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTouchedBufferBindingPointCount);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTouchedBufferBindingPointCount, static_cast<Uint>(target), 0);
+            return m_touchedBindingPointCount[static_cast<SizeT>(target)];
+        }
+        GLenum GetClampReadColor() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetClampReadColor);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetClampReadColor, 0, 0);
+            return m_clampReadColor;
+        }
+        const FloatVec4& GetClearColor() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetClearColor);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetClearColor, 0, 0);
+            return m_clearColor;
+        }
+        Float GetClearDepth() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetClearDepth);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetClearDepth, 0, 0);
+            return m_clearDepth;
+        }
+        Uint32 GetClearStencil() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetClearStencil);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetClearStencil, 0, 0);
+            return m_clearStencil;
+        }
+        BoolVec4 GetColorMaskIndexed(Uint index) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetColorMaskIndexed);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetColorMaskIndexed, index, 0);
+            return m_colorMask[index];
+        }
+        CullFaceMode GetCullFaceMode() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetCullFaceMode);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetCullFaceMode, 0, 0);
+            return m_cullFaceMode;
+        }
+        const CurrentVertexAttributeValue& GetCurrentVertexAttribute(Uint index) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetCurrentVertexAttribute);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetCurrentVertexAttribute, index, 0);
+            if (index >= kMaxVertexAttribs) {
+                static const CurrentVertexAttributeValue defaultValue{};
+                MGLOG_E_ONCE("PipeInputs::GetCurrentVertexAttribute: index %u is out of range", index);
+                return defaultValue;
+            }
+            return m_currentVertexAttribute[index];
+        }
+        DepthTestFunc GetDepthFunc() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetDepthFunc);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetDepthFunc, 0, 0);
+            return m_depthFunc;
+        }
+        Bool GetDepthMask() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetDepthMask);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetDepthMask, 0, 0);
+            return m_depthMask;
+        }
+        const FloatVec2& GetDepthRangeIndexed(Uint index) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetDepthRangeIndexed);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetDepthRangeIndexed, index, 0);
+            if (index >= kMaxViewports) {
+                MOBILEGL_ASSERT(false, "Depth range index out of range: %u", index);
+                return m_depthRange[0];
+            }
+            return m_depthRange[index];
+        }
+        Float GetLineWidth() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetLineWidth);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetLineWidth, 0, 0);
+            return m_lineWidth;
+        }
+        LogicOperation GetLogicOp() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetLogicOp);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetLogicOp, 0, 0);
+            return m_logicOp;
+        }
+        Int GetMaxTouchedTextureUnit() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetMaxTouchedTextureUnit);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetMaxTouchedTextureUnit, 0, 0);
+            return m_maxTouchedTextureUnit;
+        }
+        Float GetMinSampleShadingValue() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetMinSampleShadingValue);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetMinSampleShadingValue, 0, 0);
+            return m_minSampleShadingValue;
+        }
+        const FloatVec2& GetPatchDefaultInnerLevel() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPatchDefaultInnerLevel);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPatchDefaultInnerLevel, 0, 0);
+            return m_patchDefaultInnerLevel;
+        }
+        const FloatVec4& GetPatchDefaultOuterLevel() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPatchDefaultOuterLevel);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPatchDefaultOuterLevel, 0, 0);
+            return m_patchDefaultOuterLevel;
+        }
+        Uint GetPatchVertices() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPatchVertices);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPatchVertices, 0, 0);
+            return m_patchVertices;
+        }
+        Uint GetPipelineStateVersion() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPipelineStateVersion);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPipelineStateVersion, 0, 0);
+            return m_pipelineStateVersion;
+        }
+        Uint GetRenderStateParametersVersion() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetRenderStateParametersVersion);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetRenderStateParametersVersion, 0, 0);
+            return m_renderStateParametersVersion;
+        }
+        PixelStoreParameters GetPixelStoreParameters(Bool isUnpack) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPixelStoreParameters);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPixelStoreParameters, isUnpack ? 1u : 0u, 0);
+            return m_pixelStore[isUnpack ? 1 : 0];
+        }
+        GLenum GetPolygonModeFront() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPolygonModeFront);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPolygonModeFront, 0, 0);
+            return m_polygonModeFront;
+        }
+        Float GetPolygonOffsetFactor() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPolygonOffsetFactor);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPolygonOffsetFactor, 0, 0);
+            return m_polygonOffsetFactor;
+        }
+        Float GetPolygonOffsetUnits() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPolygonOffsetUnits);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPolygonOffsetUnits, 0, 0);
+            return m_polygonOffsetUnits;
+        }
+        Uint32 GetPrimitiveRestartIndex() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetPrimitiveRestartIndex);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetPrimitiveRestartIndex, 0, 0);
+            return m_primitiveRestartIndex;
+        }
+        ProvokingVertexMode GetProvokingVertexMode() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetProvokingVertexMode);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetProvokingVertexMode, 0, 0);
+            return m_provokingVertexMode;
+        }
+        const RenderStateParameters& GetRenderStateParameters() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetRenderStateParameters);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetRenderStateParameters, 0, 0);
+            return m_renderState;
+        }
+        Uint64 GetSamplingResolutionGeneration() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetSamplingResolutionGeneration);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetSamplingResolutionGeneration, 0, 0);
+            return m_samplingResolutionGeneration;
+        }
+        const IntVec4& GetScissorBox() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetScissorBox);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetScissorBox, 0, 0);
+            return m_scissorBox;
+        }
+        const StencilFaceState& GetStencilState(StencilFace face) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetStencilState);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetStencilState, static_cast<Uint>(face), 0);
+            return m_stencil[face == StencilFace::Back ? 1 : 0];
+        }
+        Uint64 GetTextureBindGeneration() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTextureBindGeneration);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTextureBindGeneration, 0, 0);
+            return m_textureBindGeneration;
+        }
+        Uint64 GetTextureContextId() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTextureContextId);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTextureContextId, 0, 0);
+            return m_textureContextId;
+        }
+        Uint64 GetTransformFeedbackCapturedVertices() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTransformFeedbackCapturedVertices);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTransformFeedbackCapturedVertices, 0, 0);
+            return m_transformFeedbackCapturedVertices;
+        }
+        Uint64 GetTransformFeedbackGeneration() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTransformFeedbackGeneration);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTransformFeedbackGeneration, 0, 0);
+            return m_transformFeedbackGeneration;
+        }
+        Uint64 GetTransformFeedbackPausedPrimitiveCounter() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTransformFeedbackPausedPrimitiveCounter);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTransformFeedbackPausedPrimitiveCounter, 0, 0);
+            return m_transformFeedbackPausedPrimitiveCounter;
+        }
+        Uint64 GetBoundTransformFeedbackLifetimeId() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBoundTransformFeedbackLifetimeId);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBoundTransformFeedbackLifetimeId, 0, 0);
+            return m_boundTransformFeedbackLifetimeId;
+        }
+        IntVec4 GetViewport() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetViewport);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetViewport, 0, 0);
+            return m_viewport;
+        }
+        const FloatVec4& GetViewportIndexed(Uint index) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetViewportIndexed);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetViewportIndexed, index, 0);
+            if (index >= kMaxViewports) {
+                MOBILEGL_ASSERT(false, "Viewport index out of range: %u", index);
+                return m_viewportIndexed[0];
+            }
+            return m_viewportIndexed[index];
+        }
+        Bool IsCapabilityEnabled(CapabilityInput cap) const {
+            MGP_INPUT_CHECK(MGPipeInputField::IsCapabilityEnabled);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::IsCapabilityEnabled, static_cast<Uint>(cap), 0);
+            const auto index = static_cast<SizeT>(cap);
+            return index < kCapabilityCount ? m_capability[index] : false;
+        }
+        // Blend and ScissorTest are the only indexed capabilities GLContext keeps; no backend
+        // asks for another (VulkanRenderer asks Blend). Any other cap is a read the fill cannot
+        // have served: Fatal{UnmigratedPipeInput} naming the field and the verb, the cap in a
+        // preceding MGLOG_E.
+        Bool IsCapabilityEnabledIndexed(CapabilityInput cap, Uint index) const {
+            MGP_INPUT_CHECK(MGPipeInputField::IsCapabilityEnabledIndexed);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::IsCapabilityEnabledIndexed, static_cast<Uint>(cap), index);
+            if (cap == CapabilityInput::Blend) {
+                return index < kMGMaxDrawBuffers ? m_capabilityIndexed.Blend[index] : false;
+            }
+            if (cap == CapabilityInput::ScissorTest) {
+                return index < kMaxViewports ? m_capabilityIndexed.ScissorTest[index] : false;
+            }
+            MGLOG_E("PipeInputs::IsCapabilityEnabledIndexed: no indexed storage for cap=%d (index=%u)",
+                    static_cast<int>(cap), index);
+            MGPipeInputPoisonFatalForVerb(MGPipeInputField::IsCapabilityEnabledIndexed, m_currentVerb);
+        }
+        Bool IsTransformFeedbackActive() const {
+            MGP_INPUT_CHECK(MGPipeInputField::IsTransformFeedbackActive);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::IsTransformFeedbackActive, 0, 0);
+            return m_transformFeedbackActive;
+        }
+        Bool IsTransformFeedbackPaused() const {
+            MGP_INPUT_CHECK(MGPipeInputField::IsTransformFeedbackPaused);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::IsTransformFeedbackPaused, 0, 0);
+            return m_transformFeedbackPaused;
+        }
+
+        // ---- O: object references ----
+        const SharedPtr<VertexArrayObject>& GetBoundVertexArray() {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBoundVertexArray);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBoundVertexArray, 0, 0);
+            return m_boundVertexArray;
+        }
+        // A target the fill left null (one outside GlobalBufferTargets / BufferBindPointTargets,
+        // or a read before any fill) is a read the fill cannot have served: the poison Fatal,
+        // the target in a preceding MGLOG_E.
+        BindingSlot<BufferObject>& GetBufferBindingSlot(BufferTarget target) {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBufferBindingSlot);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBufferBindingSlot, static_cast<Uint>(target), 0);
+            const auto index = static_cast<SizeT>(target);
+            if (index >= kBufferTargetCount || m_bufferBindingSlot[index] == nullptr) {
+                MGLOG_E("PipeInputs::GetBufferBindingSlot: no slot for target=%d", static_cast<int>(target));
+                MGPipeInputPoisonFatalForVerb(MGPipeInputField::GetBufferBindingSlot, m_currentVerb);
+            }
+            return *m_bufferBindingSlot[index];
+        }
+        BindingSlotRange1D<BufferObject>& GetBufferBindingPoint(BufferTarget target, Uint index) {
+            MGP_INPUT_CHECK(MGPipeInputField::GetBufferBindingPoint);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetBufferBindingPoint, static_cast<Uint>(target), index);
+            const auto targetIndex = static_cast<SizeT>(target);
+            if (targetIndex >= kBufferTargetCount || m_bufferBindingPointBase[targetIndex] == nullptr) {
+                MGLOG_E("PipeInputs::GetBufferBindingPoint: no binding points for target=%d (index=%u)",
+                        static_cast<int>(target), index);
+                MGPipeInputPoisonFatalForVerb(MGPipeInputField::GetBufferBindingPoint, m_currentVerb);
+            }
+            // The live storage is Array<Array<BindingSlotRange1D, BufferBindingPointCount>, N>
+            // (BufferState.h), so base[index] is the live slot GLContext would hand out.
+            return m_bufferBindingPointBase[targetIndex][index];
+        }
+        BindingSlot<FramebufferObject>& GetFramebufferBindingSlot(FramebufferTarget target) {
+            MGP_INPUT_CHECK(MGPipeInputField::GetFramebufferBindingSlot);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetFramebufferBindingSlot, static_cast<Uint>(target), 0);
+            const auto index = static_cast<SizeT>(target);
+            if (index >= kFramebufferTargetCount || m_framebufferBindingSlot[index] == nullptr) {
+                MGLOG_E("PipeInputs::GetFramebufferBindingSlot: no slot for target=%d", static_cast<int>(target));
+                MGPipeInputPoisonFatalForVerb(MGPipeInputField::GetFramebufferBindingSlot, m_currentVerb);
+            }
+            return *m_framebufferBindingSlot[index];
+        }
+        ImageTextureBinding& GetImageTextureBinding(Int unit) {
+            MGP_INPUT_CHECK(MGPipeInputField::GetImageTextureBinding);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetImageTextureBinding, static_cast<Uint>(unit), 0);
+            if (m_imageTextureBindingBase == nullptr) {
+                MGPipeInputPoisonFatalForVerb(MGPipeInputField::GetImageTextureBinding, m_currentVerb);
+            }
+            return m_imageTextureBindingBase[unit];
+        }
+        const ImageTextureBinding& GetImageTextureBinding(Int unit) const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetImageTextureBinding);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetImageTextureBinding, static_cast<Uint>(unit), 0);
+            if (m_imageTextureBindingBase == nullptr) {
+                MGPipeInputPoisonFatalForVerb(MGPipeInputField::GetImageTextureBinding, m_currentVerb);
+            }
+            return m_imageTextureBindingBase[unit];
+        }
+        const SharedPtr<ProgramObject>& GetProgramForDispatch() {
+            MGP_INPUT_CHECK(MGPipeInputField::GetProgramForDispatch);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetProgramForDispatch, 0, 0);
+            return m_programForDispatch;
+        }
+        const SharedPtr<ProgramObject>& GetProgramForDraw() {
+            MGP_INPUT_CHECK(MGPipeInputField::GetProgramForDraw);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetProgramForDraw, 0, 0);
+            return m_programForDraw;
+        }
+        const SharedPtr<ProgramObject>& GetTransformFeedbackProgram() const {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTransformFeedbackProgram);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTransformFeedbackProgram, 0, 0);
+            return m_transformFeedbackProgram;
+        }
+        TextureUnit& GetTextureUnitObject(Int unit) {
+            MGP_INPUT_CHECK(MGPipeInputField::GetTextureUnitObject);
+            MGP_INPUT_VERIFY_READ(MGPipeInputField::GetTextureUnitObject, static_cast<Uint>(unit), 0);
+            if (m_textureUnitBase == nullptr) {
+                MGPipeInputPoisonFatalForVerb(MGPipeInputField::GetTextureUnitObject, m_currentVerb);
+            }
+            return m_textureUnitBase[unit];
+        }
+
+        // ---- F: forwarded to the live context (MG_Impl/Pipe/PipeFill.cpp); sticky ----
+        // Each takes an argument that is not verb state - a GL name, a lifetime id, a target -
+        // i.e. it is a lookup or a reverse-channel write, not a state read; there is no value
+        // the filler could copy and no verb whose fill could make it stale. Phase C replaces
+        // them with handle tables and callbacks.
+        // They carry no MGP_INPUT_CHECK / MGP_INPUT_VERIFY_READ (the declared exception to
+        // P1 brief D4's "every accessor body"): a forward is a live call, not a stored value,
+        // and InvalidateCompileEnv is reached from backend initialisation before any verb has
+        // filled, where a check would be Fatal{...@<none>} on every start. Their sticky stamp
+        // is therefore consulted by no accessor; the tests pin it through
+        // MGPipeInputFieldIsFresh directly.
+        SizeT GetBufferBindingPointCount(BufferTarget target) const;
+        const SharedPtr<ProgramObject>& GetProgramObject(Uint index);
+        const SharedPtr<ITextureObject>& GetTextureObject(Uint index);
+        Bool HasOpenTransformFeedbackSpan(Uint64 lifetimeId) const;
+        void InvalidateCompileEnv();
+        Bool ValidateProgramName(Uint index) const;
+        // Dropped with an MGLOG_E_ONCE when no context is live; today's guarded sites never
+        // reach it without one.
+        void RecordError(ErrorCode code, UniquePtr<ErrorInfo> info);
+
+        // ---- the storage visitor ----
+        // Calls fn(a.<member>, b.<member>) for the field's storage and returns its result; returns
+        // false without calling fn for a forwarded field, which has none. The comparator's
+        // per-field equality and the verify corruption injector are both one call of this.
+        template <class Fn>
+        static Bool VisitStorage(MGPipeInputField field, PipeInputs& a, PipeInputs& b, Fn&& fn) {
+            switch (field) {
+#define MGP_INPUT_VISIT(Field, Member)                                                                                 \
+    case MGPipeInputField::Field:                                                                                      \
+        return fn(a.Member, b.Member);
+                MGP_INPUT_STORAGE_LIST(MGP_INPUT_VISIT)
+#undef MGP_INPUT_VISIT
+            default:
+                return false;
+            }
+        }
+        template <class Fn>
+        static Bool VisitStorage(MGPipeInputField field, const PipeInputs& a, const PipeInputs& b, Fn&& fn) {
+            switch (field) {
+#define MGP_INPUT_VISIT(Field, Member)                                                                                 \
+    case MGPipeInputField::Field:                                                                                      \
+        return fn(a.Member, b.Member);
+                MGP_INPUT_STORAGE_LIST(MGP_INPUT_VISIT)
+#undef MGP_INPUT_VISIT
+            default:
+                return false;
+            }
+        }
+
+    private:
+        // The one door into the storage from the client side (MG_Impl/Pipe/PipeFill.cpp):
+        // the filler's per-field copies and stamps, and the verify snapshot.
+        friend struct MGPipeFillAccess;
+
+        // ---- identity ----
+        const void* m_contextIdentity = nullptr;
+        Bool m_live = false;
+        MGPipeVerb m_currentVerb = MGPipeVerb::kVerbCount;
+#if MOBILEGL_PIPE_POISON
+        MGPipeFilledState m_filled{};
+#endif
+
+        // ---- V ----
+        Int m_activeTextureUnit = 0;
+        FloatVec4 m_blendColor{};
+        BlendEquation m_blendEquation[kMGMaxDrawBuffers][2]{};
+        BlendFactor m_blendFunc[kMGMaxDrawBuffers][4]{};
+        Uint m_boundTransformFeedbackName = 0;
+        SizeT m_touchedBindingPointCount[kBufferTargetCount]{};
+        GLenum m_clampReadColor = 0;
+        FloatVec4 m_clearColor{};
+        Float m_clearDepth = 0.f;
+        Uint32 m_clearStencil = 0;
+        BoolVec4 m_colorMask[kMGMaxDrawBuffers]{};
+        CullFaceMode m_cullFaceMode{};
+        CurrentVertexAttributeValue m_currentVertexAttribute[kMaxVertexAttribs]{};
+        DepthTestFunc m_depthFunc{};
+        Bool m_depthMask = false;
+        FloatVec2 m_depthRange[kMaxViewports]{};
+        Float m_lineWidth = 0.f;
+        LogicOperation m_logicOp{};
+        Int m_maxTouchedTextureUnit = -1;
+        Float m_minSampleShadingValue = 0.f;
+        FloatVec2 m_patchDefaultInnerLevel{};
+        FloatVec4 m_patchDefaultOuterLevel{};
+        Uint m_patchVertices = 0;
+        Uint m_pipelineStateVersion = 0;
+        Uint m_renderStateParametersVersion = 0;
+        PixelStoreParameters m_pixelStore[2]{}; // [0] = pack, [1] = unpack
+        GLenum m_polygonModeFront = 0;
+        Float m_polygonOffsetFactor = 0.f;
+        Float m_polygonOffsetUnits = 0.f;
+        Uint32 m_primitiveRestartIndex = 0;
+        ProvokingVertexMode m_provokingVertexMode{};
+        RenderStateParameters m_renderState{};
+        Uint64 m_samplingResolutionGeneration = 0;
+        Uint64 m_textureBindGeneration = 0;
+        Uint64 m_textureContextId = 0;
+        IntVec4 m_scissorBox{};
+        StencilFaceState m_stencil[kStencilFaceCount]{};
+        Uint64 m_transformFeedbackCapturedVertices = 0;
+        Uint64 m_transformFeedbackGeneration = 0;
+        Uint64 m_transformFeedbackPausedPrimitiveCounter = 0;
+        Uint64 m_boundTransformFeedbackLifetimeId = 0;
+        IntVec4 m_viewport{};
+        FloatVec4 m_viewportIndexed[kMaxViewports]{};
+        Bool m_capability[kCapabilityCount]{};
+        IndexedCapabilities m_capabilityIndexed{};
+        Bool m_transformFeedbackActive = false;
+        Bool m_transformFeedbackPaused = false;
+
+        // ---- O ----
+        SharedPtr<VertexArrayObject> m_boundVertexArray;
+        BindingSlot<BufferObject>* m_bufferBindingSlot[kBufferTargetCount]{};
+        BindingSlotRange1D<BufferObject>* m_bufferBindingPointBase[kBufferTargetCount]{};
+        BindingSlot<FramebufferObject>* m_framebufferBindingSlot[kFramebufferTargetCount]{};
+        ImageTextureBinding* m_imageTextureBindingBase = nullptr;
+        SharedPtr<ProgramObject> m_programForDispatch;
+        SharedPtr<ProgramObject> m_programForDraw;
+        SharedPtr<ProgramObject> m_transformFeedbackProgram;
+        TextureUnit* m_textureUnitBase = nullptr;
+    };
+
+    // The single global the backends read through MGB_CTX (ARCHITECTURE.md 9.2). An inline
+    // variable: no .cpp is needed for the definition.
+    inline PipeInputs gPipeInputs{};
+
+    // Every field has storage or is forwarded, and nothing else.
+#define MGP_INPUT_COUNT_ONE(Field, Member) +1
+    static_assert(0 MGP_INPUT_STORAGE_LIST(MGP_INPUT_COUNT_ONE) + kMGPipeForwardedFieldCount == kMGPipeInputFieldCount,
+                  "MGP_INPUT_STORAGE_LIST plus the seven forwarded fields is not the PipeInputs field set");
+#undef MGP_INPUT_COUNT_ONE
+    // The docs budget ~20 KB; the block is a few KB.
+    static_assert(sizeof(PipeInputs) < 20 * 1024, "PipeInputs outgrew its budget");
+
+#if MOBILEGL_PIPE_VERIFY
+    // PipeInputs.cpp. Per-field equality for the entry compare (P1 brief D8): V by value
+    // through G4's MGPipeFieldEqual (bitwise floats, field-wise structs), O by identity, F
+    // always equal (no storage).
+    Bool MGPipeInputsFieldEqual(MGPipeInputField field, const PipeInputs& a, const PipeInputs& b);
+    // PipeInputs.cpp. The entry compare: every field in `mask` of the pushed block against the
+    // snapshot, first differing field out. Exported from the shared library on purpose - the
+    // retrace-verify CI job proves it swapped in a verify build by finding this symbol with
+    // nm -D, so a "green" run against a library without the comparator cannot happen.
+#if defined(__GNUC__) || defined(__clang__)
+    __attribute__((visibility("default")))
+#endif
+    Bool MGPipeVerifyInputs(const PipeInputs& pushed, const PipeInputs& snapshot, const MGPipeFieldMask& mask,
+                            MGPipeInputField* outField);
+    // PipeInputs.cpp. Negative control A: perturbs one field's storage (flip a Bool, +1 a
+    // scalar, ^0x5A the first byte of a struct, flip a pointer's low bits - never
+    // dereferenced, the snapshot is only ever compared). Returns false for a forwarded field,
+    // which has nothing to corrupt.
+    Bool MGPipeApplyVerifyCorruption(PipeInputs& snapshot, MGPipeInputField field);
+#endif
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Impl/GLImpl/Drawing/GL_Drawing.cpp

@@ -11,6 +11,7 @@
 #include <MG_State/GLState/Core.h>
 #include <MG_State/EGLState/Core.h>
 #include <MG_Backend/BackendObjects.h>
+#include <MG_Impl/Pipe/PipeFill.h>
 #include "../Getter/GL_Getter.h"
 
 namespace MobileGL::MG_Impl::GLImpl {
@@ -34,8 +35,81 @@ namespace MobileGL::MG_Impl::GLImpl {
         return true;
     }
 
-    static Bool ValidateCurrentProgramForExecution(const char* functionName) {
-        return ValidateProgramForExecution(MG_State::pGLContext->GetProgramForDraw(), functionName);
+    // Takes the ALREADY-RESOLVED draw program rather than looking it up: GLContext::GetProgramForDraw
+    // is not a plain getter (it settles the program's link and SPIR-V jobs so every version a
+    // backend samples during this draw describes the program it is drawing), so the draw funnel
+    // below resolves it exactly once and hands it to both users.
+    static Bool ValidateResolvedProgramForDraw(const SharedPtr<MG_State::GLState::ProgramObject>& currentProgram,
+                                               const char* functionName) {
+        // "If there is no current program object or bound program pipeline object, the results of
+        // a draw are UNDEFINED" - and undefined is not an error (GL 4.6 core 7.3, ES 3.1 7.3).
+        // The draw is dropped, silently, which is one of the shapes "undefined" is allowed to
+        // take; recording INVALID_OPERATION here is not, and es31cSeparateShaderObjsTests'
+        // StateInteraction reads exactly that error back after useProgram(0) + bindProgramPipeline(0).
+        // A DISPATCH is the opposite rule ("INVALID_OPERATION if there is no active program for
+        // the compute shader stage"), which is why this lives on the draw path and not in the
+        // shared ValidateProgramForExecution below.
+        if (!currentProgram) return false;
+        if (!ValidateProgramForExecution(currentProgram, functionName)) return false;
+
+        // GL 4.6 core 7.4.1, the pipeline validation rule every vertex-transferring command
+        // inherits: it is an INVALID_OPERATION when a tessellation control, tessellation
+        // evaluation or geometry stage has an executable but no program supplies an executable
+        // VERTEX shader. A non-separable program cannot reach this - the link rule forbids the
+        // shape - so in practice it catches a program pipeline assembled out of stage programs,
+        // which today draws happily and renders nothing.
+        //
+        // Asked of the EXECUTABLE, like the compute check below: for a pipeline the resolved
+        // program is the graphics composite, whose linked-shader snapshot is built out of exactly
+        // the pipeline's own graphics stage programs (GLContext::GetProgramForDraw), and the only
+        // stage compositing ever invents is a default FRAGMENT shader. A fragment-only pipeline is
+        // deliberately NOT rejected: the rule above names the three pre-rasterization stages, and
+        // nothing else here should start refusing draws GL accepts.
+        //
+        // On the DRAW path only, never in ValidateProgramForExecution itself, so a dispatch -
+        // which shares that helper and legitimately has no vertex stage - is untouched.
+        const Bool hasPreRasterizationStage = currentProgram->HasLinkedShaderStage(ShaderStage::Geometry) ||
+                                              currentProgram->HasLinkedShaderStage(ShaderStage::TessControl) ||
+                                              currentProgram->HasLinkedShaderStage(ShaderStage::TessEval);
+        if (hasPreRasterizationStage && !currentProgram->HasLinkedShaderStage(ShaderStage::Vertex)) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", functionName,
+                    "The program in use runs a geometry or tessellation stage but has no vertex shader stage."));
+            return false;
+        }
+
+        return true;
+    }
+
+    // gl_NumSamples has no SPIR-V built-in, so the source pipeline lowers it onto a reserved
+    // default-block uniform (see InjectNumSamplesBuiltinShim). This is where that uniform is paid
+    // for: the value is a property of the DRAW FRAMEBUFFER, not of the program, so one program
+    // drawn into a 4x target and then into the default framebuffer must see 4 and then 1 - which
+    // rules out baking it at link time.
+    //
+    // Per draw rather than on framebuffer changes because the pair (program, framebuffer) is what
+    // decides the value and either half can move between draws. It costs a phase-A flag read for
+    // every program that has no shim, and a 4-byte compare for the ones that do: the write only
+    // bumps the UBO content version when the number actually changes, so a run of draws into one
+    // framebuffer re-uploads nothing.
+    static void PublishDrawFramebufferSampleCount(const SharedPtr<MG_State::GLState::ProgramObject>& program) {
+        if (!program || !program->UsesReservedNumSamples()) return;
+        // GL 4.6 core 15.2.2: gl_NumSamples is the number of samples in the framebuffer, or ONE
+        // when the target is not multisampled - where glGetIntegerv(GL_SAMPLES) answers zero.
+        program->WriteReservedNumSamples(static_cast<Int>(std::max<GLint>(ResolveDrawFramebufferSampleCount(), 1)));
+    }
+
+    // The one funnel every drawing command passes through. Order is load-bearing: validate first
+    // (a rejected draw must leave state alone), then publish the sample count - which reads the
+    // DRAW FRAMEBUFFER binding, so it has to run after the caller's framebuffer state is settled
+    // and before the backend consumes the program's UBO content version.
+    static Bool PrepareCurrentProgramForDraw(const char* functionName) {
+        const auto& currentProgram = MG_State::pGLContext->GetProgramForDraw();
+        if (!ValidateResolvedProgramForDraw(currentProgram, functionName)) return false;
+        PublishDrawFramebufferSampleCount(currentProgram);
+        return true;
     }
 
     // A dispatch resolves its program through the DISPATCH accessor: with a pipeline bound
@@ -73,6 +147,20 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_TRIANGLES: return static_cast<Uint64>(count / 3);
         case GL_TRIANGLE_STRIP:
         case GL_TRIANGLE_FAN: return count >= 3 ? static_cast<Uint64>(count - 2) : 0;
+        // Adjacency primitives (GL 4.6 core table 10.1). Only a geometry stage can consume
+        // them, and it is the ADJACENT-free primitive count that reaches it: 4 vertices per
+        // line, 6 per triangle, one per step for the strips. Answering 0 here - which is what
+        // the default arm did - made AccountTransformFeedbackPrimitives bail before it had
+        // recorded anything, so an adjacency capture advanced neither the captured-vertex
+        // counter the scattered-capture path is bounded by nor the geometry-capture-draw flag
+        // that routes the transform feedback queries to the driver's own counter.
+        case GL_LINES_ADJACENCY: return static_cast<Uint64>(count / 4);
+        case GL_LINE_STRIP_ADJACENCY: return count >= 4 ? static_cast<Uint64>(count - 3) : 0;
+        case GL_TRIANGLES_ADJACENCY: return static_cast<Uint64>(count / 6);
+        case GL_TRIANGLE_STRIP_ADJACENCY: return count >= 6 ? static_cast<Uint64>((count - 4) / 2) : 0;
+        // GL_PATCHES is deliberately absent: the tessellator's amplification is not knowable
+        // on the CPU, and answering 0 is what defers GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN
+        // to the driver's own counter, which is the only correct source for a patch capture.
         default: return 0;
         }
     }
@@ -99,11 +187,17 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_LINES:
         case GL_LINE_STRIP:
         case GL_LINE_LOOP:
+        // An adjacency primitive delivers the same line/triangle to the geometry stage; the
+        // adjacent vertices are context, not part of the primitive.
+        case GL_LINES_ADJACENCY:
+        case GL_LINE_STRIP_ADJACENCY:
             verticesPerPrimitive = 2;
             break;
         case GL_TRIANGLES:
         case GL_TRIANGLE_STRIP:
         case GL_TRIANGLE_FAN:
+        case GL_TRIANGLES_ADJACENCY:
+        case GL_TRIANGLE_STRIP_ADJACENCY:
             verticesPerPrimitive = 3;
             break;
         default:
@@ -308,11 +402,21 @@ namespace MobileGL::MG_Impl::GLImpl {
             case GL_POINTS:
                 compatible = mode == GL_POINTS;
                 break;
+            // The adjacency modes belong here too (GL 4.6 core table 13.1, ES 3.2 table 12.1).
+            // This arm is only reached when the program has NO geometry or tessellation
+            // evaluation stage, and without a geometry stage the adjacent vertices are simply
+            // ignored (GL 4.6 core 10.1) - the primitive assembled IS a plain line or triangle,
+            // so the combination is legal and must capture. Omitting them raised a spurious
+            // GL_INVALID_OPERATION and dropped the draw entirely, leaving the capture buffer
+            // with its pre-draw bytes. The geometry-stage input table above already carries the
+            // same four arms; this is the second table catching up with it.
             case GL_LINES:
-                compatible = mode == GL_LINES || mode == GL_LINE_STRIP || mode == GL_LINE_LOOP;
+                compatible = mode == GL_LINES || mode == GL_LINE_STRIP || mode == GL_LINE_LOOP ||
+                             mode == GL_LINES_ADJACENCY || mode == GL_LINE_STRIP_ADJACENCY;
                 break;
             case GL_TRIANGLES:
-                compatible = mode == GL_TRIANGLES || mode == GL_TRIANGLE_STRIP || mode == GL_TRIANGLE_FAN;
+                compatible = mode == GL_TRIANGLES || mode == GL_TRIANGLE_STRIP || mode == GL_TRIANGLE_FAN ||
+                             mode == GL_TRIANGLES_ADJACENCY || mode == GL_TRIANGLE_STRIP_ADJACENCY;
                 break;
             default:
                 break;
@@ -424,6 +528,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(Clear);
         MG_Backend::gBackendFunctionsTable.GL.Clear(mask);
     }
 
@@ -432,6 +537,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElements);
         MG_Backend::gBackendFunctionsTable.GL.DrawElements(mode, count, type, indices);
     }
 
@@ -441,6 +547,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawElements);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawElements(mode, count, type, indices, drawcount);
     }
 
@@ -450,6 +557,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawElementsBaseVertex);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawElementsBaseVertex(mode, count, type, indices, drawcount,
                                                                           basevertex);
     }
@@ -459,6 +567,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawArrays);
         MG_Backend::gBackendFunctionsTable.GL.DrawArrays(mode, first, count);
     }
 
@@ -467,6 +576,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawArrays);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawArrays(mode, first, count, drawcount);
     }
 
@@ -476,6 +586,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElementsBaseVertex);
         MG_Backend::gBackendFunctionsTable.GL.DrawElementsBaseVertex(mode, count, type, indices, basevertex);
     }
 
@@ -485,6 +596,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawElementsIndirect);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawElementsIndirect(mode, type, indirect, drawcount, stride);
     }
 
@@ -493,6 +605,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawArraysIndirect);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawArraysIndirect(mode, indirect, drawcount, stride);
     }
 
@@ -502,6 +615,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawElementsIndirectCount);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawElementsIndirectCount(mode, type, indirect, drawcount,
                                                                              maxdrawcount, stride);
     }
@@ -512,6 +626,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(MultiDrawArraysIndirectCount);
         MG_Backend::gBackendFunctionsTable.GL.MultiDrawArraysIndirectCount(mode, indirect, drawcount, maxdrawcount,
                                                                            stride);
     }
@@ -522,6 +637,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawRangeElementsBaseVertex);
         MG_Backend::gBackendFunctionsTable.GL.DrawRangeElementsBaseVertex(mode, start, end, count, type, indices,
                                                                           basevertex);
     }
@@ -532,6 +648,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawRangeElements);
         MG_Backend::gBackendFunctionsTable.GL.DrawRangeElements(mode, start, end, count, type, indices);
     }
 
@@ -542,6 +659,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElementsInstancedBaseVertexBaseInstance);
         MG_Backend::gBackendFunctionsTable.GL.DrawElementsInstancedBaseVertexBaseInstance(
             mode, count, type, indices, instancecount, basevertex, baseinstance);
     }
@@ -552,6 +670,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElementsInstancedBaseVertex);
         MG_Backend::gBackendFunctionsTable.GL.DrawElementsInstancedBaseVertex(mode, count, type, indices, instancecount,
                                                                               basevertex);
     }
@@ -562,6 +681,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElementsInstancedBaseInstance);
         MG_Backend::gBackendFunctionsTable.GL.DrawElementsInstancedBaseInstance(mode, count, type, indices,
                                                                                 instancecount, baseinstance);
     }
@@ -572,6 +692,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElementsInstanced);
         MG_Backend::gBackendFunctionsTable.GL.DrawElementsInstanced(mode, count, type, indices, instancecount);
     }
 
@@ -580,6 +701,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawElementsIndirect);
         MG_Backend::gBackendFunctionsTable.GL.DrawElementsIndirect(mode, type, indirect);
     }
     void DrawArraysInstancedBaseInstance_Backend(GLenum mode, GLint first, GLsizei count, GLsizei instancecount,
@@ -588,6 +710,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawArraysInstancedBaseInstance);
         MG_Backend::gBackendFunctionsTable.GL.DrawArraysInstancedBaseInstance(mode, first, count, instancecount,
                                                                               baseinstance);
     }
@@ -597,6 +720,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawArraysInstanced);
         MG_Backend::gBackendFunctionsTable.GL.DrawArraysInstanced(mode, first, count, instancecount);
     }
 
@@ -605,6 +729,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ZoneScopedC(TRACY_ZONECOLOR_BACKEND);
 #endif
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DrawArraysIndirect);
         MG_Backend::gBackendFunctionsTable.GL.DrawArraysIndirect(mode, indirect);
     }
 
@@ -636,6 +761,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         // GL 4.3 added both dispatches to the conditional-render set (GL 4.6 core 10.9), which is
         // exactly what KHR-GL43.compute_shader.conditional-dispatching checks.
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DispatchCompute);
         dispatchCompute(numGroupsX, numGroupsY, numGroupsZ);
     }
 
@@ -688,6 +814,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         if (!ValidateCurrentProgramForCompute(__func__)) return;
         if (ConditionalRenderDiscardsCommand()) return;
+        MGP_FILL(DispatchComputeIndirect);
         dispatchComputeIndirect(indirect);
     }
 
@@ -709,10 +836,42 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         MG_State::pGLContext->SetPatchVertices(static_cast<Uint>(value));
         if (const auto patchParameteri = MG_Backend::gBackendFunctionsTable.GL.PatchParameteri) {
+            MGP_FILL(PatchParameteri);
             patchParameteri(pname, value);
         }
     }
 
+    // GL 4.6 core 11.2.2. The default tessellation levels a program with an evaluation stage and
+    // NO control stage tessellates at; both backends have to synthesize that control stage
+    // themselves (ES 3.2 and Vulkan both require one), and they compile these numbers into it, so
+    // there is no backend entry point to forward to - ES has none at all. INVALID_ENUM on a bad
+    // pname is the only error the spec lists: any float values are accepted, negatives and NaN
+    // included, and it is the tessellator that clamps them.
+    //
+    // This used to be a stub, which is why the two synthesizers hardcoded 1.0.
+    void PatchParameterfv(GLenum pname, const GLfloat* values) {
+        if (pname != GL_PATCH_DEFAULT_OUTER_LEVEL && pname != GL_PATCH_DEFAULT_INNER_LEVEL) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", __func__,
+                    "pname must be GL_PATCH_DEFAULT_OUTER_LEVEL or GL_PATCH_DEFAULT_INNER_LEVEL."));
+            return;
+        }
+        if (!values) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, "values pointer cannot be null"));
+            return;
+        }
+        if (pname == GL_PATCH_DEFAULT_OUTER_LEVEL) {
+            MG_State::pGLContext->SetPatchDefaultOuterLevel(
+                FloatVec4(values[0], values[1], values[2], values[3]));
+        } else {
+            MG_State::pGLContext->SetPatchDefaultInnerLevel(FloatVec2(values[0], values[1]));
+        }
+    }
+
     namespace {
         // GL 4.6 core 7.11.2 (and ARB_shader_image_load_store, which introduced the call): the
         // barrier bitfield is INVALID_VALUE unless every bit is one of the defined ones, with
@@ -748,9 +907,32 @@ namespace MobileGL::MG_Impl::GLImpl {
                 MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, "Backend does not support memory barriers."));
             return;
         }
+        MGP_FILL(MemoryBarrier);
         memoryBarrier(barriers);
     }
 
+    void TextureBarrier() {
+        // GL 4.5 core 8.26 / GL_ARB_texture_barrier: order every write the fixed-function
+        // framebuffer has already issued ahead of every subsequent texture fetch, so a shader may
+        // read texels of a texture that is also attached to the current framebuffer.
+        //
+        // Both backends serve this through their existing memory-barrier hook rather than a new
+        // entry point of their own: GL_FRAMEBUFFER_BARRIER_BIT is the source half (framebuffer
+        // writes) and GL_TEXTURE_FETCH_BARRIER_BIT the destination half (texture fetches), which
+        // is exactly the dependency ARB_texture_barrier defines - just expressed with the wider
+        // scope glMemoryBarrier gives it. That is a superset of the required ordering, never a
+        // subset, so it cannot under-synchronize.
+        auto memoryBarrier = MG_Backend::gBackendFunctionsTable.GL.MemoryBarrier;
+        if (!memoryBarrier) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, "Backend does not support memory barriers."));
+            return;
+        }
+        MGP_FILL(MemoryBarrier);
+        memoryBarrier(GL_TEXTURE_FETCH_BARRIER_BIT | GL_FRAMEBUFFER_BARRIER_BIT);
+    }
+
     void MemoryBarrierByRegion(GLbitfield barriers) {
         if (!ValidateMemoryBarrierBits(__func__, barriers)) return;
         auto memoryBarrierByRegion = MG_Backend::gBackendFunctionsTable.GL.MemoryBarrierByRegion;
@@ -761,19 +943,20 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "Backend does not support regional memory barriers."));
             return;
         }
+        MGP_FILL(MemoryBarrierByRegion);
         memoryBarrierByRegion(barriers);
     }
 
     void MultiDrawElementsIndirect(GLenum mode, GLenum type, const void* indirect, GLsizei drawcount, GLsizei stride) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         MultiDrawElementsIndirect_Backend(mode, type, indirect, drawcount, stride);
     }
 
     void MultiDrawArraysIndirect(GLenum mode, const void* indirect, GLsizei drawcount, GLsizei stride) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         MultiDrawArraysIndirect_Backend(mode, indirect, drawcount, stride);
     }
@@ -851,7 +1034,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         // NegativeApiErrorsTest.IndirectParameterDrawsCheckBothBuffers pins the INVALID_VALUE
         // they produce for a call made with no program bound. Same precedence decision, and
         // the same reason, as DispatchComputeIndirect above.
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         auto multiDrawElementsIndirectCount = MG_Backend::gBackendFunctionsTable.GL.MultiDrawElementsIndirectCount;
         if (!multiDrawElementsIndirectCount) {
             MG_State::pGLContext->RecordError(
@@ -872,7 +1055,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
         // See MultiDrawElementsIndirectCount, including why this one goes last.
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         auto multiDrawArraysIndirectCount = MG_Backend::gBackendFunctionsTable.GL.MultiDrawArraysIndirectCount;
         if (!multiDrawArraysIndirectCount) {
             MG_State::pGLContext->RecordError(
@@ -887,7 +1070,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     void DrawRangeElementsBaseVertex(GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type,
                                      const void* indices, GLint basevertex) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (!ValidateDrawElementsIndexType(__func__, type)) return;
         if (!ValidateNonNegativeDrawArgument(__func__, "count", count)) return;
@@ -897,7 +1080,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void DrawRangeElements(GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, const void* indices) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         DrawRangeElements_Backend(mode, start, end, count, type, indices);
     }
@@ -905,7 +1088,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     void DrawElementsInstancedBaseVertexBaseInstance(GLenum mode, GLsizei count, GLenum type, const void* indices,
                                                      GLsizei instancecount, GLint basevertex, GLuint baseinstance) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         DrawElementsInstancedBaseVertexBaseInstance_Backend(mode, count, type, indices, instancecount, basevertex,
                                                             baseinstance);
@@ -914,7 +1097,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     void DrawElementsInstancedBaseVertex(GLenum mode, GLsizei count, GLenum type, const void* indices,
                                          GLsizei instancecount, GLint basevertex) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (!ValidateDrawElementsIndexType(__func__, type)) return;
         if (!ValidateNonNegativeDrawArgument(__func__, "count", count)) return;
@@ -925,21 +1108,21 @@ namespace MobileGL::MG_Impl::GLImpl {
     void DrawElementsInstancedBaseInstance(GLenum mode, GLsizei count, GLenum type, const void* indices,
                                            GLsizei instancecount, GLuint baseinstance) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         DrawElementsInstancedBaseInstance_Backend(mode, count, type, indices, instancecount, baseinstance);
     }
 
     void DrawElementsInstanced(GLenum mode, GLsizei count, GLenum type, const void* indices, GLsizei instancecount) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         DrawElementsInstanced_Backend(mode, count, type, indices, instancecount);
     }
 
     void DrawElementsIndirect(GLenum mode, GLenum type, const void* indirect) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (!ValidateDrawElementsIndexType(__func__, type)) return;
         if (!ValidateIndirectDrawSource(__func__, indirect, kDrawElementsIndirectCommandBytes)) return;
@@ -949,21 +1132,21 @@ namespace MobileGL::MG_Impl::GLImpl {
     void DrawArraysInstancedBaseInstance(GLenum mode, GLint first, GLsizei count, GLsizei instancecount,
                                          GLuint baseinstance) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         DrawArraysInstancedBaseInstance_Backend(mode, first, count, instancecount, baseinstance);
     }
 
     void DrawArraysInstanced(GLenum mode, GLint first, GLsizei count, GLsizei instancecount) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         DrawArraysInstanced_Backend(mode, first, count, instancecount);
     }
 
     void DrawArraysIndirect(GLenum mode, const void* indirect) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (!ValidateIndirectDrawSource(__func__, indirect, kDrawArraysIndirectCommandBytes)) return;
         DrawArraysIndirect_Backend(mode, indirect);
@@ -971,7 +1154,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void DrawElementsBaseVertex(GLenum mode, GLsizei count, GLenum type, const void* indices, GLint basevertex) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (!ValidateDrawElementsIndexType(__func__, type)) return;
         if (!ValidateNonNegativeDrawArgument(__func__, "count", count)) return;
@@ -981,7 +1164,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void DrawArrays(GLenum mode, GLint first, GLsizei count) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         AccountTransformFeedbackPrimitives(mode, count);
         DrawArrays_Backend(mode, first, count);
@@ -989,7 +1172,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void MultiDrawArrays(GLenum mode, const GLint* first, const GLsizei* count, GLsizei drawcount) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (drawcount < 0) {
             MG_State::pGLContext->RecordError(
@@ -1003,7 +1186,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     void MultiDrawElements(GLenum mode, const GLsizei* count, GLenum type, const void* const* indices,
                            GLsizei drawcount) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         MultiDrawElements_Backend(mode, count, type, indices, drawcount);
     }
@@ -1011,7 +1194,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     void MultiDrawElementsBaseVertex(GLenum mode, const GLsizei* count, GLenum type, const void* const* indices,
                                      GLsizei drawcount, const GLint* basevertex) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         if (!ValidateDrawElementsIndexType(__func__, type)) return;
         if (!ValidateNonNegativeDrawArgument(__func__, "drawcount", drawcount)) return;
@@ -1035,7 +1218,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void DrawElements(GLenum mode, GLsizei count, GLenum type, const void* indices) {
         if (!ValidatePrimitiveModeEnum(__func__, mode)) return;
-        if (!ValidateCurrentProgramForExecution(__func__)) return;
+        if (!PrepareCurrentProgramForDraw(__func__)) return;
         if (!ValidatePrimitiveModeForBackend(__func__, mode)) return;
         AccountTransformFeedbackPrimitives(mode, count);
         DrawElements_Backend(mode, count, type, indices);
@@ -1083,6 +1266,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         MG_State::pGLContext->BeginTransformFeedback(primitiveMode, program);
         if (const auto beginXfb = MG_Backend::gBackendFunctionsTable.GL.BeginTransformFeedback) {
+            MGP_FILL(BeginTransformFeedback);
             beginXfb(primitiveMode);
         }
     }
@@ -1165,6 +1349,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         // Closed while the capture state is still active: a backend that captures
         // through its own driver reads the capture program and buffer bindings here.
         if (const auto endXfb = MG_Backend::gBackendFunctionsTable.GL.EndTransformFeedback) {
+            MGP_FILL(EndTransformFeedback);
             endXfb();
         }
         MG_State::pGLContext->EndTransformFeedback();
@@ -1173,9 +1358,12 @@ namespace MobileGL::MG_Impl::GLImpl {
         // the GPU work is all that is required.
         auto& backendGL = MG_Backend::gBackendFunctionsTable.GL;
         if (backendGL.FenceSync && backendGL.ClientWaitSync) {
+            MGP_FILL(FenceSync);
             if (auto sync = backendGL.FenceSync()) {
+                MGP_FILL(ClientWaitSync);
                 backendGL.ClientWaitSync(sync, GL_SYNC_FLUSH_COMMANDS_BIT, ~0ull);
                 if (backendGL.DeleteSync) {
+                    MGP_FILL(DeleteSync);
                     backendGL.DeleteSync(sync);
                 }
             }
@@ -1194,6 +1382,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         MG_State::pGLContext->SetTransformFeedbackPaused(true);
         if (const auto pauseXfb = MG_Backend::gBackendFunctionsTable.GL.PauseTransformFeedback) {
+            MGP_FILL(PauseTransformFeedback);
             pauseXfb();
         }
     }
@@ -1208,6 +1397,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         MG_State::pGLContext->SetTransformFeedbackPaused(false);
         if (const auto resumeXfb = MG_Backend::gBackendFunctionsTable.GL.ResumeTransformFeedback) {
+            MGP_FILL(ResumeTransformFeedback);
             resumeXfb();
         }
     }
@@ -1413,6 +1603,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                 continue;
             }
             if (const auto deleteXfb = MG_Backend::gBackendFunctionsTable.GL.DeleteTransformFeedback) {
+                MGP_FILL(DeleteTransformFeedback);
                 deleteXfb(id);
             }
             MG_State::pGLContext->MarkTransformFeedbackObjectForDeletion(id);
@@ -1444,6 +1635,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         MG_State::pGLContext->BindTransformFeedbackObject(id);
         if (const auto bindXfb = MG_Backend::gBackendFunctionsTable.GL.BindTransformFeedback) {
+            MGP_FILL(BindTransformFeedback);
             bindXfb(id);
         }
     }
@@ -1459,7 +1651,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     // (GL 4.6 core 10.3.7).
     static void DrawTransformFeedbackImpl(const char* functionName, GLenum mode, GLuint id, GLuint stream,
                                           GLsizei instancecount) {
-        if (!ValidateCurrentProgramForExecution(functionName)) return;
+        if (!PrepareCurrentProgramForDraw(functionName)) return;
         if (!ValidatePrimitiveModeForBackend(functionName, mode)) return;
         if (instancecount < 0) {
             MG_State::pGLContext->RecordError(
@@ -1482,8 +1674,13 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              std::to_string(id) + " is not a transform feedback object name."));
             return;
         }
-        // GL_MAX_VERTEX_STREAMS is 1, so stream 0 is the only one that exists.
-        if (stream != 0) {
+        // GL 4.6 core 10.3.7 bounds `stream` by GL_MAX_VERTEX_STREAMS, which this implementation
+        // answers as 1 - so stream 0 is the only one that exists and anything else is
+        // INVALID_VALUE. Read from the getter rather than written as `stream != 0` so the two can
+        // never drift: if vertex-stream support ever lands, this bound moves with the limit.
+        GLint maxVertexStreams = 1;
+        GetIntegerv(GL_MAX_VERTEX_STREAMS, &maxVertexStreams);
+        if (stream >= static_cast<GLuint>(std::max(maxVertexStreams, 1))) {
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidValue,
                 MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", functionName,
@@ -1501,6 +1698,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
 
+        // `stream` is provably 0 here (the bound above is 1), so this is stream 0's record.
         const Uint64 vertices = MG_State::pGLContext->GetTransformFeedbackRecordedVertices(id);
         if (vertices == 0) return;
         const auto count = static_cast<GLsizei>(vertices);

MobileGL/MG_Impl/GLImpl/Drawing/GL_Drawing.h

@@ -32,8 +32,10 @@ namespace MobileGL::MG_Impl::GLImpl {
     void DispatchCompute(GLuint numGroupsX, GLuint numGroupsY, GLuint numGroupsZ);
     void DispatchComputeIndirect(GLintptr indirect);
     void PatchParameteri(GLenum pname, GLint value);
+    void PatchParameterfv(GLenum pname, const GLfloat* values);
     void MemoryBarrier(GLbitfield barriers);
     void MemoryBarrierByRegion(GLbitfield barriers);
+    void TextureBarrier();
     void MultiDrawElementsIndirect(GLenum mode, GLenum type, const void* indirect, GLsizei drawcount, GLsizei stride);
     void MultiDrawArraysIndirect(GLenum mode, const void* indirect, GLsizei drawcount, GLsizei stride);
     void MultiDrawElementsIndirectCount(GLenum mode, GLenum type, const void* indirect, GLintptr drawcount,

MobileGL/MG_Impl/GLImpl/Exporting/Definitions.cpp

@@ -160,7 +160,7 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, ReleaseShaderCompiler) DECLARE_GL_FUNCTION_S
 DECLARE_GL_FUNCTION_HEAD(void, RenderbufferStorage, GLenum target, GLenum internalformat, GLsizei width, GLsizei height) DECLARE_GL_FUNCTION_END_NO_RETURN(void, RenderbufferStorage, target, internalformat, width, height)
 DECLARE_GL_FUNCTION_HEAD(void, SampleCoverage, GLfloat value, GLboolean invert) DECLARE_GL_FUNCTION_END_NO_RETURN(void, SampleCoverage, value, invert)
 DECLARE_GL_FUNCTION_HEAD(void, Scissor, GLint x, GLint y, GLsizei width, GLsizei height) DECLARE_GL_FUNCTION_END_NO_RETURN(void, Scissor, x, y, width, height)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, ShaderBinary, GLsizei count, const GLuint* shaders, GLenum binaryformat, const void* binary, GLsizei length) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ShaderBinary, count, shaders, binaryformat, binary, length)
+DECLARE_GL_FUNCTION_HEAD(void, ShaderBinary, GLsizei count, const GLuint* shaders, GLenum binaryformat, const void* binary, GLsizei length) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ShaderBinary, count, shaders, binaryformat, binary, length)
 DECLARE_GL_FUNCTION_HEAD(void, ShaderSource, GLuint shader, GLsizei count, const GLchar* const* string, const GLint* length) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ShaderSource, shader, count, string, length)
 DECLARE_GL_FUNCTION_HEAD(void, StencilFunc, GLenum func, GLint ref, GLuint mask) DECLARE_GL_FUNCTION_END_NO_RETURN(void, StencilFunc, func, ref, mask)
 DECLARE_GL_FUNCTION_HEAD(void, StencilFuncSeparate, GLenum face, GLenum func, GLint ref, GLuint mask) DECLARE_GL_FUNCTION_END_NO_RETURN(void, StencilFuncSeparate, face, func, ref, mask)
@@ -411,7 +411,7 @@ DECLARE_GL_FUNCTION_HEAD(void, ReadnPixels, GLint x, GLint y, GLsizei width, GLs
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnUniformfv, GLuint program, GLint location, GLsizei bufSize, GLfloat* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetnUniformfv, program, location, bufSize, params)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnUniformiv, GLuint program, GLint location, GLsizei bufSize, GLint* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetnUniformiv, program, location, bufSize, params)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnUniformuiv, GLuint program, GLint location, GLsizei bufSize, GLuint* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetnUniformuiv, program, location, bufSize, params)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, MinSampleShading, GLfloat value) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, MinSampleShading, value)
+DECLARE_GL_FUNCTION_HEAD(void, MinSampleShading, GLfloat value) DECLARE_GL_FUNCTION_END_NO_RETURN(void, MinSampleShading, value)
 DECLARE_GL_FUNCTION_HEAD(void, PatchParameteri, GLenum pname, GLint value) DECLARE_GL_FUNCTION_END_NO_RETURN(void, PatchParameteri, pname, value)
 DECLARE_GL_FUNCTION_HEAD(void, TexParameterIiv, GLenum target, GLenum pname, const GLint* params) DECLARE_GL_FUNCTION_END_NO_RETURN(void, TexParameterIiv, target, pname, params)
 DECLARE_GL_FUNCTION_HEAD(void, TexParameterIuiv, GLenum target, GLenum pname, const GLuint* params) DECLARE_GL_FUNCTION_END_NO_RETURN(void, TexParameterIuiv, target, pname, params)
@@ -923,7 +923,7 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, GetActiveSubroutineName, GLuint program, GLe
 DECLARE_GL_FUNCTION_STUB_HEAD(void, UniformSubroutinesuiv, GLenum shadertype, GLsizei count, const GLuint* indices) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, UniformSubroutinesuiv, shadertype, count, indices)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetUniformSubroutineuiv, GLenum shadertype, GLint location, GLuint* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetUniformSubroutineuiv, shadertype, location, params)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetProgramStageiv, GLuint program, GLenum shadertype, GLenum pname, GLint* values) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetProgramStageiv, program, shadertype, pname, values)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, PatchParameterfv, GLenum pname, const GLfloat* values) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, PatchParameterfv, pname, values)
+DECLARE_GL_FUNCTION_HEAD(void, PatchParameterfv, GLenum pname, const GLfloat* values) DECLARE_GL_FUNCTION_END_NO_RETURN(void, PatchParameterfv, pname, values)
 DECLARE_GL_FUNCTION_HEAD(void, DrawTransformFeedback, GLenum mode, GLuint id) DECLARE_GL_FUNCTION_END_NO_RETURN(void, DrawTransformFeedback, mode, id)
 DECLARE_GL_FUNCTION_HEAD(void, DrawTransformFeedbackStream, GLenum mode, GLuint id, GLuint stream) DECLARE_GL_FUNCTION_END_NO_RETURN(void, DrawTransformFeedbackStream, mode, id, stream)
 DECLARE_GL_FUNCTION_HEAD(void, BeginQueryIndexed, GLenum target, GLuint index, GLuint id) DECLARE_GL_FUNCTION_END_NO_RETURN(void, BeginQueryIndexed, target, index, id)
@@ -994,7 +994,7 @@ DECLARE_GL_FUNCTION_HEAD(void, BindTextures, GLuint first, GLsizei count, const
 DECLARE_GL_FUNCTION_HEAD(void, BindSamplers, GLuint first, GLsizei count, const GLuint* samplers) DECLARE_GL_FUNCTION_END_NO_RETURN(void, BindSamplers, first, count, samplers)
 DECLARE_GL_FUNCTION_HEAD(void, BindImageTextures, GLuint first, GLsizei count, const GLuint* textures) DECLARE_GL_FUNCTION_END_NO_RETURN(void, BindImageTextures, first, count, textures)
 DECLARE_GL_FUNCTION_HEAD(void, BindVertexBuffers, GLuint first, GLsizei count, const GLuint* buffers, const GLintptr* offsets, const GLsizei* strides) DECLARE_GL_FUNCTION_END_NO_RETURN(void, BindVertexBuffers, first, count, buffers, offsets, strides)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, ClipControl, GLenum origin, GLenum depth) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ClipControl, origin, depth)
+DECLARE_GL_FUNCTION_HEAD(void, ClipControl, GLenum origin, GLenum depth) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ClipControl, origin, depth)
 DECLARE_GL_FUNCTION_HEAD(void, CreateTransformFeedbacks, GLsizei n, GLuint* ids) DECLARE_GL_FUNCTION_END_NO_RETURN(void, CreateTransformFeedbacks, n, ids)
 DECLARE_GL_FUNCTION_HEAD(void, TransformFeedbackBufferBase, GLuint xfb, GLuint index, GLuint buffer) DECLARE_GL_FUNCTION_END_NO_RETURN(void, TransformFeedbackBufferBase, xfb, index, buffer)
 DECLARE_GL_FUNCTION_HEAD(void, TransformFeedbackBufferRange, GLuint xfb, GLuint index, GLuint buffer, GLintptr offset, GLsizeiptr size) DECLARE_GL_FUNCTION_END_NO_RETURN(void, TransformFeedbackBufferRange, xfb, index, buffer, offset, size)
@@ -1107,11 +1107,11 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnConvolutionFilter, GLenum target, GLenum
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnSeparableFilter, GLenum target, GLenum format, GLenum type, GLsizei rowBufSize, void* row, GLsizei columnBufSize, void* column, void* span) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetnSeparableFilter, target, format, type, rowBufSize, row, columnBufSize, column, span)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnHistogram, GLenum target, GLboolean reset, GLenum format, GLenum type, GLsizei bufSize, void* values) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetnHistogram, target, reset, format, type, bufSize, values)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetnMinmax, GLenum target, GLboolean reset, GLenum format, GLenum type, GLsizei bufSize, void* values) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetnMinmax, target, reset, format, type, bufSize, values)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, TextureBarrier, void) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TextureBarrier, )
-DECLARE_GL_FUNCTION_STUB_HEAD(void, SpecializeShader, GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants, const GLuint* pConstantIndex, const GLuint* pConstantValue) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, SpecializeShader, shader, pEntryPoint, numSpecializationConstants, pConstantIndex, pConstantValue)
+DECLARE_GL_FUNCTION_HEAD(void, TextureBarrier, void) DECLARE_GL_FUNCTION_END_NO_RETURN(void, TextureBarrier, )
+DECLARE_GL_FUNCTION_HEAD(void, SpecializeShader, GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants, const GLuint* pConstantIndex, const GLuint* pConstantValue) DECLARE_GL_FUNCTION_END_NO_RETURN(void, SpecializeShader, shader, pEntryPoint, numSpecializationConstants, pConstantIndex, pConstantValue)
 DECLARE_GL_FUNCTION_HEAD(void, MultiDrawArraysIndirectCount, GLenum mode, const void* indirect, GLintptr drawcount, GLsizei maxdrawcount, GLsizei stride) DECLARE_GL_FUNCTION_END_NO_RETURN(void, MultiDrawArraysIndirectCount, mode, indirect, drawcount, maxdrawcount, stride)
 DECLARE_GL_FUNCTION_HEAD(void, MultiDrawElementsIndirectCount, GLenum mode, GLenum type, const void* indirect, GLintptr drawcount, GLsizei maxdrawcount, GLsizei stride) DECLARE_GL_FUNCTION_END_NO_RETURN(void, MultiDrawElementsIndirectCount, mode, type, indirect, drawcount, maxdrawcount, stride)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, PolygonOffsetClamp, GLfloat factor, GLfloat units, GLfloat clamp) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, PolygonOffsetClamp, factor, units, clamp)
+DECLARE_GL_FUNCTION_HEAD(void, PolygonOffsetClamp, GLfloat factor, GLfloat units, GLfloat clamp) DECLARE_GL_FUNCTION_END_NO_RETURN(void, PolygonOffsetClamp, factor, units, clamp)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, PrimitiveBoundingBoxARB, GLfloat minX, GLfloat minY, GLfloat minZ, GLfloat minW, GLfloat maxX, GLfloat maxY, GLfloat maxZ, GLfloat maxW) DECLARE_GL_FUNCTION_STUB_END(void, PrimitiveBoundingBoxARB, minX, minY, minZ, minW, maxX, maxY, maxZ, maxW)
 DECLARE_GL_FUNCTION_STUB_HEAD(GLuint64, GetTextureHandleARB, GLuint texture) DECLARE_GL_FUNCTION_STUB_END(GLuint64, GetTextureHandleARB, texture)
 DECLARE_GL_FUNCTION_STUB_HEAD(GLuint64, GetTextureSamplerHandleARB, GLuint texture, GLuint sampler) DECLARE_GL_FUNCTION_STUB_END(GLuint64, GetTextureSamplerHandleARB, texture, sampler)
@@ -1150,7 +1150,7 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, GetProgramLocalParameterdvARB, GLenum target
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetProgramLocalParameterfvARB, GLenum target, GLuint index, GLfloat* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetProgramLocalParameterfvARB, target, index, params)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetProgramStringARB, GLenum target, GLenum pname, void* string) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetProgramStringARB, target, pname, string)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, FramebufferTextureFaceARB, GLenum target, GLenum attachment, GLuint texture, GLint level, GLenum face) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, FramebufferTextureFaceARB, target, attachment, texture, level, face)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, SpecializeShaderARB, GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants, const GLuint* pConstantIndex, const GLuint* pConstantValue) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, SpecializeShaderARB, shader, pEntryPoint, numSpecializationConstants, pConstantIndex, pConstantValue)
+DECLARE_GL_FUNCTION_HEAD(void, SpecializeShaderARB, GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants, const GLuint* pConstantIndex, const GLuint* pConstantValue) DECLARE_GL_FUNCTION_END_NO_RETURN(void, SpecializeShader, shader, pEntryPoint, numSpecializationConstants, pConstantIndex, pConstantValue)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, Uniform1i64ARB, GLint location, GLint64 x) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, Uniform1i64ARB, location, x)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, Uniform2i64ARB, GLint location, GLint64 x, GLint64 y) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, Uniform2i64ARB, location, x, y)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, Uniform3i64ARB, GLint location, GLint64 x, GLint64 y, GLint64 z) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, Uniform3i64ARB, location, x, y, z)
@@ -2049,7 +2049,7 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, GetPixelTransformParameterivEXT, GLenum targ
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GetPixelTransformParameterfvEXT, GLenum target, GLenum pname, GLfloat* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GetPixelTransformParameterfvEXT, target, pname, params)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, PointParameterfEXT, GLenum pname, GLfloat param) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, PointParameterfEXT, pname, param)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, PointParameterfvEXT, GLenum pname, const GLfloat* params) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, PointParameterfvEXT, pname, params)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, PolygonOffsetClampEXT, GLfloat factor, GLfloat units, GLfloat clamp) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, PolygonOffsetClampEXT, factor, units, clamp)
+DECLARE_GL_FUNCTION_HEAD(void, PolygonOffsetClampEXT, GLfloat factor, GLfloat units, GLfloat clamp) DECLARE_GL_FUNCTION_END_NO_RETURN(void, PolygonOffsetClamp, factor, units, clamp)
 DECLARE_GL_FUNCTION_HEAD(void, ProvokingVertexEXT, GLenum mode) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ProvokingVertex, mode)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, RasterSamplesEXT, GLuint samples, GLboolean fixedsamplelocations) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, RasterSamplesEXT, samples, fixedsamplelocations)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, SecondaryColor3bEXT, GLbyte red, GLbyte green, GLbyte blue) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, SecondaryColor3bEXT, red, green, blue)
@@ -2546,7 +2546,7 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, ShadingRateImageBarrierNV, GLboolean synchro
 DECLARE_GL_FUNCTION_STUB_HEAD(void, ShadingRateImagePaletteNV, GLuint viewport, GLuint first, GLsizei count, const GLenum* rates) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ShadingRateImagePaletteNV, viewport, first, count, rates)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, ShadingRateSampleOrderNV, GLenum order) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ShadingRateSampleOrderNV, order)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, ShadingRateSampleOrderCustomNV, GLenum rate, GLuint samples, const GLint* locations) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ShadingRateSampleOrderCustomNV, rate, samples, locations)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, TextureBarrierNV, void) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TextureBarrierNV, )
+DECLARE_GL_FUNCTION_HEAD(void, TextureBarrierNV, void) DECLARE_GL_FUNCTION_END_NO_RETURN(void, TextureBarrier, )
 DECLARE_GL_FUNCTION_STUB_HEAD(void, TexImage2DMultisampleCoverageNV, GLenum target, GLsizei coverageSamples, GLsizei colorSamples, GLint internalFormat, GLsizei width, GLsizei height, GLboolean fixedSampleLocations) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TexImage2DMultisampleCoverageNV, target, coverageSamples, colorSamples, internalFormat, width, height, fixedSampleLocations)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, TexImage3DMultisampleCoverageNV, GLenum target, GLsizei coverageSamples, GLsizei colorSamples, GLint internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLboolean fixedSampleLocations) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TexImage3DMultisampleCoverageNV, target, coverageSamples, colorSamples, internalFormat, width, height, depth, fixedSampleLocations)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, TextureImage2DMultisampleNV, GLuint texture, GLenum target, GLsizei samples, GLint internalFormat, GLsizei width, GLsizei height, GLboolean fixedSampleLocations) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TextureImage2DMultisampleNV, texture, target, samples, internalFormat, width, height, fixedSampleLocations)

MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.cpp

@@ -15,6 +15,7 @@
 #include <MG_Impl/GLImpl/Texture/Validators.h>
 #include <MG_Impl/GLImpl/Getter/GL_Getter.h>
 #include <MG_State/GLState/ErrorState/Error.h>
+#include <MG_Impl/Pipe/PipeFill.h>
 #include <MG_Util/Converters/GLToStr/GLEnumConverter.h>
 #include <MG_Util/Converters/GLToMG/TextureEnumConverter.h>
 #include <MG_Util/Converters/MGToMG/TextureEnumConverter.h>
@@ -474,6 +475,75 @@ namespace MobileGL::MG_Impl::GLImpl {
             }
         }
 
+        // GL 4.6 core 9.2.8 conditions that depend only on the framebuffer and the attachment
+        // point. Shared, because glFramebufferTexture / 1D / 2D / 3D / TextureLayer are aliases of
+        // one another in that section and a CTS case that walks the family must not get five
+        // different answers - which is exactly what happened when these lived in one helper that
+        // only two of the five went through.
+        Bool ValidateFramebufferTextureAttachmentPoint(const char* functionName,
+                                                       const SharedPtr<MG_State::GLState::FramebufferObject>&
+                                                           framebufferObject,
+                                                       FramebufferAttachmentType attachmentType) {
+            // "An INVALID_OPERATION error is generated if COLOR_ATTACHMENTm is used with m greater
+            // than or equal to MAX_COLOR_ATTACHMENTS."
+            if (!FramebufferImpl::ValidateColorAttachmentInRange(attachmentType, functionName)) return false;
+            // "An INVALID_OPERATION error is generated if zero is bound to target." MobileGL keeps
+            // a real FramebufferObject for framebuffer 0, so a null test can never see this - the
+            // object is always there, and framebuffer 0 has to be recognised by identity instead,
+            // the same comparison DrawBuffers_State makes. Without this an attach onto the default
+            // framebuffer silently REPLACED its colour attachment, permanently desynchronising it
+            // from what the swapchain keeps publishing.
+            const auto& defaultFramebufferInfo = FramebufferImpl::pDefaultFramebufferInfo;
+            if (!framebufferObject ||
+                (defaultFramebufferInfo && framebufferObject == defaultFramebufferInfo->defaultFBO)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidOperation,
+                    MakeUnique<GenericErrorInfo>(
+                        "MG_Impl/GLImpl", functionName,
+                        "No framebuffer object is bound to the target; the default framebuffer's attachments "
+                        "cannot be named."));
+                return false;
+            }
+            return true;
+        }
+
+        // The other half of 9.2.8: "level must be greater than or equal to zero", and for a
+        // texture with immutable storage it "must be smaller than the number of levels the texture
+        // has". Split from the attachment-point half because the caller only has a texture object
+        // once the detach (texture == 0) case is behind it.
+        Bool ValidateFramebufferTextureLevel(const char* functionName,
+                                             const SharedPtr<MG_State::GLState::ITextureObject>& textureObject,
+                                             GLint level) {
+            if (level < 0) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", functionName,
+                                                 "Texture level must be non-negative."));
+                return false;
+            }
+            if (!textureObject || !textureObject->IsImmutable()) {
+                // A mutable texture has no level bound here: a level it has not specified yet is
+                // not an error, it just leaves the framebuffer incomplete.
+                return true;
+            }
+            // GetAddressableLevelCount(), NOT GetImmutableLevels(): for a VIEW the latter is
+            // deliberately the ORIGINAL texture's count (GL 4.6 core 8.18 defines
+            // TEXTURE_IMMUTABLE_LEVELS on a view that way), which is far too large a bound - a
+            // two-level view onto a ten-level texture would accept level 5 and attach an image
+            // nothing can draw into.
+            const Uint levelBound = textureObject->GetAddressableLevelCount();
+            if (static_cast<Uint>(level) >= levelBound) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>(
+                        "MG_Impl/GLImpl", functionName,
+                        std::format("Texture level {} is beyond the {} level(s) this texture has.", level,
+                                    levelBound)));
+                return false;
+            }
+            return true;
+        }
+
         void AttachFramebufferTextureWithUploadTarget(const char* functionName, GLenum target, GLenum attachment,
                                                       GLuint texture, GLint level,
                                                       TextureUploadTarget textureUploadTarget, Bool layered = false) {
@@ -482,10 +552,24 @@ namespace MobileGL::MG_Impl::GLImpl {
             }
 
             if (attachment == GL_DEPTH_STENCIL_ATTACHMENT) {
+                // `layered` has to travel with the split. GL_DEPTH_STENCIL_ATTACHMENT is only a
+                // shorthand for attaching the same image to both halves (GL 4.6 core 9.2.6), so
+                // whether glFramebufferTexture made it LAYERED is a property of the call, not of
+                // which half is being recorded - and dropping it here (the parameter defaults to
+                // false) recorded a non-layered depth/stencil attachment beside a layered colour
+                // one for every layered target. That is an inconsistent framebuffer by 9.4.1's
+                // own rule, and downstream it means the depth/stencil attachment covers layer 0
+                // alone: DirectVulkan built its view with layerCount 1 under a framebuffer
+                // declaring N layers (VUID-VkFramebufferCreateInfo-flags-04535), and DirectGLES
+                // attached one layer of it beside a layered colour target, which the driver
+                // answers with GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS - every draw silently
+                // produced nothing. This is the shape
+                // texture_cube_map_array.stencil_attachments_*_layered and
+                // geometry_shader.layered_framebuffer.stencil_support are built on.
                 AttachFramebufferTextureWithUploadTarget(functionName, target, GL_DEPTH_ATTACHMENT, texture, level,
-                                                        textureUploadTarget);
+                                                        textureUploadTarget, layered);
                 AttachFramebufferTextureWithUploadTarget(functionName, target, GL_STENCIL_ATTACHMENT, texture, level,
-                                                        textureUploadTarget);
+                                                        textureUploadTarget, layered);
                 return;
             }
 
@@ -497,13 +581,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
             auto& bindingSlot = MG_State::pGLContext->GetFramebufferBindingSlot(framebufferTarget);
             auto& framebufferObject = bindingSlot.GetBoundObject();
-            if (!framebufferObject) {
-                MG_State::pGLContext->RecordError(
-                    ErrorCode::InvalidOperation,
-                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", functionName,
-                                                 "Framebuffer target is bound to no framebuffer object."));
-                return;
-            }
+            if (!ValidateFramebufferTextureAttachmentPoint(functionName, framebufferObject, attachmentType)) return;
 
             if (texture == 0) {
                 framebufferObject->Detach(attachmentType);
@@ -518,6 +596,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                                  std::format("Texture object {} is not valid.", texture)));
                 return;
             }
+            if (!ValidateFramebufferTextureLevel(functionName, textureObject, level)) return;
 
             const auto expectedTextureTarget = MG_Util::ConvertTextureUploadTargetToTextureTarget(textureUploadTarget);
             if (expectedTextureTarget == TextureTarget::Unknown ||
@@ -538,6 +617,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void BlitFramebuffer_Backend(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0,
                                  GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter) {
+        MGP_FILL(BlitFramebuffer);
         MG_Backend::gBackendFunctionsTable.GL.BlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1,
                                                               mask, filter);
     }
@@ -551,6 +631,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             MGLOG_E_ONCE("glBlitNamedFramebuffer skipped: backend does not implement explicit framebuffer blit.");
             return;
         }
+        MGP_FILL(BlitNamedFramebuffer);
         blitNamedFramebuffer(readFramebuffer, drawFramebuffer, srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1,
                              dstY1, mask, filter);
     }
@@ -562,6 +643,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             MGLOG_E_ONCE("glClearNamedFramebufferfv skipped: backend does not implement explicit framebuffer clear.");
             return;
         }
+        MGP_FILL(ClearNamedFramebufferfv);
         clearNamedFramebufferfv(framebuffer, buffer, drawbuffer, value);
     }
 
@@ -572,6 +654,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             MGLOG_E_ONCE("glClearNamedFramebufferfi skipped: backend does not implement explicit framebuffer clear.");
             return;
         }
+        MGP_FILL(ClearNamedFramebufferfi);
         clearNamedFramebufferfi(framebuffer, buffer, drawbuffer, depth, stencil);
     }
 
@@ -582,6 +665,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             MGLOG_E_ONCE("glClearNamedFramebufferiv skipped: backend does not implement explicit framebuffer clear.");
             return;
         }
+        MGP_FILL(ClearNamedFramebufferiv);
         clearNamedFramebufferiv(framebuffer, buffer, drawbuffer, value);
     }
 
@@ -592,6 +676,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             MGLOG_E_ONCE("glClearNamedFramebufferuiv skipped: backend does not implement explicit framebuffer clear.");
             return;
         }
+        MGP_FILL(ClearNamedFramebufferuiv);
         clearNamedFramebufferuiv(framebuffer, buffer, drawbuffer, value);
     }
 
@@ -624,16 +709,33 @@ namespace MobileGL::MG_Impl::GLImpl {
     // GL_MAX_SAMPLES is the ceiling over all formats; an integer format has its own
     // (GL_MAX_INTEGER_SAMPLES) and GL 4.6 core 9.2.4 makes exceeding it INVALID_OPERATION.
     // The multisample TEXTURE path resolves the limit per format the same way
-    // (GL_Texture.cpp, GetMaxSupportedTextureSamples). Both are floored to the value MobileGL
-    // advertises: on a driver where the two differ - Adreno reports GL_MAX_SAMPLES 4 and
-    // GL_MAX_INTEGER_SAMPLES 1 - rejecting the advertised count here only moves the failure
-    // from the driver into MobileGL, so the frontend accepts it and the backend clamps the
-    // count it actually hands the driver.
+    // (GL_Texture.cpp, GetMaxSupportedTextureSamples), and both now enforce exactly what their
+    // pname advertises. The integer ceiling used to be floored at GL_MAX_SAMPLES so that the
+    // frontend would accept a count it had advertised globally - but on Adreno and Mali the
+    // integer path is genuinely one sample, and accepting four only moved the failure from an
+    // honest INVALID_OPERATION here to a silently under-allocated renderbuffer.
+    // The head of the per-format renderbuffer sample list the backend probed, or 0 when nothing
+    // was probed for it. Same shape as GetProbedMaxTextureSamples in GL_Texture.cpp, and reads
+    // the same cache glGetInternalformativ(GL_RENDERBUFFER, ..., GL_SAMPLES) answers from.
+    static Int GetProbedMaxRenderbufferSamples(TextureInternalFormat format) {
+        if (MG_Backend::pActiveBackendObject == nullptr) {
+            return 0;
+        }
+        const SizeT targetIndex = MG_Backend::GetRenderbufferFormatCapabilityTargetIndex();
+        const SizeT formatIndex = static_cast<SizeT>(format);
+        if (targetIndex >= MG_Backend::kFormatCapabilityTargetCount ||
+            formatIndex >= MG_Backend::kFormatCapabilityFormatCount) {
+            return 0;
+        }
+        const auto& sampleCounts =
+            MG_Backend::pActiveBackendObject->GetFormatCapabilities().SampleCounts[targetIndex][formatIndex];
+        return sampleCounts.empty() ? 0 : sampleCounts.front();
+    }
+
     Int GetMaxRenderbufferSamplesForFormat_State(TextureInternalFormat format) {
         if (MG_Backend::pActiveBackendObject == nullptr) {
             return std::numeric_limits<Int>::max();
         }
-        const auto& dynamicParameters = MG_Backend::pActiveBackendObject->GetDynamicParameters();
 
         GLenum normalizedInternalFormat = MG_Util::ConvertTextureInternalFormatToGLEnum(format);
         GLenum normalizedFormat = GL_RGBA;
@@ -644,13 +746,24 @@ namespace MobileGL::MG_Impl::GLImpl {
                                                               &normalizedType);
         const Bool isIntegerFormat = normalizedFormat == GL_RED_INTEGER || normalizedFormat == GL_RG_INTEGER ||
                                      normalizedFormat == GL_RGB_INTEGER || normalizedFormat == GL_RGBA_INTEGER;
+        // The per-format probe first, for the same reason the texture path takes it first: GL 4.6
+        // core 9.2.4 words the error as "samples is greater than the maximum number of samples
+        // supported for internalformat (see GetInternalformativ)", and
+        // glGetInternalformativ(GL_RENDERBUFFER, ..., GL_SAMPLES) is answered from exactly this
+        // list. It was never consulted here - the TODO that deferred it was written before the
+        // query was backed and had gone stale - so a format whose multisample probes fail inside
+        // a category that allows four was accepted at four, quietly allocated at one by
+        // ClampSamplesToBackendSupport, and then reported as four by
+        // glGetRenderbufferParameteriv(GL_RENDERBUFFER_SAMPLES).
+        const Int probedMaxSamples = GetProbedMaxRenderbufferSamples(format);
+        if (probedMaxSamples > 0) {
+            return probedMaxSamples;
+        }
         if (!isIntegerFormat) {
             return GetMaxRenderbufferSamples_State();
         }
-        // Per-format still, but never below the ceiling glGetIntegerv(GL_MAX_SAMPLES) promised:
-        // the driver's raw GL_MAX_INTEGER_SAMPLES stays the *backend* limit and the backend
-        // clamps to it, while the frontend honours what it advertised.
-        return std::max(dynamicParameters.MaxIntegerSamples, GetAdvertisedMaxSamples());
+        // Exactly what glGetIntegerv(GL_MAX_INTEGER_SAMPLES) reports.
+        return GetAdvertisedIntegerMaxSamples();
     }
 
     Bool ValidateRenderbufferStorageSize_State(GLsizei width, GLsizei height, const char* caller) {
@@ -682,8 +795,10 @@ namespace MobileGL::MG_Impl::GLImpl {
             return false;
         }
 
-        // TODO: Resolve the remaining per-internalformat renderbuffer sample limits once
-        // glGetInternalformativ is backed; integer formats are handled below.
+        // Per-internalformat, from the probe list glGetInternalformativ answers with, falling back
+        // to the format's category pname where nothing was probed. (This carried a TODO deferring
+        // the per-format resolution "once glGetInternalformativ is backed"; it has been backed for
+        // both renderbuffers and multisample textures since, so the deferral was collected.)
         const Int maxSamples = GetMaxRenderbufferSamplesForFormat_State(format);
         if (samples > maxSamples) {
             // GL 4.6 core 9.2.4 makes asking for more samples than the format supports
@@ -1048,13 +1163,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
         auto& bindingSlot = MG_State::pGLContext->GetFramebufferBindingSlot(framebufferTarget);
         auto& framebufferObject = bindingSlot.GetBoundObject();
-        if (!framebufferObject) {
-            MG_State::pGLContext->RecordError(
-                ErrorCode::InvalidOperation,
-                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", functionName,
-                                             "Framebuffer target is bound to no framebuffer object."));
-            return;
-        }
+        if (!ValidateFramebufferTextureAttachmentPoint(functionName, framebufferObject, attachmentType)) return;
 
         if (texture == 0) {
             framebufferObject->Detach(attachmentType);
@@ -1069,6 +1178,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              std::format("Texture object {} is not valid.", texture)));
             return;
         }
+        if (!ValidateFramebufferTextureLevel(functionName, textureObject, level)) return;
         if (layer < 0) {
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidValue,
@@ -1191,6 +1301,13 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "Framebuffer target is bound to no framebuffer object."));
             return;
         }
+        // glFramebufferTexture2D is by far the most-used member of the family and the only one
+        // that inlines its own logic instead of going through the shared helper, so the 9.2.8
+        // conditions have to be asked here explicitly.
+        if (!ValidateFramebufferTextureAttachmentPoint("FramebufferTexture2D_State", framebufferObject,
+                                                       attachmentType)) {
+            return;
+        }
 
         if (texture == 0) {
             framebufferObject->Detach(attachmentType);
@@ -1205,6 +1322,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              std::format("Texture object {} is not valid.", texture)));
             return;
         }
+        if (!ValidateFramebufferTextureLevel("FramebufferTexture2D_State", textureObject, level)) return;
 
         const auto expectedTextureTarget = MG_Util::ConvertTextureUploadTargetToTextureTarget(textureUploadTarget);
         if (expectedTextureTarget == TextureTarget::Unknown ||
@@ -1241,6 +1359,12 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
 
+        // The name's validity is an INVALID_VALUE condition (GL 4.6 core 9.2.8), and it has to be
+        // asked BEFORE the object is resolved: reporting the miss as the INVALID_OPERATION below
+        // pre-empted the shared helper's ValidateTextureName and answered the wrong error code for
+        // every texture name that was never generated.
+        if (!TextureImpl::ValidateTextureName(texture, true)) return;
+
         auto& textureObject = MG_State::pGLContext->GetTextureObject(texture);
         if (!textureObject) {
             MG_State::pGLContext->RecordError(
@@ -1291,13 +1415,10 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              std::format("Texture object {} is not valid.", texture)));
             return;
         }
-        if (level < 0) {
-            MG_State::pGLContext->RecordError(
-                ErrorCode::InvalidValue,
-                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "NamedFramebufferTexture_State",
-                                             "Texture level must be non-negative."));
-            return;
-        }
+        // The whole level condition, not just its negative half: glNamedFramebufferTexture and
+        // glFramebufferTexture are equivalent in 9.2.8, so an out-of-range immutable level has to
+        // be rejected on both or a CTS case gets two answers for one rule.
+        if (!ValidateFramebufferTextureLevel("NamedFramebufferTexture_State", textureObject, level)) return;
 
         TextureUploadTarget textureUploadTarget = TextureUploadTarget::Unknown;
         Bool layered = false;
@@ -2615,24 +2736,28 @@ namespace MobileGL::MG_Impl::GLImpl {
     void ClearBufferfi_Backend(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil) {
         // GL 4.6 core 10.9 makes ClearBuffer* conditional alongside the drawing commands.
         if (MG_State::pGLContext->ConditionalRenderDiscardsCommands()) return;
+        MGP_FILL(ClearBufferfi);
         MG_Backend::gBackendFunctionsTable.GL.ClearBufferfi(buffer, drawbuffer, depth, stencil);
     }
 
     void ClearBufferfv_Backend(GLenum buffer, GLint drawbuffer, const GLfloat* value) {
         // GL 4.6 core 10.9 makes ClearBuffer* conditional alongside the drawing commands.
         if (MG_State::pGLContext->ConditionalRenderDiscardsCommands()) return;
+        MGP_FILL(ClearBufferfv);
         MG_Backend::gBackendFunctionsTable.GL.ClearBufferfv(buffer, drawbuffer, value);
     }
 
     void ClearBufferuiv_Backend(GLenum buffer, GLint drawbuffer, const GLuint* value) {
         // GL 4.6 core 10.9 makes ClearBuffer* conditional alongside the drawing commands.
         if (MG_State::pGLContext->ConditionalRenderDiscardsCommands()) return;
+        MGP_FILL(ClearBufferuiv);
         MG_Backend::gBackendFunctionsTable.GL.ClearBufferuiv(buffer, drawbuffer, value);
     }
 
     void ClearBufferiv_Backend(GLenum buffer, GLint drawbuffer, const GLint* value) {
         // GL 4.6 core 10.9 makes ClearBuffer* conditional alongside the drawing commands.
         if (MG_State::pGLContext->ConditionalRenderDiscardsCommands()) return;
+        MGP_FILL(ClearBufferiv);
         MG_Backend::gBackendFunctionsTable.GL.ClearBufferiv(buffer, drawbuffer, value);
     }
 
@@ -2880,6 +3005,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     }
 
     void ReadPixels_Backend(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) {
+        MGP_FILL(ReadPixels);
         MG_Backend::gBackendFunctionsTable.GL.ReadPixels(x, y, width, height, format, type, pixels);
     }
 

MobileGL/MG_Impl/GLImpl/Getter/GL_Getter.cpp

@@ -7,7 +7,9 @@
 // End of Source File Header
 
 #include "GL_Getter.h"
+#include <algorithm>
 #include <cmath>
+#include <limits>
 #include <Config.h>
 #include <MGGitHash.h>
 #include <MG_Impl/GLImpl/Debug/GL_Debug.h>
@@ -28,6 +30,7 @@
 #include <MG_Util/Async/ShaderCompilePool.h>
 #include <MG_Util/ShaderTranspiler/Types.h>
 #include <MG_Backend/BackendObjects.h>
+#include <MG_Impl/Pipe/PipeFill.h>
 
 namespace MobileGL::MG_Impl::GLImpl {
     // Declared rather than #included from GL_RenderState.h on purpose: that header also declares
@@ -93,8 +96,15 @@ namespace MobileGL::MG_Impl::GLImpl {
         // limits they advertise still have to be legal.
         constexpr GLint kFrontendMaxDebugGroupStackDepth = 64;
         constexpr GLint kFrontendMaxDebugLoggedMessages = 1;
-        constexpr GLint kFrontendMaxVertexUniformComponents = 4096;
-        constexpr GLint kFrontendMaxVertexUniformVectors = 128;
+        // The *_VECTORS answers are the *_COMPONENTS ones divided by four, never a second
+        // literal: they used to be independent (4096 components against 128 vectors, 64 varying
+        // components against 8 varying vectors) and could not both be describing the same
+        // capacity. Both are shared with BuildTBuiltInResource through Types.h, because
+        // gl_MaxVertexUniformVectors and gl_MaxVaryingVectors expand from the same numbers.
+        constexpr GLint kFrontendMaxVertexUniformComponents =
+            static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_VERTEX_UNIFORM_COMPONENTS);
+        constexpr GLint kFrontendMaxVertexUniformVectors =
+            static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_VERTEX_UNIFORM_VECTORS);
         constexpr GLint kFrontendMaxVertexUniformBlocks = 14;
         constexpr GLint kFrontendMaxVertexOutputComponents = 64;
         constexpr GLint kFrontendMaxFragmentInputComponents = 128;
@@ -106,21 +116,61 @@ namespace MobileGL::MG_Impl::GLImpl {
         constexpr GLint kFrontendMaxGeometryTextureImageUnits = 16;
         constexpr GLint kFrontendMaxGeometryUniformComponents = 1024;
         constexpr GLint kFrontendMaxGeometryUniformBlocks = 14;
-        constexpr GLint kFrontendMaxCombinedUniformBlocks = kFrontendMaxVertexUniformBlocks +
-                                                            kFrontendMaxGeometryUniformBlocks +
-                                                            kFrontendMaxFragmentUniformBlocks;
-        constexpr GLint kFrontendMaxVaryingComponents = 64;
-        constexpr GLint kFrontendMaxVaryingVectors = 8;
+        // ARB_geometry_shader4's per-invocation count. No TBuiltInResource field and no
+        // gl_MaxGeometryShaderInvocations built-in exists to keep in step, so this is a getter
+        // answer only; 32 is the GL 4.6 core minimum (table 23.57).
+        constexpr GLint kFrontendMaxGeometryShaderInvocations = 32;
+        constexpr GLint kFrontendMaxTessControlUniformBlocks = 14;
+        constexpr GLint kFrontendMaxTessEvaluationUniformBlocks = 14;
+        // The compute stage's share of the combined sum below. Compute's own per-stage answer is
+        // backend-derived (GL_MAX_COMPUTE_UNIFORM_BLOCKS reads dynamicParameters), so this is not
+        // what that query returns - it is the GL 4.3 core minimum, present here only so the
+        // combined total covers all SIX stages.
+        constexpr GLint kFrontendMaxComputeUniformBlocksShare = 14;
+        // GL 4.6 table 23.64 orders MAX_UNIFORM_BUFFER_BINDINGS >= MAX_COMBINED_UNIFORM_BLOCKS >=
+        // every per-stage count, and the sum has to run over SIX stages, not three and not five.
+        // Three (42) was the original bug. Five (70) replaced it and broke the middle term the
+        // other way: compute's per-stage count is backend-derived and clamps at the binding count,
+        // so a device reporting descriptor-indexing-scale uniform buffers (Adreno reports
+        // maxPerStageDescriptorUniformBuffers = 16777216) advertised 84 compute blocks against a
+        // combined 70. Six stages x 14 = 84, which is also exactly the binding-point count and the
+        // arithmetic the GL 4.5 minimum of 84 bindings is built from, so the ordering is now tight
+        // rather than accidental.
+        constexpr GLint kFrontendMaxCombinedUniformBlocks =
+            kFrontendMaxVertexUniformBlocks + kFrontendMaxTessControlUniformBlocks +
+            kFrontendMaxTessEvaluationUniformBlocks + kFrontendMaxGeometryUniformBlocks +
+            kFrontendMaxFragmentUniformBlocks + kFrontendMaxComputeUniformBlocksShare;
+        constexpr GLint kFrontendMaxVaryingComponents =
+            static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_VARYING_COMPONENTS);
+        constexpr GLint kFrontendMaxVaryingVectors =
+            static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_VARYING_VECTORS);
         constexpr GLint kFrontendMaxProgramTexelOffset = 7;
         constexpr GLint kFrontendMinProgramTexelOffset = -8;
         constexpr GLint kFrontendMaxTransformFeedbackInterleavedComponents = 64;
         constexpr GLint kFrontendMaxTransformFeedbackSeparateAttribs = 4;
         constexpr GLint kFrontendMaxTransformFeedbackSeparateComponents = 4;
+        // ARB_transform_feedback3's vertex-stream count. One is what this implementation can
+        // actually emit to; see the GL_MAX_VERTEX_STREAMS case for why it is not four.
+        constexpr GLint kFrontendMaxVertexStreams = 1;
         constexpr GLint kFrontendMaxGeometryOutputVertices = 256;
         constexpr GLint kFrontendMaxGeometryTotalOutputComponents = 1024;
-        constexpr GLint kFrontendMinUniformBufferBindings = 36;
+        // GL 4.5 core table 23.64 requires 84 indexed uniform binding points, and that is exactly
+        // how wide the state layer's array is (BufferState::BufferBindingPointCount) - see the
+        // GL_MAX_UNIFORM_BUFFER_BINDINGS case for why the ES driver's own, smaller count is not
+        // the ceiling here.
+        constexpr GLint kFrontendMinUniformBufferBindings = 84;
         constexpr GLint kFrontendSubpixelBits = 4;
-        constexpr GLint kFrontendMaxSamples = 4;
+        constexpr GLint kFrontendMaxSamples =
+            static_cast<GLint>(MG_Util::ShaderTranspiler::MIN_ADVERTISED_MAX_SAMPLES);
+        // ARB_shader_subroutine's two limits. NOTHING IMPLEMENTS SUBROUTINES: there is no
+        // glGetSubroutineIndex / glUniformSubroutinesuiv, only the program-interface enum
+        // plumbing. These are answered - with the GL 4.5 core minimums - because the conformance
+        // suite queries them before it checks for the feature and an INVALID_ENUM both leaves the
+        // caller reading its own uninitialised stack slot and strands an error for the next
+        // unrelated call to trip over. The extension is deliberately NOT advertised, so the
+        // numbers are a table entry, not a capability claim.
+        constexpr GLint kFrontendMaxSubroutines = 256;
+        constexpr GLint kFrontendMaxSubroutineUniformLocations = 1024;
 
         // The floors under GL_MAX_COMPUTE_WORK_GROUP_COUNT / _SIZE. Shared with the compile
         // pipeline (CaptureCompileEnv floors the same driver answers at them, and
@@ -134,9 +184,19 @@ namespace MobileGL::MG_Impl::GLImpl {
             return index < 3 ? static_cast<GLint>(MG_Util::ShaderTranspiler::MIN_COMPUTE_WORK_GROUP_SIZE[index]) : 0;
         }
 
+        // GL 4.6 core table 23.64: components + blocks * (blockSize / 4). The product has to be
+        // formed in 64 bits and saturated on the way out - it overflowed a signed 32-bit int on
+        // every Vulkan host that reports a large maxUniformBufferRange. A Mali driver answering
+        // 0xFFFFFFFF saturates to INT32_MAX in the loader, and 14 * (2147483647 / 4) + 4096 wraps
+        // to -1073737742, which the conformance suite read back as a limit "smaller than 58368".
+        // Saturating instead of wrapping is also the only honest answer: an implementation that
+        // can serve more components than a GLint holds still has to report a GLint.
         GLint GetMaxCombinedUniformComponents(GLint maxDefaultUniformComponents, GLint maxUniformBlocks,
                                               GLint maxUniformBlockSizeBytes) {
-            return maxDefaultUniformComponents + maxUniformBlocks * (maxUniformBlockSizeBytes / 4);
+            const Int64 blocks = std::max<Int64>(static_cast<Int64>(maxUniformBlocks), 0);
+            const Int64 componentsPerBlock = std::max<Int64>(static_cast<Int64>(maxUniformBlockSizeBytes), 0) / 4;
+            const Int64 total = static_cast<Int64>(maxDefaultUniformComponents) + blocks * componentsPerBlock;
+            return static_cast<GLint>(std::min<Int64>(total, std::numeric_limits<GLint>::max()));
         }
 
         bool TryDecodeIndexedBufferQuery(GLenum pname, BufferTarget& bufferTarget, IndexedBufferQueryKind& queryKind) {
@@ -304,24 +364,6 @@ namespace MobileGL::MG_Impl::GLImpl {
             return true;
         }
 
-        GLint ResolveDrawFramebufferSampleCount() {
-            const auto& drawFbo =
-                MG_State::pGLContext->GetFramebufferBindingSlot(FramebufferTarget::Draw).GetBoundObject();
-            if (!drawFbo) return 0;
-
-            GLint maxSamples = 0;
-            for (const auto& attachment : drawFbo->GetAllAttachmentObjects()) {
-                if (attachment.IsRenderbuffer() && attachment.GetRenderbuffer()) {
-                    maxSamples = std::max(maxSamples, static_cast<GLint>(attachment.GetRenderbuffer()->GetSamples()));
-                } else if (attachment.IsTexture() && attachment.GetTexture()) {
-                    // Multisample texture attachments count too (GL_SAMPLE_BUFFERS must
-                    // report 1 for any multisampled draw framebuffer).
-                    maxSamples = std::max(maxSamples, static_cast<GLint>(attachment.GetTexture()->GetSamples()));
-                }
-            }
-            return maxSamples;
-        }
-
         void RecordIndexedOnlyGetterError(const char* functionName, GLenum pname) {
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidEnum,
@@ -473,10 +515,18 @@ namespace MobileGL::MG_Impl::GLImpl {
     } // namespace
 
     // GL 4.6 core table 23.53 requires GL_MAX_SAMPLES >= 4, so the driver's value is floored
-    // before it is advertised. Every other multisample ceiling MobileGL advertises has to be
-    // floored the same way: promising 4 samples globally while answering GL_MAX_INTEGER_SAMPLES
-    // 1 - which is exactly what Adreno reports - makes the frontend reject the very count it
-    // just told the application to use. The backends clamp the realised count instead.
+    // before it is advertised. gl_MaxSamples expands from the same floored number
+    // (BuildTBuiltInResource), which is also what sizes gl_SampleMask[].
+    //
+    // THE FLOOR STOPS HERE, and that is the point. It used to be applied to
+    // GL_MAX_INTEGER_SAMPLES, GL_MAX_COLOR_TEXTURE_SAMPLES and GL_MAX_DEPTH_TEXTURE_SAMPLES too,
+    // on the reasoning that an application reads GL_MAX_SAMPLES once and hands that count to
+    // every glTexStorage*Multisample. Table 23.53 gives those three a minimum of ONE, and the
+    // reasoning had it backwards: Adreno and Mali back an integer multisample texture with a
+    // single sample, so flooring the query at 4 did not make four samples exist - it made the
+    // backend silently under-allocate (ClampSamplesToBackendSupport) while the application wrote
+    // per-sample data it could never read back. Reporting what was probed turns that into an
+    // honest "unsupported" the application can branch on.
     GLint GetAdvertisedMaxSamples() {
         if (MG_Backend::pActiveBackendObject == nullptr) {
             return kFrontendMaxSamples;
@@ -484,6 +534,50 @@ namespace MobileGL::MG_Impl::GLImpl {
         return std::max(MG_Backend::pActiveBackendObject->GetDynamicParameters().MaxSamples, kFrontendMaxSamples);
     }
 
+    // GL 4.6 core table 23.53 minimum for the per-category multisample ceilings. One, not four:
+    // see the note on GetAdvertisedMaxSamples. A zero would be a probe that never ran, so it is
+    // floored rather than trusted.
+    namespace {
+        GLint AdvertisedCategoryMaxSamples(Int MG_Backend::DynamicBackendParameters::*categoryLimit) {
+            if (MG_Backend::pActiveBackendObject == nullptr) {
+                return 1;
+            }
+            return std::max(MG_Backend::pActiveBackendObject->GetDynamicParameters().*categoryLimit, 1);
+        }
+    } // namespace
+
+    GLint GetAdvertisedColorTextureMaxSamples() {
+        return AdvertisedCategoryMaxSamples(&MG_Backend::DynamicBackendParameters::MaxColorTextureSamples);
+    }
+
+    GLint GetAdvertisedDepthTextureMaxSamples() {
+        return AdvertisedCategoryMaxSamples(&MG_Backend::DynamicBackendParameters::MaxDepthTextureSamples);
+    }
+
+    GLint GetAdvertisedIntegerMaxSamples() {
+        return AdvertisedCategoryMaxSamples(&MG_Backend::DynamicBackendParameters::MaxIntegerSamples);
+    }
+
+    // Declared in GL_Getter.h, so that the draw path can feed the same number to the reserved
+    // gl_NumSamples stand-in that glGetIntegerv(GL_SAMPLES) reports.
+    GLint ResolveDrawFramebufferSampleCount() {
+        const auto& drawFbo =
+            MG_State::pGLContext->GetFramebufferBindingSlot(FramebufferTarget::Draw).GetBoundObject();
+        if (!drawFbo) return 0;
+
+        GLint maxSamples = 0;
+        for (const auto& attachment : drawFbo->GetAllAttachmentObjects()) {
+            if (attachment.IsRenderbuffer() && attachment.GetRenderbuffer()) {
+                maxSamples = std::max(maxSamples, static_cast<GLint>(attachment.GetRenderbuffer()->GetSamples()));
+            } else if (attachment.IsTexture() && attachment.GetTexture()) {
+                // Multisample texture attachments count too (GL_SAMPLE_BUFFERS must
+                // report 1 for any multisampled draw framebuffer).
+                maxSamples = std::max(maxSamples, static_cast<GLint>(attachment.GetTexture()->GetSamples()));
+            }
+        }
+        return maxSamples;
+    }
+
     /* @INSERTION_POINT:FUNCTION_IMPLEMENTATION@ */
     const GLubyte* GetString(GLenum name) {
         static String vendorString;
@@ -680,12 +774,30 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         case GL_MIN_FRAGMENT_INTERPOLATION_OFFSET:
         case GL_MAX_FRAGMENT_INTERPOLATION_OFFSET:
-        case GL_FRAGMENT_INTERPOLATION_OFFSET_BITS: {
+        case GL_FRAGMENT_INTERPOLATION_OFFSET_BITS:
+        // Same reason as the three above: the integer fallback would round the fraction to 0
+        // or 1 first, so a 0.25 sample-shading rate would answer GL_FALSE.
+        case GL_MIN_SAMPLE_SHADING_VALUE: {
             GLfloat value = 0.0f;
             GetFloatv(pname, &value);
             *params = value != 0.0f ? GL_TRUE : GL_FALSE;
             return;
         }
+        // Float-native state, so GL 4.6 core 2.2.2's "zero becomes FALSE, every other value
+        // becomes TRUE" has to be applied to the VALUE. Answering these through the integer getter
+        // below instead - which rounds - reported GL_FALSE for a perfectly non-zero level of 0.25,
+        // and every other float state in this function already reads through GetFloatv for exactly
+        // that reason.
+        case GL_PATCH_DEFAULT_OUTER_LEVEL:
+        case GL_PATCH_DEFAULT_INNER_LEVEL: {
+            const GLsizei componentCount = pname == GL_PATCH_DEFAULT_OUTER_LEVEL ? 4 : 2;
+            GLfloat levels[4] = {};
+            GetFloatv(pname, levels);
+            for (GLsizei i = 0; i < componentCount; ++i) {
+                params[i] = levels[i] != 0.0f ? GL_TRUE : GL_FALSE;
+            }
+            return;
+        }
         default:
             break;
         }
@@ -735,6 +847,22 @@ namespace MobileGL::MG_Impl::GLImpl {
             params[1] = depthRange.y();
             return;
         }
+        // glPatchParameterfv's two states. Float-native, so they are answered here rather than
+        // through the integer fallback below - which rounds, and would report 0 for a level of 0.5.
+        case GL_PATCH_DEFAULT_OUTER_LEVEL: {
+            const FloatVec4& outer = MG_State::pGLContext->GetPatchDefaultOuterLevel();
+            params[0] = outer.x();
+            params[1] = outer.y();
+            params[2] = outer.z();
+            params[3] = outer.w();
+            return;
+        }
+        case GL_PATCH_DEFAULT_INNER_LEVEL: {
+            const FloatVec2& inner = MG_State::pGLContext->GetPatchDefaultInnerLevel();
+            params[0] = inner.x();
+            params[1] = inner.y();
+            return;
+        }
         case GL_VIEWPORT_BOUNDS_RANGE: {
             const auto& dynamicParameters = MG_Backend::pActiveBackendObject->GetDynamicParameters();
             params[0] = dynamicParameters.ViewportBoundsRangeMin;
@@ -800,6 +928,11 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_POLYGON_OFFSET_UNITS:
             params[0] = MG_State::pGLContext->GetPolygonOffsetUnits();
             return;
+        case GL_POLYGON_OFFSET_CLAMP:
+            // Float-native state, so it is answered here rather than through the integer
+            // fallback: glPolygonOffsetClamp(1, 1, 0.5) must read back as 0.5, not as 0.
+            params[0] = MG_State::pGLContext->GetPolygonOffsetClamp();
+            return;
         case GL_SMOOTH_LINE_WIDTH_RANGE: {
             const auto& dynamicParameters = MG_Backend::pActiveBackendObject->GetDynamicParameters();
             params[0] = dynamicParameters.SmoothLineWidthRangeMin;
@@ -815,6 +948,11 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_SAMPLE_COVERAGE_VALUE:
             params[0] = MG_State::pGLContext->GetSampleCoverageValue();
             return;
+        case GL_MIN_SAMPLE_SHADING_VALUE:
+            // Float state, so it has to be answered here rather than through the integer
+            // fallback: glMinSampleShading(0.5) must read back as 0.5 and not as 0.
+            params[0] = MG_State::pGLContext->GetMinSampleShadingValue();
+            return;
         case GL_POINT_FADE_THRESHOLD_SIZE:
             // Float state: read it directly so the fractional part is not lost to the integer path.
             params[0] = MG_State::pGLContext->GetPointFadeThresholdSize();
@@ -1036,6 +1174,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                 : GetMinComputeWorkGroupSize(index);
             GLint backendValue = 0;
             if (getIntegeri) {
+                MGP_FILL(GetIntegeri_v);
                 getIntegeri(target, index, &backendValue);
             }
             *data = std::max(backendValue, minimum);
@@ -1186,6 +1325,13 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
 
         switch (pname) {
+        case GL_MAX_ELEMENT_INDEX:
+            // The largest value a GL_UNSIGNED_INT index may take. It has to be answered HERE and
+            // not left to the 32-bit fallback below: the conformance suite reads it with
+            // glGetInteger64v, and widening the saturated GLint would report INT32_MAX where the
+            // spec requires 2^32-1.
+            params[0] = 0xFFFFFFFFLL;
+            return;
         case GL_MAX_SHADER_STORAGE_BLOCK_SIZE:
             if (MG_Backend::pActiveBackendObject) {
                 params[0] = static_cast<GLint64>(
@@ -1209,6 +1355,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             Int64 timestamp = 0;
             if (!MG_Config::Features.DisableTimerQuery) {
                 if (const auto getGpuTimestampNs = MG_Backend::gBackendFunctionsTable.GL.GetGpuTimestampNs) {
+                    MGP_FILL(GetGpuTimestampNs);
                     timestamp = getGpuTimestampNs();
                 }
             }
@@ -1222,12 +1369,17 @@ namespace MobileGL::MG_Impl::GLImpl {
         GLint ints[4] = {};
         GetIntegerv(pname, ints);
 
+        // GL 4.6 core 22.1 gives glGetInteger64v the same accepted-pname set as glGetIntegerv, so
+        // every pname the integer getter answers with several components owes them all here too.
+        // A pname that reaches the `default:` arm writes params[0] and leaves the caller's other
+        // components holding whatever they held, with no error to say so.
         switch (pname) {
         case GL_BLEND_COLOR:
         case GL_COLOR_CLEAR_VALUE:
         case GL_COLOR_WRITEMASK:
         case GL_SCISSOR_BOX:
         case GL_VIEWPORT:
+        case GL_PATCH_DEFAULT_OUTER_LEVEL:
             for (int i = 0; i < 4; ++i) {
                 params[i] = static_cast<GLint64>(ints[i]);
             }
@@ -1237,6 +1389,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_MAX_VIEWPORT_DIMS:
         case GL_POINT_SIZE_RANGE:
         case GL_VIEWPORT_BOUNDS_RANGE:
+        case GL_PATCH_DEFAULT_INNER_LEVEL:
             params[0] = static_cast<GLint64>(ints[0]);
             params[1] = static_cast<GLint64>(ints[1]);
             return;
@@ -1268,6 +1421,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_POINT_SIZE_RANGE:
         case GL_SMOOTH_LINE_WIDTH_RANGE:
         case GL_MAX_VIEWPORT_DIMS:
+        case GL_PATCH_DEFAULT_INNER_LEVEL:
             count = 2;
             break;
         case GL_BLEND_COLOR:
@@ -1275,6 +1429,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_VIEWPORT:
         case GL_SCISSOR_BOX:
         case GL_COLOR_WRITEMASK:
+        case GL_PATCH_DEFAULT_OUTER_LEVEL:
             count = 4;
             break;
         default:
@@ -1314,6 +1469,15 @@ namespace MobileGL::MG_Impl::GLImpl {
                 *params = 0;
             return;
         }
+        // GL_TEXTURE_BUFFER_BINDING and GL_TEXTURE_BUFFER are the same token (0x8C2A): as a
+        // glGetIntegerv pname it asks which BUFFER object is bound to the buffer-texture target,
+        // not which texture is (that one is GL_TEXTURE_BINDING_BUFFER, handled by the texture-unit
+        // decoder above).
+        case GL_TEXTURE_BUFFER_BINDING: {
+            auto& obj = MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::Texture).GetBoundObject();
+            *params = obj ? static_cast<GLint>(obj->GetExternalIndex()) : 0;
+            return;
+        }
         case GL_BLEND:
             *params = MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::Blend) ? GL_TRUE : GL_FALSE;
             return;
@@ -1369,6 +1533,16 @@ namespace MobileGL::MG_Impl::GLImpl {
             // this single case serves every getter flavor.
             *params = static_cast<GLint>(MG_State::pGLContext->GetClampReadColor());
             return;
+        // glClipControl's two state variables (GL 4.5 core table 23.7). They answer from the
+        // state the entry point records, which is what the conformance suite's initial-value and
+        // set-then-get cases read - the RASTERIZATION half of clip control is a separate,
+        // backend-side question and does not gate the query.
+        case GL_CLIP_ORIGIN:
+            *params = static_cast<GLint>(MG_State::pGLContext->GetClipOrigin());
+            return;
+        case GL_CLIP_DEPTH_MODE:
+            *params = static_cast<GLint>(MG_State::pGLContext->GetClipDepthMode());
+            return;
         case GL_COLOR_CLEAR_VALUE: {
             const FloatVec4& clearColor = MG_State::pGLContext->GetClearColor();
             params[0] = static_cast<GLint>(clearColor.x());
@@ -1657,6 +1831,9 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_MAX_GEOMETRY_UNIFORM_COMPONENTS:
             *params = kFrontendMaxGeometryUniformComponents;
             return;
+        case GL_MAX_GEOMETRY_SHADER_INVOCATIONS:
+            *params = kFrontendMaxGeometryShaderInvocations;
+            return;
         case GL_MAX_IMAGE_SAMPLES:
             *params = 0; // multisampled image load/store is not exposed by the DirectGLES frontend
             return;
@@ -1710,6 +1887,59 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params =
                 StageStorageBlockCount(&MG_Backend::DynamicBackendParameters::MaxTessEvaluationShaderStorageBlocks);
             return;
+        // The tessellation per-stage resource limits. Every one of these is ALSO a GLSL built-in
+        // constant that BuildTBuiltInResource expands, and the two must report the same number
+        // (KHR-GL45.limits.max_tess_* compares them directly) - which is why the values come from
+        // the shared block in MG_Util/ShaderTranspiler/Types.h rather than from literals here.
+        // They were the whole per-stage tess family: the table had been filled in only where the
+        // honest answer was zero (the atomic counters, the image uniforms) or where a driver
+        // query existed (GL_MAX_PATCH_VERTICES, GL_MAX_TESS_GEN_LEVEL), so every pname whose
+        // answer is a real resource count fell through to GL_INVALID_ENUM.
+        case GL_MAX_TESS_CONTROL_INPUT_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_CONTROL_INPUT_COMPONENTS);
+            return;
+        case GL_MAX_TESS_CONTROL_OUTPUT_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_CONTROL_OUTPUT_COMPONENTS);
+            return;
+        case GL_MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS);
+            return;
+        case GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS);
+            return;
+        case GL_MAX_TESS_CONTROL_UNIFORM_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_CONTROL_UNIFORM_COMPONENTS);
+            return;
+        case GL_MAX_TESS_EVALUATION_INPUT_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_EVALUATION_INPUT_COMPONENTS);
+            return;
+        case GL_MAX_TESS_EVALUATION_OUTPUT_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_EVALUATION_OUTPUT_COMPONENTS);
+            return;
+        case GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS);
+            return;
+        case GL_MAX_TESS_EVALUATION_UNIFORM_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_EVALUATION_UNIFORM_COMPONENTS);
+            return;
+        case GL_MAX_TESS_PATCH_COMPONENTS:
+            *params = static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_PATCH_COMPONENTS);
+            return;
+        // Routed through the same clamp as every other per-stage block count so the
+        // MAX_UNIFORM_BUFFER_BINDINGS >= MAX_COMBINED_UNIFORM_BLOCKS >= per-stage ordering of
+        // GL 4.6 table 23.64 cannot be broken by the two families moving independently.
+        case GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS:
+            *params = ClampUniformBlockCount(kFrontendMaxTessControlUniformBlocks);
+            return;
+        case GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS:
+            *params = ClampUniformBlockCount(kFrontendMaxTessEvaluationUniformBlocks);
+            return;
+        case GL_MAX_SUBROUTINES:
+            *params = kFrontendMaxSubroutines;
+            return;
+        case GL_MAX_SUBROUTINE_UNIFORM_LOCATIONS:
+            *params = kFrontendMaxSubroutineUniformLocations;
+            return;
         case GL_MAX_TEXTURE_LOD_BIAS:
             *params = 15; // TODO
             return;
@@ -1755,8 +1985,21 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_NUM_PROGRAM_BINARY_FORMATS:
             *params = 0;
             return;
+        // GL_ARB_spirv_extensions / GL 4.6 core 22.2. An implementation that advertises no
+        // SPIR-V extension answers zero here, and glGetStringi(GL_SPIR_V_EXTENSIONS, i) is then
+        // never legally called - MobileGL runs the module through its own translation pipeline
+        // and relies on no SPIR-V extension to do it, so zero is the true answer rather than a
+        // placeholder.
+        case GL_NUM_SPIR_V_EXTENSIONS:
+            *params = 0;
+            return;
+        // GL_ARB_gl_spirv, core since 4.6: exactly one shader binary format, and the pair has to
+        // agree - an application sizes its GL_SHADER_BINARY_FORMATS array from the count.
         case GL_NUM_SHADER_BINARY_FORMATS:
-            *params = 0; // ShaderBinary entrypoints are stubbed
+            *params = 1;
+            return;
+        case GL_SHADER_BINARY_FORMATS:
+            *params = static_cast<GLint>(GL_SHADER_BINARY_FORMAT_SPIR_V);
             return;
         case GL_PACK_ALIGNMENT:
             *params = MG_State::pGLContext->GetPixelStoreParam(PixelStoreParam::PackAlignment);
@@ -1815,6 +2058,11 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_PRIMITIVE_RESTART_INDEX:
             *params = static_cast<GLint>(MG_State::pGLContext->GetPrimitiveRestartIndex());
             return;
+        case GL_POLYGON_OFFSET_CLAMP:
+            // Float state (see GetFloatv); rounded to nearest for the integer query per GL 4.6
+            // core 22.1's float-to-integer rule.
+            *params = static_cast<GLint>(std::lround(MG_State::pGLContext->GetPolygonOffsetClamp()));
+            return;
         case GL_PROGRAM_BINARY_FORMATS:
             *params = 0; // program-binary entrypoints are stubbed
             return;
@@ -1900,6 +2148,13 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_SAMPLE_MASK:
             *params = MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::SampleMask) ? GL_TRUE : GL_FALSE;
             return;
+        case GL_SAMPLE_SHADING:
+            *params = MG_State::pGLContext->IsCapabilityEnabled(CapabilityInput::SampleShading) ? GL_TRUE : GL_FALSE;
+            return;
+        case GL_MIN_SAMPLE_SHADING_VALUE:
+            // GL 4.6 core 22.2: a floating-point value queried as an integer rounds to nearest.
+            *params = static_cast<GLint>(std::lround(MG_State::pGLContext->GetMinSampleShadingValue()));
+            return;
         case GL_SAMPLE_MASK_VALUE:
             *params = static_cast<GLint>(MG_State::pGLContext->GetSampleMaskValue());
             return;
@@ -2011,6 +2266,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             Int64 timestamp = 0;
             if (!MG_Config::Features.DisableTimerQuery) {
                 if (const auto getGpuTimestampNs = MG_Backend::gBackendFunctionsTable.GL.GetGpuTimestampNs) {
+                    MGP_FILL(GetGpuTimestampNs);
                     timestamp = getGpuTimestampNs();
                 }
             }
@@ -2118,7 +2374,12 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
         case GL_MAX_ELEMENT_INDEX:
-            *params = 1024 * 1024; // TODO
+            // 64-bit state (see GetInteger64v); the 32-bit query saturates, per the GL
+            // state-query conversion rules - the same shape GL_MAX_SHADER_STORAGE_BLOCK_SIZE
+            // uses. The real answer is 2^32-1 because both backends draw with GL_UNSIGNED_INT
+            // indices and neither bounds an index value; the old `1024 * 1024` was a placeholder
+            // that no draw path ever consulted.
+            *params = INT32_MAX;
             return;
         case GL_CONTEXT_PROFILE_MASK:
             // Reports the requested context profile (EGL defaults 3.x contexts to core);
@@ -2174,8 +2435,12 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = dynamicParameters.MaxComputeTextureImageUnits;
             break;
         case GL_MAX_COMBINED_COMPUTE_UNIFORM_COMPONENTS:
+            // The CLAMPED block count, i.e. exactly what GL_MAX_COMPUTE_UNIFORM_BLOCKS answers.
+            // GL 4.6 table 23.64 defines this as the components reachable through the blocks a
+            // stage may declare, so deriving it from the raw backend number described 256 blocks
+            // an application is only ever allowed 84 of.
             *params = GetMaxCombinedUniformComponents(kFrontendMaxComputeUniformComponents,
-                                                      dynamicParameters.MaxComputeUniformBlocks,
+                                                      ClampUniformBlockCount(dynamicParameters.MaxComputeUniformBlocks),
                                                       dynamicParameters.MaxUniformBlockSize);
             break;
         case GL_MAX_COMPUTE_WORK_GROUP_INVOCATIONS:
@@ -2219,16 +2484,16 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = static_cast<GLint>(dynamicParameters.ViewportIndexProvokingVertex);
             break;
         case GL_MAX_COLOR_TEXTURE_SAMPLES:
-            *params = std::max(dynamicParameters.MaxColorTextureSamples, GetAdvertisedMaxSamples());
+            *params = GetAdvertisedColorTextureMaxSamples();
             break;
         case GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS:
             *params = GetMaxCombinedUniformComponents(kFrontendMaxFragmentUniformComponents,
-                                                      kFrontendMaxFragmentUniformBlocks,
+                                                      ClampUniformBlockCount(kFrontendMaxFragmentUniformBlocks),
                                                       dynamicParameters.MaxUniformBlockSize);
             break;
         case GL_MAX_COMBINED_GEOMETRY_UNIFORM_COMPONENTS:
             *params = GetMaxCombinedUniformComponents(kFrontendMaxGeometryUniformComponents,
-                                                      kFrontendMaxGeometryUniformBlocks,
+                                                      ClampUniformBlockCount(kFrontendMaxGeometryUniformBlocks),
                                                       dynamicParameters.MaxUniformBlockSize);
             break;
         case GL_MAX_GEOMETRY_OUTPUT_VERTICES:
@@ -2242,14 +2507,14 @@ namespace MobileGL::MG_Impl::GLImpl {
             break;
         case GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS:
             *params = GetMaxCombinedUniformComponents(kFrontendMaxVertexUniformComponents,
-                                                      kFrontendMaxVertexUniformBlocks,
+                                                      ClampUniformBlockCount(kFrontendMaxVertexUniformBlocks),
                                                       dynamicParameters.MaxUniformBlockSize);
             break;
         case GL_MAX_CUBE_MAP_TEXTURE_SIZE:
             *params = dynamicParameters.MaxCubeMapTextureSize;
             break;
         case GL_MAX_DEPTH_TEXTURE_SAMPLES:
-            *params = std::max(dynamicParameters.MaxDepthTextureSamples, GetAdvertisedMaxSamples());
+            *params = GetAdvertisedDepthTextureMaxSamples();
             break;
         case GL_MAX_FRAMEBUFFER_WIDTH:
             *params = dynamicParameters.MaxFramebufferWidth;
@@ -2276,7 +2541,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = dynamicParameters.MaxComputeImageUniforms;
             break;
         case GL_MAX_INTEGER_SAMPLES:
-            *params = std::max(dynamicParameters.MaxIntegerSamples, GetAdvertisedMaxSamples());
+            *params = GetAdvertisedIntegerMaxSamples();
             break;
         case GL_MAX_RENDERBUFFER_SIZE:
             *params = dynamicParameters.MaxRenderbufferSize;
@@ -2287,12 +2552,56 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_PATCH_VERTICES:
             *params = static_cast<GLint>(MG_State::pGLContext->GetPatchVertices());
             break;
+        // Float state, so glGetIntegerv rounds it (GL 4.6 core 2.2.2) - the exact values come back
+        // through glGetFloatv. Answered here so glGetBooleanv, which delegates to this getter for
+        // everything its own switch does not handle, does not report INVALID_ENUM for them.
+        case GL_PATCH_DEFAULT_OUTER_LEVEL: {
+            const FloatVec4& outer = MG_State::pGLContext->GetPatchDefaultOuterLevel();
+            for (Uint i = 0; i < 4; ++i) params[i] = static_cast<GLint>(std::lround(outer[i]));
+            break;
+        }
+        case GL_PATCH_DEFAULT_INNER_LEVEL: {
+            const FloatVec2& inner = MG_State::pGLContext->GetPatchDefaultInnerLevel();
+            for (Uint i = 0; i < 2; ++i) params[i] = static_cast<GLint>(std::lround(inner[i]));
+            break;
+        }
+        // GL 4.6 core table 23.66: whether the primitive-restart index terminates a patch.
+        // GL_FALSE is a legal answer and the true one - neither backend cuts a patch short, and
+        // the DirectVulkan draw path relies on this staying false (it resolves primitive restart
+        // to "never" for a PATCH_LIST topology on the strength of it).
+        case GL_PRIMITIVE_RESTART_FOR_PATCHES_SUPPORTED:
+            *params = GL_FALSE;
+            break;
         case GL_MAX_PATCH_VERTICES:
             *params = dynamicParameters.MaxPatchVertices;
             break;
         case GL_MAX_TESS_GEN_LEVEL:
             *params = dynamicParameters.MaxTessGenLevel;
             break;
+        // Same helper, and so the same arithmetic, as every other GL_MAX_COMBINED_*_UNIFORM_
+        // COMPONENTS: default-block components + blocks * (block size / 4). It reproduces the
+        // conformance suite's own formula exactly, so the two cannot drift.
+        case GL_MAX_COMBINED_TESS_CONTROL_UNIFORM_COMPONENTS:
+            *params = GetMaxCombinedUniformComponents(
+                static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_CONTROL_UNIFORM_COMPONENTS),
+                ClampUniformBlockCount(kFrontendMaxTessControlUniformBlocks), dynamicParameters.MaxUniformBlockSize);
+            break;
+        case GL_MAX_COMBINED_TESS_EVALUATION_UNIFORM_COMPONENTS:
+            *params = GetMaxCombinedUniformComponents(
+                static_cast<GLint>(MG_Util::ShaderTranspiler::MAX_TESS_EVALUATION_UNIFORM_COMPONENTS),
+                ClampUniformBlockCount(kFrontendMaxTessEvaluationUniformBlocks), dynamicParameters.MaxUniformBlockSize);
+            break;
+        // ARB_cull_distance. Backend-derived exactly like GL_MAX_CLIP_DISTANCES beside it, and
+        // for a stronger reason: a cull distance discards the whole primitive, so advertising
+        // eight the rasterizer cannot serve turns every culling draw into a silent no-op. Zero is
+        // the honest answer on a host with no cull-distance route, and the conformance suite then
+        // skips the functional cases instead of failing them deep inside a pixel comparison.
+        case GL_MAX_CULL_DISTANCES:
+            *params = dynamicParameters.MaxCullDistances;
+            break;
+        case GL_MAX_COMBINED_CLIP_AND_CULL_DISTANCES:
+            *params = dynamicParameters.MaxCombinedClipAndCullDistances;
+            break;
         case GL_MIN_PROGRAM_TEXTURE_GATHER_OFFSET:
             *params = dynamicParameters.MinProgramTextureGatherOffset;
             break;
@@ -2343,7 +2652,25 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = kFrontendMaxTransformFeedbackSeparateAttribs;
             break;
         case GL_MAX_VERTEX_STREAMS:
-            *params = 1;
+            // ONE, which is under the GL 4.5 core table 23.62 minimum of four and is a known,
+            // deliberate non-conformance. It was briefly raised to 4 on the theory that streams
+            // 1..3 could exist and be permanently empty; measuring that decision refuted it.
+            // Raising the limit un-gates two CTS cases per package across KHR-GL40..GL46 -
+            // transform_feedback.draw_xfb_stream_test (which stops being skipped) and
+            // transform_feedback3.multiple_streams (which stops reporting NotSupported) - and
+            // both then fail, because nothing in the shader pipeline supports layout(stream = N),
+            // EmitStreamVertex or EndStreamPrimitive, and because the query state machine tracks
+            // one active query per TARGET rather than per (target, stream). That is 14 new
+            // failures against 2 gained limits passes, and a 4 nothing can back is the
+            // advertised-caps lie with the sign flipped.
+            //
+            // The real fix is the feature, not the number: per-stream capture needs
+            // layout(stream = N) through the transpiler plus per-(target, stream) query slots,
+            // which DirectVulkan could back with VK_EXT_transform_feedback's geometryStreams and
+            // DirectGLES cannot back at all (ES has no vertex streams). Until that lands, one is
+            // the honest count and every stream-addressing entry point bounds itself by THIS
+            // query, so raising it later moves them all together.
+            *params = kFrontendMaxVertexStreams;
             break;
         case GL_TRANSFORM_FEEDBACK_ACTIVE:
             *params = MG_State::pGLContext->IsTransformFeedbackActive() ? 1 : 0;
@@ -2360,15 +2687,36 @@ namespace MobileGL::MG_Impl::GLImpl {
         case GL_MAX_TEXTURE_SIZE:
             *params = dynamicParameters.MaxTextureSize;
             break;
-        case GL_MAX_UNIFORM_BUFFER_BINDINGS:
+        case GL_MAX_UNIFORM_BUFFER_BINDINGS: {
             // Never advertise more bindings than the state layer's indexed-binding array can track
             // (BufferState::BufferBindingPointCount): glBindBufferBase rejects indices past that
             // capacity, and the GL CTS per-case state reset calls glBindBufferBase on every
-            // advertised index and expects no error. The floor equals the GL 3.3 core minimum
-            // (36), so the clamp never under-advertises.
+            // advertised index and expects no error. The floor is the GL 4.5 core minimum, and
+            // the array was widened to exactly it, so the two coincide by construction.
+            //
+            // WHY THE BACKEND'S OWN COUNT IS NOT THE CEILING HERE, unlike the shader-storage
+            // family. A GL uniform binding point is where an APPLICATION parks a buffer; it is
+            // not a driver binding point. Neither backend forwards it as one on the draw path:
+            // DirectGLES rebinds the blocks a program declares onto COMPACTED ES points
+            // (BindCurrentProgramWithResources maps block i to ES point i+1) and DirectVulkan
+            // resolves each block to a descriptor. So what the host driver's count bounds is how
+            // many blocks ONE PROGRAM may use, not how many points an application may bind.
+            //
+            // That per-program number is NOT GL_MAX_COMBINED_UNIFORM_BLOCKS (84, the six-stage
+            // sum): no single program can reach it. A graphics program is bounded by the five
+            // graphics stages' per-stage counts, 14 each, so 70 blocks plus the global UBO at ES
+            // point 0 = 71 - inside the ES 3.2 minimum of 72. A compute program is bounded by
+            // GL_MAX_COMPUTE_UNIFORM_BLOCKS, which on DirectGLES is the ES driver's own count
+            // (GL-scale, ~14) and on DirectVulkan is served from descriptors with no ES binding
+            // points involved. Raising any per-stage graphics count past 14 is what would break
+            // this, so that is the edit to check against the ES ceiling - not this one.
+            static_assert(static_cast<GLint>(MG_State::GLState::BufferBindingPointCount) >=
+                              kFrontendMinUniformBufferBindings,
+                          "the indexed-binding array must be able to hold every advertised uniform binding point");
             *params = std::clamp(dynamicParameters.MaxUniformBufferBindings, kFrontendMinUniformBufferBindings,
                                  static_cast<GLint>(MG_State::GLState::BufferBindingPointCount));
             break;
+        }
         case GL_MAX_UNIFORM_BLOCK_SIZE:
             *params = dynamicParameters.MaxUniformBlockSize;
             break;

MobileGL/MG_Impl/GLImpl/Getter/GL_Getter.h

@@ -25,7 +25,24 @@ namespace MobileGL::MG_Impl::GLImpl {
     GLenum GetError();
     GLenum GetGraphicsResetStatus();
     // The GL_MAX_SAMPLES value MobileGL advertises, i.e. the driver's value floored to the GL
-    // core minimum. Frontend multisample validators have to honour this ceiling for every
-    // format, otherwise MobileGL rejects a sample count it advertised itself.
+    // core minimum of 4. This is the RENDERBUFFER ceiling; the three per-category texture
+    // ceilings below have a minimum of one and are reported as probed.
     GLint GetAdvertisedMaxSamples();
+    // Exactly what GL_MAX_COLOR_TEXTURE_SAMPLES / GL_MAX_DEPTH_TEXTURE_SAMPLES /
+    // GL_MAX_INTEGER_SAMPLES report: the probed backend limit floored at the GL 4.6 core minimum
+    // of ONE (table 23.53). Exported so the frontend's storage validation enforces exactly what
+    // the query promised - it used to floor both at 4 and then let the backend quietly
+    // under-allocate whatever the driver could not actually provide.
+    GLint GetAdvertisedColorTextureMaxSamples();
+    GLint GetAdvertisedDepthTextureMaxSamples();
+    GLint GetAdvertisedIntegerMaxSamples();
+    // What glGetIntegerv(GL_SAMPLES) answers for the CURRENT draw framebuffer: the largest sample
+    // count over its attachments, and 0 for a single-sample or default framebuffer (GL 4.6 core
+    // 9.2.3 / 22.2 - GL_SAMPLE_BUFFERS is 1 exactly when this is non-zero).
+    //
+    // Shared rather than duplicated because two callers need the identical number and disagreeing
+    // would be a silent bug: the query itself, and the draw path's write of the reserved
+    // gl_NumSamples stand-in - a shader comparing gl_NumSamples against glGetIntegerv(GL_SAMPLES)
+    // is exactly what the sample_variables CTS does.
+    GLint ResolveDrawFramebufferSampleCount();
 } // namespace MobileGL::MG_Impl::GLImpl

MobileGL/MG_Impl/GLImpl/Program/GL_Program.cpp

@@ -11,6 +11,8 @@
 #include "Config.h"
 #include <cmath>
 #include <limits>
+#include <set>
+#include <MG_Util/ShaderTranspiler/ShaderCompiler.h>
 #include <MG_Impl/GLImpl/VertexArray/Validators.h>
 #include <MG_State/GLState/Core.h>
 #include <MG_Util/Converters/GLToStr/GLEnumConverter.h>
@@ -19,6 +21,7 @@
 #include <MG_Util/Converters/SPIRVCrossToGL/SpvcTypeConverter.h>
 #include <MG_Util/Async/ShaderCompilePool.h>
 #include <MG_Backend/BackendObjects.h>
+#include <MG_Impl/Pipe/PipeFill.h>
 
 namespace MobileGL::MG_Impl::GLImpl {
     // The flattened uniform type these helpers used to take as a raw glslang::TType*
@@ -30,10 +33,22 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     static bool CheckShaderNameValidity(Uint shader) {
         if (shader == 0 || !MG_State::pGLContext->ValidateShaderName(shader)) {
+            // The mirror of CheckProgramNameValidity below, and for the same reason: programs and
+            // shaders are drawn from ONE name space (ProgramState hands both out of a single
+            // generator), so a name that exists but belongs to a PROGRAM is the wrong kind of
+            // object - GL 3.3 core 2.11.x makes that INVALID_OPERATION - while a name GL never
+            // handed out is INVALID_VALUE. This half of the split was missing, so every shader
+            // entry point handed a program name reported INVALID_VALUE; the conformance suite
+            // reads exactly that code back from glSpecializeShader.
+            const ErrorCode error = (shader != 0 && MG_State::pGLContext->ValidateProgramName(shader))
+                ? ErrorCode::InvalidOperation
+                : ErrorCode::InvalidValue;
             MG_State::pGLContext->RecordError(
-                ErrorCode::InvalidValue,
+                error,
                 MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
-                                             std::to_string(shader) + " is not a valid name."));
+                                             std::to_string(shader) +
+                                                 (error == ErrorCode::InvalidOperation ? " is not a shader object."
+                                                                                       : " is not a valid name.")));
             return false;
         }
         return true;
@@ -245,6 +260,30 @@ namespace MobileGL::MG_Impl::GLImpl {
         return true;
     }
 
+    // GL 4.6 core 7.6.3: INVALID_VALUE when uniformBlockBinding >= MAX_UNIFORM_BUFFER_BINDINGS.
+    // The storage-block twin below has always had this check; the uniform one never did, and the
+    // value it stores is used as a RAW SUBSCRIPT into the state layer's fixed indexed-binding
+    // array on every draw and dispatch (DirectGLES's per-program UBO rebind, DirectVulkan's
+    // descriptor resolve, whose only guard is a MOBILEGL_ASSERT that compiles away in release).
+    // An out-of-range binding therefore did not merely go unreported - it read past the array and
+    // dereferenced whatever SharedPtr it found there.
+    bool ValidateUniformBlockBinding(GLuint binding) {
+        // Exactly what glGetIntegerv(GL_MAX_UNIFORM_BUFFER_BINDINGS) advertises: the state
+        // layer's array width, which the getter clamps to as well.
+        const SizeT maxBindingCount = MG_State::pGLContext->GetBufferBindingPointCount(BufferTarget::Uniform);
+        if (binding < maxBindingCount) {
+            return true;
+        }
+
+        MG_State::pGLContext->RecordError(
+            ErrorCode::InvalidValue,
+            MakeUnique<GenericErrorInfo>(
+                "MG_Impl/GLImpl", __func__,
+                std::format("Uniform block binding {} is not less than GL_MAX_UNIFORM_BUFFER_BINDINGS ({}).", binding,
+                            maxBindingCount)));
+        return false;
+    }
+
     bool ValidateShaderStorageBlockBinding(GLuint binding) {
         SizeT maxBindingCount = MG_State::pGLContext->GetBufferBindingPointCount(BufferTarget::ShaderStorage);
         if (MG_Backend::pActiveBackendObject) {
@@ -307,9 +346,195 @@ namespace MobileGL::MG_Impl::GLImpl {
     void CompileShader_State(GLuint shader) {
         auto& shaderObject = TryToGetShaderObject(shader);
         if (!shaderObject) return;
+        // ARB_gl_spirv: "INVALID_OPERATION is generated by CompileShader if shader has been
+        // associated with a SPIR-V binary". Such an object has no GLSL source to compile - it is
+        // waiting for glSpecializeShader, which is the operation that compiles it.
+        if (shaderObject->HasSpirvBinary()) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", __func__,
+                    "shader " + std::to_string(shader) +
+                        " holds a SPIR-V binary; use glSpecializeShader instead of glCompileShader."));
+            return;
+        }
         shaderObject->Compile();
     }
 
+    // ---------------------------------------------------------------------------------------
+    // GL_ARB_gl_spirv
+    // ---------------------------------------------------------------------------------------
+
+    void ShaderBinary_State(GLsizei count, const GLuint* shaders, GLenum binaryformat, const void* binary,
+                            GLsizei length) {
+        if (count < 0 || length < 0) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, "count and length must be non-negative."));
+            return;
+        }
+        // GL_NUM_SHADER_BINARY_FORMATS advertises exactly one format, so every other value is
+        // INVALID_ENUM (GL 4.6 core 7.2). This is the check that used to be missing entirely -
+        // the entry point was a silent stub, so an application handed a format nothing supports
+        // and was told nothing.
+        if (binaryformat != GL_SHADER_BINARY_FORMAT_SPIR_V) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "binaryformat must be GL_SHADER_BINARY_FORMAT_SPIR_V."));
+            return;
+        }
+        if (count == 0) return;
+        if (shaders == nullptr || (length > 0 && binary == nullptr)) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, "shaders and binary must not be null."));
+            return;
+        }
+        // A SPIR-V module is a sequence of 32-bit words, so a length that is not a multiple of
+        // four cannot be one (ARB_gl_spirv makes this INVALID_VALUE).
+        if ((length % 4) != 0) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "length must be a multiple of four for a SPIR-V module."));
+            return;
+        }
+
+        // EVERY name is validated before ANY of them is written: the entry point is all-or-
+        // nothing, and half-applying it would leave some objects holding a module the call was
+        // rejected for. The duplicate check is the extension's own ("INVALID_VALUE ... if the
+        // same shader object is specified more than once").
+        std::set<GLuint> seen;
+        for (GLsizei i = 0; i < count; ++i) {
+            if (!seen.insert(shaders[i]).second) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                                 "shader " + std::to_string(shaders[i]) +
+                                                     " appears more than once in `shaders`."));
+                return;
+            }
+            if (!MG_State::pGLContext->ValidateShaderName(shaders[i])) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                                 std::to_string(shaders[i]) + " is not the name of a shader object."));
+                return;
+            }
+        }
+
+        const SizeT wordCount = static_cast<SizeT>(length) / 4;
+        Vector<Uint32> module(wordCount);
+        if (wordCount != 0) {
+            Memcpy(module.data(), binary, static_cast<SizeT>(length));
+        }
+        // spirv-val here, not at glSpecializeShader: this is where the words arrive, and past it
+        // they reach SPIRV-Cross, which parses rather than validates. ARB_gl_spirv lets an
+        // implementation reject an invalid module at either call; rejecting at the earlier one
+        // means the application's error is reported next to the data that caused it.
+        if (const auto validated = MG_Util::ShaderTranspiler::ShaderCompiler::ValidateSpirvModule(module);
+            !validated) {
+            MGLOG_D("%s: rejected SPIR-V module: %s", __func__, validated.error().log.c_str());
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, validated.error().log));
+            return;
+        }
+
+        for (GLsizei i = 0; i < count; ++i) {
+            auto& shaderObject = TryToGetShaderObject(shaders[i]);
+            if (!shaderObject) continue;
+            // A copy per object, not a shared buffer: each shader object may be specialized with
+            // different constants, and each specialization re-reads its own original words.
+            Vector<Uint32> perObject = module;
+            shaderObject->SetSpirvBinary(Move(perObject));
+        }
+    }
+
+    void SpecializeShader_State(GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants,
+                                const GLuint* pConstantIndex, const GLuint* pConstantValue) {
+        auto& shaderObject = TryToGetShaderObject(shader);
+        if (!shaderObject) return;
+        if (!shaderObject->HasSpirvBinary()) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "shader " + std::to_string(shader) +
+                                                 " has no SPIR-V binary; call glShaderBinary first."));
+            return;
+        }
+        // ARB_gl_spirv: a shader that has already been specialized may not be specialized again
+        // until glShaderBinary re-associates a module with it.
+        if (shaderObject->HasBeenSpecialized()) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "shader " + std::to_string(shader) +
+                                                 " has already been specialized; re-associate its module with "
+                                                 "glShaderBinary before specializing it again."));
+            return;
+        }
+        // pEntryPoint names the entry point to specialize; there is no default. A null pointer
+        // cannot name one, and neither can the empty string.
+        if (pEntryPoint == nullptr || *pEntryPoint == '\0') {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, "pEntryPoint must name an entry point."));
+            return;
+        }
+        if (numSpecializationConstants > 0 && (pConstantIndex == nullptr || pConstantValue == nullptr)) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "pConstantIndex and pConstantValue must not be null."));
+            return;
+        }
+        // "INVALID_VALUE is generated if any value in pConstantIndex is repeated" - checked before
+        // anything is applied, for the same all-or-nothing reason glShaderBinary checks its names
+        // up front.
+        Vector<Uint32> constantIds(pConstantIndex, pConstantIndex + numSpecializationConstants);
+        Vector<Uint32> constantValues(pConstantValue, pConstantValue + numSpecializationConstants);
+        {
+            std::set<Uint32> seen;
+            for (const Uint32 id : constantIds) {
+                if (seen.insert(id).second) continue;
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                                 "constant index " + std::to_string(id) + " is repeated."));
+                return;
+            }
+        }
+
+        const String entryPoint(pEntryPoint);
+        const GLenum shaderType = MG_Util::ConvertShaderStageToGLEnum(shaderObject->GetShaderStage());
+        using SpecializationFailure = MG_Util::ShaderTranspiler::ShaderCompiler::SpecializationFailure;
+        SpecializationFailure failure = SpecializationFailure::None;
+        auto specialized = MG_Util::ShaderTranspiler::ShaderCompiler::SpecializeAndDecompileSpirvModule(
+            shaderObject->GetSpirvBinary(), shaderType, entryPoint, constantIds, constantValues, failure);
+        if (!specialized) {
+            MGLOG_D("%s: specialization failed for shader %u: %s", __func__, shader,
+                    specialized.error().log.c_str());
+            // The two conditions ARB_gl_spirv ENUMERATES are GL errors, and an erroring GL command
+            // must have no other effect - so the shader object is left exactly as it was rather
+            // than being pushed into a failed-compile state. Anything else is a genuine compile
+            // failure of a well-formed request, which the extension routes through COMPILE_STATUS
+            // and the info log exactly as glCompileShader does.
+            if (failure == SpecializationFailure::UnknownEntryPoint ||
+                failure == SpecializationFailure::UnknownConstantId) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__, specialized.error().log));
+                return;
+            }
+            shaderObject->RecordSpecializationFailure(String(specialized.error().log));
+            return;
+        }
+        shaderObject->SpecializeFromSpirv(Move(specialized.value().glsl), Move(specialized.value().xfbVaryings),
+                                          specialized.value().xfbBufferMode);
+    }
+
     // glMaxShaderCompilerThreadsKHR / glMaxShaderCompilerThreadsARB - one implementation,
     // because GL_KHR_parallel_shader_compile and GL_ARB_parallel_shader_compile define the
     // same entry point with the same semantics and GetProcAddress.cpp maps both spellings.
@@ -744,12 +969,77 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = programObject->GetBinaryRetrievableHint() ? GL_TRUE : GL_FALSE;
             break;
         case GL_PROGRAM_SEPARABLE:
-            *params = programObject->GetSeparable() ? GL_TRUE : GL_FALSE;
+            // The LATCHED flag, not the live one: glProgramParameteri's write takes effect at the
+            // next link (GL 4.6 core 7.3), so a program told to be separable and then never
+            // linked still reports GL_FALSE.
+            *params = programObject->GetLinkedSeparable() ? GL_TRUE : GL_FALSE;
             break;
 
+        // The geometry and tessellation link properties (GL 4.6 core table 23.35). Same shape as
+        // GL_COMPUTE_WORK_GROUP_SIZE above, and for the same reason: "a linked program object
+        // with a geometry shader" is one whose EXECUTABLE has the stage, so an
+        // attached-but-not-yet-linked shader must give INVALID_OPERATION rather than the previous
+        // link's value. The geometry three used to be listed here only to fall through into the
+        // INVALID_ENUM default, and the tessellation five were not listed at all.
         case GL_GEOMETRY_VERTICES_OUT:
         case GL_GEOMETRY_INPUT_TYPE:
         case GL_GEOMETRY_OUTPUT_TYPE:
+        case GL_GEOMETRY_SHADER_INVOCATIONS: {
+            if (!programObject->GetLinkStatus() || !programObject->HasLinkedShaderStage(ShaderStage::Geometry)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidOperation,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                                 std::to_string(program) +
+                                                     " is not a linked program object with a geometry shader."));
+                return;
+            }
+            switch (pname) {
+            case GL_GEOMETRY_VERTICES_OUT: *params = programObject->GetGeometryVerticesOut(); break;
+            case GL_GEOMETRY_INPUT_TYPE: *params = static_cast<GLint>(programObject->GetGeometryInputType()); break;
+            case GL_GEOMETRY_OUTPUT_TYPE: *params = static_cast<GLint>(programObject->GetGeometryOutputType()); break;
+            default: *params = programObject->GetGeometryShaderInvocations(); break;
+            }
+            MGLOG_D("%s: %s = %d", __func__, MG_Util::ConvertGLEnumToString(pname).c_str(), *params);
+            break;
+        }
+        case GL_TESS_CONTROL_OUTPUT_VERTICES: {
+            if (!programObject->GetLinkStatus() || !programObject->HasLinkedShaderStage(ShaderStage::TessControl)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidOperation,
+                    MakeUnique<GenericErrorInfo>(
+                        "MG_Impl/GLImpl", __func__,
+                        std::to_string(program) +
+                            " is not a linked program object with a tessellation control shader."));
+                return;
+            }
+            *params = programObject->GetTessControlOutputVertices();
+            MGLOG_D("%s: %s = %d", __func__, MG_Util::ConvertGLEnumToString(pname).c_str(), *params);
+            break;
+        }
+        case GL_TESS_GEN_MODE:
+        case GL_TESS_GEN_SPACING:
+        case GL_TESS_GEN_VERTEX_ORDER:
+        case GL_TESS_GEN_POINT_MODE: {
+            if (!programObject->GetLinkStatus() || !programObject->HasLinkedShaderStage(ShaderStage::TessEval)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidOperation,
+                    MakeUnique<GenericErrorInfo>(
+                        "MG_Impl/GLImpl", __func__,
+                        std::to_string(program) +
+                            " is not a linked program object with a tessellation evaluation shader."));
+                return;
+            }
+            switch (pname) {
+            case GL_TESS_GEN_MODE: *params = static_cast<GLint>(programObject->GetTessGenMode()); break;
+            case GL_TESS_GEN_SPACING: *params = static_cast<GLint>(programObject->GetTessGenSpacing()); break;
+            case GL_TESS_GEN_VERTEX_ORDER:
+                *params = static_cast<GLint>(programObject->GetTessGenVertexOrder());
+                break;
+            default: *params = programObject->GetTessGenPointMode() ? GL_TRUE : GL_FALSE; break;
+            }
+            MGLOG_D("%s: %s = %d", __func__, MG_Util::ConvertGLEnumToString(pname).c_str(), *params);
+            break;
+        }
         default:
             MGLOG_D("%s: %s", __func__, MG_Util::ConvertGLEnumToString(pname).c_str());
             MG_State::pGLContext->RecordError(
@@ -811,8 +1101,19 @@ namespace MobileGL::MG_Impl::GLImpl {
             }
             *params = shaderObject->GetInfoLog().empty() ? 0 : (GLint)shaderObject->GetInfoLog().length() + 1;
             break;
-        case GL_SHADER_SOURCE_LENGTH:
-            *params = shaderObject->GetShaderSource().empty() ? 0 : (GLint)shaderObject->GetShaderSource().length() + 1;
+        case GL_SHADER_SOURCE_LENGTH: {
+            // The APPLICATION's source, which is empty for a shader that came from glShaderBinary -
+            // see ShaderObject::GetApplicationShaderSource.
+            const auto& source = shaderObject->GetApplicationShaderSource();
+            *params = source.empty() ? 0 : (GLint)source.length() + 1;
+            break;
+        }
+        // GL_ARB_gl_spirv. GL_SPIR_V_BINARY and GL_SPIR_V_BINARY_ARB are the same token: TRUE
+        // while the object stands for an application-supplied module. It is the FIRST thing the
+        // conformance suite asks after glShaderBinary, and it used to fall into the terminal
+        // default arm below and take the whole test with it.
+        case GL_SPIR_V_BINARY:
+            *params = shaderObject->HasSpirvBinary() ? GL_TRUE : GL_FALSE;
             break;
         // GL_KHR_parallel_shader_compile. THIS CASE MUST NOT JOIN - see the identical case in
         // GetProgramiv_State. GL_COMPILE_STATUS two cases up deliberately DOES join (it has
@@ -858,13 +1159,23 @@ namespace MobileGL::MG_Impl::GLImpl {
         auto& shaderObject = TryToGetShaderObject(shader);
         if (!shaderObject) return;
 
-        auto& src = shaderObject->GetShaderSource();
+        auto& src = shaderObject->GetApplicationShaderSource();
         CopyStr(bufSize, length, source, src.c_str(), (GLsizei)src.length());
     }
 
     GLint GetUniformLocation_State(GLuint program, const GLchar* name) {
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return -1;
+        // GL 4.6 core 7.6: "INVALID_OPERATION is generated if program has not been successfully
+        // linked". Answering -1 silently is not the same thing - the conformance suite reads the
+        // error, not the location.
+        if (!programObject->GetLinkStatus()) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "program " + std::to_string(program) + " is not linked."));
+            return -1;
+        }
         auto loc = programObject->GetUniformLocation(name);
         MGLOG_D("%s: loc %02d = %s", __func__, loc, name);
         return loc;
@@ -1277,11 +1588,13 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     template <GLsizei ItemCount, typename T>
     void ProgramUniformv_State(GLuint program, GLint location, GLsizei count, T* value) {
-        if (location == -1) return;
-
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
 
+        // The link check comes BEFORE the location == -1 early-out, not after. GL 4.6 core 7.6
+        // makes an unlinked program INVALID_OPERATION regardless of the location, and -1 is
+        // exactly the location an application holds after glGetUniformLocation on such a program -
+        // so checking -1 first swallowed the very case the rule exists for.
         if (!programObject->GetLinkStatus()) {
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidOperation,
@@ -1289,6 +1602,10 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        // "If location is equal to -1, the data passed in will be silently ignored and the
+        // specified uniform variable will not be changed" - after the program itself has been
+        // found acceptable.
+        if (location == -1) return;
 
         for (GLint offset = 0; offset < count; offset++) {
             if (offset > 0 && !programObject->UniformLocationsAliasSameUniform(location, location + offset)) {
@@ -1699,8 +2016,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix2fv_State(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                        const GLfloat* value) {
-        if (location == -1) return;
-
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
 
@@ -1712,14 +2027,14 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
 
+        if (location == -1) return;
+
         UniformMatrixfv_Object(*programObject, __func__, location, count, transpose, value, 2, 2,
                                "program " + std::to_string(program));
     }
 
     void ProgramUniformMatrix3fv_State(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                        const GLfloat* value) {
-        if (location == -1) return;
-
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
 
@@ -1731,6 +2046,8 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
 
+        if (location == -1) return;
+
         for (GLint i = 0; i < count; i++) {
             if (i > 0 && !programObject->UniformLocationsAliasSameUniform(location, location + i)) {
                 // Values for elements beyond the end of the uniform array are ignored.
@@ -1756,8 +2073,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix4fv_State(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                        const GLfloat* value) {
-        if (location == -1) return;
-
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
 
@@ -1769,6 +2084,8 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
 
+        if (location == -1) return;
+
         for (GLint i = 0; i < count; i++) {
             if (i > 0 && !programObject->UniformLocationsAliasSameUniform(location, location + i)) {
                 // Values for elements beyond the end of the uniform array are ignored.
@@ -1790,8 +2107,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrixNonSquarefv_State(const char* caller, GLuint program, GLint location, GLsizei count,
                                                GLboolean transpose, const GLfloat* value, Int columns, Int rows) {
-        if (location == -1) return;
-
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
 
@@ -1803,6 +2118,8 @@ namespace MobileGL::MG_Impl::GLImpl {
             return;
         }
 
+        if (location == -1) return;
+
         UniformMatrixfv_Object(*programObject, caller, location, count, transpose, value, columns, rows,
                                "program " + std::to_string(program));
     }
@@ -1836,6 +2153,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "Program object" + std::to_string(program) + " that has been linked."));
             return;
         }
+        if (!ValidateUniformBlockBinding(uniformBlockBinding)) return;
         if (!programObject->IsActiveGlUniformBlock(uniformBlockIndex)) {
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidValue,
@@ -2083,6 +2401,15 @@ namespace MobileGL::MG_Impl::GLImpl {
         BindAttribLocation_State(program, index, name);
     }
 
+    void ShaderBinary(GLsizei count, const GLuint* shaders, GLenum binaryformat, const void* binary, GLsizei length) {
+        ShaderBinary_State(count, shaders, binaryformat, binary, length);
+    }
+
+    void SpecializeShader(GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants,
+                          const GLuint* pConstantIndex, const GLuint* pConstantValue) {
+        SpecializeShader_State(shader, pEntryPoint, numSpecializationConstants, pConstantIndex, pConstantValue);
+    }
+
     void CompileShader(GLuint shader) {
         CompileShader_State(shader);
     }
@@ -2342,7 +2669,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix2dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2352,6 +2678,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 2, 2);
     }
     void UniformMatrix3dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2368,7 +2695,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix3dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2378,6 +2704,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 3, 3);
     }
     void UniformMatrix4dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2394,7 +2721,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix4dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2404,6 +2730,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 4, 4);
     }
     void UniformMatrix2x3dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2420,7 +2747,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix2x3dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2430,6 +2756,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 2, 3);
     }
     void UniformMatrix2x4dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2446,7 +2773,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix2x4dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2456,6 +2782,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 2, 4);
     }
     void UniformMatrix3x2dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2472,7 +2799,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix3x2dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2482,6 +2808,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 3, 2);
     }
     void UniformMatrix3x4dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2498,7 +2825,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix3x4dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2508,6 +2834,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 3, 4);
     }
     void UniformMatrix4x2dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2524,7 +2851,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix4x2dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2534,6 +2860,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 4, 2);
     }
     void UniformMatrix4x3dv(GLint location, GLsizei count, GLboolean transpose, const GLdouble* value) {
@@ -2550,7 +2877,6 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     void ProgramUniformMatrix4x3dv(GLuint program, GLint location, GLsizei count, GLboolean transpose,
                                       const GLdouble* value) {
-        if (location == -1) return;
         auto& programObject = TryToGetProgramObject(program);
         if (!programObject) return;
         if (!programObject->GetLinkStatus()) {
@@ -2560,6 +2886,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "program " + std::to_string(program) + " is not linked."));
             return;
         }
+        if (location == -1) return;
         UniformMatrixdv_Object(*programObject, location, count, transpose, value, 4, 3);
     }
     void GetUniformdv(GLuint program, GLint location, GLdouble* params) {
@@ -3072,6 +3399,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              "Backend does not support shader storage block binding."));
             return;
         }
+        MGP_FILL(ShaderStorageBlockBinding);
         shaderStorageBlockBinding(program, blockName.c_str(), storageBlockBinding);
     }
 

MobileGL/MG_Impl/GLImpl/Program/GL_Program.h

@@ -13,6 +13,12 @@ namespace MobileGL::MG_Impl::GLImpl {
     void AttachShader(GLuint program, GLuint shader);
     void BindAttribLocation(GLuint program, GLuint index, const GLchar* name);
     void CompileShader(GLuint shader);
+    // GL_ARB_gl_spirv, core since 4.6. The pair is a two-step operation: glShaderBinary attaches
+    // the module to one or more shader objects, glSpecializeShader names its entry point and
+    // supplies its specialization constants and is what actually compiles them.
+    void ShaderBinary(GLsizei count, const GLuint* shaders, GLenum binaryformat, const void* binary, GLsizei length);
+    void SpecializeShader(GLuint shader, const GLchar* pEntryPoint, GLuint numSpecializationConstants,
+                          const GLuint* pConstantIndex, const GLuint* pConstantValue);
     GLuint CreateProgram(void);
     GLuint CreateShader(GLenum type);
     void DeleteProgram(GLuint program);

MobileGL/MG_Impl/GLImpl/Program/GL_ProgramPipeline.cpp

@@ -192,6 +192,15 @@ namespace MobileGL::MG_Impl::GLImpl {
                                     std::format("Program {} has not been linked successfully.", program));
                 return;
             }
+            // GL 4.6 core 7.4: "INVALID_OPERATION is generated if program was not linked with its
+            // PROGRAM_SEPARABLE status set". The LATCHED flag is the one that decides - a program
+            // whose live flag was cleared after a separable link is still a legal stage, and a
+            // program whose live flag was set after a non-separable link is not.
+            if (!programObject->GetLinkedSeparable()) {
+                RecordPipelineError(ErrorCode::InvalidOperation, __func__,
+                                    std::format("Program {} was not linked as a separable program.", program));
+                return;
+            }
         }
 
         const GLbitfield selected = stages == GL_ALL_SHADER_BITS ? kAllStageBits : stages;

MobileGL/MG_Impl/GLImpl/Query/GL_Query.cpp

@@ -12,6 +12,7 @@
 #include <MG_Backend/BackendObjects.h>
 #include <MG_State/GLState/Core.h>
 #include <MG_State/GLState/ErrorState/ErrorInfo.h>
+#include <MG_Impl/Pipe/PipeFill.h>
 
 namespace MobileGL::MG_Impl::GLImpl {
     namespace {
@@ -59,6 +60,62 @@ namespace MobileGL::MG_Impl::GLImpl {
         GLuint g_activePrimitivesGeneratedQueryId = 0;
         // Id of the query active on GL_SAMPLES_PASSED (0 = none).
         GLuint g_activeSamplesPassedQueryId = 0;
+        // Ids of the queries active on the GL_ARB_pipeline_statistics_query targets, one slot per
+        // target (0 = none). A map rather than a field per target: the eleven behave identically
+        // and none of them has any state beyond "which object is counting".
+        UnorderedMap<GLenum, GLuint> g_activePipelineStatisticsQueryIds;
+
+        // Whether MobileGL puts GL_ARB_tessellation_shader in its extension string. Read from the
+        // ADVERTISED list rather than from a capability bit for the same reason
+        // BackendSupportsTextureViews does (GL_Texture.cpp): it makes "MobileGL claims tessellation
+        // support" and "the tessellation-conditional API surface is open" the same fact by
+        // construction, so the day a backend starts advertising the string the surface below opens
+        // with it and no second edit is owed.
+        Bool AdvertisesTessellationShaderExtension() {
+            const auto& activeBackendObject = MG_Backend::pActiveBackendObject;
+            if (!activeBackendObject) return false;
+            const auto& extensions = activeBackendObject->GetRendererInfo().RendererGLInfo.Extensions;
+            return std::find(extensions.begin(), extensions.end(), E_GL_ARB_tessellation_shader) != extensions.end();
+        }
+
+        // The eleven pipeline-statistics counters (GL 4.6 core table 4.3 / ARB_pipeline_statistics_query).
+        // A 4.6 core context ACCEPTS the nine unconditional ones at glBeginQuery - there is no query
+        // by which an application could learn otherwise before calling. MobileGL instruments none of
+        // them, and says so the way GL 4.6 core 4.2.1 provides for: GL_QUERY_COUNTER_BITS answers
+        // zero for these targets, which is the spec's own signal that the counter is unsupported and
+        // its results indeterminate. That is an honest zero, not an advertised capability - the
+        // alternative, GL_INVALID_ENUM on a core entry point, is both non-conformant AND less
+        // informative.
+        //
+        // The two TESSELLATION targets are the exception, because ARB_pipeline_statistics_query
+        // makes them conditional on tessellation support rather than unconditional, and the only
+        // thing an application (or the conformance suite) can read to decide whether an
+        // implementation has it is the GL_ARB_tessellation_shader string. MobileGL does not emit it
+        // today, so these two answer GL_INVALID_ENUM: an API surface that accepts a
+        // tessellation-conditional token while withholding the string that announces the condition
+        // is self-contradictory, and it is the contradiction the suite catches
+        // (KHR-GL46.pipeline_statistics_query_tests_ARB.api_coverage_unsupported_calls, whose
+        // support probe is gl4cPipelineStatisticsQueryTests.cpp:1166-1176). The gate is the
+        // advertisement itself, not a hardcoded "no", so this is one switch and not two.
+        Bool IsPipelineStatisticsQueryTarget(GLenum target) {
+            switch (target) {
+            case GL_VERTICES_SUBMITTED:
+            case GL_PRIMITIVES_SUBMITTED:
+            case GL_VERTEX_SHADER_INVOCATIONS:
+            case GL_GEOMETRY_SHADER_INVOCATIONS:
+            case GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED:
+            case GL_FRAGMENT_SHADER_INVOCATIONS:
+            case GL_COMPUTE_SHADER_INVOCATIONS:
+            case GL_CLIPPING_INPUT_PRIMITIVES:
+            case GL_CLIPPING_OUTPUT_PRIMITIVES:
+                return true;
+            case GL_TESS_CONTROL_SHADER_PATCHES:
+            case GL_TESS_EVALUATION_SHADER_INVOCATIONS:
+                return AdvertisesTessellationShaderExtension();
+            default:
+                return false;
+            }
+        }
 
         Bool TimerQueryDisabled() {
             return MG_Config::Features.DisableTimerQuery;
@@ -108,6 +165,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         void ResetQueryObjectLocked(QueryObject* queryObject) {
             if (queryObject->backendHandle) {
                 if (const auto deleteBackendQuery = MG_Backend::gBackendFunctionsTable.GL.DeleteBackendQuery) {
+                    MGP_FILL(DeleteBackendQuery);
                     deleteBackendQuery(queryObject->backendHandle);
                 }
                 queryObject->backendHandle = nullptr;
@@ -122,6 +180,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         void EndTimeElapsedQueryLocked(QueryObject* queryObject) {
             const auto endTimeElapsedQuery = MG_Backend::gBackendFunctionsTable.GL.EndTimeElapsedQuery;
             if (endTimeElapsedQuery && queryObject->backendHandle) {
+                MGP_FILL(EndTimeElapsedQuery);
                 endTimeElapsedQuery(queryObject->backendHandle);
             }
             queryObject->active = false;
@@ -201,6 +260,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                 }
                 Uint64 result = 0;
                 const auto getQueryResult64 = MG_Backend::gBackendFunctionsTable.GL.GetQueryResult64;
+                MGP_FILL(GetQueryResult64);
                 if (queryObject->backendHandle && getQueryResult64 &&
                     !getQueryResult64(queryObject->backendHandle, /*wait=*/false, &result)) {
                     // Not ready. The whole point of the no-wait form is that the caller's
@@ -215,6 +275,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                 }
                 if (queryObject->backendHandle) {
                     if (const auto deleteBackendQuery = MG_Backend::gBackendFunctionsTable.GL.DeleteBackendQuery) {
+                        MGP_FILL(DeleteBackendQuery);
                         deleteBackendQuery(queryObject->backendHandle);
                     }
                     queryObject->backendHandle = nullptr;
@@ -230,6 +291,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                     return true;
                 }
                 const auto isQueryResultAvailable = MG_Backend::gBackendFunctionsTable.GL.IsQueryResultAvailable;
+                MGP_FILL(IsQueryResultAvailable);
                 outValue = (!isQueryResultAvailable || isQueryResultAvailable(queryObject->backendHandle)) ? 1 : 0;
                 return true;
             }
@@ -241,6 +303,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                 Uint64 result = 0;
                 if (queryObject->backendHandle) {
                     const auto getQueryResult64 = MG_Backend::gBackendFunctionsTable.GL.GetQueryResult64;
+                    MGP_FILL(GetQueryResult64);
                     if (getQueryResult64 &&
                         !getQueryResult64(queryObject->backendHandle, /*wait=*/true, &result)) {
                         // The backend could not produce the result YET (e.g. a
@@ -261,6 +324,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                     // query degrades to a zero result); the backend handle is
                     // consumed and the value cached for later reads.
                     if (const auto deleteBackendQuery = MG_Backend::gBackendFunctionsTable.GL.DeleteBackendQuery) {
+                        MGP_FILL(DeleteBackendQuery);
                         deleteBackendQuery(queryObject->backendHandle);
                     }
                     queryObject->backendHandle = nullptr;
@@ -366,10 +430,14 @@ namespace MobileGL::MG_Impl::GLImpl {
                     queryObject->target == GL_ANY_SAMPLES_PASSED_CONSERVATIVE) {
                     if (const auto endOcclusionQuery = MG_Backend::gBackendFunctionsTable.GL.EndOcclusionQuery;
                         endOcclusionQuery && queryObject->backendHandle) {
+                        MGP_FILL(EndOcclusionQuery);
                         endOcclusionQuery(queryObject->backendHandle);
                     }
                     queryObject->active = false;
                     g_activeSamplesPassedQueryId = 0;
+                } else if (IsPipelineStatisticsQueryTarget(queryObject->target)) {
+                    queryObject->active = false;
+                    g_activePipelineStatisticsQueryIds[queryObject->target] = 0;
                 } else if (queryObject->target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN ||
                            queryObject->target == GL_PRIMITIVES_GENERATED) {
                     queryObject->active = false;
@@ -382,6 +450,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             }
             if (queryObject->backendHandle) {
                 if (const auto deleteBackendQuery = MG_Backend::gBackendFunctionsTable.GL.DeleteBackendQuery) {
+                    MGP_FILL(DeleteBackendQuery);
                     deleteBackendQuery(queryObject->backendHandle);
                 }
                 queryObject->backendHandle = nullptr;
@@ -410,7 +479,9 @@ namespace MobileGL::MG_Impl::GLImpl {
             (target == GL_SAMPLES_PASSED || target == GL_ANY_SAMPLES_PASSED ||
              target == GL_ANY_SAMPLES_PASSED_CONSERVATIVE) &&
             MG_Backend::gBackendFunctionsTable.GL.BeginOcclusionQuery != nullptr;
-        if (target != GL_TIME_ELAPSED && !isTransformFeedbackQuery && !isOcclusionQuery) {
+        const Bool isPipelineStatisticsQuery = IsPipelineStatisticsQueryTarget(target);
+        if (target != GL_TIME_ELAPSED && !isTransformFeedbackQuery && !isOcclusionQuery &&
+            !isPipelineStatisticsQuery) {
             // GL_TIMESTAMP is not a valid BeginQuery target; the occlusion targets
             // need backend support.
             RecordQueryError(ErrorCode::InvalidEnum, __FUNCTION__, "Query target is not supported.");
@@ -426,10 +497,12 @@ namespace MobileGL::MG_Impl::GLImpl {
             RecordQueryError(ErrorCode::InvalidOperation, __FUNCTION__, "Query object does not exist.");
             return;
         }
-        GLuint& activeQueryId = isTransformFeedbackQuery
-            ? (target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN ? g_activePrimitivesWrittenQueryId
-                                                                  : g_activePrimitivesGeneratedQueryId)
-            : (isOcclusionQuery ? g_activeSamplesPassedQueryId : g_activeTimeElapsedQueryId);
+        GLuint& activeQueryId = isPipelineStatisticsQuery
+            ? g_activePipelineStatisticsQueryIds[target]
+            : (isTransformFeedbackQuery
+                   ? (target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN ? g_activePrimitivesWrittenQueryId
+                                                                         : g_activePrimitivesGeneratedQueryId)
+                   : (isOcclusionQuery ? g_activeSamplesPassedQueryId : g_activeTimeElapsedQueryId));
         if (activeQueryId != 0) {
             RecordQueryError(ErrorCode::InvalidOperation, __FUNCTION__,
                              "A query is already active on this target.");
@@ -448,10 +521,15 @@ namespace MobileGL::MG_Impl::GLImpl {
         ResetQueryObjectLocked(queryObject); // discard any previous result
         queryObject->target = target;
         queryObject->active = true;
-        if (isTransformFeedbackQuery) {
+        if (isPipelineStatisticsQuery) {
+            // Nothing to start: the counter is uninstrumented and GL_QUERY_COUNTER_BITS says so.
+            // The object still becomes a real, target-latched query so every other rule about it
+            // (re-use with another target, double-begin, EndQuery pairing) keeps holding.
+        } else if (isTransformFeedbackQuery) {
             // Prefer real GPU transform-feedback queries (exact with geometry shaders);
             // the CPU accounting delta stays as the fallback when the backend lacks them.
             const auto beginXfbPrimitivesQuery = MG_Backend::gBackendFunctionsTable.GL.BeginXfbPrimitivesQuery;
+            MGP_FILL(BeginXfbPrimitivesQuery);
             queryObject->backendHandle =
                 beginXfbPrimitivesQuery ? beginXfbPrimitivesQuery(target == GL_PRIMITIVES_GENERATED) : nullptr;
             queryObject->counterSnapshot = TransformFeedbackCounterForTarget(target);
@@ -460,9 +538,11 @@ namespace MobileGL::MG_Impl::GLImpl {
             queryObject->geometryCaptureDrawSnapshot =
                 MG_State::pGLContext->GetTransformFeedbackGeometryCaptureDraws();
         } else if (isOcclusionQuery) {
+            MGP_FILL(BeginOcclusionQuery);
             queryObject->backendHandle = MG_Backend::gBackendFunctionsTable.GL.BeginOcclusionQuery();
         } else {
             const auto beginTimeElapsedQuery = MG_Backend::gBackendFunctionsTable.GL.BeginTimeElapsedQuery;
+            MGP_FILL(BeginTimeElapsedQuery);
             queryObject->backendHandle =
                 (!TimerQueryDisabled() && beginTimeElapsedQuery) ? beginTimeElapsedQuery() : nullptr;
         }
@@ -476,15 +556,19 @@ namespace MobileGL::MG_Impl::GLImpl {
             (target == GL_SAMPLES_PASSED || target == GL_ANY_SAMPLES_PASSED ||
              target == GL_ANY_SAMPLES_PASSED_CONSERVATIVE) &&
             MG_Backend::gBackendFunctionsTable.GL.BeginOcclusionQuery != nullptr;
-        if (target != GL_TIME_ELAPSED && !isTransformFeedbackQuery && !isOcclusionQuery) {
+        const Bool isPipelineStatisticsQuery = IsPipelineStatisticsQueryTarget(target);
+        if (target != GL_TIME_ELAPSED && !isTransformFeedbackQuery && !isOcclusionQuery &&
+            !isPipelineStatisticsQuery) {
             RecordQueryError(ErrorCode::InvalidEnum, __FUNCTION__, "Query target is not supported.");
             return;
         }
         const std::lock_guard<std::mutex> lock(g_queryObjectsMutex);
-        GLuint& activeQueryId = isTransformFeedbackQuery
-            ? (target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN ? g_activePrimitivesWrittenQueryId
-                                                                  : g_activePrimitivesGeneratedQueryId)
-            : (isOcclusionQuery ? g_activeSamplesPassedQueryId : g_activeTimeElapsedQueryId);
+        GLuint& activeQueryId = isPipelineStatisticsQuery
+            ? g_activePipelineStatisticsQueryIds[target]
+            : (isTransformFeedbackQuery
+                   ? (target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN ? g_activePrimitivesWrittenQueryId
+                                                                         : g_activePrimitivesGeneratedQueryId)
+                   : (isOcclusionQuery ? g_activeSamplesPassedQueryId : g_activeTimeElapsedQueryId));
         if (activeQueryId == 0) {
             RecordQueryError(ErrorCode::InvalidOperation, __FUNCTION__, "No query is active on this target.");
             return;
@@ -494,9 +578,21 @@ namespace MobileGL::MG_Impl::GLImpl {
             activeQueryId = 0; // should not happen; keep state consistent
             return;
         }
+        if (isPipelineStatisticsQuery) {
+            // The result is a definite zero rather than an unread backend handle, so a later
+            // GetQueryObject* answers immediately and never waits on something that was never
+            // started. GL_QUERY_COUNTER_BITS = 0 is what marks that zero indeterminate.
+            queryObject->cachedResult = 0;
+            queryObject->resultCached = true;
+            queryObject->active = false;
+            queryObject->ended = true;
+            activeQueryId = 0;
+            return;
+        }
         if (isTransformFeedbackQuery) {
             if (queryObject->backendHandle) {
                 if (const auto endXfbPrimitivesQuery = MG_Backend::gBackendFunctionsTable.GL.EndXfbPrimitivesQuery) {
+                    MGP_FILL(EndXfbPrimitivesQuery);
                     endXfbPrimitivesQuery(queryObject->backendHandle);
                 }
             }
@@ -506,6 +602,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             if (!queryObject->backendHandle || PrefersCpuTransformFeedbackResult(queryObject)) {
                 if (queryObject->backendHandle) {
                     if (const auto deleteBackendQuery = MG_Backend::gBackendFunctionsTable.GL.DeleteBackendQuery) {
+                        MGP_FILL(DeleteBackendQuery);
                         deleteBackendQuery(queryObject->backendHandle);
                     }
                     queryObject->backendHandle = nullptr;
@@ -522,6 +619,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         if (isOcclusionQuery) {
             if (const auto endOcclusionQuery = MG_Backend::gBackendFunctionsTable.GL.EndOcclusionQuery;
                 endOcclusionQuery && queryObject->backendHandle) {
+                MGP_FILL(EndOcclusionQuery);
                 endOcclusionQuery(queryObject->backendHandle);
             }
             queryObject->active = false;
@@ -560,6 +658,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         ResetQueryObjectLocked(queryObject); // discard any previous result
         queryObject->target = target;
         const auto queryCounterTimestamp = MG_Backend::gBackendFunctionsTable.GL.QueryCounterTimestamp;
+        MGP_FILL(QueryCounterTimestamp);
         queryObject->backendHandle =
             (!TimerQueryDisabled() && queryCounterTimestamp) ? queryCounterTimestamp() : nullptr;
         queryObject->ended = true;
@@ -657,7 +756,12 @@ namespace MobileGL::MG_Impl::GLImpl {
                 *params = static_cast<GLint>(g_activePrimitivesGeneratedQueryId);
                 break;
             default:
-                *params = 0;
+                if (IsPipelineStatisticsQueryTarget(target)) {
+                    const auto it = g_activePipelineStatisticsQueryIds.find(target);
+                    *params = it != g_activePipelineStatisticsQueryIds.end() ? static_cast<GLint>(it->second) : 0;
+                } else {
+                    *params = 0;
+                }
                 break;
             }
             return;
@@ -668,6 +772,14 @@ namespace MobileGL::MG_Impl::GLImpl {
             // entry points / timestamp valid bits at call time, not at table
             // init), and the MOBILEGL_DISABLE_TIMERQUERY kill switch always
             // wins.
+            if (IsPipelineStatisticsQueryTarget(target)) {
+                // Zero: GL 4.6 core 4.2.1's way of saying the counter is not implemented and its
+                // results are indeterminate. The conformance suite reads exactly this and skips
+                // the functional half of each such target, which is the outcome an uninstrumented
+                // counter should produce.
+                *params = 0;
+                return;
+            }
             if (target == GL_SAMPLES_PASSED || target == GL_ANY_SAMPLES_PASSED ||
                 target == GL_ANY_SAMPLES_PASSED_CONSERVATIVE) {
                 const Bool occlusionSupported = MG_Backend::gBackendFunctionsTable.GL.BeginOcclusionQuery != nullptr;
@@ -676,6 +788,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             }
             const Bool timerTarget = target == GL_TIME_ELAPSED || target == GL_TIMESTAMP;
             const auto isTimerQuerySupported = MG_Backend::gBackendFunctionsTable.GL.IsTimerQuerySupported;
+            MGP_FILL(IsTimerQuerySupported);
             const Bool supported =
                 timerTarget && !TimerQueryDisabled() && isTimerQuerySupported && isTimerQuerySupported();
             *params = supported ? 64 : 0;
@@ -741,14 +854,24 @@ namespace MobileGL::MG_Impl::GLImpl {
     }
 
     namespace {
+        Bool IsPerVertexStreamQueryTarget(GLenum target) {
+            return target == GL_PRIMITIVES_GENERATED || target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN;
+        }
+
         // The indexed query entry points differ from the plain ones only in the vertex
         // stream they address (GL 4.6 core 4.2.1): index must be below GL_MAX_VERTEX_STREAMS
-        // for the two transform feedback targets and zero for every other target. With a
-        // single vertex stream both bounds are 1, so a valid call is always index 0 and
-        // forwards to the unindexed implementation.
+        // for the two transform feedback targets and zero for every other target. MobileGL
+        // implements ONE vertex stream, so both bounds are 1 and a valid call is always index 0 -
+        // which is what makes the three forwards below equivalent to the unindexed entry points.
+        //
+        // THAT EQUIVALENCE IS THE WHOLE JUSTIFICATION, and it is read out of the getter rather
+        // than assumed: the moment GL_MAX_VERTEX_STREAMS answers more than one, index 1..3 starts
+        // reaching EndQueryIndexed and GetQueryIndexediv, which resolve the active query from
+        // per-TARGET globals and would end - or report - a query begun on a different stream.
+        // Raising that limit therefore means giving each active query a stream index and
+        // comparing it here, not just changing the number.
         Bool ValidateQueryStreamIndex(const char* function, GLenum target, GLuint index) {
-            const Bool perStreamTarget =
-                target == GL_PRIMITIVES_GENERATED || target == GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN;
+            const Bool perStreamTarget = IsPerVertexStreamQueryTarget(target);
             GLint maxVertexStreams = 1;
             if (perStreamTarget) {
                 GetIntegerv(GL_MAX_VERTEX_STREAMS, &maxVertexStreams);
@@ -761,6 +884,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                                              : "index must be zero for this query target.");
             return false;
         }
+
     } // namespace
 
     void BeginQueryIndexed(GLenum target, GLuint index, GLuint id) {
@@ -806,6 +930,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         const auto deleteBackendQuery = MG_Backend::gBackendFunctionsTable.GL.DeleteBackendQuery;
         for (const auto& [_, queryObject] : orphans) {
             if (deleteBackendQuery && queryObject->backendHandle) {
+                MGP_FILL(DeleteBackendQuery);
                 deleteBackendQuery(queryObject->backendHandle);
             }
             delete queryObject;

MobileGL/MG_Impl/GLImpl/RenderState/GL_RenderState.cpp

@@ -328,10 +328,50 @@ namespace MobileGL::MG_Impl::GLImpl {
         MG_State::pGLContext->SetSampleCoverage(std::clamp(static_cast<Float>(value), 0.0f, 1.0f), invert == GL_TRUE);
     }
 
+    // ARB_sample_shading / GL 4.6 core 14.3.1: "value is clamped to [0, 1] when specified", so
+    // there is no error to raise - a caller that asks for 2.0 gets 1.0 and GL_MIN_SAMPLE_SHADING_-
+    // VALUE reads back 1.0. Was a logging no-op while ARB_sample_shading was advertised, which
+    // let an application enable GL_SAMPLE_SHADING and then quietly get the driver's default rate.
+    void MinSampleShading_State(GLfloat value) {
+        MG_State::pGLContext->SetMinSampleShadingValue(std::clamp(static_cast<Float>(value), 0.0f, 1.0f));
+    }
+
     void PolygonOffset_State(GLfloat factor, GLfloat units) {
         MG_State::pGLContext->SetPolygonOffset(static_cast<Float>(factor), static_cast<Float>(units));
     }
 
+    void PolygonOffsetClamp_State(GLfloat factor, GLfloat units, GLfloat clamp) {
+        // GL 4.6 core 14.6.5 / GL_EXT_polygon_offset_clamp. No error cases: any three floats are
+        // legal, and clamp = 0 is exactly glPolygonOffset. Whether the backend can APPLY the clamp
+        // is a separate question (see the DirectGLES/DirectVulkan forwarding); the state is
+        // recorded either way, because GL_POLYGON_OFFSET_CLAMP has to read back what was written.
+        MG_State::pGLContext->SetPolygonOffsetClamped(static_cast<Float>(factor), static_cast<Float>(units),
+                                                      static_cast<Float>(clamp));
+    }
+
+    void ClipControl_State(GLenum origin, GLenum depth) {
+        // GL 4.5 core 13.5: both arguments are strict enums, and either being wrong is
+        // GL_INVALID_ENUM with the state left untouched.
+        if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "glClipControl origin must be GL_LOWER_LEFT or GL_UPPER_LEFT; got " +
+                                                 MG_Util::ConvertGLEnumToString(origin) + "."));
+            return;
+        }
+        if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", __func__,
+                    "glClipControl depth must be GL_NEGATIVE_ONE_TO_ONE or GL_ZERO_TO_ONE; got " +
+                        MG_Util::ConvertGLEnumToString(depth) + "."));
+            return;
+        }
+        MG_State::pGLContext->SetClipControl(origin, depth);
+    }
+
     void PolygonMode_State(GLenum face, GLenum mode) {
         // GL 3.3 core: separate front/back polygon modes were removed in 3.1, so the only legal
         // face is GL_FRONT_AND_BACK. GL_FRONT / GL_BACK must be rejected (some desktop drivers
@@ -1013,10 +1053,22 @@ namespace MobileGL::MG_Impl::GLImpl {
         SampleCoverage_State(value, invert);
     }
 
+    void MinSampleShading(GLfloat value) {
+        MinSampleShading_State(value);
+    }
+
     void PolygonOffset(GLfloat factor, GLfloat units) {
         PolygonOffset_State(factor, units);
     }
 
+    void PolygonOffsetClamp(GLfloat factor, GLfloat units, GLfloat clamp) {
+        PolygonOffsetClamp_State(factor, units, clamp);
+    }
+
+    void ClipControl(GLenum origin, GLenum depth) {
+        ClipControl_State(origin, depth);
+    }
+
     void PolygonMode(GLenum face, GLenum mode) {
         PolygonMode_State(face, mode);
     }

MobileGL/MG_Impl/GLImpl/RenderState/GL_RenderState.h

@@ -38,7 +38,10 @@ namespace MobileGL::MG_Impl::GLImpl {
     void StencilFunc(GLenum func, GLint ref, GLuint mask);
     void Scissor(GLint x, GLint y, GLsizei width, GLsizei height);
     void SampleCoverage(GLfloat value, GLboolean invert);
+    void MinSampleShading(GLfloat value);
     void PolygonOffset(GLfloat factor, GLfloat units);
+    void PolygonOffsetClamp(GLfloat factor, GLfloat units, GLfloat clamp);
+    void ClipControl(GLenum origin, GLenum depth);
     void PolygonMode(GLenum face, GLenum mode);
     void PointSize(GLfloat size);
     void PointParameterf(GLenum pname, GLfloat param);

MobileGL/MG_Impl/GLImpl/Sampler/GL_Sampler.cpp

@@ -13,6 +13,7 @@
 #include <MG_State/GLState/Core.h>
 #include <MG_Util/Converters/GLToMG/TextureEnumConverter.h>
 #include <MG_Util/Converters/MGToGL/TextureEnumConverter.h>
+#include <MG_Util/Math/FixedPointConversion.h>
 
 namespace MobileGL::MG_Impl::GLImpl {
     namespace {
@@ -22,6 +23,50 @@ namespace MobileGL::MG_Impl::GLImpl {
             return static_cast<Float>(*(const GLint*)param);
         }
 
+        // GL_TEXTURE_BORDER_COLOR is the only sampler parameter with more than one component, and it
+        // is also the only one whose meaning depends on WHICH entry point wrote it. Everything else
+        // reads exactly one component and does not care.
+        Bool IsVectorOnlySamplerPname(GLenum pname) {
+            return pname == GL_TEXTURE_BORDER_COLOR;
+        }
+
+        // A state query returns the value CONVERTED to the type the caller asked for (GL 4.6 core
+        // 2.2.2 / 6.1), never the other type's bits. These two are the sampler side of the numeric
+        // casts GetTexParameterfv_State/GetTexParameteriv_State already do on the texture side; the
+        // sampler path funnels all three spellings through one void* function, which is precisely how
+        // it came to write a fixed type regardless of the caller.
+        //
+        // Truncation rather than rounding for the float -> integer direction, matching the texture
+        // twin (GetTexParameteriv_State's static_cast<GLint> on MIN_LOD/MAX_LOD/LOD_BIAS): the two
+        // spellings of the same state disagreeing is the bug being fixed here, and a texture and a
+        // sampler queried the same way must answer the same number.
+        void StoreSamplerScalar(void* params, Bool isFloat, Bool isUnsignedInteger, Float value) {
+            if (isFloat) {
+                *(GLfloat*)params = value;
+                return;
+            }
+            // Via GLint in both integer spellings: a direct float -> GLuint cast of a negative value
+            // (GL_TEXTURE_MIN_LOD defaults to -1000) is undefined behaviour, while the two-step
+            // conversion is the well-defined modular one, and it is what the texture-side
+            // GetTexParameterIuiv fallback does.
+            const GLint asInt = static_cast<GLint>(value);
+            if (isUnsignedInteger) {
+                *(GLuint*)params = static_cast<GLuint>(asInt);
+            } else {
+                *(GLint*)params = asInt;
+            }
+        }
+
+        void StoreSamplerEnum(void* params, Bool isFloat, Bool isUnsignedInteger, GLenum value) {
+            if (isFloat) {
+                *(GLfloat*)params = static_cast<GLfloat>(value);
+            } else if (isUnsignedInteger) {
+                *(GLuint*)params = value;
+            } else {
+                *(GLint*)params = static_cast<GLint>(value);
+            }
+        }
+
         Bool ValidateSamplerParameterValue(GLenum pname, const void* param, Bool isFloat, Bool isUnsignedInteger) {
             if (param == nullptr) return false;
 
@@ -56,8 +101,15 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
     } // namespace
 
+    // `isIntegerCommand` distinguishes the "I" spellings (glSamplerParameterIiv / Iuiv) from the
+    // plain ones. It only matters for GL_TEXTURE_BORDER_COLOR, and there it decides everything:
+    // GL 4.6 core 8.10 says the I forms store the components unmodified with an integer internal
+    // type, while glSamplerParameteriv converts them to floating point with equation 2.2. Routing
+    // both to the same setter - which is what this file used to do - meant glSamplerParameteriv
+    // stored raw integers (so a border of 255 became float 255.0 instead of the spec's ~1.19e-7)
+    // and glSamplerParameterIiv lost the fact that it was ever an integer at all.
     void SetSamplerParam_State(GLuint sampler, GLenum pname, const void* param, bool isFloat,
-                               bool isUnsignedInteger) {
+                               bool isUnsignedInteger, bool isIntegerCommand) {
         if (param == nullptr) return;
         if (!SamplerImpl::ValidateSamplerName(sampler)) return;
 
@@ -112,6 +164,13 @@ namespace MobileGL::MG_Impl::GLImpl {
             if (isFloat) {
                 const auto* values = (const GLfloat*)param;
                 samplerObj->SetBorderColor(FloatVec4(values[0], values[1], values[2], values[3]));
+            } else if (!isIntegerCommand) {
+                // glSamplerParameteriv: GL 4.6 core equation 2.2 into the FLOAT border colour.
+                const auto* values = (const GLint*)param;
+                samplerObj->SetBorderColor(FloatVec4(MG_Util::SignedNormalizedInt32ToFloat(values[0]),
+                                                     MG_Util::SignedNormalizedInt32ToFloat(values[1]),
+                                                     MG_Util::SignedNormalizedInt32ToFloat(values[2]),
+                                                     MG_Util::SignedNormalizedInt32ToFloat(values[3])));
             } else if (isUnsignedInteger) {
                 const auto* values = (const GLuint*)param;
                 samplerObj->SetBorderColorUI(UintVec4(values[0], values[1], values[2], values[3]));
@@ -128,7 +187,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     }
 
     void GetSamplerParam_State(GLuint sampler, GLenum pname, void* params, bool isFloat,
-                               bool isUnsignedInteger) {
+                               bool isUnsignedInteger, bool isIntegerCommand) {
         if (params == nullptr) return;
         if (!SamplerImpl::ValidateSamplerName(sampler)) return;
 
@@ -141,47 +200,56 @@ namespace MobileGL::MG_Impl::GLImpl {
         if (!SamplerImpl::ValidateSamplerObject(sampler)) return;
 
         using namespace MG_Util;
+        // Every scalar pname goes through StoreSamplerScalar/StoreSamplerEnum so the CALLER'S form
+        // decides the destination type. Writing a fixed type regardless - which is what these case
+        // labels used to do - hands back the other type's bit pattern rather than a converted value:
+        // glGetSamplerParameterfv(GL_TEXTURE_WRAP_S) deposited the integer 10497 into a GLfloat and
+        // the caller read 1.47e-41, and glGetSamplerParameteriv(GL_TEXTURE_MIN_LOD) deposited the
+        // IEEE bits of -1000.0f and the caller read -998637568. Sixteen (pname, entry-point) pairs
+        // were broken this way; only MAX_ANISOTROPY_EXT and BORDER_COLOR branched correctly, which is
+        // how the same bug class was already found and fixed once for a single pname.
         switch (pname) {
         case GL_TEXTURE_WRAP_S:
-            *(GLuint*)params = MG_Util::ConvertSamplerWrapModeToGLEnum(samplerObj->GetWrapS());
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerWrapModeToGLEnum(samplerObj->GetWrapS()));
             break;
         case GL_TEXTURE_WRAP_T:
-            *(GLuint*)params = MG_Util::ConvertSamplerWrapModeToGLEnum(samplerObj->GetWrapT());
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerWrapModeToGLEnum(samplerObj->GetWrapT()));
             break;
         case GL_TEXTURE_WRAP_R:
-            *(GLuint*)params = MG_Util::ConvertSamplerWrapModeToGLEnum(samplerObj->GetWrapR());
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerWrapModeToGLEnum(samplerObj->GetWrapR()));
             break;
         case GL_TEXTURE_MIN_FILTER:
-            *(GLuint*)params =
-                MG_Util::ConvertSamplerFilterModeToGLEnum(samplerObj->GetMinFilter(), samplerObj->GetMipmapMode());
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerFilterModeToGLEnum(samplerObj->GetMinFilter(),
+                                                                       samplerObj->GetMipmapMode()));
             break;
         case GL_TEXTURE_MAG_FILTER:
-            *(GLuint*)params =
-                MG_Util::ConvertSamplerFilterModeToGLEnum(samplerObj->GetMagFilter(), SamplerMipmapMode::None);
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerFilterModeToGLEnum(samplerObj->GetMagFilter(),
+                                                                       SamplerMipmapMode::None));
             break;
         case GL_TEXTURE_MIN_LOD:
-            *(GLfloat*)params = samplerObj->GetMinLod();
+            StoreSamplerScalar(params, isFloat, isUnsignedInteger, samplerObj->GetMinLod());
             break;
         case GL_TEXTURE_MAX_LOD:
-            *(GLfloat*)params = samplerObj->GetMaxLod();
+            StoreSamplerScalar(params, isFloat, isUnsignedInteger, samplerObj->GetMaxLod());
             break;
         case GL_TEXTURE_LOD_BIAS:
-            *(GLfloat*)params = samplerObj->GetLodBias();
+            StoreSamplerScalar(params, isFloat, isUnsignedInteger, samplerObj->GetLodBias());
             break;
         case GL_TEXTURE_MAX_ANISOTROPY_EXT:
-            if (isFloat) {
-                *(GLfloat*)params = samplerObj->GetMaxAnisotropy();
-            } else if (isUnsignedInteger) {
-                *(GLuint*)params = static_cast<GLuint>(samplerObj->GetMaxAnisotropy());
-            } else {
-                *(GLint*)params = static_cast<GLint>(samplerObj->GetMaxAnisotropy());
-            }
+            StoreSamplerScalar(params, isFloat, isUnsignedInteger, samplerObj->GetMaxAnisotropy());
             break;
         case GL_TEXTURE_COMPARE_MODE:
-            *(GLuint*)params = MG_Util::ConvertSamplerCompareModeToGLEnum(samplerObj->GetCompareMode());
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerCompareModeToGLEnum(samplerObj->GetCompareMode()));
             break;
         case GL_TEXTURE_COMPARE_FUNC:
-            *(GLuint*)params = MG_Util::ConvertSamplerCompareFuncToGLEnum(samplerObj->GetSamplerCompareFunc());
+            StoreSamplerEnum(params, isFloat, isUnsignedInteger,
+                             MG_Util::ConvertSamplerCompareFuncToGLEnum(samplerObj->GetSamplerCompareFunc()));
             break;
         case GL_TEXTURE_BORDER_COLOR: {
             if (isFloat) {
@@ -191,6 +259,16 @@ namespace MobileGL::MG_Impl::GLImpl {
                 out[1] = color.y();
                 out[2] = color.z();
                 out[3] = color.w();
+            } else if (!isIntegerCommand) {
+                // glGetSamplerParameteriv: the inverse of the write side, GL 4.6 core equation 2.3.
+                // Exactly inverse, so a {0,1,2,4} written with glSamplerParameteriv reads back as
+                // {0,1,2,4}; a bare truncating cast answered {0,0,0,0}.
+                const auto& color = samplerObj->GetBorderColor();
+                auto* out = (GLint*)params;
+                out[0] = MG_Util::FloatToSignedNormalizedInt32(color.x());
+                out[1] = MG_Util::FloatToSignedNormalizedInt32(color.y());
+                out[2] = MG_Util::FloatToSignedNormalizedInt32(color.z());
+                out[3] = MG_Util::FloatToSignedNormalizedInt32(color.w());
             } else if (isUnsignedInteger) {
                 const auto& color = samplerObj->GetBorderColorUI();
                 auto* out = (GLuint*)params;
@@ -293,16 +371,10 @@ namespace MobileGL::MG_Impl::GLImpl {
         if (sampler == 0) {
             textureUnit.SetSamplerObject(nullptr);
         } else {
-            // GL 3.3 core 3.8.2: BindSampler on a name GenSamplers never returned - or one already
-            // deleted - is INVALID_OPERATION. SamplerParameter* raises INVALID_VALUE for the same
-            // name, which is why this cannot go through the shared SamplerImpl validator.
-            if (!MG_State::pGLContext->ValidateSamplerName(sampler)) {
-                MG_State::pGLContext->RecordError(
-                    ErrorCode::InvalidOperation,
-                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "BindSampler_State",
-                                                 std::format("Invalid sampler name {}", sampler)));
-                return;
-            }
+            // GL 4.6 core 8.2: BindSampler on a name GenSamplers never returned - or one already
+            // deleted - is INVALID_OPERATION, and so is every other sampler entry point on such a
+            // name, so the shared validator answers for all of them.
+            if (!SamplerImpl::ValidateSamplerName(sampler)) return;
             Bool doesSamplerObjectCreated = MG_State::pGLContext->ValidateSamplerObject(sampler);
             if (!doesSamplerObjectCreated) {
                 MG_State::pGLContext->CreateSamplerObject(sampler);
@@ -356,30 +428,50 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     /* @INSERTION_POINT:FUNCTION_IMPLEMENTATION@ */
     void GetSamplerParameteriv(GLuint sampler, GLenum pname, GLint* params) {
-        GetSamplerParam_State(sampler, pname, params, false, false);
+        GetSamplerParam_State(sampler, pname, params, false, false, false);
     }
 
     void SamplerParameterIuiv(GLuint sampler, GLenum pname, const GLuint* param) {
-        SetSamplerParam_State(sampler, pname, param, false, true);
+        SetSamplerParam_State(sampler, pname, param, false, true, true);
     }
 
     void SamplerParameterIiv(GLuint sampler, GLenum pname, const GLint* param) {
-        SetSamplerParam_State(sampler, pname, param, false, false);
+        SetSamplerParam_State(sampler, pname, param, false, false, true);
     }
 
     void SamplerParameteriv(GLuint sampler, GLenum pname, const GLint* param) {
-        SetSamplerParam_State(sampler, pname, param, false, false);
+        SetSamplerParam_State(sampler, pname, param, false, false, false);
     }
 
     void SamplerParameterfv(GLuint sampler, GLenum pname, const GLfloat* param) {
-        SetSamplerParam_State(sampler, pname, param, true, false);
+        SetSamplerParam_State(sampler, pname, param, true, false, false);
     }
 
+    // GL 4.6 core 8.10: the scalar spellings take "the value of pname", so a pname with more than one
+    // component is INVALID_ENUM here rather than something to read four components of. Guarding at
+    // the entry point rather than downstream is also what stops the vector path reading twelve bytes
+    // past the caller's single stack scalar - taking the address of a by-value argument and handing
+    // it to a four-component reader is what these used to do. The texture-side twins already answer
+    // INVALID_ENUM for GL_TEXTURE_BORDER_COLOR (TexParameteri/f name it as unsupported outright).
     void SamplerParameteri(GLuint sampler, GLenum pname, GLint param) {
+        if (IsVectorOnlySamplerPname(pname)) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "SamplerParameteri",
+                                             "pname has more than one component and needs a vector form."));
+            return;
+        }
         SamplerParameteriv(sampler, pname, &param);
     }
 
     void SamplerParameterf(GLuint sampler, GLenum pname, GLfloat param) {
+        if (IsVectorOnlySamplerPname(pname)) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "SamplerParameterf",
+                                             "pname has more than one component and needs a vector form."));
+            return;
+        }
         SamplerParameterfv(sampler, pname, &param);
     }
 
@@ -388,15 +480,15 @@ namespace MobileGL::MG_Impl::GLImpl {
     }
 
     void GetSamplerParameterIuiv(GLuint sampler, GLenum pname, GLuint* params) {
-        GetSamplerParam_State(sampler, pname, params, false, true);
+        GetSamplerParam_State(sampler, pname, params, false, true, true);
     }
 
     void GetSamplerParameterIiv(GLuint sampler, GLenum pname, GLint* params) {
-        GetSamplerParam_State(sampler, pname, params, false, false);
+        GetSamplerParam_State(sampler, pname, params, false, false, true);
     }
 
     void GetSamplerParameterfv(GLuint sampler, GLenum pname, GLfloat* params) {
-        GetSamplerParam_State(sampler, pname, params, true, false);
+        GetSamplerParam_State(sampler, pname, params, true, false, false);
     }
 
     void GenSamplers(GLsizei count, GLuint* samplers) {

MobileGL/MG_Impl/GLImpl/Sampler/Validators.cpp

@@ -12,11 +12,17 @@
 #include <MG_Util/Converters/GLToMG/TextureEnumConverter.h>
 
 namespace MobileGL::MG_Impl::GLImpl::SamplerImpl {
+    // GL 4.6 core 8.2: "An INVALID_OPERATION error is generated if sampler is not the name of a
+    // sampler object previously returned from a call to GenSamplers." That class is shared by every
+    // sampler entry point - BindSampler, SamplerParameter*, GetSamplerParameter* - so this one gate
+    // answers for all of them. It used to report INVALID_VALUE (the GL 3.3 wording), which forced
+    // BindSampler to carry a bespoke duplicate of the same check just to get the class right.
     Bool ValidateSamplerName(GLuint sampler) {
         if (!MG_State::pGLContext->ValidateSamplerName(sampler)) {
             MG_State::pGLContext->RecordError(
-                ErrorCode::InvalidValue, MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "ValidateSamplerName",
-                                                                      std::format("Invalid sampler name {}", sampler)));
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "ValidateSamplerName",
+                                             std::format("Invalid sampler name {}", sampler)));
             return false;
         }
         return true;

MobileGL/MG_Impl/GLImpl/Sync/GL_Sync.cpp

@@ -9,6 +9,7 @@
 #include "GL_Sync.h"
 #include <MG_Backend/BackendObjects.h>
 #include <MG_State/GLState/Core.h>
+#include <MG_Impl/Pipe/PipeFill.h>
 
 namespace MobileGL::MG_Impl::GLImpl {
     namespace {
@@ -56,6 +57,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         syncObject->condition = condition;
         syncObject->flags = flags;
         if (const auto backendFenceSync = MG_Backend::gBackendFunctionsTable.GL.FenceSync) {
+            MGP_FILL(FenceSync);
             syncObject->backendHandle = backendFenceSync();
         }
         const GLsync handle = reinterpret_cast<GLsync>(syncObject);
@@ -94,6 +96,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         if (!backendClientWaitSync || !syncObject->backendHandle) {
             return GL_ALREADY_SIGNALED; // legacy always-signaled fallback
         }
+        MGP_FILL(ClientWaitSync);
         return backendClientWaitSync(syncObject->backendHandle, flags, timeout);
     }
 
@@ -119,6 +122,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         const auto backendWaitSync = MG_Backend::gBackendFunctionsTable.GL.WaitSync;
         if (backendWaitSync && syncObject->backendHandle) {
+            MGP_FILL(WaitSync);
             backendWaitSync(syncObject->backendHandle, flags, timeout);
         }
     }
@@ -139,6 +143,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
         const auto backendDeleteSync = MG_Backend::gBackendFunctionsTable.GL.DeleteSync;
         if (backendDeleteSync && syncObject->backendHandle) {
+            MGP_FILL(DeleteSync);
             backendDeleteSync(syncObject->backendHandle);
         }
         delete syncObject;
@@ -174,6 +179,7 @@ namespace MobileGL::MG_Impl::GLImpl {
             break;
         case GL_SYNC_STATUS: {
             const auto backendGetSyncStatus = MG_Backend::gBackendFunctionsTable.GL.GetSyncStatus;
+            MGP_FILL(GetSyncStatus);
             const Bool signaled = !backendGetSyncStatus || !syncObject->backendHandle ||
                                   backendGetSyncStatus(syncObject->backendHandle);
             value = signaled ? GL_SIGNALED : GL_UNSIGNALED;
@@ -227,6 +233,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         const auto backendDeleteSync = MG_Backend::gBackendFunctionsTable.GL.DeleteSync;
         for (const auto& [_, syncObject] : orphans) {
             if (backendDeleteSync && syncObject->backendHandle) {
+                MGP_FILL(DeleteSync);
                 backendDeleteSync(syncObject->backendHandle);
             }
             delete syncObject;

MobileGL/MG_Impl/GLImpl/Texture/GL_Texture.h

@@ -8,9 +8,24 @@
 
 #pragma once
 #include <Includes.h>
+#include <MG_State/GLState/TextureState/TextureObject.h>
 
 namespace MobileGL::MG_Impl::GLImpl {
     /* @INSERTION_POINT:FUNCTION_DECLARATION@ */
+    // Answers a texture-image query straight out of the CPU shadow, into client memory or a bound
+    // PIXEL_PACK_BUFFER. This is the whole of glGetTexImage on a build with no backend readback, and
+    // it is also the sound fallback for a backend that has no GPU image to read: with no image,
+    // nothing GPU-side can ever have written the texture, so the shadow IS its content.
+    //
+    // It answers a NARROWER contract than glGetTexImage's, and refuses what it cannot do rather than
+    // answering wrongly. The copy is verbatim: it performs no format or type conversion, and it packs
+    // rows tightly, honouring only GL_PACK_SWAP_BYTES and the bitmap GL_PACK_LSB_FIRST path. A
+    // request whose (format, type) texel size differs from the texture's own, or a pixel-store state
+    // that adds row padding / a row-length override / a skip offset, is rejected with
+    // GL_INVALID_OPERATION (see ValidateShadowReadbackLayout, which spells out why each is unsafe).
+    void CopyTextureImageToClientOrPBO_State(const SharedPtr<MG_State::GLState::ITextureObject>& textureObject,
+                                             TextureUploadTarget textureUploadTarget, GLint level, GLenum format,
+                                             GLenum type, GLsizei bufSize, void* pixels, const char* caller);
     // The sized internal formats a buffer texture accepts (GL 4.6 core table 8.16). The buffer
     // clears take the same list, so it is shared rather than written out twice.
     Bool IsBufferTextureInternalFormat(GLenum internalformat);

MobileGL/MG_Impl/GLImpl/Texture/Validators.cpp

@@ -103,6 +103,28 @@ namespace MobileGL::MG_Impl::GLImpl::TextureImpl {
         return true;
     }
 
+    Bool ValidateCubeMapArrayShape(TextureUploadTarget target, GLsizei width, GLsizei height, GLsizei depth,
+                                   const char* caller) {
+        if (target != TextureUploadTarget::CubeMapArray && target != TextureUploadTarget::ProxyCubeMapArray) {
+            return true;
+        }
+        if (width != height) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", caller,
+                                             "Cube map array levels must be square (width == height)"));
+            return false;
+        }
+        if (depth % 6 != 0) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", caller,
+                                             "Cube map array depth must be a multiple of six"));
+            return false;
+        }
+        return true;
+    }
+
     Bool ValidateTextureSizeWithTextureUploadTarget(TextureUploadTarget target, GLsizei width, GLsizei height) {
         if (target == TextureUploadTarget::CubeMapPositiveX || target == TextureUploadTarget::CubeMapNegativeX ||
             target == TextureUploadTarget::CubeMapPositiveY || target == TextureUploadTarget::CubeMapNegativeY ||

MobileGL/MG_Impl/GLImpl/Texture/Validators.h

@@ -20,6 +20,13 @@ namespace MobileGL::MG_Impl::GLImpl::TextureImpl {
     Bool ValidateTexturePixelDataType(TexturePixelDataType texturePixelDataType);
     Bool ValidateTextureLevelNumber(Int level);
     Bool ValidateTextureSizeWithTextureUploadTarget(TextureUploadTarget target, GLsizei width, GLsizei height);
+    // The two shape rules a cube-map-array level owes (GL 4.6 core 8.5): its faces are square, and
+    // its depth counts whole cubes. Both are GL_INVALID_VALUE. This used to be spelled inline in
+    // glTexStorage3D only, which is why glTexImage3D let both violations through - every entry
+    // point that DEFINES a cube-array level calls this now, so the two cannot drift again. A
+    // non-cube-array upload target answers true untouched.
+    Bool ValidateCubeMapArrayShape(TextureUploadTarget target, GLsizei width, GLsizei height, GLsizei depth,
+                                   const char* caller);
     Bool ValidateTextureSizeRange(Int width, Int height, Int depth);
     Bool ValidateTextureInternalFormat(TextureInternalFormat format);
     Bool ValidateTextureBorderNumber(Int border);

MobileGL/MG_Impl/GLImpl/VertexArray/Validators.cpp

@@ -12,15 +12,15 @@
 #include <MG_State/GLState/ErrorState/Error.h>
 #include <MG_Util/Converters/MGToGL/DataTypeConverter.h>
 #include <MG_Util/Converters/MGToStr/DataTypeConverter.h>
+#include <MG_Util/ShaderTranspiler/CompileEnv.h>
 
 namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl {
     Uint GetMaxVertexAttribs() {
-        constexpr Uint capacity = static_cast<Uint>(MG_State::GLState::VertexArrayObject::MAX_VERTEX_ATTRIBS);
-        if (!MG_Backend::pActiveBackendObject) return capacity;
-
-        const Int backendLimit = MG_Backend::pActiveBackendObject->GetDynamicParameters().MaxVertexAttribs;
-        if (backendLimit <= 0) return capacity;
-        return std::min(static_cast<Uint>(backendLimit), capacity);
+        // Shared with reflection's limit and with gl_MaxVertexAttribs; see ResolveMaxVertexAttribs.
+        const Bool hasBackend = MG_Backend::pActiveBackendObject != nullptr;
+        const Int backendLimit =
+            hasBackend ? MG_Backend::pActiveBackendObject->GetDynamicParameters().MaxVertexAttribs : 0;
+        return static_cast<Uint>(MG_Util::ShaderTranspiler::ResolveMaxVertexAttribs(hasBackend, backendLimit));
     }
 
     Uint GetMaxVertexAttribBindings() {

MobileGL/MG_Impl/Pipe/PipeFill.cpp

@@ -0,0 +1,614 @@
+// MobileGL - MobileGL/MG_Impl/Pipe/PipeFill.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+// The client side of the PipeInputs block (ARCHITECTURE.md 9.2 phase A): the only place in
+// the push arm that reads MG_State::pGLContext. Holds the per-verb filler, the F-class
+// forwarders, IsLive, the MOBILEGL_PIPE_POISON_OMIT knob and - in a verify build - the
+// second arm (SnapshotFromGLContext), the entry compare, the compare-at-read hook and the
+// MOBILEGL_PIPE_VERIFY_CORRUPT / _FATAL knobs. Compiled only under MOBILEGL_PIPE_PUSH
+// (CMakeLists.txt appends it to SOURCE_FILES there).
+#include <MG_State/GLState/Core.h>
+#include <MG_State/GLState/BufferState/BufferState.h>
+#include <MG_Backend/MGPipe/PipeInputs.h>
+#include <MG_Impl/Pipe/PipeFill.h>
+#include <MG_Pipe/PipeMutation.h>
+#include <Config.h>
+
+#include <atomic>
+#include <cstdlib>
+#include <cstring>
+
+namespace MobileGL::MG_Pipe {
+    using GLContext = MG_State::GLState::GLContext;
+
+    // The one door into PipeInputs' storage on the client side. A struct rather than a
+    // list of friend functions so the header names exactly one friend.
+    struct MGPipeFillAccess {
+        // Copies ONE field's storage out of the live context by calling the GLContext
+        // accessor of the same name (P1 brief D4: no derivation logic is re-implemented
+        // here, which is what keeps the copy semantically identical by construction).
+        // A forwarded field has no storage and copies nothing.
+        static void CopyField(PipeInputs& dst, GLContext& ctx, MGPipeInputField field) {
+            using F = MGPipeInputField;
+            using MG_State::GLState::BufferBindPointTargets;
+            using MG_State::GLState::GlobalBufferTargets;
+            switch (field) {
+            case F::GetActiveTextureUnit:
+                dst.m_activeTextureUnit = ctx.GetActiveTextureUnit();
+                break;
+            case F::GetBlendColor:
+                dst.m_blendColor = ctx.GetBlendColor();
+                break;
+            case F::GetBlendEquationIndexed:
+                for (Uint i = 0; i < kMGMaxDrawBuffers; ++i) {
+                    ctx.GetBlendEquationIndexed(i, dst.m_blendEquation[i][0], dst.m_blendEquation[i][1]);
+                }
+                break;
+            case F::GetBlendFuncIndexed:
+                for (Uint i = 0; i < kMGMaxDrawBuffers; ++i) {
+                    ctx.GetBlendFuncIndexed(i, dst.m_blendFunc[i][0], dst.m_blendFunc[i][1], dst.m_blendFunc[i][2],
+                                            dst.m_blendFunc[i][3]);
+                }
+                break;
+            case F::GetBoundTransformFeedbackName:
+                dst.m_boundTransformFeedbackName = ctx.GetBoundTransformFeedbackName();
+                break;
+            case F::GetBoundVertexArray:
+                dst.m_boundVertexArray = ctx.GetBoundVertexArray();
+                break;
+            case F::GetBufferBindingSlot:
+                // Every global target has a slot; Index stays null - GLContext resolves it
+                // through the bound VAO's element-buffer slot (Core.cpp), a derivation no
+                // FillPoints.def row can copy - and a read of it is the poison Fatal in the
+                // accessor. No backend reads it today (every slot read is DrawIndirect,
+                // DispatchIndirect, Parameter or PixelPack).
+                for (const auto target : GlobalBufferTargets) {
+                    dst.m_bufferBindingSlot[static_cast<SizeT>(target)] = &ctx.GetBufferBindingSlot(target);
+                }
+                break;
+            case F::GetBufferBindingPoint:
+                // The live storage is Array<Array<BindingSlotRange1D, BufferBindingPointCount>, N>
+                // (BufferState.h), so the address of point 0 is the base of that target's row.
+                for (const auto target : BufferBindPointTargets) {
+                    dst.m_bufferBindingPointBase[static_cast<SizeT>(target)] = &ctx.GetBufferBindingPoint(target, 0);
+                }
+                break;
+            case F::GetTouchedBufferBindingPointCount:
+                for (const auto target : BufferBindPointTargets) {
+                    dst.m_touchedBindingPointCount[static_cast<SizeT>(target)] =
+                        ctx.GetTouchedBufferBindingPointCount(target);
+                }
+                break;
+            case F::GetClampReadColor:
+                dst.m_clampReadColor = ctx.GetClampReadColor();
+                break;
+            case F::GetClearColor:
+                dst.m_clearColor = ctx.GetClearColor();
+                break;
+            case F::GetClearDepth:
+                dst.m_clearDepth = ctx.GetClearDepth();
+                break;
+            case F::GetClearStencil:
+                dst.m_clearStencil = ctx.GetClearStencil();
+                break;
+            case F::GetColorMaskIndexed:
+                for (Uint i = 0; i < kMGMaxDrawBuffers; ++i) {
+                    dst.m_colorMask[i] = ctx.GetColorMaskIndexed(i);
+                }
+                break;
+            case F::GetCullFaceMode:
+                dst.m_cullFaceMode = ctx.GetCullFaceMode();
+                break;
+            case F::GetCurrentVertexAttribute:
+                for (Uint i = 0; i < PipeInputs::kMaxVertexAttribs; ++i) {
+                    dst.m_currentVertexAttribute[i] = ctx.GetCurrentVertexAttribute(i);
+                }
+                break;
+            case F::GetDepthFunc:
+                dst.m_depthFunc = ctx.GetDepthFunc();
+                break;
+            case F::GetDepthMask:
+                dst.m_depthMask = ctx.GetDepthMask();
+                break;
+            case F::GetDepthRangeIndexed:
+                for (Uint i = 0; i < PipeInputs::kMaxViewports; ++i) {
+                    dst.m_depthRange[i] = ctx.GetDepthRangeIndexed(i);
+                }
+                break;
+            case F::GetFramebufferBindingSlot:
+                for (SizeT i = 0; i < PipeInputs::kFramebufferTargetCount; ++i) {
+                    dst.m_framebufferBindingSlot[i] =
+                        &ctx.GetFramebufferBindingSlot(static_cast<PipeInputs::FramebufferTarget>(i));
+                }
+                break;
+            case F::GetImageTextureBinding:
+                // Array<ImageTextureBinding, MAX_TEXTURE_IMAGE_UNITS> (TextureState.h): unit 0's
+                // address is the base.
+                dst.m_imageTextureBindingBase = &ctx.GetImageTextureBinding(0);
+                break;
+            case F::GetLineWidth:
+                dst.m_lineWidth = ctx.GetLineWidth();
+                break;
+            case F::GetLogicOp:
+                dst.m_logicOp = ctx.GetLogicOp();
+                break;
+            case F::GetMaxTouchedTextureUnit:
+                dst.m_maxTouchedTextureUnit = ctx.GetMaxTouchedTextureUnit();
+                break;
+            case F::GetMinSampleShadingValue:
+                dst.m_minSampleShadingValue = ctx.GetMinSampleShadingValue();
+                break;
+            case F::GetPatchDefaultInnerLevel:
+                dst.m_patchDefaultInnerLevel = ctx.GetPatchDefaultInnerLevel();
+                break;
+            case F::GetPatchDefaultOuterLevel:
+                dst.m_patchDefaultOuterLevel = ctx.GetPatchDefaultOuterLevel();
+                break;
+            case F::GetPatchVertices:
+                dst.m_patchVertices = ctx.GetPatchVertices();
+                break;
+            case F::GetPipelineStateVersion:
+                dst.m_pipelineStateVersion = ctx.GetPipelineStateVersion();
+                break;
+            case F::GetPixelStoreParameters:
+                dst.m_pixelStore[0] = ctx.GetPixelStoreParameters(false);
+                dst.m_pixelStore[1] = ctx.GetPixelStoreParameters(true);
+                break;
+            case F::GetPolygonModeFront:
+                dst.m_polygonModeFront = ctx.GetPolygonModeFront();
+                break;
+            case F::GetPolygonOffsetFactor:
+                dst.m_polygonOffsetFactor = ctx.GetPolygonOffsetFactor();
+                break;
+            case F::GetPolygonOffsetUnits:
+                dst.m_polygonOffsetUnits = ctx.GetPolygonOffsetUnits();
+                break;
+            case F::GetPrimitiveRestartIndex:
+                dst.m_primitiveRestartIndex = ctx.GetPrimitiveRestartIndex();
+                break;
+            case F::GetProgramForDispatch:
+                dst.m_programForDispatch = ctx.GetProgramForDispatch();
+                break;
+            case F::GetProgramForDraw:
+                dst.m_programForDraw = ctx.GetProgramForDraw();
+                break;
+            case F::GetProvokingVertexMode:
+                dst.m_provokingVertexMode = ctx.GetProvokingVertexMode();
+                break;
+            case F::GetRenderStateParameters:
+                dst.m_renderState = ctx.GetRenderStateParameters();
+                break;
+            case F::GetRenderStateParametersVersion:
+                dst.m_renderStateParametersVersion = ctx.GetRenderStateParametersVersion();
+                break;
+            case F::GetSamplingResolutionGeneration:
+                dst.m_samplingResolutionGeneration = ctx.GetSamplingResolutionGeneration();
+                break;
+            case F::GetScissorBox:
+                dst.m_scissorBox = ctx.GetScissorBox();
+                break;
+            case F::GetStencilState:
+                dst.m_stencil[0] = ctx.GetStencilState(StencilFace::Front);
+                dst.m_stencil[1] = ctx.GetStencilState(StencilFace::Back);
+                break;
+            case F::GetTextureBindGeneration:
+                dst.m_textureBindGeneration = ctx.GetTextureBindGeneration();
+                break;
+            case F::GetTextureContextId:
+                dst.m_textureContextId = ctx.GetTextureContextId();
+                break;
+            case F::GetTextureUnitObject:
+                // Array<TextureUnit, MAX_TEXTURE_IMAGE_UNITS> (TextureState.h): unit 0 is the base.
+                dst.m_textureUnitBase = &ctx.GetTextureUnitObject(0);
+                break;
+            case F::GetTransformFeedbackCapturedVertices:
+                dst.m_transformFeedbackCapturedVertices = ctx.GetTransformFeedbackCapturedVertices();
+                break;
+            case F::GetTransformFeedbackGeneration:
+                dst.m_transformFeedbackGeneration = ctx.GetTransformFeedbackGeneration();
+                break;
+            case F::GetTransformFeedbackPausedPrimitiveCounter:
+                dst.m_transformFeedbackPausedPrimitiveCounter = ctx.GetTransformFeedbackPausedPrimitiveCounter();
+                break;
+            case F::GetTransformFeedbackProgram:
+                dst.m_transformFeedbackProgram = ctx.GetTransformFeedbackProgram();
+                break;
+            case F::GetViewport:
+                dst.m_viewport = ctx.GetViewport();
+                break;
+            case F::GetViewportIndexed:
+                for (Uint i = 0; i < PipeInputs::kMaxViewports; ++i) {
+                    dst.m_viewportIndexed[i] = ctx.GetViewportIndexed(i);
+                }
+                break;
+            case F::IsCapabilityEnabled:
+                // Every capability, FramebufferSrgb included: it copies today's constant false
+                // (MEASUREMENTS.md), so no value changes.
+                for (SizeT i = 0; i < PipeInputs::kCapabilityCount; ++i) {
+                    dst.m_capability[i] = ctx.IsCapabilityEnabled(static_cast<CapabilityInput>(i));
+                }
+                break;
+            case F::IsCapabilityEnabledIndexed:
+                // The only two indexed capabilities GLContext keeps (RenderState).
+                for (Uint i = 0; i < kMGMaxDrawBuffers; ++i) {
+                    dst.m_capabilityIndexed.Blend[i] = ctx.IsCapabilityEnabledIndexed(CapabilityInput::Blend, i);
+                }
+                for (Uint i = 0; i < PipeInputs::kMaxViewports; ++i) {
+                    dst.m_capabilityIndexed.ScissorTest[i] =
+                        ctx.IsCapabilityEnabledIndexed(CapabilityInput::ScissorTest, i);
+                }
+                break;
+            case F::IsTransformFeedbackActive:
+                dst.m_transformFeedbackActive = ctx.IsTransformFeedbackActive();
+                break;
+            case F::IsTransformFeedbackPaused:
+                dst.m_transformFeedbackPaused = ctx.IsTransformFeedbackPaused();
+                break;
+            case F::GetBoundTransformFeedbackLifetimeId:
+                dst.m_boundTransformFeedbackLifetimeId = ctx.GetBoundTransformFeedbackLifetimeId();
+                break;
+            // The seven forwarded fields: nothing to copy.
+            case F::GetBufferBindingPointCount:
+            case F::GetProgramObject:
+            case F::GetTextureObject:
+            case F::HasOpenTransformFeedbackSpan:
+            case F::InvalidateCompileEnv:
+            case F::ValidateProgramName:
+            case F::RecordError:
+            case F::kFieldCount:
+                break;
+            }
+        }
+
+        static void SetIdentity(PipeInputs& inputs, GLContext* ctx) {
+            inputs.m_live = ctx != nullptr;
+            inputs.m_contextIdentity = ctx;
+        }
+        static void SetVerb(PipeInputs& inputs, MGPipeVerb verb) { inputs.m_currentVerb = verb; }
+#if MOBILEGL_PIPE_POISON
+        static MGPipeFilledState& Filled(PipeInputs& inputs) { return inputs.m_filled; }
+#endif
+    };
+
+    namespace {
+        GLContext* LiveContext() { return MG_State::pGLContext.get(); }
+
+        template <class T>
+        const SharedPtr<T>& NullShared() {
+            static const SharedPtr<T> null;
+            return null;
+        }
+
+        [[noreturn]] void BadKnob(const char* knob, const char* value, const char* why) {
+            MGLOG_F("MGPipe: Fatal{PipeVerifyBadKnob, \"%s=%s\": %s}", knob, value, why);
+            std::abort();
+        }
+
+        // ---- MOBILEGL_PIPE_POISON_OMIT (negative control B, P1 brief D6) ----
+        // The filler skips the STAMP (never the value) of one (verb, field) pair: an omission
+        // indistinguishable from a forgotten FillPoints.def row, so that verb's read of the
+        // field is Fatal{UnmigratedPipeInput, "Field@Verb"} and no other verb is affected.
+        struct PoisonOmission {
+            Bool Armed = false;
+            MGPipeVerb Verb = MGPipeVerb::kVerbCount;
+            MGPipeInputField Field = MGPipeInputField::kFieldCount;
+        };
+        PoisonOmission g_omission;
+        Bool g_omissionKnobParsed = false;
+        String g_omissionKnobValue; // the value the last parse saw
+
+        // Parsed on the first fill and again only when the value changes. A lane loads
+        // Features once, before any fill, so that is one parse per process there; a forked
+        // test child that sets Features after its parent already filled gets its own parse,
+        // which is what puts the parser and its Fatal{PipeVerifyBadKnob} under a unit test.
+        // An empty value never clears an omission a test armed through MGPipeSetPoisonOmission.
+        void ParsePoisonOmissionKnob() {
+            const String& knob = MG_Config::Features.PipePoisonOmit;
+            if (g_omissionKnobParsed && knob == g_omissionKnobValue) return;
+            g_omissionKnobParsed = true;
+            g_omissionKnobValue = knob;
+            if (knob.empty()) return;
+            const auto colon = knob.find(':');
+            if (colon == String::npos || colon == 0 || colon + 1 >= knob.size()) {
+                BadKnob("MOBILEGL_PIPE_POISON_OMIT", knob.c_str(), "expected <Verb>:<FieldName>");
+            }
+            const String verbName = knob.substr(0, colon);
+            const String fieldName = knob.substr(colon + 1);
+            const auto verb = MGPipeFindVerb(verbName.c_str());
+            if (!verb) BadKnob("MOBILEGL_PIPE_POISON_OMIT", knob.c_str(), "no such verb in kMGPipeVerbNames");
+            const auto field = MGPipeFindInputField(fieldName.c_str());
+            if (!field) BadKnob("MOBILEGL_PIPE_POISON_OMIT", knob.c_str(), "no such field in kMGPipeInputFieldNames");
+            MGPipeSetPoisonOmission(verbName.c_str(), fieldName.c_str());
+        }
+
+        [[maybe_unused]] Bool IsOmitted(MGPipeVerb verb, MGPipeInputField field) {
+            return g_omission.Armed && g_omission.Verb == verb && g_omission.Field == field;
+        }
+
+#if MOBILEGL_PIPE_VERIFY
+        // ---- the MOBILEGL_PIPE_VERIFY comparator (P1 brief D8) ----
+        // Two mechanisms, both active only when Features.PipeVerify is set: the ENTRY compare
+        // once per verb (the pushed block against a second snapshot of the live context,
+        // taken at the same instant - tautological until P2 gives the first arm a real
+        // filler, and kept falsifiable by MOBILEGL_PIPE_VERIFY_CORRUPT), and the
+        // COMPARE-AT-READ in every accessor (the stored value against a fresh read of the
+        // live context at the moment the backend reads it - the arm that is real in P1: it
+        // catches a value that changed between the verb boundary and the read).
+        PipeInputs g_snapshot{};    // the second arm
+        PipeInputs g_readScratch{}; // where the compare-at-read re-read lands
+
+        // The read hook arms at the first fill (ArmVerify below), so it cannot see a read
+        // made before that. That window is covered by the poison instead: MGP_INPUT_CHECK
+        // precedes MGP_INPUT_VERIFY_READ in every accessor and a stamp of 0 is never fresh,
+        // so such a read is Fatal{UnmigratedPipeInput, "<Field>@<none>"} before the hook
+        // could matter - which holds only while a verify build always carries the poison.
+        static_assert(MOBILEGL_PIPE_POISON, "the compare-at-read hook relies on the poison for reads before the first fill");
+
+        struct VerifyState {
+            Bool Parsed = false;
+            Bool Enabled = false;
+            Bool Fatal = true;
+            Bool InHook = false; // a re-read that re-enters an accessor is not re-verified
+            Optional<MGPipeInputField> Corrupt;
+            String CorruptKnob; // the MOBILEGL_PIPE_VERIFY_CORRUPT value the last arm saw
+            std::atomic<Uint64> Divergences{0};
+            ~VerifyState() {
+                const Uint64 count = Divergences.load(std::memory_order_relaxed);
+                if (count != 0) {
+                    MGLOG_E("MGPipe: verify summary - %llu divergence(s) survived MOBILEGL_PIPE_VERIFY_FATAL=0",
+                            static_cast<unsigned long long>(count));
+                }
+            }
+        };
+        VerifyState g_verify;
+
+        // Armed on the first fill and re-armed when any of the three verify knobs'
+        // Features value (PipeVerify, PipeVerifyFatal, PipeVerifyCorrupt) differs from what
+        // the last arm latched (the same reason as ParsePoisonOmissionKnob: one arm per lane
+        // process, a fresh arm for a forked test child that turns a knob after its parent
+        // filled). Cost: two Bool compares and one String compare per fill, verify builds only.
+        void ArmVerify() {
+            const auto& features = MG_Config::Features;
+            if (g_verify.Parsed && g_verify.Enabled == features.PipeVerify && g_verify.Fatal == features.PipeVerifyFatal &&
+                g_verify.CorruptKnob == features.PipeVerifyCorrupt) {
+                return;
+            }
+            g_verify.Parsed = true;
+            g_verify.Enabled = features.PipeVerify;
+            g_verify.Fatal = features.PipeVerifyFatal;
+            g_verify.CorruptKnob = features.PipeVerifyCorrupt;
+            g_verify.Corrupt = Optional<MGPipeInputField>{};
+            if (!g_verify.Enabled) return;
+            const String& corrupt = g_verify.CorruptKnob;
+            if (!corrupt.empty()) {
+                const auto field = MGPipeFindInputField(corrupt.c_str());
+                if (!field) {
+                    BadKnob("MOBILEGL_PIPE_VERIFY_CORRUPT", corrupt.c_str(), "no such field in kMGPipeInputFieldNames");
+                }
+                g_verify.Corrupt = field;
+            }
+            // The lanes grep for this line: a verify run whose log lacks it never armed.
+            MGLOG_I("MGPipe: verify armed - %u fields, %u verbs, fatal=%d", static_cast<unsigned>(kMGPipeInputFieldCount),
+                    static_cast<unsigned>(kMGPipeVerbCount), g_verify.Fatal ? 1 : 0);
+            if (g_verify.Corrupt) {
+                MGLOG_I("MGPipe: verify corruption armed - %s", kMGPipeInputFieldNames[static_cast<SizeT>(*g_verify.Corrupt)]);
+            }
+        }
+
+        void ReportDivergence(MGPipeInputField field, const char* where) {
+            const Uint64 serial = MGPipeFillAccess::Filled(gPipeInputs).CurrentVerbSerial;
+            MGLOG_F("MGPipe: Fatal{PipeVerifyDiffer, \"%s@%s\", verb=%llu, where=%s}",
+                    kMGPipeInputFieldNames[static_cast<SizeT>(field)], MGPipeVerbName(gPipeInputs.CurrentVerb()),
+                    static_cast<unsigned long long>(serial), where);
+            if (g_verify.Fatal) std::abort();
+            g_verify.Divergences.fetch_add(1, std::memory_order_relaxed);
+        }
+
+        void EntryCompare(PipeInputs& inputs, const MGPipeFieldMask& mask) {
+            if (!g_verify.Enabled) return;
+            SnapshotFromGLContext(g_snapshot, mask);
+            // Negative control A: perturb the SNAPSHOT arm, so a green run goes red naming the
+            // field. A field outside this verb's mask is not compared and stays untouched.
+            if (g_verify.Corrupt && MGPipeFieldMaskHas(mask, *g_verify.Corrupt)) {
+                MGPipeApplyVerifyCorruption(g_snapshot, *g_verify.Corrupt);
+            }
+            MGPipeInputField differing = MGPipeInputField::kFieldCount;
+            if (!MGPipeVerifyInputs(inputs, g_snapshot, mask, &differing)) ReportDivergence(differing, "entry");
+        }
+#endif // MOBILEGL_PIPE_VERIFY
+    } // namespace
+
+#if MOBILEGL_PIPE_VERIFY
+    void SnapshotFromGLContext(PipeInputs& snapshot, const MGPipeFieldMask& mask) {
+        auto* ctx = LiveContext();
+        MGPipeFillAccess::SetIdentity(snapshot, ctx);
+        MGPipeFillAccess::SetVerb(snapshot, gPipeInputs.CurrentVerb());
+        if (ctx == nullptr) return;
+        for (SizeT i = 0; i < kMGPipeInputFieldCount; ++i) {
+            const auto field = static_cast<MGPipeInputField>(i);
+            if (!MGPipeFieldMaskHas(mask, field) || kMGPipeInputFieldSticky[i]) continue;
+            MGPipeFillAccess::CopyField(snapshot, *ctx, field);
+        }
+    }
+
+    void MGPipeVerifyReadHook(const PipeInputs& self, MGPipeInputField field, Uint index0, Uint index1) {
+        if (&self != &gPipeInputs || !g_verify.Enabled || g_verify.InHook) return;
+        const auto index = static_cast<SizeT>(field);
+        if (kMGPipeInputFieldSticky[index]) return;
+        auto* ctx = LiveContext();
+        if (ctx == nullptr) return;
+        // The whole field is re-read and compared - a superset of "the same indices", so a
+        // divergence in an index the backend did not ask for is still a divergence between
+        // the boundary value and the live value. The indices only decorate the report. The
+        // cost is per backend read (GetRenderStateParameters re-copies and compares the whole
+        // struct; GetProgramForDraw re-joins the pending link), inside the verify budget and
+        // to be kept in mind when reading the verify lane's wall time.
+        // InHook: the re-read calls the same GLContext accessor the filler calls, and
+        // GetProgramForDraw's join can re-enter a backend and with it another gPipeInputs
+        // accessor; that inner read is a plain load rather than a second hook, so the hook
+        // never recurses (and never reports the inner read against a half-copied scratch).
+        g_verify.InHook = true;
+        MGPipeFillAccess::CopyField(g_readScratch, *ctx, field);
+        const Bool equal = MGPipeInputsFieldEqual(field, self, g_readScratch);
+        g_verify.InHook = false;
+        if (equal) return;
+        MGLOG_E("MGPipe: verify read of %s (index %u, %u) differs from the live context", kMGPipeInputFieldNames[index],
+                index0, index1);
+        ReportDivergence(field, "read");
+    }
+#endif // MOBILEGL_PIPE_VERIFY
+
+    // ---- push on mutation (P1 lane finding F2) ----
+    // A backend that writes a frontend object inside its own verb moves a value the verb
+    // boundary already copied: Magma's ResolveSamplerDescriptor synthesises a fallback
+    // texture for an unbound sampler and its AllocateStorage/SetInternalFormat bump the
+    // context's sampling-resolution generation, so every read of that field after the
+    // fallback differs from the live context (the two SampledSetStaleness / six
+    // UnboundImageDescriptor entries the verify lane aborted on). The frontend mutator
+    // spells MGP_NOTE_MUTATION(Field) at the point of the move and lands here.
+    //
+    // Only the value is refreshed. The stamp is deliberately left alone: a field whose stamp
+    // this verb withheld (negative control B) must stay stale, and a field the verb never
+    // filled must stay Fatal{UnmigratedPipeInput} on the next read rather than be healed by
+    // an unrelated frontend write.
+    void MGPipeNoteFrontendMutation(MGPipeInputField field) {
+        PipeInputs& inputs = gPipeInputs;
+        auto* ctx = LiveContext();
+        if (ctx == nullptr) return;
+        const auto verb = inputs.CurrentVerb();
+        if (verb == MGPipeVerb::kVerbCount) return; // nothing has filled the block yet
+        const auto index = static_cast<SizeT>(field);
+        if (kMGPipeInputFieldSticky[index]) return; // forwarded: no storage to refresh
+        const MGPipeFieldMask& mask =
+            kMGPipeClassFieldMask[static_cast<SizeT>(kMGPipeVerbClass[static_cast<SizeT>(verb)])];
+        if (!MGPipeFieldMaskHas(mask, field)) return; // this verb never pushed it
+        MGPipeFillAccess::CopyField(inputs, *ctx, field);
+    }
+
+    void MGPipeSetPoisonOmission(const char* verb, const char* field) {
+        if (verb == nullptr || field == nullptr) {
+            g_omission = PoisonOmission{};
+            return;
+        }
+        const auto v = MGPipeFindVerb(verb);
+        const auto f = MGPipeFindInputField(field);
+        if (!v || !f) BadKnob("MOBILEGL_PIPE_POISON_OMIT", verb, "unknown verb or field");
+        g_omission.Armed = true;
+        g_omission.Verb = *v;
+        g_omission.Field = *f;
+#if MOBILEGL_PIPE_POISON
+        MGLOG_I("MGPipe: poison omission armed - %s@%s", field, verb);
+#else
+        MGLOG_W_ONCE("MGPipe: poison omission %s@%s requested but the poison is not compiled in "
+                     "(MOBILEGL_PIPE_POISON=0): no stamp exists to omit",
+                     field, verb);
+#endif
+    }
+
+    // ---- liveness ----
+    Bool PipeInputs::IsLive() const { return LiveContext() != nullptr; }
+
+    // ---- the seven F-class forwarders ----
+    SizeT PipeInputs::GetBufferBindingPointCount(BufferTarget target) const {
+        const auto* ctx = LiveContext();
+        return ctx != nullptr ? ctx->GetBufferBindingPointCount(target) : 0;
+    }
+
+    const SharedPtr<PipeInputs::ProgramObject>& PipeInputs::GetProgramObject(Uint index) {
+        auto* ctx = LiveContext();
+        return ctx != nullptr ? ctx->GetProgramObject(index) : NullShared<ProgramObject>();
+    }
+
+    const SharedPtr<PipeInputs::ITextureObject>& PipeInputs::GetTextureObject(Uint index) {
+        auto* ctx = LiveContext();
+        return ctx != nullptr ? ctx->GetTextureObject(index) : NullShared<ITextureObject>();
+    }
+
+    Bool PipeInputs::HasOpenTransformFeedbackSpan(Uint64 lifetimeId) const {
+        const auto* ctx = LiveContext();
+        return ctx != nullptr && ctx->HasOpenTransformFeedbackSpan(lifetimeId);
+    }
+
+    void PipeInputs::InvalidateCompileEnv() {
+        if (auto* ctx = LiveContext()) ctx->InvalidateCompileEnv();
+    }
+
+    Bool PipeInputs::ValidateProgramName(Uint index) const {
+        const auto* ctx = LiveContext();
+        return ctx != nullptr && ctx->ValidateProgramName(index);
+    }
+
+    void PipeInputs::RecordError(ErrorCode code, UniquePtr<ErrorInfo> info) {
+        auto* ctx = LiveContext();
+        if (ctx == nullptr) {
+            MGLOG_E_ONCE("PipeInputs::RecordError: no live context, dropping error %d", static_cast<int>(code));
+            return;
+        }
+        ctx->RecordError(code, Move(info));
+    }
+
+    void MGPipeLeaveVerb() {
+        PipeInputs& inputs = gPipeInputs;
+#if MOBILEGL_PIPE_POISON
+        // Same bump the next fill would make, without a verb to fill from: no field is
+        // stamped, so every stamp this verb made falls behind the serial.
+        ++MGPipeFillAccess::Filled(inputs).CurrentVerbSerial;
+#endif
+        MGPipeFillAccess::SetVerb(inputs, MGPipeVerb::kVerbCount);
+    }
+
+    // ---- the filler ----
+    void MGPipeFillForVerb(MGPipeVerb verb) {
+        PipeInputs& inputs = gPipeInputs;
+        ParsePoisonOmissionKnob();
+#if MOBILEGL_PIPE_VERIFY
+        ArmVerify();
+#else
+        // The runtime knob without the compiled comparator is a no-op that would look green;
+        // this warning is what a lane's arming assertion turns into red.
+        if (MG_Config::Features.PipeVerify) {
+            MGLOG_W_ONCE("MGPipe: MOBILEGL_PIPE_VERIFY=1 requested but the comparator is not compiled in "
+                         "(configure with -DMOBILEGL_PIPE_VERIFY=ON)");
+        }
+#endif
+#if MOBILEGL_PIPE_POISON
+        MGPipeFilledState& filled = MGPipeFillAccess::Filled(inputs);
+        // Starts at 1: FilledGen == 0 is "never filled", and MGPipeInputFieldIsFresh refuses
+        // it on both branches, so a read before this first bump is
+        // Fatal{UnmigratedPipeInput, "<Field>@<none>"} rather than default storage.
+        ++filled.CurrentVerbSerial;
+#endif
+        MGPipeFillAccess::SetVerb(inputs, verb);
+        auto* ctx = LiveContext();
+        MGPipeFillAccess::SetIdentity(inputs, ctx);
+        if (ctx == nullptr) return;
+        const MGPipeFieldMask& mask = kMGPipeClassFieldMask[static_cast<SizeT>(kMGPipeVerbClass[static_cast<SizeT>(verb)])];
+        for (SizeT i = 0; i < kMGPipeInputFieldCount; ++i) {
+            const auto field = static_cast<MGPipeInputField>(i);
+            if (!MGPipeFieldMaskHas(mask, field)) continue;
+#if MOBILEGL_PIPE_POISON
+            if (kMGPipeInputFieldSticky[i]) {
+                // Stamped once by the first fill that sees a live context; fresh through the
+                // Sticky -> FilledGen != 0 branch of MGPipeInputFieldIsFresh from then on.
+                if (filled.FilledGen[i] == 0) filled.FilledGen[i] = 1;
+                continue;
+            }
+#else
+            if (kMGPipeInputFieldSticky[i]) continue;
+#endif
+            MGPipeFillAccess::CopyField(inputs, *ctx, field);
+#if MOBILEGL_PIPE_POISON
+            // The value is copied either way; only the stamp is withheld for the omitted pair.
+            if (!IsOmitted(verb, field)) filled.FilledGen[i] = filled.CurrentVerbSerial;
+#endif
+        }
+#if MOBILEGL_PIPE_VERIFY
+        EntryCompare(inputs, mask);
+#endif
+    }
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Impl/Pipe/PipeFill.h

@@ -0,0 +1,55 @@
+// MobileGL - MobileGL/MG_Impl/Pipe/PipeFill.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+// The fill point (ARCHITECTURE.md 9.2, P1 brief D7). MG_Impl spells MGP_FILL(Verb); as the
+// statement immediately before every call through gBackendFunctionsTable.GL - after every
+// early return the call is behind, inside the loop body for a call made in a loop - so the
+// frontend fills the PipeInputs block for exactly the verbs that reach a backend. In the
+// pull build the macro is ((void)0) and the pull build is byte-identical to a tree without
+// it.
+#if MOBILEGL_PIPE_PUSH
+#include <MG_Pipe/MGPipe.h>
+namespace MobileGL::MG_Pipe {
+    struct PipeInputs;
+
+    // PipeFill.cpp. Bumps the per-verb serial, records the verb and the context identity,
+    // and copies every field in the verb class's may-read mask (kMGPipeClassFieldMask) out
+    // of the live GLContext, stamping each with the new serial. In a verify build it then
+    // runs the entry compare against a second snapshot (P1 brief D8).
+    void MGPipeFillForVerb(MGPipeVerb verb);
+
+    // Ends the verb in flight without starting another: bumps the serial, so every field the
+    // verb stamped goes stale, and puts the current verb back to "none", so a read made after
+    // it aborts as Fatal{UnmigratedPipeInput, "<Field>@<none>"} - which is what such a read
+    // is - instead of naming whichever verb happened to be filled last. Nothing in the GL
+    // entry points calls this: a real verb is always followed by the next verb's fill. It
+    // exists for a caller that drives a backend helper directly and wants its declaration to
+    // stop where it says it stops (MG_Test/ScopedPipeVerb.h).
+    void MGPipeLeaveVerb();
+
+    // PipeFill.cpp. Negative control B (P1 brief D6): the filler withholds the STAMP - never
+    // the value - of `field` at `verb`, so that verb's read of it is
+    // Fatal{UnmigratedPipeInput, "Field@Verb"} while every other verb is unaffected. The
+    // MOBILEGL_PIPE_POISON_OMIT knob ("<Verb>:<FieldName>") calls this once, on the first
+    // fill; tests call it directly. Both null clears the omission. An unknown name is
+    // Fatal{PipeVerifyBadKnob}.
+    void MGPipeSetPoisonOmission(const char* verb, const char* field);
+
+#if MOBILEGL_PIPE_VERIFY
+    // PipeFill.cpp. The second arm of the comparator (P1 brief D8, ARCHITECTURE.md 13.2-2):
+    // fills `snapshot` from the live GLContext the old way, for every field in `mask`. This
+    // is the branch that survives P13, which is why it is its own function rather than the
+    // filler's loop.
+    void SnapshotFromGLContext(PipeInputs& snapshot, const MGPipeFieldMask& mask);
+#endif
+} // namespace MobileGL::MG_Pipe
+#define MGP_FILL(Verb) ::MobileGL::MG_Pipe::MGPipeFillForVerb(::MobileGL::MG_Pipe::MGPipeVerb::Verb)
+#else
+#define MGP_FILL(Verb) ((void)0)
+#endif

MobileGL/MG_IntegrationTest/CMakeLists.txt

@@ -51,6 +51,7 @@ endif()
 add_executable(MobileGLIntegrationTest
     Main.cpp
     Harness/HeadlessGL.cpp
+    Harness/BackendCapsPeek.cpp
     Scenarios/OrientationScenario.cpp
     Scenarios/CrossFrameBufferScenario.cpp
     Scenarios/ResidentIndexScenario.cpp
@@ -58,13 +59,18 @@ add_executable(MobileGLIntegrationTest
     Scenarios/DrawParametersScenario.cpp
     Scenarios/AsyncCompileScenario.cpp
     Scenarios/XfbAfterClipDistanceScenario.cpp
+    Scenarios/UnwrittenPositionOutputScenario.cpp
+    Scenarios/SampleMaskScopeScenario.cpp
+    Scenarios/SampledSetStalenessScenario.cpp
     Scenarios/ThreeChannelAttachmentScenario.cpp
     Scenarios/SnormAttachmentScenario.cpp
     Scenarios/PipelineFailureScenario.cpp
     Scenarios/AdvertisedLimitsScenario.cpp
     Scenarios/PixelStoreSweepScenario.cpp
+    Scenarios/PrimitiveRestartScenario.cpp
     Scenarios/FragCoordOriginScenario.cpp
     Scenarios/ClearThenReadPixelsScenario.cpp
+    Scenarios/SampleVariablesScenario.cpp
     Scenarios/DepthStencilReadbackScenario.cpp
     Scenarios/DepthStencilReadbackMatrixScenario.cpp
     Scenarios/DepthStencilReadbackAttachmentShapeScenario.cpp
@@ -86,6 +92,7 @@ add_executable(MobileGLIntegrationTest
     Scenarios/SsboDeclarationFormScenario.cpp
     Scenarios/Glsl420DeclarationScenario.cpp
     Scenarios/IoBlockNameCollisionScenario.cpp
+    Scenarios/UnlocatedIoBlockScenario.cpp
     Scenarios/TessellationDrawModeScenario.cpp
     Scenarios/GeometryDrawModeScenario.cpp
     Scenarios/PostLinkAttachScenario.cpp
@@ -95,19 +102,33 @@ add_executable(MobileGLIntegrationTest
     Scenarios/VertexAttribBindingScenario.cpp
     Scenarios/XfbCaptureBufferReuseScenario.cpp
     Scenarios/XfbPrimitiveQueryScenario.cpp
+    Scenarios/PrimitivesGeneratedNoXfbScenario.cpp
+    Scenarios/XfbRepeatedCaptureScenario.cpp
+    Scenarios/TessellationXfbCaptureScenario.cpp
+    Scenarios/PointSizeDemotionScenario.cpp
     Scenarios/VertexArrayEnableDisableScenario.cpp
     Scenarios/CopyImageLevelRangeScenario.cpp
     Scenarios/CopyImageLayeredScenario.cpp
+    Scenarios/CopyImagePacked16Scenario.cpp
     Scenarios/TextureViewScenario.cpp
     Scenarios/PackedWordReadbackScenario.cpp
     Scenarios/LayeredAttachmentBarrierScenario.cpp
+    Scenarios/LayeredAttachmentShapeScenario.cpp
     Scenarios/LayeredTextureReadbackScenario.cpp
     Scenarios/AtomicCounterScenario.cpp
+    Scenarios/LargeArenaAdoptionScenario.cpp
     Scenarios/SsboArrayDynamicIndexScenario.cpp
     Scenarios/StorageBufferRegrowScenario.cpp
+    Scenarios/SpirvShaderBinaryScenario.cpp
     Scenarios/RelinkStageSetScenario.cpp
     Scenarios/GuiBatchScenario.cpp
     Scenarios/UnboundImageDescriptorScenario.cpp
+    Scenarios/IntegerBorderColorScenario.cpp
+    Scenarios/ClearTexImageUndefinedLevelZeroScenario.cpp
+    Scenarios/RenderbufferBlendFormatScenario.cpp
+    Scenarios/DualSourceBlendScenario.cpp
+    Scenarios/PipeVerifyArmingScenario.cpp
+    Scenarios/PoisonOmissionScenario.cpp
 )
 
 target_include_directories(MobileGLIntegrationTest PRIVATE
@@ -273,9 +294,9 @@ if (MOBILEGL_ITEST_VK_ICD)
     if (MOBILEGL_ITEST_VK_ICD MATCHES "lvp_icd|lavapipe")
         message(STATUS "Integration tests: lavapipe ICD - forcing the iterationRP repairs on")
         list(APPEND MGL_ITEST_VULKAN_ENV
-            "MOBILEGL_FIX_ITERATIONRP_SUBGROUP_SCRATCH=1"
-            "MOBILEGL_DERIVE_NUM_SUBGROUPS=1"
-            "MOBILEGL_ITERATIONRP_FIX_BARRIER=1")
+            "MOBILEGL_MAGMA_FIX_ITERATIONRP_SUBGROUP_SCRATCH=1"
+            "MOBILEGL_MAGMA_DERIVE_NUM_SUBGROUPS=1"
+            "MOBILEGL_MAGMA_ITERATIONRP_FIX_BARRIER=1")
     endif()
 endif()
 
@@ -338,7 +359,37 @@ mgl_itest_join_environment(MGL_ITEST_VULKAN_OPTIMISTIC_ENVIRONMENT
     "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_ASYNC_SHADER_COMPILE=1"
     "MOBILEGL_ASYNC_OPTIMISTIC_SHADER_STATUS=1" ${MGL_ITEST_VULKAN_ENV})
 mgl_itest_join_environment(MGL_ITEST_GLES_NO_VIEWPORT_EMULATION_ENVIRONMENT
-    "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION=0" ${MGL_ITEST_COMMON_ENV})
+    "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION=0" ${MGL_ITEST_COMMON_ENV})
+# MOBILEGL_LOG_FILE_PATH alongside the pin, because the arming assertion needs somewhere to
+# read the library's own report from. The strip's arming signal is a latched MGLOG_I and there
+# is no other way for a test process to learn that it fired - MG_Config is not reachable from
+# this module on Android, where it links the shipping library. The path is per-lane so nothing
+# else appends to it, and the case only trusts the bytes written after it started.
+mgl_itest_join_environment(MGL_ITEST_GLES_UNLOCATED_IO_BLOCKS_ENVIRONMENT
+    "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS=1"
+    "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/unlocated-io-blocks.log"
+    ${MGL_ITEST_COMMON_ENV})
+mgl_itest_join_environment(MGL_ITEST_GLES_WIDENED_PACKED16_ENVIRONMENT
+    "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_ESPRYT_WIDEN_PACKED16_STORAGE=1" ${MGL_ITEST_COMMON_ENV})
+# Same shape as the UnlocatedIoBlocks entry: the log path is where the reroute's latched
+# MGLOG_I lands, and the arming case only trusts the bytes written after it started.
+mgl_itest_join_environment(MGL_ITEST_VULKAN_PRIMGEN_REROUTE_ENVIRONMENT
+    "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE=1"
+    "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/primgen-query-reroute.log"
+    ${MGL_ITEST_VULKAN_ENV})
+# The point-size demotion pinned on, per backend, with a per-lane log file for the arming
+# assertion - the same MOBILEGL_LOG_FILE_PATH reasoning as the UnlocatedIoBlocks lane above.
+# Two lanes because the demotion runs in the SHARED phase-B chain and each backend then
+# consumes it differently (Espryt respells the driver-side capture request, Magma binds the
+# SPIR-V Xfb decorations to the carrier).
+mgl_itest_join_environment(MGL_ITEST_GLES_POINT_SIZE_DEMOTION_ENVIRONMENT
+    "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_POINT_SIZE_DEMOTION=1"
+    "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/point-size-demotion-gles.log"
+    ${MGL_ITEST_COMMON_ENV})
+mgl_itest_join_environment(MGL_ITEST_VULKAN_POINT_SIZE_DEMOTION_ENVIRONMENT
+    "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_POINT_SIZE_DEMOTION=1"
+    "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/point-size-demotion-vulkan.log"
+    ${MGL_ITEST_VULKAN_ENV})
 
 # TIMEOUT on every entry: a GPU test that wedges must fail the run, not hang it.
 set(MGL_ITEST_TIMEOUT 120)
@@ -405,6 +456,23 @@ gtest_discover_tests(MobileGLIntegrationTest
         ENVIRONMENT "${MGL_ITEST_GLES_FORCED_DS_ENVIRONMENT}"
 )
 
+# UnlocatedIoBlockScenario with the interface-block location strip PINNED ON, for the same
+# reason the depth/stencil entry above pins its emulation: without it this scenario is
+# UNFALSIFIABLE on the machines this suite runs on. llvmpipe carries a located interface block
+# correctly, so the driver POST that arms the strip on Mali answers "healthy" here and the
+# emulation never runs - the ambient registration would be exercising the un-stripped path
+# twice and calling it coverage. With the variable set, the blocks really are emitted with no
+# location and the assertion is about the spelling the device gets.
+gtest_discover_tests(MobileGLIntegrationTest
+    TEST_PREFIX "DirectGLES.UnlocatedIoBlocks."
+    TEST_FILTER "UnlocatedIoBlockScenario.*"
+    DISCOVERY_TIMEOUT 30
+    PROPERTIES
+        LABELS integration-gpu
+        TIMEOUT ${MGL_ITEST_TIMEOUT}
+        ENVIRONMENT "${MGL_ITEST_GLES_UNLOCATED_IO_BLOCKS_ENVIRONMENT}"
+)
+
 # AsyncCompileScenario, with asynchronous compilation PINNED ON per backend.
 #
 # Not a duplicate of what the two ambient registrations already run: they run whatever
@@ -501,3 +569,245 @@ gtest_discover_tests(MobileGLIntegrationTest
         TIMEOUT ${MGL_ITEST_TIMEOUT}
         ENVIRONMENT "${MGL_ITEST_GLES_NO_VIEWPORT_EMULATION_ENVIRONMENT}"
 )
+
+# PrimitivesGeneratedNoXfbScenario again, with the GL_PRIMITIVES_GENERATED statistics
+# reroute PINNED ON. The ambient DirectVulkan registration runs the same cases under the
+# bring-up probe's Auto verdict, so between the two entries both accounting paths answer
+# the same GL questions and must produce the same numbers - the "two pools must agree"
+# gate this machine can hold that the affected device cannot. The pinned entry is also
+# the only one whose arming case runs: it asserts the renderer's latched MGLOG_I, so a
+# silently-disarmed reroute (an inverted override mapping, a lost gate) fails here
+# instead of leaving every equality case vacuously green. DirectVulkan only - the flag
+# steers nothing on DirectGLES.
+gtest_discover_tests(MobileGLIntegrationTest
+    TEST_PREFIX "DirectVulkan.PrimGenReroute."
+    TEST_FILTER "PrimitivesGeneratedNoXfbScenario.*"
+    DISCOVERY_TIMEOUT 30
+    PROPERTIES
+        LABELS integration-gpu
+        TIMEOUT ${MGL_ITEST_TIMEOUT}
+        ENVIRONMENT "${MGL_ITEST_VULKAN_PRIMGEN_REROUTE_ENVIRONMENT}"
+)
+
+# The packed16 copy scenarios again, with the 8-bit storage widening PINNED ON. The ambient
+# registrations above cover the narrow storage - on every CI driver the widening's POST
+# probe finds no field-order mirror, so Auto keeps the native 16-bit path - which means the
+# storage every AFFECTED device will actually run would otherwise execute nowhere at all:
+# no CI driver has the Mali bug that arms it. This lane is what proves the widened storage
+# is client-invisible (same packed words in and out on every leg the 18 failing CTS bodies
+# used, the renderbuffer one included). DirectGLES only - the flag steers nothing on
+# DirectVulkan, which has always stored these formats widened.
+gtest_discover_tests(MobileGLIntegrationTest
+    TEST_PREFIX "DirectGLES.WidenedPacked16."
+    TEST_FILTER "CopyImagePacked16Scenario.*"
+    DISCOVERY_TIMEOUT 30
+    PROPERTIES
+        LABELS integration-gpu
+        TIMEOUT ${MGL_ITEST_TIMEOUT}
+        ENVIRONMENT "${MGL_ITEST_GLES_WIDENED_PACKED16_ENVIRONMENT}"
+)
+
+# PointSizeDemotionScenario with the demotion PINNED ON, per backend, for the reason every
+# pinned lane above exists: llvmpipe and lavapipe both HOST gl_PointSize in tessellation and
+# geometry stages, so the ambient registrations run these captures through the built-in and
+# the demotion - the path every affected Mali device actually takes - would execute nowhere.
+# The ambient runs stay the negative control: same scenario, same CPU-computed bytes, native
+# path. Both backends, because the demotion is shared phase-B work with two different
+# consumers (the ESSL capture respelling vs the SPIR-V Xfb carrier binding).
+gtest_discover_tests(MobileGLIntegrationTest
+    TEST_PREFIX "DirectGLES.PointSizeDemotion."
+    TEST_FILTER "PointSizeDemotionScenario.*"
+    DISCOVERY_TIMEOUT 30
+    PROPERTIES
+        LABELS integration-gpu
+        TIMEOUT ${MGL_ITEST_TIMEOUT}
+        ENVIRONMENT "${MGL_ITEST_GLES_POINT_SIZE_DEMOTION_ENVIRONMENT}"
+)
+
+gtest_discover_tests(MobileGLIntegrationTest
+    TEST_PREFIX "DirectVulkan.PointSizeDemotion."
+    TEST_FILTER "PointSizeDemotionScenario.*"
+    DISCOVERY_TIMEOUT 30
+    PROPERTIES
+        LABELS integration-gpu
+        TIMEOUT ${MGL_ITEST_TIMEOUT}
+        ENVIRONMENT "${MGL_ITEST_VULKAN_POINT_SIZE_DEMOTION_ENVIRONMENT}"
+)
+
+# --- the third CI mode: MOBILEGL_PIPE_VERIFY -----------------------------------
+#
+# ARCHITECTURE.md 13.2-(2) asks for a THIRD build mode next to pull and push: two state models in
+# one address space, compared field by field at every verb boundary and again at every accessor
+# read, 5-10x slower and never shipped. These entries are that mode's lane. They exist only when
+# the library was configured with -DMOBILEGL_PIPE_VERIFY=ON, which is deliberate and is half of
+# what makes the lane falsifiable: `ctest -L integration-verify --no-tests=error` in a build that
+# forgot the option matches NO tests and fails, instead of reporting a green run of nothing.
+#
+# The other half is PipeVerifyArmingScenario.Armed, which asserts the library's own arming line -
+# because MOBILEGL_PIPE_VERIFY=1 in the environment of a library that never compiled the
+# comparator in is a silent no-op that looks exactly like a clean pass.
+#
+# Three things about the ENVIRONMENT properties below, each of which has already gone wrong once
+# in this file:
+#   * every list APPENDS ${MGL_ITEST_COMMON_ENV} / ${MGL_ITEST_VULKAN_ENV}. A ctest ENVIRONMENT
+#     entry overrides the job environment for the names it lists, so an entry that named only its
+#     own knobs would lose the EGL vendor and Vulkan ICD pinning and run against whichever driver
+#     the loader found first.
+#   * the ambient Verify. entries name NEITHER MOBILEGL_PIPE_VERIFY_CORRUPT NOR
+#     MOBILEGL_PIPE_POISON_OMIT. That is what lets CI's two always-on negative-control steps
+#     export those knobs in the JOB environment and have them reach the test processes; a
+#     property entry of the same name would silently win and the controls would prove nothing.
+#   * MOBILEGL_LOG_FILE_PATH is per lane, and "per lane" is the exact limit of what it proves. It
+#     is the only channel a test process has for reading the library's own report (MG_Config is not
+#     reachable from this module), but the log is opened fopen(path, "w"), so every process in a
+#     lane TRUNCATES it: after an ambient lane of 400-odd entries the file holds the LAST process
+#     and nothing else. Reading it is therefore only sound in a filtered, one-entry lane - which is
+#     why the arming case has a lane and a log of its own below, and why neither this file nor CI
+#     may read the ambient logs as evidence about the entries that ran before the last one. The
+#     ambient path is kept for post-mortems (and to keep library chatter out of ctest's capture).
+if (MOBILEGL_PIPE_VERIFY)
+    # 900s, not the ambient 120: the comparator re-reads every field of the fill mask at the verb
+    # boundary and again at every accessor read, which the design budgets at 5-10x.
+    set(MGL_ITEST_VERIFY_TIMEOUT 900)
+
+    mgl_itest_join_environment(MGL_ITEST_GLES_VERIFY_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_PIPE_VERIFY=1"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-verify-DirectGLES.log"
+        ${MGL_ITEST_COMMON_ENV})
+    mgl_itest_join_environment(MGL_ITEST_VULKAN_VERIFY_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_PIPE_VERIFY=1"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-verify-DirectVulkan.log"
+        ${MGL_ITEST_VULKAN_ENV})
+
+    # The arming assertion's own lane, one case per backend, with a log path nothing else writes to.
+    #
+    # PipeVerifyArmingScenario.Armed reads the library's log, and the log is a per-LANE resource: it
+    # is opened fopen(path, "w"), so every process in a lane truncates it. In the ambient Verify.
+    # lane that is 400-odd processes on one path, run `-j 4` in CI, and a whole-file read there
+    # races a neighbour's bring-up. Every other log-reading scenario in this file (UnlocatedIoBlocks,
+    # the primgen reroute, the point-size demotion) is registered exactly like this for the same
+    # reason. MGITEST_PIPE_ARMING_LANE is a harness marker - the library never reads it - and it is
+    # what makes the case skip in the ambient lane instead of racing there.
+    mgl_itest_join_environment(MGL_ITEST_GLES_VERIFY_ARMING_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_PIPE_VERIFY=1" "MGITEST_PIPE_ARMING_LANE=1"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-verify-arming-DirectGLES.log"
+        ${MGL_ITEST_COMMON_ENV})
+    mgl_itest_join_environment(MGL_ITEST_VULKAN_VERIFY_ARMING_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_PIPE_VERIFY=1" "MGITEST_PIPE_ARMING_LANE=1"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-verify-arming-DirectVulkan.log"
+        ${MGL_ITEST_VULKAN_ENV})
+
+    # Negative control A (G4). MOBILEGL_PIPE_VERIFY_FATAL=0 so the process SURVIVES its own
+    # divergence and the case can read the report back out of the log; the CI step that exports
+    # the same corruption against the ambient lane, where FATAL keeps its default of 1, asserts
+    # the other half - that a divergence aborts and reds the entry.
+    mgl_itest_join_environment(MGL_ITEST_GLES_VERIFY_CORRUPT_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_PIPE_VERIFY=1"
+        "MOBILEGL_PIPE_VERIFY_CORRUPT=GetRenderStateParameters" "MOBILEGL_PIPE_VERIFY_FATAL=0"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-verify-corrupt-DirectGLES.log"
+        ${MGL_ITEST_COMMON_ENV})
+    mgl_itest_join_environment(MGL_ITEST_VULKAN_VERIFY_CORRUPT_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_PIPE_VERIFY=1"
+        "MOBILEGL_PIPE_VERIFY_CORRUPT=GetRenderStateParameters" "MOBILEGL_PIPE_VERIFY_FATAL=0"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-verify-corrupt-DirectVulkan.log"
+        ${MGL_ITEST_VULKAN_ENV})
+
+    # Negative control B (G5). The omission skips the STAMP of one field for one verb while still
+    # copying its value, which is indistinguishable from a fill row nobody wrote; the scenario
+    # forks, so the resulting std::abort() is a datum in waitpid() rather than a dead lane.
+    mgl_itest_join_environment(MGL_ITEST_GLES_POISON_OMIT_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectGLES" "MOBILEGL_PIPE_VERIFY=1"
+        "MOBILEGL_PIPE_POISON_OMIT=GenerateMipmap:GetActiveTextureUnit"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-poison-omit-DirectGLES.log"
+        ${MGL_ITEST_COMMON_ENV})
+    mgl_itest_join_environment(MGL_ITEST_VULKAN_POISON_OMIT_ENVIRONMENT
+        "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_PIPE_VERIFY=1"
+        "MOBILEGL_PIPE_POISON_OMIT=GenerateMipmap:GetActiveTextureUnit"
+        "MOBILEGL_LOG_FILE_PATH=${CMAKE_CURRENT_BINARY_DIR}/pipe-poison-omit-DirectVulkan.log"
+        ${MGL_ITEST_VULKAN_ENV})
+
+    # The whole suite again, per backend, with the comparator armed. Same scenarios, same
+    # assertions, but every backend read of frontend state is now checked against a snapshot taken
+    # from the live context at the verb boundary - which is what "the 742 integration entries
+    # prove push equals pull" means. Labelled integration-gpu as well so a verify build's
+    # `ctest -L integration-gpu` still describes the whole registration set.
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectGLES.Verify."
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_GLES_VERIFY_ENVIRONMENT}"
+    )
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectVulkan.Verify."
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_VULKAN_VERIFY_ENVIRONMENT}"
+    )
+
+    # The arming assertion, one entry per backend. This is the entry that fails a lane whose library
+    # never armed: it runs the same library and the same MOBILEGL_PIPE_VERIFY=1 as the ambient
+    # entries above, but unlike them it cannot be green against a library with no comparator
+    # compiled in. Its log is its own, so `-j 4` cannot make it flake.
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectGLES.VerifyArming."
+        TEST_FILTER "PipeVerifyArmingScenario.Armed"
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_GLES_VERIFY_ARMING_ENVIRONMENT}"
+    )
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectVulkan.VerifyArming."
+        TEST_FILTER "PipeVerifyArmingScenario.Armed"
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_VULKAN_VERIFY_ARMING_ENVIRONMENT}"
+    )
+
+    # One case each: the knobs are process-wide, so a corrupted or poisoned process cannot also be
+    # running the ambient assertions. These four entries are the ones that assert the RED - they
+    # pass when the comparator and the poison report, and go red when either stops.
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectGLES.VerifyCorrupted."
+        TEST_FILTER "PipeVerifyArmingScenario.CorruptedFieldIsReported"
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_GLES_VERIFY_CORRUPT_ENVIRONMENT}"
+    )
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectVulkan.VerifyCorrupted."
+        TEST_FILTER "PipeVerifyArmingScenario.CorruptedFieldIsReported"
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_VULKAN_VERIFY_CORRUPT_ENVIRONMENT}"
+    )
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectGLES.PoisonOmitted."
+        TEST_FILTER "PoisonOmissionScenario.OmittedFieldAbortsOnThatVerb"
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_GLES_POISON_OMIT_ENVIRONMENT}"
+    )
+    gtest_discover_tests(MobileGLIntegrationTest
+        TEST_PREFIX "DirectVulkan.PoisonOmitted."
+        TEST_FILTER "PoisonOmissionScenario.OmittedFieldAbortsOnThatVerb"
+        DISCOVERY_TIMEOUT 30
+        PROPERTIES
+            LABELS "integration-gpu\;integration-verify"
+            TIMEOUT ${MGL_ITEST_VERIFY_TIMEOUT}
+            ENVIRONMENT "${MGL_ITEST_VULKAN_POISON_OMIT_ENVIRONMENT}"
+    )
+endif()

MobileGL/MG_IntegrationTest/Harness/BackendCapsPeek.cpp

@@ -0,0 +1,42 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Harness/BackendCapsPeek.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#include "BackendCapsPeek.h"
+
+#if !defined(__ANDROID__)
+#include <MG_Backend/BackendObject.h>
+
+namespace MobileGL::MG_Backend {
+    // Declared in MG_Backend/BackendObjects.h, which also pulls in both backends' headers
+    // and, through them, their loaders; the reference alone is all that is needed here.
+    extern UniquePtr<BackendObject>& pActiveBackendObject;
+} // namespace MobileGL::MG_Backend
+#endif
+
+namespace MGITest {
+
+    bool PeekComputeWorkGroupCaps(int outCount[3], int outSize[3]) {
+#if defined(__ANDROID__)
+        (void)outCount;
+        (void)outSize;
+        return false;
+#else
+        const auto& backend = MobileGL::MG_Backend::pActiveBackendObject;
+        if (!backend) {
+            return false;
+        }
+        const MobileGL::MG_Backend::DynamicBackendParameters& caps = backend->GetDynamicParameters();
+        for (int axis = 0; axis < 3; ++axis) {
+            outCount[axis] = caps.MaxComputeWorkGroupCount[axis];
+            outSize[axis] = caps.MaxComputeWorkGroupSize[axis];
+        }
+        return true;
+#endif
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Harness/BackendCapsPeek.h

@@ -0,0 +1,29 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Harness/BackendCapsPeek.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// The one place this module looks past the GL API into the active backend's caps block.
+//
+// It exists for exactly one assertion: that the six per-axis compute limits the MGPipe
+// caps block carries (DynamicBackendParameters::MaxComputeWorkGroupCount/Size, plan B
+// section 4.4.1) are the same numbers glGetIntegeri_v answers today, since P0.5 retires
+// the getter in favour of the caps. A separate translation unit, because the scenario
+// sources include the GL headers with prototypes and MobileGL's umbrella header is not
+// meant to meet them in one file.
+
+#pragma once
+
+namespace MGITest {
+
+    // Copies the active backend's MaxComputeWorkGroupCount / MaxComputeWorkGroupSize into the
+    // two arrays and returns true. Returns false, touching nothing, where the caps block is
+    // out of reach: on Android this module links the SHIPPING libMobileGL.so, built
+    // -fvisibility=hidden, so no internal symbol resolves; on desktop it links MobileGL_s and
+    // the read is direct.
+    bool PeekComputeWorkGroupCaps(int outCount[3], int outSize[3]);
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/AdvertisedLimitsScenario.cpp

@@ -26,9 +26,11 @@
 // quantities, so an entry that only fails on DirectVulkan is a translation bug and one that
 // fails on both is a table bug.
 
+#include <algorithm>
 #include <string>
 #include <vector>
 
+#include "../Harness/BackendCapsPeek.h"
 #include "../Harness/HeadlessGL.h"
 #include "../Harness/ScenarioFixture.h"
 
@@ -56,7 +58,13 @@ namespace MGITest {
 
         const std::vector<LimitBound>& BufferLimitTable() {
             static const std::vector<LimitBound> table = {
-                {GL_MAX_UNIFORM_BUFFER_BINDINGS, "GL_MAX_UNIFORM_BUFFER_BINDINGS", 36, 256},
+                // 84 is the GL 4.5 core table 23.64 minimum, and also the width of the state
+                // layer's indexed-binding array - the two were made to coincide when the array
+                // was widened from 36, which had made the clamp in GL_Getter degenerate.
+                {GL_MAX_UNIFORM_BUFFER_BINDINGS, "GL_MAX_UNIFORM_BUFFER_BINDINGS", 84, 256},
+                // 14 uniform blocks on each of the FIVE graphics stages. The sum used to count
+                // three, and the two tessellation stages were simply missing from it.
+                {GL_MAX_COMBINED_UNIFORM_BLOCKS, "GL_MAX_COMBINED_UNIFORM_BLOCKS", 70, 256},
                 {GL_MAX_COMPUTE_UNIFORM_BLOCKS, "GL_MAX_COMPUTE_UNIFORM_BLOCKS", 12, 256},
                 {GL_MAX_COMPUTE_SHADER_STORAGE_BLOCKS, "GL_MAX_COMPUTE_SHADER_STORAGE_BLOCKS", 8, 256},
                 {GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS, "GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS", 8, 256},
@@ -133,6 +141,49 @@ namespace MGITest {
                     << relation.blocksName << " = " << blocks << " exceeds " << relation.bindingsName << " = "
                     << bindings << "; a shader may declare more blocks than there are binding points to bind them to";
             }
+
+            // THE MIDDLE TERM, which the relation quoted above always had and this case never
+            // checked. It is the one that actually broke: widening the binding-point array to 84
+            // raised what every PER-STAGE count clamps to, while the combined value was a
+            // five-stage sum of 70 - so a device reporting descriptor-indexing-scale uniform
+            // buffers (Adreno: maxPerStageDescriptorUniformBuffers = 16777216) advertised 84
+            // compute uniform blocks inside a combined limit of 70. Per-stage <= combined is
+            // exactly the assertion that says so, and it costs one glGetIntegerv per row.
+            struct StageAgainstCombined {
+                GLenum stage;
+                const char* stageName;
+                GLenum combined;
+                const char* combinedName;
+            };
+            const StageAgainstCombined stageRelations[] = {
+                {GL_MAX_COMPUTE_UNIFORM_BLOCKS, "GL_MAX_COMPUTE_UNIFORM_BLOCKS", GL_MAX_COMBINED_UNIFORM_BLOCKS,
+                 "GL_MAX_COMBINED_UNIFORM_BLOCKS"},
+                {GL_MAX_VERTEX_UNIFORM_BLOCKS, "GL_MAX_VERTEX_UNIFORM_BLOCKS", GL_MAX_COMBINED_UNIFORM_BLOCKS,
+                 "GL_MAX_COMBINED_UNIFORM_BLOCKS"},
+                {GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS, "GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS",
+                 GL_MAX_COMBINED_UNIFORM_BLOCKS, "GL_MAX_COMBINED_UNIFORM_BLOCKS"},
+                {GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS, "GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS",
+                 GL_MAX_COMBINED_UNIFORM_BLOCKS, "GL_MAX_COMBINED_UNIFORM_BLOCKS"},
+                {GL_MAX_GEOMETRY_UNIFORM_BLOCKS, "GL_MAX_GEOMETRY_UNIFORM_BLOCKS", GL_MAX_COMBINED_UNIFORM_BLOCKS,
+                 "GL_MAX_COMBINED_UNIFORM_BLOCKS"},
+                {GL_MAX_FRAGMENT_UNIFORM_BLOCKS, "GL_MAX_FRAGMENT_UNIFORM_BLOCKS", GL_MAX_COMBINED_UNIFORM_BLOCKS,
+                 "GL_MAX_COMBINED_UNIFORM_BLOCKS"},
+                {GL_MAX_COMPUTE_SHADER_STORAGE_BLOCKS, "GL_MAX_COMPUTE_SHADER_STORAGE_BLOCKS",
+                 GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS, "GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS"},
+                {GL_MAX_FRAGMENT_SHADER_STORAGE_BLOCKS, "GL_MAX_FRAGMENT_SHADER_STORAGE_BLOCKS",
+                 GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS, "GL_MAX_COMBINED_SHADER_STORAGE_BLOCKS"},
+            };
+            for (const StageAgainstCombined& relation : stageRelations) {
+                GLint stage = -1;
+                GLint combined = -1;
+                glGetIntegerv(relation.stage, &stage);
+                glGetIntegerv(relation.combined, &combined);
+                ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR)) << relation.stageName;
+                EXPECT_LE(stage, combined)
+                    << relation.stageName << " = " << stage << " exceeds " << relation.combinedName << " = "
+                    << combined << "; GL 4.6 table 23.64 orders MAX_*_BUFFER_BINDINGS >= MAX_COMBINED_*_BLOCKS >= "
+                       "every per-stage count, and a single-stage program may use its whole per-stage allowance";
+            }
         }
 
         // KHR-GL44.multi_bind.functional_bind_buffers_range sizes each of an indexed target's
@@ -199,6 +250,80 @@ namespace MGITest {
                    "derived component limits are computed in";
         }
 
+        // The GL 4.5 core minimums that had no case in the getter at all, or that were still
+        // carrying an ES/GL3.3-tier number. Every one of these answered GL_INVALID_ENUM or a
+        // too-small value against a context advertising 4.6, and each is the FIRST call its
+        // conformance case makes - so the case died before it could measure anything.
+        //
+        // The cull pair is deliberately absent: zero is a legal answer there (a backend with no
+        // cull-distance route MUST report it), so it is checked for answerability only, below.
+        TEST_F(AdvertisedLimitsScenario, EveryGL45CoreMinimumIsMet) {
+            const std::vector<LimitBound> table = {
+                {GL_MAX_VARYING_VECTORS, "GL_MAX_VARYING_VECTORS", 15, 256},
+                {GL_MAX_VERTEX_UNIFORM_VECTORS, "GL_MAX_VERTEX_UNIFORM_VECTORS", 256, 1 << 20},
+                {GL_MAX_VARYING_COMPONENTS, "GL_MAX_VARYING_COMPONENTS", 60, 1 << 20},
+                // GL_MAX_VERTEX_STREAMS is deliberately absent. GL 4.5 requires 4 and MobileGL
+                // answers 1, which is a KNOWN non-conformance rather than an oversight: raising
+                // the number un-gates two transform-feedback CTS cases per package across
+                // KHR-GL40..GL46 that then fail, because no part of the shader pipeline supports
+                // layout(stream = N). See the GL_MAX_VERTEX_STREAMS case in GL_Getter.cpp. Adding
+                // a row here would pin a number the implementation cannot back.
+                {GL_MAX_GEOMETRY_SHADER_INVOCATIONS, "GL_MAX_GEOMETRY_SHADER_INVOCATIONS", 32, 256},
+                {GL_MAX_SUBROUTINES, "GL_MAX_SUBROUTINES", 256, 1 << 20},
+                {GL_MAX_SUBROUTINE_UNIFORM_LOCATIONS, "GL_MAX_SUBROUTINE_UNIFORM_LOCATIONS", 1024, 1 << 20},
+                {GL_MAX_TESS_CONTROL_INPUT_COMPONENTS, "GL_MAX_TESS_CONTROL_INPUT_COMPONENTS", 128, 1 << 16},
+                {GL_MAX_TESS_CONTROL_OUTPUT_COMPONENTS, "GL_MAX_TESS_CONTROL_OUTPUT_COMPONENTS", 128, 1 << 16},
+                {GL_MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS, "GL_MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS", 4096,
+                 1 << 20},
+                {GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS, "GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS", 16, 256},
+                {GL_MAX_TESS_CONTROL_UNIFORM_COMPONENTS, "GL_MAX_TESS_CONTROL_UNIFORM_COMPONENTS", 1024, 1 << 20},
+                {GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS, "GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS", 14, 256},
+                {GL_MAX_TESS_EVALUATION_INPUT_COMPONENTS, "GL_MAX_TESS_EVALUATION_INPUT_COMPONENTS", 128, 1 << 16},
+                {GL_MAX_TESS_EVALUATION_OUTPUT_COMPONENTS, "GL_MAX_TESS_EVALUATION_OUTPUT_COMPONENTS", 128, 1 << 16},
+                {GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS, "GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS", 16, 256},
+                {GL_MAX_TESS_EVALUATION_UNIFORM_COMPONENTS, "GL_MAX_TESS_EVALUATION_UNIFORM_COMPONENTS", 1024,
+                 1 << 20},
+                {GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS, "GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS", 14, 256},
+                {GL_MAX_TESS_PATCH_COMPONENTS, "GL_MAX_TESS_PATCH_COMPONENTS", 120, 1 << 16},
+                {GL_MAX_COMBINED_TESS_CONTROL_UNIFORM_COMPONENTS, "GL_MAX_COMBINED_TESS_CONTROL_UNIFORM_COMPONENTS",
+                 58368, 1 << 30},
+                {GL_MAX_COMBINED_TESS_EVALUATION_UNIFORM_COMPONENTS,
+                 "GL_MAX_COMBINED_TESS_EVALUATION_UNIFORM_COMPONENTS", 58368, 1 << 30},
+            };
+            for (const LimitBound& bound : table) {
+                GLint value = -424242;
+                glGetIntegerv(bound.pname, &value);
+                const unsigned int error = FirstGLError();
+                EXPECT_EQ(error, GLenum(GL_NO_ERROR)) << bound.name << " is not answerable: " << GLErrorName(error);
+                if (error != GL_NO_ERROR) continue;
+                EXPECT_GE(value, bound.minimum) << bound.name << " = " << value << " is below the GL 4.5 minimum "
+                                                << bound.minimum;
+                EXPECT_LE(value, bound.ceiling) << bound.name << " = " << value << " exceeds the ceiling "
+                                                << bound.ceiling;
+            }
+
+            // ARB_cull_distance's pair. Zero is honest on a backend with no cull-distance route,
+            // so only answerability and the combined-limit ordering are checked here.
+            GLint cull = -1;
+            GLint clip = -1;
+            GLint combined = -1;
+            glGetIntegerv(GL_MAX_CULL_DISTANCES, &cull);
+            glGetIntegerv(GL_MAX_CLIP_DISTANCES, &clip);
+            glGetIntegerv(GL_MAX_COMBINED_CLIP_AND_CULL_DISTANCES, &combined);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR)) << "the ARB_cull_distance queries must not error";
+            EXPECT_GE(cull, 0);
+            EXPECT_GE(combined, cull) << "GL 4.6 core 11.1.3.10: the combined limit is at least the cull one";
+            EXPECT_GE(combined, clip) << "GL 4.6 core 11.1.3.10: the combined limit is at least the clip one";
+
+            // GL_MAX_ELEMENT_INDEX is 64-bit state: the required 2^32-1 does not fit a GLint, so
+            // the wide query must answer it and the narrow one must saturate rather than wrap.
+            GLint64 elementIndex = -1;
+            glGetInteger64v(GL_MAX_ELEMENT_INDEX, &elementIndex);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            EXPECT_GE(elementIndex, static_cast<GLint64>(4294967295LL))
+                << "GL 4.5 core table 23.55 sets the GL_MAX_ELEMENT_INDEX minimum at 2^32-1";
+        }
+
         // ARB_viewport_array's own limits. They are advertised from three different places -
         // GL_MAX_VIEWPORTS from the frontend's indexed state width, the bounds range and the
         // subpixel bits from the backend caps table - and each backend fills that table from a
@@ -255,5 +380,250 @@ namespace MGITest {
             EXPECT_GE(viewportDims[1], maxRenderbufferSize);
         }
 
+
+        // THE INDEXED AND PER-PROGRAM QUERIES THAT NAME FRONTEND STATE, pinned on both lanes.
+        //
+        // Both backends used to carry their own arms for GL_SHADER_STORAGE_BUFFER_* and
+        // GL_IMAGE_BINDING_* inside GLFunctionsTable::GetIntegeri_v, and their own
+        // GetInteger64i_v / GetProgramiv table entries. None of it was reachable: GL_Getter and
+        // GL_Program answer every one of these pnames from the frontend's own state and return
+        // before the table is consulted. The duplicates did not even agree - the backend arms
+        // clamped a bound range to the buffer's current storage, which GL 4.6 core tables
+        // 23.4/23.5 do not permit - so the code was one refactor away from becoming the answer.
+        // These cases pin what the frontend actually reports, so a future move of any of it back
+        // behind the interface has to keep saying the same thing.
+        TEST_F(AdvertisedLimitsScenario, IndexedBufferBindingsAreReportedVerbatimOnBothWidths) {
+            GLuint buffer = 0;
+            glGenBuffers(1, &buffer);
+            glBindBuffer(GL_SHADER_STORAGE_BUFFER, buffer);
+            glBufferData(GL_SHADER_STORAGE_BUFFER, 1024, nullptr, GL_DYNAMIC_DRAW);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+
+            // A range that is NOT the whole buffer, so a clamp to the store would be visible.
+            glBindBufferRange(GL_SHADER_STORAGE_BUFFER, 1, buffer, 256, 512);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+
+            GLint binding32 = -1;
+            GLint start32 = -1;
+            GLint size32 = -1;
+            glGetIntegeri_v(GL_SHADER_STORAGE_BUFFER_BINDING, 1, &binding32);
+            glGetIntegeri_v(GL_SHADER_STORAGE_BUFFER_START, 1, &start32);
+            glGetIntegeri_v(GL_SHADER_STORAGE_BUFFER_SIZE, 1, &size32);
+            EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            EXPECT_EQ(binding32, static_cast<GLint>(buffer));
+            EXPECT_EQ(start32, 256);
+            EXPECT_EQ(size32, 512);
+
+            // The 64-bit width has to agree pname for pname. It has no backend entry of its own
+            // and derives everything from the 32-bit answer above plus its own buffer arm.
+            GLint64 binding64 = -1;
+            GLint64 start64 = -1;
+            GLint64 size64 = -1;
+            glGetInteger64i_v(GL_SHADER_STORAGE_BUFFER_BINDING, 1, &binding64);
+            glGetInteger64i_v(GL_SHADER_STORAGE_BUFFER_START, 1, &start64);
+            glGetInteger64i_v(GL_SHADER_STORAGE_BUFFER_SIZE, 1, &size64);
+            EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            EXPECT_EQ(binding64, static_cast<GLint64>(buffer));
+            EXPECT_EQ(start64, static_cast<GLint64>(256));
+            EXPECT_EQ(size64, static_cast<GLint64>(512));
+
+            // An unbound index answers zero rather than erroring or leaking the driver's answer.
+            GLint unbound = -1;
+            glGetIntegeri_v(GL_SHADER_STORAGE_BUFFER_BINDING, 0, &unbound);
+            EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            EXPECT_EQ(unbound, 0);
+
+            // THE ARM THAT SEPARATES VERBATIM FROM CLAMPED. GL 4.6 core tables 23.4/23.5 report
+            // the size glBindBufferRange was ASKED for; it does not follow the buffer, so
+            // shrinking the store underneath the binding must not move it. A clamp to the
+            // current storage - which is exactly what both backends' deleted arms did - answers
+            // 128 here, and answers 0 for the bind-then-allocate shape
+            // KHR-GL43.shader_storage_buffer_object.basic-binding uses.
+            glBufferData(GL_SHADER_STORAGE_BUFFER, 128, nullptr, GL_DYNAMIC_DRAW);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            GLint startAfterShrink = -1;
+            GLint sizeAfterShrink = -1;
+            GLint64 sizeAfterShrink64 = -1;
+            glGetIntegeri_v(GL_SHADER_STORAGE_BUFFER_START, 1, &startAfterShrink);
+            glGetIntegeri_v(GL_SHADER_STORAGE_BUFFER_SIZE, 1, &sizeAfterShrink);
+            glGetInteger64i_v(GL_SHADER_STORAGE_BUFFER_SIZE, 1, &sizeAfterShrink64);
+            EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            EXPECT_EQ(startAfterShrink, 256)
+                << "the bound range's start followed the buffer through a re-specification";
+            EXPECT_EQ(sizeAfterShrink, 512)
+                << "the bound range's size was clamped to the buffer's current 128-byte storage; the range is "
+                   "state of the BINDING POINT and is reported verbatim";
+            EXPECT_EQ(sizeAfterShrink64, static_cast<GLint64>(512))
+                << "the 64-bit width disagreed with the 32-bit one about the same pname";
+
+            glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, 0);
+            glDeleteBuffers(1, &buffer);
+            (void)FirstGLError();
+        }
+
+        TEST_F(AdvertisedLimitsScenario, ImageUnitBindingsAreReportedFromTheFrontendState) {
+            GLint maxImageUnits = 0;
+            glGetIntegerv(GL_MAX_IMAGE_UNITS, &maxImageUnits);
+            (void)FirstGLError();
+            if (maxImageUnits < 2) GTEST_SKIP() << "no image units to bind on this lane";
+
+            GLuint texture = 0;
+            glGenTextures(1, &texture);
+            glBindTexture(GL_TEXTURE_2D, texture);
+            glTexStorage2D(GL_TEXTURE_2D, 2, GL_RGBA8, 8, 8);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+
+            glBindImageTexture(1, texture, 1, GL_FALSE, 0, GL_READ_ONLY, GL_RGBA8);
+            ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+
+            struct Expectation {
+                GLenum pname;
+                const char* name;
+                GLint expected;
+            };
+            const Expectation expectations[] = {
+                {GL_IMAGE_BINDING_NAME, "GL_IMAGE_BINDING_NAME", static_cast<GLint>(texture)},
+                {GL_IMAGE_BINDING_LEVEL, "GL_IMAGE_BINDING_LEVEL", 1},
+                {GL_IMAGE_BINDING_LAYERED, "GL_IMAGE_BINDING_LAYERED", GL_FALSE},
+                {GL_IMAGE_BINDING_LAYER, "GL_IMAGE_BINDING_LAYER", 0},
+                {GL_IMAGE_BINDING_ACCESS, "GL_IMAGE_BINDING_ACCESS", GL_READ_ONLY},
+                {GL_IMAGE_BINDING_FORMAT, "GL_IMAGE_BINDING_FORMAT", GL_RGBA8},
+            };
+            for (const Expectation& expectation : expectations) {
+                GLint value = -424242;
+                glGetIntegeri_v(expectation.pname, 1, &value);
+                EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR)) << expectation.name;
+                EXPECT_EQ(value, expectation.expected) << expectation.name;
+
+                // Same pname through the wide width - it must not fall through to a driver that
+                // knows nothing about MobileGL's image-unit state.
+                GLint64 wide = -424242;
+                glGetInteger64i_v(expectation.pname, 1, &wide);
+                EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR)) << expectation.name << " (64-bit)";
+                EXPECT_EQ(wide, static_cast<GLint64>(expectation.expected)) << expectation.name << " (64-bit)";
+            }
+
+            glBindImageTexture(1, 0, 0, GL_FALSE, 0, GL_READ_ONLY, GL_RGBA8);
+            glDeleteTextures(1, &texture);
+            (void)FirstGLError();
+        }
+
+        // glGetProgramiv(GL_COMPUTE_WORK_GROUP_SIZE) is a LINK ARTIFACT of the program the
+        // application wrote. DirectVulkan used to answer it from its own spirv-reflect cache and
+        // DirectGLES by forwarding to the driver's ESSL program - neither of which the
+        // application ever named - while GL_Program.cpp has always answered it from
+        // ProgramObject::GetComputeLocalSize. This pins the declared local size on both lanes.
+        TEST_F(AdvertisedLimitsScenario, ComputeLocalSizeComesFromTheLinkedProgram) {
+            static const char* kSource = R"(#version 430 core
+layout(local_size_x = 4, local_size_y = 3, local_size_z = 2) in;
+layout(std430, binding = 0) buffer Output { uint g_data[]; };
+void main() { g_data[gl_LocalInvocationIndex] = 1u; }
+)";
+            const GLuint shader = glCreateShader(GL_COMPUTE_SHADER);
+            glShaderSource(shader, 1, &kSource, nullptr);
+            glCompileShader(shader);
+            GLint compiled = 0;
+            glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+            if (compiled == GL_FALSE) {
+                char log[2048] = {};
+                glGetShaderInfoLog(shader, sizeof(log) - 1, nullptr, log);
+                glDeleteShader(shader);
+                (void)FirstGLError();
+                GTEST_SKIP() << "no compute shader support on this lane: " << log;
+            }
+            const GLuint program = glCreateProgram();
+            glAttachShader(program, shader);
+            glLinkProgram(program);
+            glDeleteShader(shader);
+            GLint linked = 0;
+            glGetProgramiv(program, GL_LINK_STATUS, &linked);
+            if (linked == GL_FALSE) {
+                char log[2048] = {};
+                glGetProgramInfoLog(program, sizeof(log) - 1, nullptr, log);
+                glDeleteProgram(program);
+                (void)FirstGLError();
+                GTEST_SKIP() << "the compute program did not link on this lane: " << log;
+            }
+
+            GLint localSize[3] = {-1, -1, -1};
+            glGetProgramiv(program, GL_COMPUTE_WORK_GROUP_SIZE, localSize);
+            EXPECT_EQ(FirstGLError(), GLenum(GL_NO_ERROR));
+            EXPECT_EQ(localSize[0], 4);
+            EXPECT_EQ(localSize[1], 3);
+            EXPECT_EQ(localSize[2], 2);
+
+            // A program with no compute stage must answer INVALID_OPERATION, not a stale or
+            // defaulted (1, 1, 1) - the frontend's rule, and the one a backend that answers from
+            // its own reflection cache cannot express.
+            const GLuint empty = glCreateProgram();
+            GLint ignored[3] = {0, 0, 0};
+            glGetProgramiv(empty, GL_COMPUTE_WORK_GROUP_SIZE, ignored);
+            EXPECT_EQ(FirstGLError(), GLenum(GL_INVALID_OPERATION))
+                << "GL 4.6 core 7.13: the query is only defined for a linked program with a compute shader";
+
+            glDeleteProgram(empty);
+            glDeleteProgram(program);
+            (void)FirstGLError();
+        }
+
+        // THE SIX COMPUTE LIMITS THAT OUTLIVE THE GETTER. GL_MAX_COMPUTE_WORK_GROUP_COUNT and
+        // GL_MAX_COMPUTE_WORK_GROUP_SIZE, three axes each, are the only indexed pnames the
+        // DEVICE answers rather than the frontend (glGetIntegeri_v on Espryt, VkPhysicalDevice-
+        // Limits on Magma), and therefore the only ones that have to cross the MGPipe boundary
+        // once GetIntegeri_v is retired (plan B section 4.4.6 / P0.5). They ride in MGPCaps by
+        // inclusion, as DynamicBackendParameters::MaxComputeWorkGroupCount/Size, filled by both
+        // backends at capability init. This case pins that the caps copy and the live getter
+        // answer are one number - the getter floors the backend's raw answer at the GL 4.3
+        // minimum, so the comparison is against the floored caps value - and pins the
+        // GL-visible half on every lane: answerability, the floors, vector/indexed agreement
+        // and the index bound. On a lane where the caps block is out of reach (Android links
+        // the shipping .so) only the GL-visible half runs.
+        TEST_F(AdvertisedLimitsScenario, ComputeWorkGroupLimitsAreTheCapsBlocksAnswer) {
+            struct Axis {
+                GLenum pname;
+                const char* name;
+                GLint minimum[3]; // GL 4.3 core table 23.60
+            };
+            const Axis axes[] = {
+                {GL_MAX_COMPUTE_WORK_GROUP_COUNT, "GL_MAX_COMPUTE_WORK_GROUP_COUNT", {65535, 65535, 65535}},
+                {GL_MAX_COMPUTE_WORK_GROUP_SIZE, "GL_MAX_COMPUTE_WORK_GROUP_SIZE", {1024, 1024, 64}},
+            };
+            int capsCount[3] = {0, 0, 0};
+            int capsSize[3] = {0, 0, 0};
+            const bool capsVisible = PeekComputeWorkGroupCaps(capsCount, capsSize);
+
+            for (const Axis& axis : axes) {
+                GLint indexed[3] = {-1, -1, -1};
+                for (GLuint i = 0; i < 3; ++i) {
+                    glGetIntegeri_v(axis.pname, i, &indexed[i]);
+                    ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR)) << axis.name << "[" << i << "]";
+                    EXPECT_GE(indexed[i], axis.minimum[i])
+                        << axis.name << "[" << i << "] = " << indexed[i]
+                        << " is below the GL 4.3 core table 23.60 minimum " << axis.minimum[i];
+                }
+                GLint vector[3] = {-1, -1, -1};
+                glGetIntegerv(axis.pname, vector);
+                ASSERT_EQ(FirstGLError(), GLenum(GL_NO_ERROR)) << axis.name;
+                for (int i = 0; i < 3; ++i) {
+                    EXPECT_EQ(vector[i], indexed[i])
+                        << axis.name << "[" << i << "]: the vector query and the indexed query disagree";
+                }
+                GLint outOfRange = -424242;
+                glGetIntegeri_v(axis.pname, 3, &outOfRange);
+                EXPECT_EQ(FirstGLError(), GLenum(GL_INVALID_VALUE))
+                    << axis.name << "[3]: an index past the three axes is INVALID_VALUE (GL 4.6 core 22.1)";
+
+                if (!capsVisible) continue;
+                const int* capsAxis = axis.pname == GL_MAX_COMPUTE_WORK_GROUP_COUNT ? capsCount : capsSize;
+                for (int i = 0; i < 3; ++i) {
+                    EXPECT_EQ(std::max(capsAxis[i], axis.minimum[i]), indexed[i])
+                        << axis.name << "[" << i << "]: MGPCaps carries " << capsAxis[i]
+                        << " but glGetIntegeri_v answers " << indexed[i]
+                        << " - the caps block and the getter path must be one number, because P0.5 retires "
+                           "the getter in favour of the caps";
+                }
+            }
+        }
+
     } // namespace
 } // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/AtomicCounterScenario.cpp

@@ -225,4 +225,43 @@ void main() {
         EXPECT_EQ(values[1], reseed[1] + 2 * kInvocations) << "the re-seeded value at offset 4 did not reach the shader";
     }
 
+    // A CPU glBufferSubData issued AFTER a dispatch, read back with NO further GPU work in
+    // between. Each backend has its own way to invert this pair, and both are pinned here.
+    // DirectGLES queues app SubData ranges for the draw-time staged-copy flush (the upload
+    // ring) instead of uploading in place, and readback of a GPU-written buffer overwrites
+    // the frontend shadow with the driver copy - so if the readback path forgets to flush the
+    // queued range first, the newer CPU write is REVERTED by the readback and offset 0 reads
+    // the dispatch's value instead of the reseed. DirectVulkan adopts the buffer into
+    // coherent GPU memory the moment the dispatch resolves its descriptor, so the SubData
+    // write lands in the very bytes the GPU reads - while the dispatch still sits recorded in
+    // the deferred frame command buffer. Unless the frontend retires that pending work before
+    // writing the adopted store (BufferObject::UploadSubData), the dispatch executes ON TOP
+    // of the reseed and offset 0 reads reseed + increments instead of the reseed. Offset 4
+    // pins the other direction for both: the upload must leave bytes outside its range - the
+    // dispatch's results - untouched.
+    TEST_F(AtomicCounterScenario, SubDataAfterDispatchSurvivesAnImmediateReadback) {
+        if (!Ready() || IsSkipped()) return;
+
+        const GLuint zero = MakeCounterBuffer(0, {0u, 0u});
+        MakeCounterBuffer(1, {0u});
+        ASSERT_EQ(FirstGLError(), 0u);
+
+        Dispatch();
+
+        const unsigned int reseed = 4242u;
+        glBindBuffer(GL_ATOMIC_COUNTER_BUFFER, zero);
+        glBufferSubData(GL_ATOMIC_COUNTER_BUFFER, 0, sizeof(reseed), &reseed);
+        glBindBuffer(GL_ATOMIC_COUNTER_BUFFER, 0);
+        ASSERT_EQ(FirstGLError(), 0u) << "re-seeding the counter buffer raised a GL error";
+
+        const std::vector<unsigned int> values = ReadCounters(zero, 2);
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_EQ(values[0], reseed)
+            << "offset 0 read back " << values[0] << "; the dispatch's value (" << kInvocations
+            << ") means the readback ran before the queued SubData range was flushed and reverted it";
+        EXPECT_EQ(values[1], 2 * kInvocations)
+            << "offset 4 read back " << values[1] << "; the SubData flush must leave bytes outside its "
+            << "range untouched";
+    }
+
 } // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/ClearTexImageUndefinedLevelZeroScenario.cpp

@@ -0,0 +1,250 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/ClearTexImageUndefinedLevelZeroScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - glClearTexImage ON A TEXTURE WHOSE GL LEVEL 0 WAS NEVER DEFINED.
+//
+// KHR-GL4[456].clear_tex_image.* builds exactly one shape: fillTexture() issues ONE
+// glTexImage2D(GL_TEXTURE_2D, m_texLevel, ...) - the only texImage2D in the whole format/level
+// family - sets GL_TEXTURE_MAX_LEVEL to that level, clears it and reads it back with
+// glGetTexImage(..., m_texLevel, ...). For m_texLevel > 0 the levels BELOW the defined one have no
+// storage at all, and the split in the conformance results was on that alone: every texLevel_0 body
+// passed on DirectVulkan and every texLevel != 0 body failed, across all four internal formats and
+// all three entry points.
+//
+// The frontend understands this shape - the clear is a pure CPU-shadow write, and
+// ValidateTextureImageQuery deliberately does not demand mip completeness for a readback. The
+// Vulkan backend did not: VkTextureManager takes storage mip 0 as the physical image extent, so a
+// texture with no level 0 got no VkImage, SyncTextureAndGetDescriptor answered nullptr, and
+// VulkanRenderer::GetTextureImage took a silent early return - leaving the caller's buffer exactly
+// as it found it. The conformance failures carried no <Text> at all, because nothing raised a GL
+// error: the destination was simply never written, so the test compared its own zero-initialized
+// buffer against the clear value.
+//
+// The fix this pins is the readback fallback: with NO VkImage, nothing GPU-side can ever have
+// written the texture, so the CPU shadow IS its content and is the correct answer. It is gated on
+// "no image exists at all" and not on "syncing was inconvenient - a blanket shadow answer would
+// return stale bytes for every render-to-texture result instead.
+//
+// NOT covered here, and deliberately: such a texture still has no VkImage, so it remains invisible
+// to SAMPLING and rendering on DirectVulkan. Backing the image from the lowest defined level is a
+// separate change (it moves every GL-level-to-subresource translation in the backend); this
+// scenario asserts the readback contract only, and the DirectGLES leg - which has always been able
+// to define a lone level N - is the built-in control for what the answer should be.
+
+#include <array>
+#include <cstdint>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // The conformance family's own shape: a mid-chain level of a texture that has nothing else.
+        constexpr GLint kDefinedLevel = 3;
+        constexpr GLsizei kLevelExtent = 8;
+
+        struct Texel8 {
+            GLubyte r = 0, g = 0, b = 0, a = 0;
+            bool operator==(const Texel8& other) const {
+                return r == other.r && g == other.g && b == other.b && a == other.a;
+            }
+        };
+
+        std::ostream& operator<<(std::ostream& os, const Texel8& c) {
+            return os << "rgba(" << int(c.r) << "," << int(c.g) << "," << int(c.b) << "," << int(c.a) << ")";
+        }
+
+        // The conformance test's clear value is a single repeated component; 5 is what it uses, and
+        // it is deliberately neither 0 (an unwritten destination) nor 255 (a saturated one).
+        constexpr Texel8 kClearValue{5, 5, 5, 5};
+        constexpr Texel8 kInitialValue{200, 100, 50, 255};
+
+        class ClearTexImageUndefinedLevelZeroScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                DrainErrors();
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                if (m_texture != 0) {
+                    glBindTexture(GL_TEXTURE_2D, 0);
+                    glDeleteTextures(1, &m_texture);
+                    m_texture = 0;
+                }
+                DrainErrors();
+            }
+
+            static void DrainErrors() {
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+            }
+
+            // One level and nothing else, through glTexImage2D - deliberately NOT glTexStorage2D,
+            // which would define the whole chain and could not express "level 0 does not exist".
+            void MakeTextureWithOnlyLevel(GLint level) {
+                if (m_texture != 0) glDeleteTextures(1, &m_texture);
+                glGenTextures(1, &m_texture);
+                glBindTexture(GL_TEXTURE_2D, m_texture);
+                const std::vector<Texel8> initial(static_cast<std::size_t>(kLevelExtent) * kLevelExtent, kInitialValue);
+                glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA8, kLevelExtent, kLevelExtent, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                             initial.data());
+                // What the conformance case does: MAX_LEVEL names the one level that exists, and
+                // BASE_LEVEL is left at its default 0 - which is what makes level 0 undefined AND
+                // nominally the base level, the shape the backend could not express.
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, level);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                ASSERT_EQ(FirstGLError(), 0u) << "texture setup with only level " << level;
+            }
+
+            std::vector<Texel8> ReadLevel(GLint level) {
+                std::vector<Texel8> pixels(static_cast<std::size_t>(kLevelExtent) * kLevelExtent, Texel8{0, 0, 0, 0});
+                glBindTexture(GL_TEXTURE_2D, m_texture);
+                glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, pixels.data());
+                EXPECT_EQ(FirstGLError(), 0u) << "glGetTexImage(level " << level << ") left a GL error behind";
+                return pixels;
+            }
+
+            void ExpectAllTexels(const char* what, const std::vector<Texel8>& pixels, Texel8 expected) {
+                std::size_t offenders = 0;
+                Texel8 firstBad{};
+                for (const Texel8& pixel : pixels) {
+                    if (pixel == expected) continue;
+                    if (offenders == 0) firstBad = pixel;
+                    ++offenders;
+                }
+                EXPECT_EQ(offenders, 0u) << what << ": got " << firstBad << " instead of " << expected << " ("
+                                         << offenders << " of " << pixels.size() << " texels wrong)";
+            }
+
+            // Level 0 defined, a GAP, then `level` defined. GL keeps the intervening levels at a zero
+            // extent, so the backend's mip walk stops at the gap and the VkImage ends up with FEWER
+            // mip levels than the GL level count - which is a different shape from "no image at all"
+            // and is why the readback has to bound the level against the IMAGE.
+            void MakeTextureWithAGapBefore(GLint level) {
+                if (m_texture != 0) glDeleteTextures(1, &m_texture);
+                glGenTextures(1, &m_texture);
+                glBindTexture(GL_TEXTURE_2D, m_texture);
+                const std::vector<Texel8> base(static_cast<std::size_t>(kLevelExtent) * kLevelExtent, kInitialValue);
+                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, kLevelExtent, kLevelExtent, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                             base.data());
+                const std::vector<Texel8> gapped(static_cast<std::size_t>(kLevelExtent) * kLevelExtent, kInitialValue);
+                glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA8, kLevelExtent, kLevelExtent, 0, GL_RGBA,
+                             GL_UNSIGNED_BYTE, gapped.data());
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, level);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                ASSERT_EQ(FirstGLError(), 0u) << "texture setup with a gap before level " << level;
+            }
+
+            GLuint m_texture = 0;
+        };
+
+    } // namespace
+
+    // The regression. Before the fix glGetTexImage wrote nothing at all on DirectVulkan, so the
+    // caller's buffer kept whatever it already held - which is why the conformance failures showed
+    // the test's own zero-initialized memory and carried no GL error.
+    TEST_F(ClearTexImageUndefinedLevelZeroScenario, ClearAndReadBackALevelWhoseLowerLevelsDoNotExist) {
+        if (!Ready()) GTEST_SKIP();
+        MakeTextureWithOnlyLevel(kDefinedLevel);
+
+        // Pre-flight: the level reads back as what was uploaded. This is what makes the assertion
+        // after the clear falsifiable - without it, a readback that silently wrote nothing could not
+        // be told from one that wrote the right answer.
+        ExpectAllTexels("before the clear", ReadLevel(kDefinedLevel), kInitialValue);
+
+        glClearTexImage(m_texture, kDefinedLevel, GL_RGBA, GL_UNSIGNED_BYTE, &kClearValue);
+        EXPECT_EQ(FirstGLError(), 0u) << "glClearTexImage was rejected";
+
+        ExpectAllTexels("after the clear", ReadLevel(kDefinedLevel), kClearValue);
+        Gl().EndFrame();
+    }
+
+    // The same shape through glClearTexSubImage, which is a separate entry point in the conformance
+    // family and failed on exactly the same bodies.
+    TEST_F(ClearTexImageUndefinedLevelZeroScenario, ClearSubImageOfALevelWhoseLowerLevelsDoNotExist) {
+        if (!Ready()) GTEST_SKIP();
+        MakeTextureWithOnlyLevel(kDefinedLevel);
+
+        glClearTexSubImage(m_texture, kDefinedLevel, 0, 0, 0, kLevelExtent, kLevelExtent, 1, GL_RGBA,
+                           GL_UNSIGNED_BYTE, &kClearValue);
+        EXPECT_EQ(FirstGLError(), 0u) << "glClearTexSubImage was rejected";
+
+        ExpectAllTexels("after the sub-image clear", ReadLevel(kDefinedLevel), kClearValue);
+        Gl().EndFrame();
+    }
+
+    // The negative control: an ORDINARY texture, whose level 0 does exist, must keep answering from
+    // the GPU image rather than being diverted onto the shadow. A fallback that fired unconditionally
+    // would pass the two tests above and this one too - but it would also hand back stale bytes for
+    // anything the GPU had written, which is why the partial-clear check below matters: the readback
+    // has to see a region the backend cleared and a region it did not, in one image.
+    TEST_F(ClearTexImageUndefinedLevelZeroScenario, AnOrdinaryLevelZeroTextureStillReadsBackCorrectly) {
+        if (!Ready()) GTEST_SKIP();
+        MakeTextureWithOnlyLevel(0);
+
+        ExpectAllTexels("before the clear", ReadLevel(0), kInitialValue);
+
+        // Clear only the left half, so the answer is neither "all initial" nor "all cleared".
+        glClearTexSubImage(m_texture, 0, 0, 0, 0, kLevelExtent / 2, kLevelExtent, 1, GL_RGBA, GL_UNSIGNED_BYTE,
+                           &kClearValue);
+        EXPECT_EQ(FirstGLError(), 0u) << "glClearTexSubImage was rejected";
+
+        const std::vector<Texel8> pixels = ReadLevel(0);
+        ASSERT_EQ(pixels.size(), static_cast<std::size_t>(kLevelExtent) * kLevelExtent);
+        for (int y = 0; y < kLevelExtent; ++y) {
+            for (int x = 0; x < kLevelExtent; ++x) {
+                const Texel8 expected = x < kLevelExtent / 2 ? kClearValue : kInitialValue;
+                const Texel8 actual = pixels[static_cast<std::size_t>(y) * kLevelExtent + x];
+                ASSERT_EQ(actual, expected) << "at (" << x << "," << y << ")";
+            }
+        }
+        Gl().EndFrame();
+    }
+
+    // The adjacent shape the first fix did NOT cover: level 0 defined, a gap, then the level being
+    // read. This one DOES get a VkImage - just one with fewer mip levels than GL thinks the texture
+    // has - so the "no VkImage" test passes and the GL level was written straight into
+    // imageSubresource.mipLevel and into a VkImageMemoryBarrier's baseMipLevel. An out-of-range
+    // subresource is a promise the driver takes at face value; the glCopyImageSubData path two
+    // functions away grew the same guard after it SIGSEGV'd inside the Adreno driver.
+    //
+    // The level being read really does hold its own data (the shadow is its only copy, since nothing
+    // ever uploaded it), so the correct answer is the uploaded bytes - not a decline.
+    TEST_F(ClearTexImageUndefinedLevelZeroScenario, ReadBackALevelSeparatedFromLevelZeroByAGap) {
+        if (!Ready()) GTEST_SKIP();
+        MakeTextureWithAGapBefore(kDefinedLevel);
+
+        ExpectAllTexels("before the clear", ReadLevel(kDefinedLevel), kInitialValue);
+
+        glClearTexImage(m_texture, kDefinedLevel, GL_RGBA, GL_UNSIGNED_BYTE, &kClearValue);
+        EXPECT_EQ(FirstGLError(), 0u) << "glClearTexImage was rejected";
+
+        ExpectAllTexels("after the clear", ReadLevel(kDefinedLevel), kClearValue);
+
+        // Level 0 is backed by the real image and must still read back from it, so the level bound is
+        // about the level and not about the texture.
+        ExpectAllTexels("level 0 after clearing level 3", ReadLevel(0), kInitialValue);
+        Gl().EndFrame();
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/CopyImagePacked16Scenario.cpp

@@ -0,0 +1,375 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/CopyImagePacked16Scenario.cpp
+// Copyright (c) 2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - glCopyImageSubData PRESERVES 16-BIT PACKED WORDS ACROSS AN ARRAY MIP LEVEL.
+//
+// The shape is lifted verbatim from the 18 Espryt bodies of KHR-GL4x.copy_image.functional
+// that survived every earlier wave: the three internal formats MobileGL can keep as 16-bit
+// packed ES storage - GL_RGB5 (stored GL_RGB565), GL_RGB5_A1, GL_RGBA4 - crossed with the
+// target pairs that put a GL_TEXTURE_2D_ARRAY's MIP LEVEL 1 on one side of the copy. On the
+// affected Mali the mirrored *_REV field order is a property of WHOLE ALLOCATIONS (shape-
+// and context-dependent; the failing 30x30x12 arrays carry it at every level, the small
+// arrays of the suite's passing iterations do not), and glCopyImageSubData - a raw
+// texel-block move - between a mirrored allocation and a plain one lands the fields
+// reversed: src word 0x0047 arrives as 0x8C20 (its 5_5_5_1 -> 1_5_5_5_REV re-encoding),
+// 0x0007 as 0x3800, byte-exact on every failing body. Uploads and readbacks of the same
+// image are clean (the driver decodes its own layout consistently), which is why only the
+// copy path ever crossed the two layouts and why the CTS's "source image was not modified"
+// checks always passed.
+//
+// The array is 30x30x12 with THREE levels and the flat endpoint is 7x7 with three levels
+// (7/3/1) because that is the allocation the failures pin - the CTS builds every functional
+// texture with FUNCTIONAL_TEST_N_LEVELS = 3 (makeTextureComplete(0, 2)) - and any deviation
+// from the measured shape might sit on the clean side of whatever allocation heuristic picks
+// the driver's layout.
+//
+// The repair under test is the packed16 storage widening
+// (PixelFormatNormalizeOptionBit::WidenPacked16Norm): where the POST probe
+// (SelfTest::CopyImageMirrorsPacked16FieldOrder) measures the mirror - or
+// MOBILEGL_ESPRYT_WIDEN_PACKED16_STORAGE forces it - the three formats are stored as
+// GL_RGB8/GL_RGBA8, leaving no 16-bit packed image for a copy to disagree about. The client
+// word still round-trips exactly: the canonical shadow is already UNorm8, and an n-bit field
+// encodes to UNorm8 and back losslessly for every n <= 8.
+//
+// This scenario runs in BOTH configurations, and both must hand back identical client words:
+//   * the ambient registrations take the narrow path on a clean driver (llvmpipe has no
+//     mirror, so Auto keeps the native 16-bit storage - the pre-existing behaviour stays
+//     covered);
+//   * the DirectGLES.WidenedPacked16. registration pins MOBILEGL_ESPRYT_WIDEN_PACKED16_STORAGE=1,
+//     which is the storage every affected device will actually run - without it the repair
+//     is unfalsifiable off-device, because no CI driver has the bug that arms it.
+// The Mali mirror itself CANNOT be reproduced here; only the on-device CTS run can show the
+// widening killing the 18 bodies. What this scenario pins is that the widened storage is
+// client-invisible: same words in, same words out, on every leg the failing bodies used.
+//
+// DirectVulkan is the control - Magma has always resolved these formats to RGBA8 - so a
+// failure on both backends means the scenario is wrong, and a failure on DirectGLES alone
+// means the widening (or the narrow path it replaces) is.
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr int kBaseSize = 30; // array level 0; level 1 is 15x15
+        constexpr int kLevel1Size = kBaseSize / 2;
+        constexpr int kLayers = 12;
+        constexpr int kFlatSize = 7; // the plain-2D / renderbuffer endpoint, level 0
+        // Copies cover the whole flat endpoint and land at (8, 8) inside the 15x15 level so
+        // that offsets are honoured, not just texel (0, 0): 8 + 7 == 15 reaches the far edge.
+        constexpr int kRegion = kFlatSize;
+        constexpr int kArrayOffset = 8;
+
+        struct PackedFormatCase {
+            GLenum internalFormat; // the spelling the CTS uses
+            GLenum transferFormat;
+            GLenum transferType;
+            const char* name;
+        };
+
+        // Per-texel varying words, every field inside its width, so a swapped field order (or
+        // a mis-addressed row) cannot cancel out the way a uniform fill would let it.
+        GLushort MakeWord(GLenum type, int i) {
+            switch (type) {
+            case GL_UNSIGNED_SHORT_5_6_5: {
+                const int r = i % 32, g = (i * 7 + 3) % 64, b = (i * 5 + 11) % 32;
+                return static_cast<GLushort>((r << 11) | (g << 5) | b);
+            }
+            case GL_UNSIGNED_SHORT_4_4_4_4: {
+                const int r = i % 16, g = (i * 3 + 1) % 16, b = (i * 7 + 5) % 16, a = (i * 5 + 2) % 16;
+                return static_cast<GLushort>((r << 12) | (g << 8) | (b << 4) | a);
+            }
+            case GL_UNSIGNED_SHORT_5_5_5_1: {
+                const int r = i % 32, g = (i * 7 + 3) % 32, b = (i * 3 + 11) % 32, a = i % 2;
+                return static_cast<GLushort>((r << 11) | (g << 6) | (b << 1) | a);
+            }
+            default:
+                return 0;
+            }
+        }
+
+        std::vector<GLushort> MakeWords(GLenum type, int count, int seed) {
+            std::vector<GLushort> words(static_cast<size_t>(count));
+            for (int i = 0; i < count; ++i) {
+                words[static_cast<size_t>(i)] = MakeWord(type, i + seed);
+            }
+            return words;
+        }
+
+        class CopyImagePacked16Scenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                // 16-bit rows are 2-byte aligned; the default 4-byte row alignment would pad
+                // every odd-width row of the 15x15 level and shear the comparisons.
+                glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
+                glPixelStorei(GL_PACK_ALIGNMENT, 2);
+                if (!CopyImageSubDataUsable()) {
+                    GTEST_SKIP() << "glCopyImageSubData is unavailable on backend " << Gl().BackendName();
+                }
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
+                glPixelStorei(GL_PACK_ALIGNMENT, 4);
+                for (const GLuint texture : m_textures) {
+                    glDeleteTextures(1, &texture);
+                }
+                m_textures.clear();
+                if (m_renderbuffer != 0) {
+                    glDeleteRenderbuffers(1, &m_renderbuffer);
+                    m_renderbuffer = 0;
+                }
+                if (m_fbo != 0) {
+                    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                    glDeleteFramebuffers(1, &m_fbo);
+                    m_fbo = 0;
+                }
+            }
+
+            bool CopyImageSubDataUsable() {
+                GLuint probe[2] = {0, 0};
+                glGenTextures(2, probe);
+                for (const GLuint texture : probe) {
+                    glBindTexture(GL_TEXTURE_2D_ARRAY, texture);
+                    glTexStorage3D(GL_TEXTURE_2D_ARRAY, 1, GL_RGBA8, 1, 1, 1);
+                }
+                glBindTexture(GL_TEXTURE_2D_ARRAY, 0);
+                while (glGetError() != GL_NO_ERROR) {
+                }
+                glCopyImageSubData(probe[0], GL_TEXTURE_2D_ARRAY, 0, 0, 0, 0, probe[1], GL_TEXTURE_2D_ARRAY, 0, 0, 0,
+                                   0, 1, 1, 1);
+                const bool usable = glGetError() == GL_NO_ERROR;
+                glDeleteTextures(2, probe);
+                return usable;
+            }
+
+            // The CTS's own mutable shape: glTexImage3D per level, filter NEAREST, THREE levels
+            // (30/15/7) with the chain clamped to them. Level 2 carries its own fill so nothing
+            // below can pass by reading a level that was never written.
+            GLuint MakeArrayTexture(const PackedFormatCase& format, const std::vector<GLushort>& level0,
+                                    const std::vector<GLushort>& level1) {
+                GLuint texture = 0;
+                glGenTextures(1, &texture);
+                m_textures.push_back(texture);
+                glBindTexture(GL_TEXTURE_2D_ARRAY, texture);
+                glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAX_LEVEL, 2);
+                glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, static_cast<GLint>(format.internalFormat), kBaseSize, kBaseSize,
+                             kLayers, 0, format.transferFormat, format.transferType, level0.data());
+                glTexImage3D(GL_TEXTURE_2D_ARRAY, 1, static_cast<GLint>(format.internalFormat), kLevel1Size,
+                             kLevel1Size, kLayers, 0, format.transferFormat, format.transferType, level1.data());
+                const int level2Size = kLevel1Size / 2;
+                const auto level2 = MakeWords(format.transferType, level2Size * level2Size * kLayers, 211);
+                glTexImage3D(GL_TEXTURE_2D_ARRAY, 2, static_cast<GLint>(format.internalFormat), level2Size,
+                             level2Size, kLayers, 0, format.transferFormat, format.transferType, level2.data());
+                glBindTexture(GL_TEXTURE_2D_ARRAY, 0);
+                return texture;
+            }
+
+            // Three levels (7/3/1) like the CTS's plain endpoints; `texels` is level 0, the one
+            // every assertion reads.
+            GLuint MakeFlatTexture(const PackedFormatCase& format, const std::vector<GLushort>& texels) {
+                GLuint texture = 0;
+                glGenTextures(1, &texture);
+                m_textures.push_back(texture);
+                glBindTexture(GL_TEXTURE_2D, texture);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 2);
+                glTexImage2D(GL_TEXTURE_2D, 0, static_cast<GLint>(format.internalFormat), kFlatSize, kFlatSize, 0,
+                             format.transferFormat, format.transferType, texels.data());
+                for (int level = 1; level <= 2; ++level) {
+                    const int size = std::max(kFlatSize >> level, 1);
+                    const auto fill = MakeWords(format.transferType, size * size, 97 + level);
+                    glTexImage2D(GL_TEXTURE_2D, level, static_cast<GLint>(format.internalFormat), size, size, 0,
+                                 format.transferFormat, format.transferType, fill.data());
+                }
+                glBindTexture(GL_TEXTURE_2D, 0);
+                return texture;
+            }
+
+            std::vector<GLushort> ReadTexImage(GLenum target, GLuint texture, int level,
+                                               const PackedFormatCase& format, size_t texelCount) {
+                std::vector<GLushort> words(texelCount, 0);
+                glBindTexture(target, texture);
+                glGetTexImage(target, level, format.transferFormat, format.transferType, words.data());
+                glBindTexture(target, 0);
+                return words;
+            }
+
+            // Every word of `got` inside the kRegion-square at (x0, y0) of a width-wide layer-0
+            // image equals the corresponding source word, and every word outside it still holds
+            // `fill`'s. Failures name the texel and both words, which is what turns a field-order
+            // regression into a one-line diagnosis.
+            void ExpectRegion(const std::vector<GLushort>& got, int width, int x0, int y0,
+                              const std::vector<GLushort>& source, int sourceWidth, int sourceX0, int sourceY0,
+                              const std::vector<GLushort>& fill, const char* what) {
+                for (int y = 0; y < width; ++y) {
+                    for (int x = 0; x < width && static_cast<size_t>(y * width + x) < got.size(); ++x) {
+                        const bool inRegion =
+                            x >= x0 && x < x0 + kRegion && y >= y0 && y < y0 + kRegion;
+                        const GLushort actual = got[static_cast<size_t>(y * width + x)];
+                        const GLushort expected =
+                            inRegion ? source[static_cast<size_t>((sourceY0 + y - y0) * sourceWidth + sourceX0 +
+                                                                  (x - x0))]
+                                     : fill[static_cast<size_t>(y * width + x)];
+                        EXPECT_EQ(actual, expected)
+                            << what << ": texel (" << x << ", " << y << ")"
+                            << (inRegion ? " (copied)" : " (untouched)") << " holds 0x" << std::hex << actual
+                            << ", expected 0x" << expected;
+                        if (actual != expected) return; // one texel names the defect; 224 more would bury it
+                    }
+                }
+            }
+
+            std::vector<GLuint> m_textures;
+            GLuint m_renderbuffer = 0;
+            GLuint m_fbo = 0;
+        };
+
+        const PackedFormatCase kFormats[] = {
+            {GL_RGB5, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, "rgb5"},
+            {GL_RGB5_A1, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, "rgb5_a1"},
+            {GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, "rgba4"},
+        };
+
+        // texture_2d (the ES image behind GL_TEXTURE_RECTANGLE too) -> the array's level 1:
+        // the array-as-destination direction of 12 of the 18 failing bodies.
+        TEST_F(CopyImagePacked16Scenario, FlatImageLandsInArrayMipLevelIntact) {
+            if (!Ready() || IsSkipped()) return;
+            for (const PackedFormatCase& format : kFormats) {
+                const auto level0 = MakeWords(format.transferType, kBaseSize * kBaseSize * kLayers, 1);
+                const auto level1 = MakeWords(format.transferType, kLevel1Size * kLevel1Size * kLayers, 7);
+                const auto flat = MakeWords(format.transferType, kFlatSize * kFlatSize, 131);
+                const GLuint array = MakeArrayTexture(format, level0, level1);
+                const GLuint source = MakeFlatTexture(format, flat);
+                ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR)) << format.name << ": setup failed";
+
+                glCopyImageSubData(source, GL_TEXTURE_2D, 0, 0, 0, 0, array, GL_TEXTURE_2D_ARRAY, 1, kArrayOffset,
+                                   kArrayOffset, 0, kRegion, kRegion, 1);
+                ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR))
+                    << format.name << ": glCopyImageSubData raised an error";
+
+                const auto got = ReadTexImage(GL_TEXTURE_2D_ARRAY, array, 1, format,
+                                              static_cast<size_t>(kLevel1Size) * kLevel1Size * kLayers);
+                ExpectRegion(got, kLevel1Size, kArrayOffset, kArrayOffset, flat, kFlatSize, 0, 0, level1,
+                             (std::string("2d->2d_array level 1, ") + format.name).c_str());
+                // The source must not have moved - the CTS asserts this before it ever looks at
+                // the destination, and it is what pins the corruption to the copy itself.
+                const auto sourceAfter =
+                    ReadTexImage(GL_TEXTURE_2D, source, 0, format, static_cast<size_t>(kFlatSize) * kFlatSize);
+                ExpectRegion(sourceAfter, kFlatSize, 0, 0, flat, kFlatSize, 0, 0, flat,
+                             (std::string("source after 2d->2d_array, ") + format.name).c_str());
+            }
+        }
+
+        // The array's level 1 -> texture_2d: the array-as-source direction of the other 6
+        // bodies (2d_array -> 3d and 2d_array -> rectangle both read the level-1 array).
+        TEST_F(CopyImagePacked16Scenario, ArrayMipLevelLandsInFlatImageIntact) {
+            if (!Ready() || IsSkipped()) return;
+            for (const PackedFormatCase& format : kFormats) {
+                const auto level0 = MakeWords(format.transferType, kBaseSize * kBaseSize * kLayers, 1);
+                const auto level1 = MakeWords(format.transferType, kLevel1Size * kLevel1Size * kLayers, 7);
+                const auto fill = MakeWords(format.transferType, kFlatSize * kFlatSize, 131);
+                const GLuint array = MakeArrayTexture(format, level0, level1);
+                const GLuint destination = MakeFlatTexture(format, fill);
+                ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR)) << format.name << ": setup failed";
+
+                glCopyImageSubData(array, GL_TEXTURE_2D_ARRAY, 1, kArrayOffset, kArrayOffset, 0, destination,
+                                   GL_TEXTURE_2D, 0, 0, 0, 0, kRegion, kRegion, 1);
+                ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR))
+                    << format.name << ": glCopyImageSubData raised an error";
+
+                const auto got = ReadTexImage(GL_TEXTURE_2D, destination, 0, format,
+                                              static_cast<size_t>(kFlatSize) * kFlatSize);
+                ExpectRegion(got, kFlatSize, 0, 0, level1, kLevel1Size, kArrayOffset, kArrayOffset, fill,
+                             (std::string("2d_array level 1 -> 2d, ") + format.name).c_str());
+            }
+        }
+
+        // renderbuffer -> the array's level 1: the leg the remaining 3 bodies use, and the one
+        // that requires the renderbuffer's ES storage to move together with the textures' -
+        // glCopyImageSubData needs both endpoints in the same driver format, so a widening that
+        // reached textures alone would break exactly here.
+        TEST_F(CopyImagePacked16Scenario, RenderbufferLandsInArrayMipLevelIntact) {
+            if (!Ready() || IsSkipped()) return;
+            for (const PackedFormatCase& format : kFormats) {
+                const auto level0 = MakeWords(format.transferType, kBaseSize * kBaseSize * kLayers, 1);
+                const auto level1 = MakeWords(format.transferType, kLevel1Size * kLevel1Size * kLayers, 7);
+                const GLuint array = MakeArrayTexture(format, level0, level1);
+
+                if (m_renderbuffer == 0) glGenRenderbuffers(1, &m_renderbuffer);
+                glBindRenderbuffer(GL_RENDERBUFFER, m_renderbuffer);
+                glRenderbufferStorage(GL_RENDERBUFFER, format.internalFormat, kFlatSize, kFlatSize);
+                if (m_fbo == 0) glGenFramebuffers(1, &m_fbo);
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, m_renderbuffer);
+                ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE))
+                    << format.name << ": the renderbuffer is not attachable";
+                // Field values picked to encode exactly in the narrow fields AND in their
+                // UNorm8 expansions, so the expected word is the same whichever storage the
+                // configuration picked - which is the point of the whole scenario.
+                const int maxG = format.transferType == GL_UNSIGNED_SHORT_5_6_5 ? 63 : 31;
+                const int max = format.transferType == GL_UNSIGNED_SHORT_4_4_4_4 ? 15 : 31;
+                const int maxGreen = format.transferType == GL_UNSIGNED_SHORT_4_4_4_4 ? 15 : maxG;
+                const GLfloat clearColor[4] = {static_cast<GLfloat>(8 % (max + 1)) / max,
+                                               static_cast<GLfloat>(maxGreen / 2) / maxGreen,
+                                               static_cast<GLfloat>(max - 2) / max, 1.0f};
+                // The context is shared with every scenario in this process; a scissor left on
+                // would clip the clear and hand the copy undefined renderbuffer texels.
+                glDisable(GL_SCISSOR_TEST);
+                glClearBufferfv(GL_COLOR, 0, clearColor);
+                glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR)) << format.name << ": setup failed";
+
+                glCopyImageSubData(m_renderbuffer, GL_RENDERBUFFER, 0, 0, 0, 0, array, GL_TEXTURE_2D_ARRAY, 1,
+                                   kArrayOffset, kArrayOffset, 0, kRegion, kRegion, 1);
+                ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR))
+                    << format.name << ": glCopyImageSubData raised an error";
+
+                GLushort clearedWord = 0;
+                switch (format.transferType) {
+                case GL_UNSIGNED_SHORT_5_6_5:
+                    clearedWord = static_cast<GLushort>((8 << 11) | ((maxGreen / 2) << 5) | (max - 2));
+                    break;
+                case GL_UNSIGNED_SHORT_5_5_5_1:
+                    clearedWord = static_cast<GLushort>((8 << 11) | ((maxGreen / 2) << 6) | ((max - 2) << 1) | 1);
+                    break;
+                case GL_UNSIGNED_SHORT_4_4_4_4:
+                    clearedWord = static_cast<GLushort>((8 << 12) | ((maxGreen / 2) << 8) | ((max - 2) << 4) | 15);
+                    break;
+                default:
+                    break;
+                }
+                std::vector<GLushort> expectedRegion(static_cast<size_t>(kRegion) * kRegion, clearedWord);
+                const auto got = ReadTexImage(GL_TEXTURE_2D_ARRAY, array, 1, format,
+                                              static_cast<size_t>(kLevel1Size) * kLevel1Size * kLayers);
+                ExpectRegion(got, kLevel1Size, kArrayOffset, kArrayOffset, expectedRegion, kRegion, 0, 0, level1,
+                             (std::string("renderbuffer -> 2d_array level 1, ") + format.name).c_str());
+            }
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/DualSourceBlendScenario.cpp

@@ -0,0 +1,238 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/DualSourceBlendScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - A DUAL-SOURCE BLEND DRAW HAS TO SURVIVE ON EVERY DRIVER.
+//
+// GL_SRC1_COLOR / GL_ONE_MINUS_SRC1_COLOR / GL_SRC1_ALPHA / GL_ONE_MINUS_SRC1_ALPHA
+// (ARB_blend_func_extended, core since 3.3) need a backend capability that not every device has:
+// GL_EXT_blend_func_extended on the ES driver, or the dualSrcBlend device feature on Vulkan. When
+// the capability IS there both backends translate the factors properly, and that has always
+// worked. When it is NOT, both backends used to THROW_EXCEPTION at draw time - and
+// MG_Util/Types.h's THROW_EXCEPTION is a plain `throw`, with no catch anywhere in MG_Impl or
+// MG_Backend, so the exception unwound out through the C GL ABI and killed the process. An
+// application asking for a blend factor the device cannot do is a picture problem, never a reason
+// to take the process down.
+//
+// Both are now a DECLINE: the attachment is drawn with blending off and neutral One/Zero factors,
+// and the loss is logged once. So a dual-source draw has exactly two defined outcomes, and this
+// scenario pins that it lands on one of them and never on a crash:
+//
+//   capability present - src0 * src1 + dst * (1 - src1)
+//   capability absent  - src0, written straight through
+//
+// What each CI lane actually reaches: lavapipe has dualSrcBlend, so the DirectVulkan lane runs the
+// whole sequence and measures the blend. Mesa's GLES front end on llvmpipe has no
+// GL_EXT_blend_func_extended, so the ESSL stage carrying `layout(index = 1)` never compiles and the
+// program renders nothing - the DirectGLES lane therefore SKIPS on the capability probe in SetUp
+// rather than measuring a picture the driver never produced. The DECLINE arm itself - the path this
+// scenario exists for - is unit-tested against stubbed capabilities in
+// MG_Test/Framebuffer/FramebufferTest.cpp (DualSourceBlendIsDeclinedRatherThanThrownWhenTheExtensionIsMissing),
+// which is the only place it can be reached without a driver that lacks the extension.
+//
+// The Vulkan half has a second edge the last case covers: the dual-source VUIDs
+// (VUID-VkPipelineColorBlendAttachmentState-srcColorBlendFactor-00608 and its three siblings)
+// forbid a VK_BLEND_FACTOR_SRC1_* anywhere in VkPipelineColorBlendAttachmentState without the
+// feature, whatever blendEnable says - so leaving the factors in place while clearing the enable
+// would still be invalid pipeline state.
+
+#include <cstdint>
+#include <string>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr int kExtent = 16;
+
+        constexpr const char* kVertexSource = R"(#version 330 core
+void main()
+{
+    switch (gl_VertexID)
+    {
+      case 0: gl_Position = vec4(-1.0, 1.0, 0.0, 1.0); break;
+      case 1: gl_Position = vec4( 1.0, 1.0, 0.0, 1.0); break;
+      case 2: gl_Position = vec4(-1.0,-1.0, 0.0, 1.0); break;
+      case 3: gl_Position = vec4( 1.0,-1.0, 0.0, 1.0); break;
+    }
+}
+)";
+
+        // Two outputs on the SAME location, indices 0 and 1: the shader-side spelling of
+        // dual-source output (GLSL 3.30 4.4.2, the `index` layout qualifier). No
+        // glBindFragDataLocationIndexed needed, which keeps the program buildable through the
+        // harness's compile-and-link helper.
+        constexpr const char* kDualSourceFragmentSource = R"(#version 330 core
+uniform vec4 uSrc0;
+uniform vec4 uSrc1;
+layout(location = 0, index = 0) out vec4 fragColor0;
+layout(location = 0, index = 1) out vec4 fragColor1;
+void main()
+{
+    fragColor0 = uSrc0;
+    fragColor1 = uSrc1;
+}
+)";
+
+        class DualSourceBlendScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                glGenVertexArrays(1, &m_vao);
+                glGenRenderbuffers(1, &m_renderbuffer);
+                glBindRenderbuffer(GL_RENDERBUFFER, m_renderbuffer);
+                glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, kExtent, kExtent);
+                glGenFramebuffers(1, &m_fbo);
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, m_renderbuffer);
+                ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE));
+
+                std::string error;
+                m_program = CompileProgram(kVertexSource, kDualSourceFragmentSource, &error);
+                m_programError = error;
+                glViewport(0, 0, kExtent, kExtent);
+                glDisable(GL_SCISSOR_TEST);
+                glDisable(GL_DEPTH_TEST);
+
+                // Capability probe, not an assertion. A GL link that succeeded is not proof that
+                // the BACKEND can run the program: DirectGLES transpiles to ESSL lazily at first
+                // use, and GLSL ES has no `index` layout qualifier outside
+                // GL_EXT_blend_func_extended, so on a driver without it the stage never compiles
+                // and the draw renders nothing. One unblended white draw tells the two apart, and
+                // the cases skip rather than measure a picture the driver never produced.
+                if (m_program != 0) {
+                    glDisable(GL_BLEND);
+                    glBlendFunc(GL_ONE, GL_ZERO);
+                    Draw(/*src0=*/1.0f, /*src1=*/1.0f);
+                    glFinish();
+                    const Image probe = ReadPixels(kExtent, kExtent);
+                    m_programRenders =
+                        !probe.Empty() && static_cast<int>(probe.At(kExtent / 2, kExtent / 2).r) > 245;
+                }
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glDisable(GL_BLEND);
+                glBlendFunc(GL_ONE, GL_ZERO);
+                glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                if (m_fbo != 0) glDeleteFramebuffers(1, &m_fbo);
+                if (m_renderbuffer != 0) glDeleteRenderbuffers(1, &m_renderbuffer);
+                if (m_program != 0) glDeleteProgram(m_program);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+            }
+
+            void Draw(float src0, float src1) {
+                glUseProgram(m_program);
+                glUniform4f(glGetUniformLocation(m_program, "uSrc0"), src0, src0, src0, 1.0f);
+                glUniform4f(glGetUniformLocation(m_program, "uSrc1"), src1, src1, src1, 1.0f);
+                glBindVertexArray(m_vao);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glBindVertexArray(0);
+                glUseProgram(0);
+            }
+
+            // Both cases share this gate: nothing below can be measured on a backend that cannot
+            // run a dual-source fragment program at all. Returns the skip reason, empty when the
+            // program runs - NOT a void helper that calls GTEST_SKIP itself, because GTEST_SKIP
+            // expands to a `return` and would leave only the HELPER, letting the case run its
+            // assertions anyway and report Failed instead of Skipped.
+            std::string WhyTheProgramCannotRun() const {
+                if (m_program == 0) {
+                    return "this driver cannot build a dual-source fragment shader: " + m_programError;
+                }
+                if (!m_programRenders) {
+                    return "this backend links a dual-source fragment program but renders nothing with it "
+                           "(GLSL ES has no `index` layout qualifier without GL_EXT_blend_func_extended)";
+                }
+                return {};
+            }
+
+            GLuint m_renderbuffer = 0;
+            GLuint m_fbo = 0;
+            GLuint m_vao = 0;
+            unsigned int m_program = 0;
+            bool m_programRenders = false;
+            std::string m_programError;
+        };
+
+    } // namespace
+
+    // The whole point of the scenario: this sequence used to be a process kill on any device
+    // without the capability, and it has to be a picture either way.
+    //
+    // dst is black, src0 is white and src1 is mid-grey, with SRC1_COLOR / ONE_MINUS_SRC1_COLOR.
+    //   blended  = 1.0 * 0.5 + 0.0 * 0.5 = 0.5  -> ~128
+    //   declined = 1.0                          ->  255
+    // Anything else means the factors were mistranslated rather than either honoured or declined.
+    TEST_F(DualSourceBlendScenario, DualSourceBlendDrawProducesOneOfTheTwoDefinedResults) {
+        if (!Ready()) GTEST_SKIP();
+        if (const std::string reason = WhyTheProgramCannotRun(); !reason.empty()) GTEST_SKIP() << reason;
+
+        glDisable(GL_BLEND);
+        glBlendFunc(GL_ONE, GL_ZERO);
+        Draw(/*src0=*/0.0f, /*src1=*/0.0f);
+
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC1_COLOR, GL_ONE_MINUS_SRC1_COLOR);
+        EXPECT_EQ(FirstGLError(), 0u) << "glBlendFunc must accept the GL_SRC1_* factors - they are core since 3.3";
+        Draw(/*src0=*/1.0f, /*src1=*/0.5f);
+        glFinish();
+        glDisable(GL_BLEND);
+        EXPECT_EQ(FirstGLError(), 0u) << "the dual-source draw left a GL error behind";
+
+        const Image image = ReadPixels(kExtent, kExtent);
+        ASSERT_FALSE(image.Empty());
+        const Rgba8 centre = image.At(kExtent / 2, kExtent / 2);
+        const int red = static_cast<int>(centre.r);
+        const bool blended = red > 100 && red < 160;
+        const bool declined = red > 245;
+        EXPECT_TRUE(blended || declined)
+            << "got " << centre << ", which is neither the dual-source blend (~128) nor the declined "
+            << "straight-through source (255) - the SRC1 factors were mistranslated";
+        Gl().EndFrame();
+    }
+
+    // The same factors with blending DISABLED. Nothing may blend, and on the Vulkan side nothing
+    // may reach VkPipelineColorBlendAttachmentState carrying a VK_BLEND_FACTOR_SRC1_* on a device
+    // without dualSrcBlend - the VUIDs bind to the struct, not to blendEnable. The picture is the
+    // source either way, so this case is really "no crash, no error, no surprise".
+    TEST_F(DualSourceBlendScenario, DualSourceFactorsWithBlendingDisabledJustWriteTheSource) {
+        if (!Ready()) GTEST_SKIP();
+        if (const std::string reason = WhyTheProgramCannotRun(); !reason.empty()) GTEST_SKIP() << reason;
+
+        glDisable(GL_BLEND);
+        glBlendFunc(GL_ONE, GL_ZERO);
+        Draw(/*src0=*/0.0f, /*src1=*/0.0f);
+
+        glBlendFunc(GL_SRC1_ALPHA, GL_ONE_MINUS_SRC1_ALPHA);
+        Draw(/*src0=*/1.0f, /*src1=*/0.25f);
+        glFinish();
+        EXPECT_EQ(FirstGLError(), 0u) << "a draw with SRC1 factors and blending off left a GL error behind";
+
+        const Image image = ReadPixels(kExtent, kExtent);
+        ASSERT_FALSE(image.Empty());
+        const Rgba8 centre = image.At(kExtent / 2, kExtent / 2);
+        EXPECT_GT(static_cast<int>(centre.r), 245)
+            << "got " << centre << ": blending is disabled, so the source has to be written straight through";
+        Gl().EndFrame();
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/IntegerBorderColorScenario.cpp

@@ -0,0 +1,391 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/IntegerBorderColorScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - AN INTEGER GL_TEXTURE_BORDER_COLOR REACHES AN isampler2D AS AN INTEGER.
+//
+// KHR-GL46.texture_border_clamp.Texture2D{R32I,R32UI} (and the 2DArray/3D siblings) set the border
+// colour with glSamplerParameterIiv/Iuiv, sample outside the texture through an integer sampler and
+// expect the value back. MobileGL returned 1132396544 on Espryt - which is 0x437F0000, the IEEE-754
+// bits of 255.0f, i.e. the float border-colour register read through an integer sampler - and 0 on
+// Magma, where the border fell through to VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK.
+//
+// Two independent halves, and this scenario covers both because it goes through the frontend:
+//
+//   * the STATE had no record of which entry point wrote the border colour. All three
+//     representations are kept numerically in step, so the value alone cannot say whether the
+//     application called glTexParameterfv or glTexParameterIiv.
+//   * each backend then had exactly one border-colour call site: glTexParameterfv /
+//     glSamplerParameterfv on DirectGLES, and a snap-to-one-of-four-predefined-values on
+//     DirectVulkan that never emitted the VK_BORDER_COLOR_INT_* family at all.
+//
+// The border value is deliberately outside every predefined VkBorderColor and outside anything a
+// float register could round-trip: (255, -1, 7, 3) is neither transparent black, nor opaque black,
+// nor opaque white, so on DirectVulkan it can only be delivered through VK_EXT_custom_border_color.
+// That makes the scenario a real test of the extension path on lavapipe rather than a palette hit.
+//
+// Both an integer image view and an integer border colour are involved, which is the other half of
+// the Vulkan rule: VK_BORDER_COLOR_FLOAT_* on an integer image view is undefined behaviour
+// regardless of the value, so even a border of (0,0,0,1) has to resolve to INT_OPAQUE_BLACK.
+// InsideTexelsAreUnaffected is what keeps that from being asserted vacuously.
+
+#include <array>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr int kOutputWidth = 8;
+        constexpr int kOutputHeight = 8;
+
+        // The texture's own texel, and the border. Neither is a Vulkan palette entry, and the border
+        // is deliberately not derivable from the texel.
+        constexpr std::int32_t kInsideTexel[4] = {11, 22, 33, 44};
+        constexpr std::int32_t kBorderColor[4] = {255, -1, 7, 3};
+
+        constexpr const char* kVertexSource = R"(#version 330 core
+void main()
+{
+    switch (gl_VertexID)
+    {
+      case 0: gl_Position = vec4(-1.0, 1.0, 0.0, 1.0); break;
+      case 1: gl_Position = vec4( 1.0, 1.0, 0.0, 1.0); break;
+      case 2: gl_Position = vec4(-1.0,-1.0, 0.0, 1.0); break;
+      case 3: gl_Position = vec4( 1.0,-1.0, 0.0, 1.0); break;
+    }
+}
+)";
+
+        // One channel per draw, so a failure names the component that is wrong. The coordinate is a
+        // uniform rather than a literal so the same program serves the border sample and the inside
+        // sample and nothing can be constant-folded differently between them.
+        std::string FragmentSource(int channel) {
+            static const char* kChannels[4] = {"x", "y", "z", "w"};
+            return std::string("#version 330 core\n\nuniform isampler2D smp;\nuniform vec2 uCoord;\n\n"
+                               "out int out_color;\n\nvoid main()\n{\n    out_color = texture(smp, uCoord).") +
+                   kChannels[channel] + ";\n}\n";
+        }
+
+        class IntegerBorderColorScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+
+                // 2x2 RGBA32I. Integer textures are not filterable, so NEAREST is mandatory.
+                const std::int32_t texels[4][4] = {{kInsideTexel[0], kInsideTexel[1], kInsideTexel[2], kInsideTexel[3]},
+                                                  {kInsideTexel[0], kInsideTexel[1], kInsideTexel[2], kInsideTexel[3]},
+                                                  {kInsideTexel[0], kInsideTexel[1], kInsideTexel[2], kInsideTexel[3]},
+                                                  {kInsideTexel[0], kInsideTexel[1], kInsideTexel[2], kInsideTexel[3]}};
+                glGenTextures(1, &m_sourceTexture);
+                glBindTexture(GL_TEXTURE_2D, m_sourceTexture);
+                glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA32I, 2, 2);
+                glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 2, 2, GL_RGBA_INTEGER, GL_INT, texels);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+                ASSERT_EQ(FirstGLError(), 0u) << "source texture setup left a GL error behind";
+
+                // 8x8 R32I render target: an integer readback, so nothing is normalized on the way
+                // out and a wrong value is reported as the number it actually was.
+                glGenTextures(1, &m_outputTexture);
+                glBindTexture(GL_TEXTURE_2D, m_outputTexture);
+                glTexStorage2D(GL_TEXTURE_2D, 1, GL_R32I, kOutputWidth, kOutputHeight);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                glGenFramebuffers(1, &m_fbo);
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_outputTexture, 0);
+                ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), GLenum(GL_FRAMEBUFFER_COMPLETE));
+                glGenVertexArrays(1, &m_vao);
+                ASSERT_EQ(FirstGLError(), 0u) << "output framebuffer setup left a GL error behind";
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                if (m_sampler != 0) {
+                    glBindSampler(0, 0);
+                    glDeleteSamplers(1, &m_sampler);
+                    m_sampler = 0;
+                }
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                if (m_fbo != 0) glDeleteFramebuffers(1, &m_fbo);
+                if (m_outputTexture != 0) glDeleteTextures(1, &m_outputTexture);
+                if (m_sourceTexture != 0) glDeleteTextures(1, &m_sourceTexture);
+                if (m_narrowTexture != 0) glDeleteTextures(1, &m_narrowTexture);
+                glBindFramebuffer(GL_FRAMEBUFFER, 0);
+            }
+
+            // Samples `coord` through the integer sampler and returns every texel the draw wrote.
+            std::vector<std::int32_t> RenderChannel(int channel, float coordX, float coordY) {
+                const std::string fragment = FragmentSource(channel);
+                std::string error;
+                const unsigned int program = CompileProgram(kVertexSource, fragment.c_str(), &error);
+                if (program == 0) {
+                    ADD_FAILURE() << "channel " << channel << ": program did not build: " << error;
+                    return {};
+                }
+
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glViewport(0, 0, kOutputWidth, kOutputHeight);
+                glDisable(GL_SCISSOR_TEST);
+                glDisable(GL_DEPTH_TEST);
+                // A clear value nothing under test can produce, so an undrawn target is not mistaken
+                // for a correct one.
+                const GLint clearValue[4] = {-559038737, 0, 0, 0};
+                glClearBufferiv(GL_COLOR, 0, clearValue);
+
+                glUseProgram(program);
+                glActiveTexture(GL_TEXTURE0);
+                glBindTexture(GL_TEXTURE_2D, m_sourceTexture);
+                glUniform1i(glGetUniformLocation(program, "smp"), 0);
+                glUniform2f(glGetUniformLocation(program, "uCoord"), coordX, coordY);
+                glBindVertexArray(m_vao);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glBindVertexArray(0);
+
+                std::vector<std::int32_t> texels(static_cast<std::size_t>(kOutputWidth) * kOutputHeight, 0);
+                glReadPixels(0, 0, kOutputWidth, kOutputHeight, GL_RED_INTEGER, GL_INT, texels.data());
+                glUseProgram(0);
+                glDeleteProgram(program);
+                return texels;
+            }
+
+            void ExpectAllTexels(const char* what, int channel, std::int32_t expected,
+                                 const std::vector<std::int32_t>& texels) {
+                if (texels.empty()) return;
+                std::size_t offenders = 0;
+                std::int32_t firstBad = 0;
+                for (const std::int32_t texel : texels) {
+                    if (texel == expected) continue;
+                    if (offenders == 0) firstBad = texel;
+                    ++offenders;
+                }
+                EXPECT_EQ(offenders, 0u) << what << " component " << channel << " returned " << firstBad
+                                         << " instead of " << expected << " (" << offenders << " of " << texels.size()
+                                         << " texels wrong)";
+            }
+
+            // Every component of the border, in one place, so both the texture-object and the
+            // sampler-object case assert exactly the same thing.
+            void ExpectBorderIsDelivered(const char* what) {
+                for (int channel = 0; channel < 4; ++channel) {
+                    // (-0.5, -0.5) is a full texture width outside the image on both axes, so
+                    // CLAMP_TO_BORDER can only answer with the border colour.
+                    const std::vector<std::int32_t> texels = RenderChannel(channel, -0.5f, -0.5f);
+                    EXPECT_EQ(FirstGLError(), 0u) << what << ": the border draw left a GL error behind";
+                    ExpectAllTexels(what, channel, kBorderColor[channel], texels);
+                }
+            }
+
+            // A narrow-format source built on demand, for the clamp cases. Returns the texture, which
+            // the caller owns until TearDown deletes it through m_narrowTexture.
+            void MakeNarrowSource(GLenum internalFormat, GLenum clientFormat, const void* texels,
+                                  const GLint* border, bool borderIsUnsigned) {
+                glGenTextures(1, &m_narrowTexture);
+                glBindTexture(GL_TEXTURE_2D, m_narrowTexture);
+                glTexStorage2D(GL_TEXTURE_2D, 1, internalFormat, 2, 2);
+                glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 2, 2, clientFormat,
+                                internalFormat == GL_R8UI ? GL_UNSIGNED_BYTE : GL_BYTE, texels);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+                if (borderIsUnsigned) {
+                    const GLuint asUnsigned[4] = {static_cast<GLuint>(border[0]), static_cast<GLuint>(border[1]),
+                                                  static_cast<GLuint>(border[2]), static_cast<GLuint>(border[3])};
+                    glTexParameterIuiv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, asUnsigned);
+                } else {
+                    glTexParameterIiv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border);
+                }
+                ASSERT_EQ(FirstGLError(), 0u) << "narrow source setup left a GL error behind";
+            }
+
+            // The narrow sources are single-channel, so only component 0 carries anything, and the
+            // sampler declaration has to match the format's signedness.
+            std::vector<std::int32_t> RenderNarrowBorder(bool isUnsignedSampler) {
+                const std::string fragment =
+                    std::string("#version 330 core\n\nuniform ") + (isUnsignedSampler ? "usampler2D" : "isampler2D") +
+                    " smp;\nuniform vec2 uCoord;\n\nout int out_color;\n\nvoid main()\n{\n"
+                    "    out_color = int(texture(smp, uCoord).x);\n}\n";
+                std::string error;
+                const unsigned int program = CompileProgram(kVertexSource, fragment.c_str(), &error);
+                if (program == 0) {
+                    ADD_FAILURE() << "narrow-border program did not build: " << error;
+                    return {};
+                }
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glViewport(0, 0, kOutputWidth, kOutputHeight);
+                glDisable(GL_SCISSOR_TEST);
+                glDisable(GL_DEPTH_TEST);
+                const GLint clearValue[4] = {-559038737, 0, 0, 0};
+                glClearBufferiv(GL_COLOR, 0, clearValue);
+                glUseProgram(program);
+                glActiveTexture(GL_TEXTURE0);
+                glBindTexture(GL_TEXTURE_2D, m_narrowTexture);
+                glUniform1i(glGetUniformLocation(program, "smp"), 0);
+                glUniform2f(glGetUniformLocation(program, "uCoord"), -0.5f, -0.5f);
+                glBindVertexArray(m_vao);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glBindVertexArray(0);
+                std::vector<std::int32_t> texels(static_cast<std::size_t>(kOutputWidth) * kOutputHeight, 0);
+                glReadPixels(0, 0, kOutputWidth, kOutputHeight, GL_RED_INTEGER, GL_INT, texels.data());
+                glUseProgram(0);
+                glDeleteProgram(program);
+                return texels;
+            }
+
+            GLuint m_sourceTexture = 0;
+            GLuint m_outputTexture = 0;
+            GLuint m_fbo = 0;
+            GLuint m_vao = 0;
+            GLuint m_sampler = 0;
+            GLuint m_narrowTexture = 0;
+        };
+
+    } // namespace
+
+    // The floor, and the control that keeps the two tests below from passing vacuously: an INSIDE
+    // sample has to fetch the texture's own texel. If this fails the sampler, the shader or the
+    // integer readback is broken and nothing about the border colour has been measured.
+    TEST_F(IntegerBorderColorScenario, InsideTexelsAreUnaffectedByTheBorderColour) {
+        if (!Ready()) GTEST_SKIP();
+
+        glBindTexture(GL_TEXTURE_2D, m_sourceTexture);
+        glTexParameterIiv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, kBorderColor);
+        ASSERT_EQ(FirstGLError(), 0u) << "glTexParameterIiv(GL_TEXTURE_BORDER_COLOR) was rejected";
+
+        for (int channel = 0; channel < 4; ++channel) {
+            const std::vector<std::int32_t> texels = RenderChannel(channel, 0.5f, 0.5f);
+            EXPECT_EQ(FirstGLError(), 0u) << "the inside draw left a GL error behind";
+            ExpectAllTexels("inside sample", channel, kInsideTexel[channel], texels);
+        }
+        Gl().EndFrame();
+    }
+
+    // The regression, texture-object spelling. glTexParameterIiv is the entry point the frontend
+    // already accepted and then flattened into the same FloatVec4 every other spelling wrote.
+    TEST_F(IntegerBorderColorScenario, TexParameterIivBorderColourSurvivesToAnIntegerSampler) {
+        if (!Ready()) GTEST_SKIP();
+
+        glBindTexture(GL_TEXTURE_2D, m_sourceTexture);
+        glTexParameterIiv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, kBorderColor);
+        ASSERT_EQ(FirstGLError(), 0u) << "glTexParameterIiv(GL_TEXTURE_BORDER_COLOR) was rejected";
+
+        ExpectBorderIsDelivered("glTexParameterIiv");
+        Gl().EndFrame();
+    }
+
+    // The regression, sampler-object spelling - which is the one the conformance cases actually use,
+    // and a separate code path in both backends (BackendSamplerObject::Sync on DirectGLES, and the
+    // sampler cache key on DirectVulkan, where a border colour that is not part of the key would
+    // alias two samplers that differ only in it).
+    TEST_F(IntegerBorderColorScenario, SamplerParameterIivBorderColourSurvivesToAnIntegerSampler) {
+        if (!Ready()) GTEST_SKIP();
+
+        glGenSamplers(1, &m_sampler);
+        ASSERT_NE(m_sampler, 0u);
+        glSamplerParameteri(m_sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glSamplerParameteri(m_sampler, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glSamplerParameteri(m_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+        glSamplerParameteri(m_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+        glSamplerParameterIiv(m_sampler, GL_TEXTURE_BORDER_COLOR, kBorderColor);
+        ASSERT_EQ(FirstGLError(), 0u) << "sampler-object setup was rejected";
+
+        // The texture object carries a DIFFERENT border colour, so a pass here cannot come from the
+        // texture's own state leaking through: GL 4.6 core 8.10 says a bound sampler object's state
+        // wins over the texture's for every sampling parameter.
+        const std::int32_t decoyBorder[4] = {0, 0, 0, 0};
+        glBindTexture(GL_TEXTURE_2D, m_sourceTexture);
+        glTexParameterIiv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, decoyBorder);
+        glBindSampler(0, m_sampler);
+        ASSERT_EQ(FirstGLError(), 0u) << "binding the sampler object was rejected";
+
+        ExpectBorderIsDelivered("glSamplerParameterIiv");
+        glBindSampler(0, 0);
+        Gl().EndFrame();
+    }
+
+    // GL 4.6 core 8.14.2: "For floating-point and integer formats, border values are clamped to the
+    // representable range of the format." A border of 300 on a GL_R8I texture is 127, not 300 - and
+    // VK_BORDER_COLOR_INT_CUSTOM_EXT delivers whatever it is handed, with format VK_FORMAT_UNDEFINED
+    // there is nothing for the driver to clamp against, so the clamp has to happen before the value
+    // leaves MobileGL. DirectGLES gets it right for free (the ES driver knows the texture format),
+    // which is what makes this a cross-backend divergence and not only a spec one.
+    TEST_F(IntegerBorderColorScenario, ASignedIntegerBorderIsClampedToTheFormatsRepresentableRange) {
+        if (!Ready()) GTEST_SKIP();
+
+        const std::int8_t texels[4] = {1, 1, 1, 1};
+        const GLint border[4] = {300, 0, 0, 1};
+        MakeNarrowSource(GL_R8I, GL_RED_INTEGER, texels, border, /*borderIsUnsigned=*/false);
+
+        const std::vector<std::int32_t> sampled = RenderNarrowBorder(/*isUnsignedSampler=*/false);
+        EXPECT_EQ(FirstGLError(), 0u) << "the clamped-border draw left a GL error behind";
+        ExpectAllTexels("R8I border 300", 0, 127, sampled);
+        Gl().EndFrame();
+    }
+
+    // The reciprocal half, and the one that decides how the two integer forms relate: -1 written
+    // through glTexParameterIiv against an UNSIGNED format. GL 4.6 core 8.10 stores an "I"-form
+    // border unmodified with an integer internal data type and defines no sign conversion between
+    // the two integer forms, so the stored bits are reinterpreted in the sampled format's own
+    // signedness: 0xFFFFFFFF, clamped to the format's maximum of 255.
+    //
+    // That is the DRIVER's answer, established by running this case rather than by reading the spec:
+    // clamping to 0 is an equally defensible reading of the same paragraph, and DirectVulkan can be
+    // made to produce either - but DirectGLES forwards the value to the ES driver verbatim and cannot
+    // deviate, so choosing 0 would mean the same program sampling 0 on Magma and 255 on Espryt. The
+    // whole point of carrying the border colour's form is to stop that class of divergence, so the
+    // backends agree on the driver's answer.
+    //
+    // The clamp itself is still doing the work: without it the value reaches the driver as
+    // 0xFFFFFFFF against a format whose maximum is 255, with format VK_FORMAT_UNDEFINED and so
+    // nothing for the driver to clamp against.
+    TEST_F(IntegerBorderColorScenario, ANegativeBorderOnAnUnsignedFormatClampsToTheFormatsMaximum) {
+        if (!Ready()) GTEST_SKIP();
+
+        const std::uint8_t texels[4] = {1, 1, 1, 1};
+        const GLint border[4] = {-1, 0, 0, 1};
+        MakeNarrowSource(GL_R8UI, GL_RED_INTEGER, texels, border, /*borderIsUnsigned=*/false);
+
+        const std::vector<std::int32_t> sampled = RenderNarrowBorder(/*isUnsignedSampler=*/true);
+        EXPECT_EQ(FirstGLError(), 0u) << "the clamped-border draw left a GL error behind";
+        ExpectAllTexels("R8UI border -1", 0, 255, sampled);
+        Gl().EndFrame();
+    }
+
+    // The same clamp from the unambiguous side: a value written through the UNSIGNED form that is
+    // simply too large for the format. No sign reinterpretation is involved, so both backends and
+    // the spec agree that 5000 on a GL_R8UI texture is 255.
+    TEST_F(IntegerBorderColorScenario, AnOversizedUnsignedBorderIsClampedToTheFormatsMaximum) {
+        if (!Ready()) GTEST_SKIP();
+
+        const std::uint8_t texels[4] = {1, 1, 1, 1};
+        const GLint border[4] = {5000, 0, 0, 1};
+        MakeNarrowSource(GL_R8UI, GL_RED_INTEGER, texels, border, /*borderIsUnsigned=*/true);
+
+        const std::vector<std::int32_t> sampled = RenderNarrowBorder(/*isUnsignedSampler=*/true);
+        EXPECT_EQ(FirstGLError(), 0u) << "the clamped-border draw left a GL error behind";
+        ExpectAllTexels("R8UI border 5000", 0, 255, sampled);
+        Gl().EndFrame();
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/IterationRPFirstReductionScenario.cpp

@@ -137,7 +137,7 @@ namespace MGITest {
             // invocations, i.e. an advertised subgroup width in [16, 256]. A device
             // outside that window (lavapipe's 8-lane subgroups give 64 subgroups) cannot
             // run the fixture's verbatim reduction at all, so the scenario SKIPS there -
-            // the pack itself replays through the FixIterationRPSubgroupScratch patch, which
+            // the pack itself replays through the MagmaFixIterationRPSubgroupScratch patch, which
             // this probe deliberately does not model. The width only gates the domain;
             // lane placement and group counts still come from observed values alone.
             bool SubgroupWidthInSourceDomain() const {

MobileGL/MG_IntegrationTest/Scenarios/LargeArenaAdoptionScenario.cpp

@@ -0,0 +1,278 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/LargeArenaAdoptionScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - MESH-ARENA-SIZED BUFFERS, END TO END.
+//
+// A buffer store of at least 16MiB is adopted into the backend's persistently and
+// coherently mapped GPU storage the moment it is defined (BufferObject::
+// TryAdoptLargeStorage): the CPU shadow is dropped and every later write lands
+// directly in GPU-visible memory with no per-write driver call. Minecraft 26.3
+// streams chunk meshes into 128MB vertex arenas with plain glNamedBufferSubData -
+// on Mali, every driver-mediated route for that write into a busy mutable store
+// either parks the calling thread or ghost-copies the whole arena on a driver
+// worker (~167ms per touched arena: the recurring in-world hiccup this adoption
+// removed). Every existing buffer scenario uses stores far below the threshold,
+// so without this file the adopted path would have zero coverage.
+//
+// What is pinned, deliberately through the same API mix Minecraft uses:
+//   * a glBufferSubData written AFTER the arena was drawn (in flight) reaches the
+//     next draw - the write-visibility contract adoption must not weaken;
+//   * GetBufferSubData reads back the latest CPU write - the shadow IS the map;
+//   * a compute-shader write through an SSBO binding of the same arena is read
+//     back - the GPU-written path for adopted stores (glFinish + direct read).
+
+#include <array>
+#include <cstring>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // Comfortably past the 16MiB adoption threshold, and the vertex payload sits
+        // deep inside the store so an implementation that quietly clamped or aliased
+        // the adopted range would miss it.
+        constexpr GLsizeiptr kArenaBytes = GLsizeiptr(24) * 1024 * 1024;
+        constexpr GLintptr kVertexOffset = GLintptr(20) * 1024 * 1024;
+
+        constexpr const char* kVertexSource = R"(#version 430 core
+layout(location = 0) in vec2 a_pos;
+layout(location = 1) in vec3 a_color;
+out vec3 v_color;
+void main() {
+    v_color = a_color;
+    gl_Position = vec4(a_pos, 0.0, 1.0);
+}
+)";
+
+        constexpr const char* kFragmentSource = R"(#version 430 core
+in vec3 v_color;
+out vec4 o_color;
+void main() { o_color = vec4(v_color, 1.0); }
+)";
+
+        constexpr const char* kMarkerComputeSource = R"(#version 430 core
+layout(local_size_x = 1) in;
+layout(std430, binding = 0) buffer Arena { uint word; };
+void main() { word = 0xC0FFEEu; }
+)";
+
+        struct Vertex {
+            float x, y;
+            float r, g, b;
+        };
+
+        // A full-viewport quad, colored uniformly so one center readback speaks for
+        // the whole draw.
+        std::vector<Vertex> QuadVertices(float r, float g, float b) {
+            return {
+                {-1.f, -1.f, r, g, b}, {1.f, -1.f, r, g, b}, {1.f, 1.f, r, g, b},
+                {-1.f, -1.f, r, g, b}, {1.f, 1.f, r, g, b},  {-1.f, 1.f, r, g, b},
+            };
+        }
+
+        class LargeArenaAdoptionScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                m_program = LinkProgram(kVertexSource, kFragmentSource);
+                ASSERT_NE(m_program, 0u) << m_buildLog;
+
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                glGenBuffers(1, &m_arena);
+                glBindBuffer(GL_ARRAY_BUFFER, m_arena);
+                // The NULL-data definition is the adoption point (and Minecraft's
+                // arena-creation idiom).
+                glBufferData(GL_ARRAY_BUFFER, kArenaBytes, nullptr, GL_DYNAMIC_DRAW);
+                glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+                                      reinterpret_cast<void*>(kVertexOffset));
+                glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+                                      reinterpret_cast<void*>(kVertexOffset + 2 * sizeof(float)));
+                glEnableVertexAttribArray(0);
+                glEnableVertexAttribArray(1);
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glUseProgram(0);
+                glBindVertexArray(0);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                if (m_arena != 0) glDeleteBuffers(1, &m_arena);
+                if (m_program != 0) glDeleteProgram(m_program);
+                if (m_compute != 0) glDeleteProgram(m_compute);
+                m_vao = 0;
+                m_arena = 0;
+                m_program = 0;
+                m_compute = 0;
+            }
+
+            unsigned int CompileStage(GLenum stage, const char* source) {
+                const GLuint shader = glCreateShader(stage);
+                glShaderSource(shader, 1, &source, nullptr);
+                glCompileShader(shader);
+                GLint compiled = 0;
+                glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+                if (compiled == GL_FALSE) {
+                    char log[2048] = {};
+                    glGetShaderInfoLog(shader, sizeof(log) - 1, nullptr, log);
+                    m_buildLog = std::string("shader did not compile: ") + log;
+                    glDeleteShader(shader);
+                    return 0;
+                }
+                return shader;
+            }
+
+            unsigned int LinkProgram(const char* vs, const char* fs) {
+                const GLuint v = CompileStage(GL_VERTEX_SHADER, vs);
+                if (v == 0) return 0;
+                const GLuint f = CompileStage(GL_FRAGMENT_SHADER, fs);
+                if (f == 0) {
+                    glDeleteShader(v);
+                    return 0;
+                }
+                const GLuint program = glCreateProgram();
+                glAttachShader(program, v);
+                glAttachShader(program, f);
+                glLinkProgram(program);
+                glDeleteShader(v);
+                glDeleteShader(f);
+                GLint linked = 0;
+                glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                if (linked == GL_FALSE) {
+                    char log[2048] = {};
+                    glGetProgramInfoLog(program, sizeof(log) - 1, nullptr, log);
+                    m_buildLog = std::string("program did not link: ") + log;
+                    glDeleteProgram(program);
+                    return 0;
+                }
+                return program;
+            }
+
+            void UploadQuad(float r, float g, float b) {
+                const auto vertices = QuadVertices(r, g, b);
+                glBindBuffer(GL_ARRAY_BUFFER, m_arena);
+                glBufferSubData(GL_ARRAY_BUFFER, kVertexOffset,
+                                GLsizeiptr(vertices.size() * sizeof(Vertex)), vertices.data());
+            }
+
+            void DrawQuad() {
+                glViewport(0, 0, Gl().Width(), Gl().Height());
+                glClearColor(0.f, 0.f, 0.f, 1.f);
+                glClear(GL_COLOR_BUFFER_BIT);
+                glUseProgram(m_program);
+                glBindVertexArray(m_vao);
+                glDrawArrays(GL_TRIANGLES, 0, 6);
+            }
+
+            std::array<unsigned char, 4> CenterPixel() {
+                std::array<unsigned char, 4> px = {0, 0, 0, 0};
+                glReadPixels(Gl().Width() / 2, Gl().Height() / 2, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE,
+                             px.data());
+                return px;
+            }
+
+            unsigned int m_program = 0;
+            unsigned int m_compute = 0;
+            unsigned int m_vao = 0;
+            unsigned int m_arena = 0;
+            std::string m_buildLog;
+        };
+
+    } // namespace
+
+    // The Minecraft shape: the arena is drawn, the frame retires, and a
+    // glBufferSubData rewrites the SAME vertex bytes while the previous frame's
+    // draw may still be in flight. The next draw must show the NEW bytes.
+    TEST_F(LargeArenaAdoptionScenario, SubDataAfterAnInFlightDrawReachesTheNextDraw) {
+        if (!Ready() || IsSkipped()) return;
+
+        UploadQuad(1.f, 0.f, 0.f);
+        DrawQuad();
+        auto px = CenterPixel();
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_GT(px[0], 200) << "the first draw from the adopted arena never landed";
+        EXPECT_LT(px[1], 50);
+
+        Gl().EndFrame();
+
+        UploadQuad(0.f, 1.f, 0.f);
+        DrawQuad();
+        px = CenterPixel();
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_GT(px[1], 200) << "the cross-frame rewrite of the adopted arena did not reach the draw; "
+                                 "the old color means the write went to bytes the draw no longer reads";
+        EXPECT_LT(px[0], 50) << "the draw still shows the previous frame's bytes";
+    }
+
+    // The shadow IS the mapping: a readback straight after a CPU write must hand
+    // back exactly those bytes.
+    TEST_F(LargeArenaAdoptionScenario, ReadbackSeesTheLatestCpuWrite) {
+        if (!Ready() || IsSkipped()) return;
+
+        const auto vertices = QuadVertices(0.25f, 0.5f, 0.75f);
+        glBindBuffer(GL_ARRAY_BUFFER, m_arena);
+        glBufferSubData(GL_ARRAY_BUFFER, kVertexOffset,
+                        GLsizeiptr(vertices.size() * sizeof(Vertex)), vertices.data());
+        std::vector<Vertex> read(vertices.size());
+        glGetBufferSubData(GL_ARRAY_BUFFER, kVertexOffset,
+                           GLsizeiptr(read.size() * sizeof(Vertex)), read.data());
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_EQ(0, std::memcmp(read.data(), vertices.data(), read.size() * sizeof(Vertex)))
+            << "GetBufferSubData of the adopted arena returned different bytes than the SubData wrote";
+    }
+
+    // A GPU write through an SSBO binding of the adopted arena must be visible to
+    // a CPU readback - the path that waits out the GPU and reads the coherent
+    // mapping directly.
+    TEST_F(LargeArenaAdoptionScenario, GpuWriteIntoTheArenaIsReadBack) {
+        if (!Ready() || IsSkipped()) return;
+
+        GLint maxComputeStorageBlocks = 0;
+        glGetIntegerv(GL_MAX_COMPUTE_SHADER_STORAGE_BLOCKS, &maxComputeStorageBlocks);
+        if (maxComputeStorageBlocks < 1) {
+            GTEST_SKIP() << "no compute shader storage blocks on this driver";
+        }
+        const GLuint compute = CompileStage(GL_COMPUTE_SHADER, kMarkerComputeSource);
+        ASSERT_NE(compute, 0u) << m_buildLog;
+        m_compute = glCreateProgram();
+        glAttachShader(m_compute, compute);
+        glLinkProgram(m_compute);
+        glDeleteShader(compute);
+        GLint linked = 0;
+        glGetProgramiv(m_compute, GL_LINK_STATUS, &linked);
+        ASSERT_EQ(linked, GL_TRUE);
+
+        const unsigned int seed = 0u;
+        glBindBuffer(GL_ARRAY_BUFFER, m_arena);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(seed), &seed);
+        glBindBufferRange(GL_SHADER_STORAGE_BUFFER, 0, m_arena, 0, sizeof(unsigned int));
+        glUseProgram(m_compute);
+        glDispatchCompute(1, 1, 1);
+        glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT | GL_BUFFER_UPDATE_BARRIER_BIT);
+
+        unsigned int marker = 0;
+        glGetBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(marker), &marker);
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_EQ(marker, 0xC0FFEEu)
+            << "the compute write into the adopted arena did not reach the CPU readback";
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/PipeVerifyArmingScenario.cpp

@@ -0,0 +1,269 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/PipeVerifyArmingScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - THE MOBILEGL_PIPE_VERIFY COMPARATOR IS ARMED, AND SAYS SO, AND CAN GO RED.
+//
+// The third CI mode (ARCHITECTURE.md 13.2-(2)) runs the whole integration suite with two state
+// models in one address space: the PipeInputs block the frontend fills at every verb boundary,
+// and a SnapshotFromGLContext() taken from the live GLContext. A green run of that mode is only
+// worth something if the comparator was actually RUNNING - and "MOBILEGL_PIPE_VERIFY=1 against a
+// library that was not built with -DMOBILEGL_PIPE_VERIFY=ON" is a no-op that looks exactly like a
+// clean pass. That is the failure mode this scenario exists to make impossible:
+//
+//   Armed                    - the environment says the comparator is on for this process, so the
+//                              library must SAY it armed. It asserts a library observable against
+//                              the environment, the same shape UnlocatedIoBlockScenario's arming
+//                              case and AsyncCompileScenario::ExtensionStringMatchesTheConfiguration
+//                              use. A lane whose library never armed FAILS here; it never passes.
+//   CorruptedFieldIsReported - the negative control for the comparator itself (gate G4). With
+//                              MOBILEGL_PIPE_VERIFY_CORRUPT naming a field, the snapshot arm is
+//                              perturbed before the entry compare, so a comparator that works must
+//                              report Fatal{PipeVerifyDiffer, "<Field>@<Verb>"}. A comparator that
+//                              compares nothing stays quiet and this case goes red.
+//
+// The observable is the library's own log, because MG_Config is not reachable from this module
+// (on Android it links the SHIPPING libMobileGL.so, built -fvisibility=hidden) and the arming
+// signal is a latched MGLOG_I. The ctest entry sets MOBILEGL_LOG_FILE_PATH; this only reads it.
+//
+// Note on scope, and why Armed runs in a lane of its own. The log file is opened with
+// fopen(path, "w") at the first log write of a process (MG_Util/Debug/Log.cpp, InitFile), so each
+// process TRUNCATES it. That is fine for one process and false for many: in the ambient Verify.
+// lane, 400-odd sibling entries share the one MOBILEGL_LOG_FILE_PATH, and CI runs that lane with
+// `ctest -j 4`, so a neighbour's bring-up can truncate the file between this case's draw and its
+// read. Every existing scenario in this suite that reads the library log (UnlocatedIoBlockScenario,
+// the primgen reroute, the point-size demotion) is registered in a FILTERED lane with a log path of
+// its own for exactly that reason, and this case now follows them: it runs in the VerifyArming.
+// entries, which set MGITEST_PIPE_ARMING_LANE=1 and their own log, and skips everywhere else.
+//
+// What that proves, stated honestly: the arming line is a property of (this library, this
+// environment), not of an individual test body, and the VerifyArming. entry runs the same library
+// with the same MOBILEGL_PIPE_VERIFY=1 as its ~400 ambient siblings. One process per backend is
+// therefore the whole of the evidence available for "the lane armed" - the per-process claim the
+// shared log CANNOT support, because it only ever holds the last writer.
+//
+// Within the process: the arming line is latched at the FIRST fill, which may be the harness
+// bring-up rather than this test's draw, so the arming search is whole-file on purpose; the
+// divergence search is restricted to the bytes this case appended, which is where a differ belongs.
+
+#include <cstdint>
+#include <cstdlib>
+#include <filesystem>
+#include <fstream>
+#include <iterator>
+#include <string>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // The three strings the comparator contracts to print (the brief's D8 reporting shape).
+        // They are spelled here once so a rename of either half is one compile-visible edit.
+        constexpr const char* kArmedLine = "MGPipe: verify armed";
+        constexpr const char* kDifferPrefix = "Fatal{PipeVerifyDiffer";
+        constexpr const char* kUnmigratedPrefix = "Fatal{UnmigratedPipeInput";
+
+        // Set by the VerifyArming. ctest entries and by nothing else. It is a HARNESS variable, not
+        // a library knob (hence the MGITEST_ prefix): the library never reads it. It exists because
+        // this case reads a log file, and a log file is a per-LANE resource - see the note at the
+        // top of the file.
+        constexpr const char* kArmingLaneMarker = "MGITEST_PIPE_ARMING_LANE";
+
+        constexpr const char* kVS = R"(#version 330 core
+in vec2 aPos;
+void main() { gl_Position = vec4(aPos, 0.0, 1.0); }
+)";
+
+        constexpr const char* kFS = R"(#version 330 core
+out vec4 o_color;
+void main() { o_color = vec4(0.25, 0.5, 0.75, 1.0); }
+)";
+
+        // Reads the environment the way MG_ConfigLoader does (ScenarioFixture.h documents the
+        // rule); a string knob is "set" when it is present and non-empty, which is exactly what
+        // MG_ConfigLoader's QueryEnvVariable turns into a non-empty Features member.
+        bool StringKnobIsSet(const char* name) {
+            const char* value = std::getenv(name);
+            return value != nullptr && *value != '\0';
+        }
+
+        class PipeVerifyArmingScenario : public ScenarioTest {
+        protected:
+            // The library log this process is writing, or an empty path when none was configured.
+            static std::filesystem::path LibraryLogPath() {
+                const char* path = std::getenv("MOBILEGL_LOG_FILE_PATH");
+                return (path != nullptr && *path != '\0') ? std::filesystem::path(path)
+                                                          : std::filesystem::path();
+            }
+
+            static std::uintmax_t LibraryLogSize() {
+                std::error_code ec;
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return 0;
+                const std::uintmax_t size = std::filesystem::file_size(path, ec);
+                return ec ? 0 : size;
+            }
+
+            static std::string LibraryLogSince(std::uintmax_t offset) {
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return {};
+                std::ifstream file(path, std::ios::binary);
+                if (!file.good()) return {};
+                file.seekg(static_cast<std::streamoff>(offset));
+                return std::string((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
+            }
+
+            static std::string LibraryLog() { return LibraryLogSince(0); }
+
+            // One frame that crosses several verb boundaries: a clear (kClear), a draw (kDraw) and
+            // a readback (kReadback). Three of the nine fill classes, so an entry compare that only
+            // ran for one of them still has something to say.
+            void DrawOneFrame() {
+                HeadlessGL& gl = Gl();
+                std::string error;
+                const unsigned int program = CompileProgram(kVS, kFS, &error);
+                ASSERT_NE(program, 0u) << error;
+
+                static const float kQuad[] = {-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
+                GLuint vao = 0;
+                GLuint vbo = 0;
+                glGenVertexArrays(1, &vao);
+                glBindVertexArray(vao);
+                glGenBuffers(1, &vbo);
+                glBindBuffer(GL_ARRAY_BUFFER, vbo);
+                glBufferData(GL_ARRAY_BUFFER, sizeof(kQuad), kQuad, GL_STATIC_DRAW);
+                glEnableVertexAttribArray(0);
+                glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
+
+                BindDefaultFramebuffer();
+                glViewport(0, 0, gl.Width(), gl.Height());
+                ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+                glUseProgram(program);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+                Rgba8 pixel{};
+                glReadPixels(gl.Width() / 2, gl.Height() / 2, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &pixel);
+
+                glBindVertexArray(0);
+                glDeleteBuffers(1, &vbo);
+                glDeleteVertexArrays(1, &vao);
+                m_centre = pixel;
+            }
+
+            Rgba8 m_centre{};
+        };
+
+        // THE CASE THAT FAILS A LANE WHOSE LIBRARY NEVER ARMED.
+        //
+        // Every other entry in the integration-verify lane renders the same frames it renders in the
+        // ambient lane and would be just as green against a library with no comparator compiled in -
+        // which is precisely how a verify lane goes green having verified nothing. This case is the
+        // one that cannot: the environment pins MOBILEGL_PIPE_VERIFY=1, therefore the library must
+        // have said "MGPipe: verify armed" in its own log, and if it did not, the mode is not running.
+        TEST_F(PipeVerifyArmingScenario, Armed) {
+            if (!Ready()) return;
+
+            if (!StringKnobIsSet(kArmingLaneMarker)) {
+                GTEST_SKIP() << "this case reads the library's log file, so it runs in the VerifyArming. "
+                                "lane, which owns a log path no other entry writes to. In the ambient "
+                                "Verify. lane 400-odd entries share one path and each truncates it "
+                                "(Log.cpp opens it \"w\"), so a whole-file read here would race a "
+                                "neighbour under ctest -j 4. Set by the ctest entry, never by hand.";
+            }
+            if (AmbientQuirkFromEnvironment("MOBILEGL_PIPE_VERIFY") != AmbientQuirk::On) {
+                GTEST_SKIP() << "this case needs MOBILEGL_PIPE_VERIFY=1 for the whole process, which is "
+                                "what the Verify. ctest entries set; with the variable unset the "
+                                "comparator is dormant even in a build that compiled it in";
+            }
+            if (LibraryLogPath().empty()) {
+                GTEST_SKIP() << "MOBILEGL_PIPE_VERIFY is pinned on but MOBILEGL_LOG_FILE_PATH is not "
+                                "set, so the library has nowhere to record that it armed; the Verify. "
+                                "ctest entries set both";
+            }
+            if (StringKnobIsSet("MOBILEGL_PIPE_VERIFY_CORRUPT")) {
+                GTEST_SKIP() << "MOBILEGL_PIPE_VERIFY_CORRUPT is armed in this process, so a divergence "
+                                "is the EXPECTED outcome and asserting on its absence here would be "
+                                "backwards; the VerifyCorrupted. lane owns that half";
+            }
+
+            const std::uintmax_t before = LibraryLogSize();
+            ASSERT_NO_FATAL_FAILURE(DrawOneFrame());
+            EXPECT_EQ(FirstGLError(), 0u);
+
+            // Whole file, not just the appended bytes: the arming line is latched at the FIRST fill
+            // of the process, which may already have happened during the harness bring-up. The file
+            // is truncated at this process's first log write, so it still carries nothing else.
+            const std::string whole = LibraryLog();
+            EXPECT_NE(whole.find(kArmedLine), std::string::npos)
+                << "MOBILEGL_PIPE_VERIFY=1 is set for this process and a frame was cleared, drawn and "
+                   "read back, and the library never reported arming the comparator. Either this "
+                   "library was not built with -DMOBILEGL_PIPE_VERIFY=ON (in which case the whole lane "
+                   "is verifying nothing), or the arming MGLOG_I is gone. Log:\n"
+                << whole;
+
+            const std::string appended = LibraryLogSince(before);
+            EXPECT_EQ(appended.find(kDifferPrefix), std::string::npos)
+                << "the comparator reported a push/pull divergence on an ordinary frame:\n"
+                << appended;
+            EXPECT_EQ(appended.find(kUnmigratedPrefix), std::string::npos)
+                << "a backend read a field the verb's fill table does not list (add the row to "
+                   "MG_Pipe/FillPoints.def, never mark the field sticky):\n"
+                << appended;
+        }
+
+        // NEGATIVE CONTROL A (gate G4): a deliberately corrupted snapshot field must turn a green
+        // verify run red, naming that field and the verb it diverged on.
+        //
+        // It runs in its own lane (VerifyCorrupted.) because the knob is process-wide, and with
+        // MOBILEGL_PIPE_VERIFY_FATAL=0 so the process survives its own divergence and this case can
+        // read the report back out of the log. The CI step that runs the SAME knob against the
+        // ambient lane - where FATAL keeps its default - asserts the other half: there, the
+        // divergence must abort and ctest must go red.
+        TEST_F(PipeVerifyArmingScenario, CorruptedFieldIsReported) {
+            if (!Ready()) return;
+
+            if (!StringKnobIsSet("MOBILEGL_PIPE_VERIFY_CORRUPT")) {
+                GTEST_SKIP() << "this case is the comparator's negative control and needs "
+                                "MOBILEGL_PIPE_VERIFY_CORRUPT=<FieldName> for the whole process, which "
+                                "is what the VerifyCorrupted. ctest entries set";
+            }
+            if (AmbientQuirkFromEnvironment("MOBILEGL_PIPE_VERIFY") != AmbientQuirk::On) {
+                GTEST_SKIP() << "MOBILEGL_PIPE_VERIFY_CORRUPT is set but MOBILEGL_PIPE_VERIFY is not, so "
+                                "the comparator is dormant and there is nothing to corrupt";
+            }
+            if (LibraryLogPath().empty()) {
+                GTEST_SKIP() << "MOBILEGL_LOG_FILE_PATH is not set, so the library has nowhere to report "
+                                "the divergence; the VerifyCorrupted. ctest entries set both";
+            }
+
+            const std::string knob = std::getenv("MOBILEGL_PIPE_VERIFY_CORRUPT");
+            const std::uintmax_t before = LibraryLogSize();
+            ASSERT_NO_FATAL_FAILURE(DrawOneFrame());
+
+            const std::string appended = LibraryLogSince(before);
+            const std::string expected = std::string(kDifferPrefix) + ", \"" + knob + "@";
+            EXPECT_NE(appended.find(expected), std::string::npos)
+                << "MOBILEGL_PIPE_VERIFY_CORRUPT=" << knob
+                << " perturbs that field in the snapshot arm before every entry compare, so a working "
+                   "comparator must have reported " << expected << "...\". It reported nothing, which "
+                   "means the comparator is not comparing - and every green entry in this lane is "
+                   "green for no reason. Log appended by this case:\n"
+                << appended;
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/PointSizeDemotionScenario.cpp

@@ -0,0 +1,522 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/PointSizeDemotionScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - THE gl_PointSize DEMOTION IS CLIENT-INVISIBLE, AND IT ACTUALLY ARMS.
+//
+// On a device that hosts the built-in in tessellation/geometry stages (llvmpipe and
+// lavapipe both do), gl_PointSize travels as itself; on one that does not (the Mali
+// devices this exists for), phase B demotes it to an ordinary varying
+// (ShaderCompiler::DemoteTessellationGeometryPointSizeForProgram) and the capture
+// machinery follows it there. This scenario runs in BOTH configurations and must hand
+// back identical bytes: the ambient registrations take the native path, and the
+// PointSizeDemotion. registrations pin MOBILEGL_POINT_SIZE_DEMOTION=1 so the demotion
+// runs on the same healthy drivers - CopyImagePacked16Scenario's dual-configuration
+// contract, applied to a value chain instead of a storage format.
+//
+// The VALUE is the whole contract: every case writes gl_PointSize in one stage, reads it
+// back out of gl_in[] in the next, and captures it by name under rasterizer discard, so
+// one wrong link anywhere in VS -> TCS -> TES -> GS -> capture lands in the readback.
+// The RASTERIZED size is deliberately not asserted anywhere: with the built-in unhosted
+// it falls back to 1.0 by spec on both targets, which is exactly the honest residue the
+// demotion documents (point_rendering-style bodies keep failing truthfully).
+//
+// The assertions are on the captured BYTES against a CPU-computed reference, never on
+// the absence of a GL error: every failure this guards against is silent.
+
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
+#include <filesystem>
+#include <fstream>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr float kPoison = -987654.0f;
+
+        const char* const kFragmentSource = R"(#version 460 core
+layout(location = 0) out vec4 fragColor;
+void main()
+{
+    fragColor = vec4(1.0, 0.0, 0.0, 1.0);
+}
+)";
+
+        // The full chain, with per-vertex VARIATION seeded in the vertex stage so a control
+        // invocation that read or wrote the wrong slot changes the sum: 2,3,4 arrive, 3,4,5
+        // leave, the evaluation stage sums its patch to 12, the geometry stage doubles what
+        // it read to 24.
+        const char* const kChainVertexSource = R"(#version 460 core
+void main()
+{
+    gl_Position  = vec4(0.0, 0.0, 0.0, 1.0);
+    gl_PointSize = 2.0 + float(gl_VertexID);
+}
+)";
+
+        const char* const kChainTessControlSource = R"(#version 460 core
+layout(vertices = 3) out;
+void main()
+{
+    gl_out[gl_InvocationID].gl_Position  = gl_in[gl_InvocationID].gl_Position;
+    gl_out[gl_InvocationID].gl_PointSize = gl_in[gl_InvocationID].gl_PointSize + 1.0;
+    gl_TessLevelOuter[0] = 1.0;
+    gl_TessLevelOuter[1] = 1.0;
+    gl_TessLevelOuter[2] = 1.0;
+    gl_TessLevelInner[0] = 1.0;
+}
+)";
+
+        const char* const kChainTessEvalSource = R"(#version 460 core
+layout(triangles, equal_spacing, cw, point_mode) in;
+void main()
+{
+    gl_Position  = vec4(0.0, 0.0, 0.0, 1.0);
+    gl_PointSize = gl_in[0].gl_PointSize + gl_in[1].gl_PointSize + gl_in[2].gl_PointSize;
+}
+)";
+
+        const char* const kChainGeometrySource = R"(#version 460 core
+layout(points) in;
+layout(points, max_vertices = 1) out;
+void main()
+{
+    gl_Position  = gl_in[0].gl_Position;
+    gl_PointSize = gl_in[0].gl_PointSize * 2.0;
+    EmitVertex();
+    EndPrimitive();
+}
+)";
+
+        // The geometry-only chain: no tessellation required of the stack at all.
+        const char* const kPointVertexSource = R"(#version 460 core
+void main()
+{
+    gl_Position  = vec4(0.0, 0.0, 0.0, 1.0);
+    gl_PointSize = 7.0;
+}
+)";
+
+        const char* const kPointGeometrySource = R"(#version 460 core
+layout(points) in;
+layout(points, max_vertices = 1) out;
+void main()
+{
+    gl_Position  = gl_in[0].gl_Position;
+    gl_PointSize = gl_in[0].gl_PointSize + 1.0;
+    EmitVertex();
+    EndPrimitive();
+}
+)";
+
+        // A capture stage that only READS the incoming point size and never writes its own.
+        // Legal GL, and the shape that separates "the demotion arms" from "the demotion knows
+        // a capture is coming": with the built-in gone, only the capture request can put a
+        // carrier back for a by-name capture to bind to.
+        const char* const kReadOnlyGeometrySource = R"(#version 460 core
+layout(points) in;
+layout(points, max_vertices = 1) out;
+out float g_echo;
+void main()
+{
+    gl_Position = gl_in[0].gl_Position;
+    g_echo      = gl_in[0].gl_PointSize;
+    EmitVertex();
+    EndPrimitive();
+}
+)";
+
+        const char* const kEchoFragmentSource = R"(#version 460 core
+in float g_echo;
+layout(location = 0) out vec4 fragColor;
+void main()
+{
+    fragColor = vec4(g_echo, 0.0, 0.0, 1.0);
+}
+)";
+
+        class PointSizeDemotionScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                DrainErrors();
+            }
+
+            void TearDown() override {
+                if (Ready()) {
+                    glUseProgram(0);
+                    for (const GLuint program : m_programs) {
+                        glDeleteProgram(program);
+                    }
+                    m_programs.clear();
+                    glBindVertexArray(0);
+                    if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                    m_vao = 0;
+                }
+                ScenarioTest::TearDown();
+            }
+
+            static void DrainErrors() {
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+            }
+
+            static bool BackendHostsTessellation() {
+                GLint maxTessGenLevel = 0;
+                glGetIntegerv(GL_MAX_TESS_GEN_LEVEL, &maxTessGenLevel);
+                DrainErrors();
+                return maxTessGenLevel >= 1;
+            }
+
+            static std::string InfoLog(GLuint object, bool isShader) {
+                GLint length = 0;
+                if (isShader) {
+                    glGetShaderiv(object, GL_INFO_LOG_LENGTH, &length);
+                } else {
+                    glGetProgramiv(object, GL_INFO_LOG_LENGTH, &length);
+                }
+                std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                if (isShader) {
+                    glGetShaderInfoLog(object, length + 1, nullptr, buffer.data());
+                } else {
+                    glGetProgramInfoLog(object, length + 1, nullptr, buffer.data());
+                }
+                return buffer.data();
+            }
+
+            GLuint BuildCaptureProgram(const std::vector<std::pair<GLenum, const char*>>& stages,
+                                       const std::vector<const char*>& varyings) {
+                m_buildLog.clear();
+                std::vector<GLuint> shaders;
+                bool ok = true;
+                for (const auto& [stage, source] : stages) {
+                    const GLuint shader = glCreateShader(stage);
+                    glShaderSource(shader, 1, &source, nullptr);
+                    glCompileShader(shader);
+                    GLint compiled = 0;
+                    glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+                    shaders.push_back(shader);
+                    if (compiled == GL_FALSE) {
+                        m_buildLog = InfoLog(shader, true) + "\n--- source ---\n" + source;
+                        ok = false;
+                        break;
+                    }
+                }
+                GLuint program = 0;
+                if (ok) {
+                    program = glCreateProgram();
+                    for (const GLuint shader : shaders) {
+                        glAttachShader(program, shader);
+                    }
+                    glTransformFeedbackVaryings(program, static_cast<GLsizei>(varyings.size()),
+                                                varyings.data(), GL_INTERLEAVED_ATTRIBS);
+                    glLinkProgram(program);
+                    GLint linked = GL_FALSE;
+                    glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                    if (linked == GL_FALSE) {
+                        m_buildLog = InfoLog(program, false);
+                        glDeleteProgram(program);
+                        program = 0;
+                    }
+                }
+                for (const GLuint shader : shaders) {
+                    glDeleteShader(shader);
+                }
+                if (program != 0) m_programs.push_back(program);
+                return program;
+            }
+
+            // One capture span over `vertexCount` vertices of `drawMode`, recorded as
+            // GL_POINTS. The buffer is poison-filled first so bytes the capture never wrote
+            // name themselves.
+            std::vector<float> RunCaptureSpan(GLuint program, GLenum drawMode, GLsizei vertexCount,
+                                              std::size_t capturedFloats) {
+                const std::vector<float> poison(capturedFloats, kPoison);
+                GLuint xfbBuffer = 0;
+                glGenBuffers(1, &xfbBuffer);
+                glBindBuffer(GL_ARRAY_BUFFER, xfbBuffer);
+                glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(capturedFloats * sizeof(float)),
+                             poison.data(), GL_STATIC_COPY);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+
+                glBindVertexArray(m_vao);
+                glUseProgram(program);
+                glEnable(GL_RASTERIZER_DISCARD);
+                glBeginTransformFeedback(GL_POINTS);
+                glDrawArrays(drawMode, 0, vertexCount);
+                glEndTransformFeedback();
+                glDisable(GL_RASTERIZER_DISCARD);
+
+                std::vector<float> readback(capturedFloats, kPoison);
+                glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
+                                   static_cast<GLsizeiptr>(capturedFloats * sizeof(float)),
+                                   readback.data());
+                glUseProgram(0);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+                glDeleteBuffers(1, &xfbBuffer);
+                return readback;
+            }
+
+            static ::testing::AssertionResult ComponentIs(const std::vector<float>& data,
+                                                          std::size_t index, float expected,
+                                                          float epsilon = 1e-4f) {
+                if (index >= data.size()) {
+                    return ::testing::AssertionFailure()
+                           << "component " << index << " is past the capture buffer";
+                }
+                const float actual = data[index];
+                if (actual == kPoison) {
+                    return ::testing::AssertionFailure()
+                           << "component " << index << " still holds the poison value - the capture "
+                           << "never reached these bytes (expected " << expected << ")";
+                }
+                if (std::isnan(actual) || std::abs(actual - expected) > epsilon) {
+                    return ::testing::AssertionFailure()
+                           << "component " << index << " is " << actual << ", expected " << expected;
+                }
+                return ::testing::AssertionSuccess();
+            }
+
+            // The library log, for the arming case. Same machinery and same reasoning as
+            // UnlocatedIoBlockScenario: MOBILEGL_LOG_FILE_PATH is read at log-init, the file
+            // is appended to by every process in the lane, and only bytes appended after the
+            // snapshot may satisfy an assertion.
+            static std::filesystem::path LibraryLogPath() {
+                const char* path = std::getenv("MOBILEGL_LOG_FILE_PATH");
+                return (path != nullptr && *path != '\0') ? std::filesystem::path(path)
+                                                          : std::filesystem::path();
+            }
+
+            static std::uintmax_t LibraryLogSize() {
+                std::error_code ec;
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return 0;
+                const std::uintmax_t size = std::filesystem::file_size(path, ec);
+                return ec ? 0 : size;
+            }
+
+            static std::string LibraryLogSince(std::uintmax_t offset) {
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return {};
+                std::ifstream file(path, std::ios::binary);
+                if (!file.good()) return {};
+                file.seekg(static_cast<std::streamoff>(offset));
+                return std::string((std::istreambuf_iterator<char>(file)),
+                                   std::istreambuf_iterator<char>());
+            }
+
+            std::string m_buildLog;
+
+        private:
+            GLuint m_vao = 0;
+            std::vector<GLuint> m_programs;
+        };
+
+        // The five-stage chain. 24.0 can only arrive if the vertex mirror, both control-stage
+        // redirects (read AND write), the evaluation stage's three gl_in reads and the
+        // geometry stage's read all carried the right value - one wrong link and the sum
+        // moves. point_mode with every level at 1 emits three points; the first record proves
+        // the mechanism, exactly as TessellationXfbCaptureScenario reasons.
+        TEST_F(PointSizeDemotionScenario, TheValueSurvivesTheFiveStageChainIntoTheCapture) {
+            if (!Ready()) return;
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " ("
+                             << Gl().RendererString() << ")";
+            }
+            glPatchParameteri(GL_PATCH_VERTICES, 3);
+            DrainErrors();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kChainVertexSource},
+                                                        {GL_TESS_CONTROL_SHADER, kChainTessControlSource},
+                                                        {GL_TESS_EVALUATION_SHADER, kChainTessEvalSource},
+                                                        {GL_GEOMETRY_SHADER, kChainGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_PointSize"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            const std::vector<float> captured = RunCaptureSpan(program, GL_PATCHES, 3, 3);
+            EXPECT_TRUE(ComponentIs(captured, 0, 24.0f));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // The same chain without a geometry stage: the capture then binds to the evaluation
+        // stage's value (the sum, 12.0) - which is also the boundary where a demoted program
+        // switches its capture carrier from the Io chain to the capture name.
+        TEST_F(PointSizeDemotionScenario, TheEvaluationStageOwnsTheCaptureWithoutAGeometryStage) {
+            if (!Ready()) return;
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " ("
+                             << Gl().RendererString() << ")";
+            }
+            glPatchParameteri(GL_PATCH_VERTICES, 3);
+            DrainErrors();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kChainVertexSource},
+                                                        {GL_TESS_CONTROL_SHADER, kChainTessControlSource},
+                                                        {GL_TESS_EVALUATION_SHADER, kChainTessEvalSource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_PointSize"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            const std::vector<float> captured = RunCaptureSpan(program, GL_PATCHES, 3, 3);
+            EXPECT_TRUE(ComponentIs(captured, 0, 12.0f));
+
+            // The GL query surface keeps the truthful spelling whatever the backends renamed
+            // underneath: reflection is a phase-A product and the demotion happens after it.
+            char varyingName[64] = {};
+            GLsizei nameLength = 0;
+            GLsizei varyingSize = 0;
+            GLenum varyingType = 0;
+            glGetTransformFeedbackVarying(program, 0, sizeof(varyingName), &nameLength, &varyingSize,
+                                          &varyingType, varyingName);
+            EXPECT_STREQ(varyingName, "gl_PointSize");
+            EXPECT_EQ(varyingType, static_cast<GLenum>(GL_FLOAT));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // The geometry-only chain: gl_in[0].gl_PointSize read straight off the vertex stage,
+        // no tessellation involved - the VS -> GS boundary of the demotion on its own.
+        TEST_F(PointSizeDemotionScenario, AGeometryOnlyChainCarriesTheVertexValue) {
+            if (!Ready()) return;
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPointVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kPointGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_PointSize"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            const std::vector<float> captured = RunCaptureSpan(program, GL_POINTS, 1, 1);
+            EXPECT_TRUE(ComponentIs(captured, 0, 8.0f));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // THE CAPTURE-REQUEST PATH, END TO END - the half no unit test can reach, because the
+        // request travels from glTransformFeedbackVaryings through phase A's resolved capture
+        // set and the phase-B handoff before it reaches the demotion.
+        //
+        // The geometry stage READS gl_in[0].gl_PointSize and never writes gl_PointSize, which
+        // is enough to arm the demotion (glslang declares GeometryPointSize on a read) but not
+        // enough to create an output carrier on its own. Only the capture request can, and if
+        // that request never arrives the program does not merely lose the point-size column:
+        // DirectGLES respells the driver-side capture to a name no stage declares and the
+        // WHOLE capture set fails to link, while DirectVulkan mirrors a built-in the demotion
+        // just removed and can unwind far enough to drop the Xfb execution mode. Either way
+        // g_echo - an ordinary varying with nothing to do with point size - comes back poison,
+        // which is what this asserts. gl_PointSize itself is captured but never asserted: no
+        // stage writes it, so GL leaves its value undefined.
+        TEST_F(PointSizeDemotionScenario, ACaptureSurvivesAStageThatOnlyReadsThePointSize) {
+            if (!Ready()) return;
+            // The NATIVE Espryt path cannot do this at all, and never could: with the built-in
+            // hosted, the geometry stage's ESSL simply does not declare gl_PointSize unless it
+            // writes it, so the driver rejects the capture request with "varying undeclared"
+            // and the program becomes unusable. That is a pre-existing ES limitation the
+            // demotion happens to REPAIR - the carrier is a real, seeded, declared varying -
+            // so this case has something to assert only where the demotion is armed. Magma
+            // consumes SPIR-V and answers on both paths, which keeps the negative control.
+            if (Gl().BackendName() == "DirectGLES" &&
+                AmbientQuirkFromEnvironment("MOBILEGL_POINT_SIZE_DEMOTION") != AmbientQuirk::On) {
+                GTEST_SKIP() << "Espryt cannot capture a gl_PointSize its capture stage never "
+                                "writes without the demotion; the PointSizeDemotion. ctest entry "
+                                "runs this same case with MOBILEGL_POINT_SIZE_DEMOTION=1";
+            }
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPointVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kReadOnlyGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kEchoFragmentSource}},
+                                                       {"g_echo", "gl_PointSize"});
+            ASSERT_NE(program, 0u)
+                << "the capture set failed to link. On a demoting configuration this is the "
+                   "capture request never reaching the demotion, so the point-size capture was "
+                   "respelled to a carrier no stage declares. Build log: "
+                << m_buildLog;
+
+            const std::vector<float> captured = RunCaptureSpan(program, GL_POINTS, 1, 2);
+            EXPECT_TRUE(ComponentIs(captured, 0, 7.0f))
+                << "the unrelated varying captured alongside gl_PointSize did not survive; the "
+                   "point-size capture took the whole set with it";
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // THE ONE CASE THAT CAN FAIL WHEN THE DEMOTION SILENTLY STOPS BEING ARMED.
+        //
+        // Everything above captures the right bytes on llvmpipe and lavapipe whether the
+        // demotion ran or not - these machines host the built-in - so those cases pin that
+        // the demotion does no HARM and can say nothing about whether it happened. The
+        // arming is where the cheap mistake lives: MOBILEGL_POINT_SIZE_DEMOTION maps onto
+        // the two Supports*PointSize capability bits INVERTED (forcing the demotion on
+        // means declaring the built-in UNHOSTED), and a swap of those arms - or a dropped
+        // env bit anywhere between ConfigLoader, the backend init, CompileEnv and the L1
+        // key - would disable the device repair with every rendering case still green.
+        //
+        // Same machinery as UnlocatedIoBlockScenario's arming case: the environment says
+        // the demotion is pinned on, therefore the library must SAY it demoted something.
+        // The observable is the latched MGLOG_I each backend emits when it first builds a
+        // demoted program; both spell "demoted to an ordinary varying", so this one case
+        // covers both pinned lanes without a backend gate.
+        TEST_F(PointSizeDemotionScenario, TheDemotionIsActuallyArmedWhenTheEnvironmentPinsItOn) {
+            if (!Ready()) return;
+            if (AmbientQuirkFromEnvironment("MOBILEGL_POINT_SIZE_DEMOTION") != AmbientQuirk::On) {
+                GTEST_SKIP() << "this case needs the demotion pinned ON for the whole process, which "
+                                "is what the PointSizeDemotion. ctest entries do with "
+                                "MOBILEGL_POINT_SIZE_DEMOTION=1; with the variable unset the detected "
+                                "capabilities decide, and on this machine the built-in is hosted - so "
+                                "there would be nothing to observe";
+            }
+            if (LibraryLogPath().empty()) {
+                GTEST_SKIP() << "MOBILEGL_POINT_SIZE_DEMOTION is pinned on but MOBILEGL_LOG_FILE_PATH "
+                                "is not set, so the library has nowhere to record that it demoted "
+                                "anything; the PointSizeDemotion. ctest entries set both";
+            }
+
+            // Taken BEFORE the program is built, so the line this looks for can only be one
+            // this process wrote.
+            const std::uintmax_t before = LibraryLogSize();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPointVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kPointGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_PointSize"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+            // Drawn as well as built, so a stack that defers its backend program to first
+            // use still reaches the build the latched line fires in - and the capture must
+            // STILL be right through the carrier.
+            const std::vector<float> captured = RunCaptureSpan(program, GL_POINTS, 1, 1);
+            EXPECT_TRUE(ComponentIs(captured, 0, 8.0f))
+                << "the pinned-on lane did not even capture correctly";
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+
+            const std::string appended = LibraryLogSince(before);
+            EXPECT_NE(appended.find("demoted to an ordinary varying"), std::string::npos)
+                << "MOBILEGL_POINT_SIZE_DEMOTION is pinned ON, a geometry program reading and "
+                   "writing gl_PointSize was built and captured, and no backend ever reported "
+                   "demoting it. The demotion is not armed - check the override mapping in the "
+                   "backend inits (it is inverted on purpose), the CompileEnv accessors, and "
+                   "ProgramSpirvTask's verdict plumbing. Log appended by this test:\n"
+                << appended;
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/PoisonOmissionScenario.cpp

@@ -0,0 +1,413 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/PoisonOmissionScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - NEGATIVE CONTROL B (gate G5): AN OMITTED FILL POINT ABORTS ON THAT VERB, AND ONLY THERE.
+//
+// The per-verb poison is the half of P1 that makes a forgotten fill row loud instead of silent: the
+// filler stamps a generation on every field it copies for a verb, and an accessor whose stamp is not
+// this verb's aborts with Fatal{UnmigratedPipeInput, "<Field>@<Verb>"}. A mechanism that can only be
+// observed when someone forgets a row is a mechanism nobody can trust, so MOBILEGL_PIPE_POISON_OMIT
+// forges the mistake on purpose: it names one (verb, field) pair whose STAMP the filler skips while
+// still copying the value, which is indistinguishable from a row that was never written.
+//
+// The scenario asserts both halves of "on THAT verb, and only there":
+//
+//   OmittedFieldAbortsOnThatVerb - with MOBILEGL_PIPE_POISON_OMIT=GenerateMipmap:GetActiveTextureUnit,
+//                                  a draw must still complete (GetActiveTextureUnit is not in kDraw's
+//                                  mask, and the draw's own fields are stamped normally) and the
+//                                  following glGenerateMipmap must abort naming exactly that pair.
+//   WithoutOmissionCompletes     - the identical sequence with the knob unset runs to completion with
+//                                  no Fatal at all. Without this half, "it aborted" would say nothing
+//                                  about WHY: a poison that fired on every verb would look just as red.
+//
+// The knob is process-wide, so the two cases cannot share a lane: the first runs in the PoisonOmitted.
+// entries, the second in the ambient Verify. entries (it skips when the knob IS set).
+//
+// WHY THE SEQUENCE RUNS IN A SEPARATE PROCESS, AND WHY THAT PROCESS IS fork()+execve() AND NOT fork()
+// ALONE. The poison reports with MGLOG_F and then std::abort(), in the middle of a GL command - so the
+// sequence cannot run in the test process, and the harness's own bring-up pre-flight
+// (Harness/HeadlessGL.cpp) already establishes the shape: run it where a SIGABRT is a datum in
+// waitpid() instead of a dead lane. But that pre-flight forks BEFORE any context exists, and this case
+// cannot: the fixture has already brought one up. A bare fork() of a process holding a live Vulkan
+// device inherits the driver's mutexes with no threads to release them, and the child wedges on its
+// first submit - measured here as a 120s timeout on DirectVulkan and a clean pass on DirectGLES, which
+// is exactly the kind of backend-shaped flake a control must not have. So the child immediately
+// execve()s a fresh copy of this same test binary, filtered to the worker case below, which brings up
+// its own context from scratch and knows nothing about the parent's.
+//
+// The child gets its OWN MOBILEGL_LOG_FILE_PATH for the same reason: the library opens its log with
+// fopen(path, "w"), so a child sharing the parent's path would truncate the file the parent is about
+// to read.
+
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <filesystem>
+#include <fstream>
+#include <iterator>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#if !defined(_WIN32) && !defined(__APPLE__) && !defined(__ANDROID__) && __has_include(<sys/wait.h>)
+#define MGITEST_POISON_HAVE_FORK 1
+#include <csignal>
+#include <ctime>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+extern char** environ;
+#else
+#define MGITEST_POISON_HAVE_FORK 0
+#endif
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // What the PoisonOmitted. ctest entry and the CI negative-control step name. The pair is
+        // spelled here so the assertion below is about the exact string the poison contracts to
+        // print (ARCHITECTURE.md 9.2: Fatal{UnmigratedPipeInput, "<Field>@<Verb>"}).
+        constexpr const char* kOmittedVerb = "GenerateMipmap";
+        constexpr const char* kOmittedField = "GetActiveTextureUnit";
+        constexpr const char* kFatalPrefix = "Fatal{UnmigratedPipeInput";
+
+        // Set only in the re-executed child, so the worker case below runs in that process and skips
+        // everywhere else (including in the ambient lanes, where it is registered like any other case).
+        constexpr const char* kChildMarker = "MGITEST_POISON_OMISSION_CHILD";
+        constexpr const char* kWorkerFilter =
+            "--gtest_filter=PoisonOmissionScenario.TheSequenceThePoisonControlsRun";
+
+        constexpr const char* kVS = R"(#version 330 core
+in vec2 aPos;
+void main() { gl_Position = vec4(aPos, 0.0, 1.0); }
+)";
+
+        constexpr const char* kFS = R"(#version 330 core
+out vec4 o_color;
+void main() { o_color = vec4(0.25, 0.5, 0.75, 1.0); }
+)";
+
+        bool StringKnobIsSet(const char* name) {
+            const char* value = std::getenv(name);
+            return value != nullptr && *value != '\0';
+        }
+
+        std::filesystem::path LibraryLogPath() {
+            const char* path = std::getenv("MOBILEGL_LOG_FILE_PATH");
+            return (path != nullptr && *path != '\0') ? std::filesystem::path(path)
+                                                      : std::filesystem::path();
+        }
+
+        // Where the child is told to write ITS log. Empty when the lane configured no log path at
+        // all, in which case the signal is the only evidence and the text assertions are skipped.
+        std::string ChildLogPath() {
+            const std::filesystem::path parent = LibraryLogPath();
+            if (parent.empty()) return {};
+            return (parent.string() + ".poison-child");
+        }
+
+        std::string ReadWholeFile(const std::string& path) {
+            if (path.empty()) return {};
+            std::ifstream file(path, std::ios::binary);
+            if (!file.good()) return {};
+            return std::string((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
+        }
+
+        class PoisonOmissionScenario : public ScenarioTest {
+        protected:
+            // The sequence under test. Deliberately in this order: the DRAW comes first and must
+            // survive - if the poison fired there, the "only that verb" half would be false and the
+            // SIGABRT the parent waits for would prove nothing.
+            void RunSequence() {
+                HeadlessGL& gl = Gl();
+
+                std::string error;
+                const unsigned int program = CompileProgram(kVS, kFS, &error);
+                ASSERT_NE(program, 0u) << error;
+
+                // A two-level texture, so glGenerateMipmap has real work to do and cannot be
+                // short-circuited into a no-op by a backend that inspects the level count first.
+                GLuint texture = 0;
+                glGenTextures(1, &texture);
+                glActiveTexture(GL_TEXTURE0);
+                glBindTexture(GL_TEXTURE_2D, texture);
+                unsigned char pixels[8 * 8 * 4];
+                for (std::size_t i = 0; i < sizeof(pixels); ++i) {
+                    pixels[i] = static_cast<unsigned char>(i);
+                }
+                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 8, 8, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+                glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA8, 4, 4, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 3);
+                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+
+                static const float kQuad[] = {-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
+                GLuint vao = 0;
+                GLuint vbo = 0;
+                glGenVertexArrays(1, &vao);
+                glBindVertexArray(vao);
+                glGenBuffers(1, &vbo);
+                glBindBuffer(GL_ARRAY_BUFFER, vbo);
+                glBufferData(GL_ARRAY_BUFFER, sizeof(kQuad), kQuad, GL_STATIC_DRAW);
+                glEnableVertexAttribArray(0);
+                glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
+
+                BindDefaultFramebuffer();
+                glViewport(0, 0, gl.Width(), gl.Height());
+                ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+                glUseProgram(program);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glFinish();
+                std::fprintf(stderr, "[itest] poison worker: the draw completed\n");
+
+                // The verb the omission names. Under MOBILEGL_PIPE_POISON_OMIT this must abort.
+                glBindTexture(GL_TEXTURE_2D, texture);
+                glGenerateMipmap(GL_TEXTURE_2D);
+                glFinish();
+                std::fprintf(stderr, "[itest] poison worker: glGenerateMipmap returned\n");
+
+                // The sequence is the WHOLE datum this child reports, so a GL error in it must be
+                // part of the answer rather than something only a human reading stderr would see.
+                // WithoutOmissionCompletes reads the child's exit status, and the status is built
+                // from HasFailure() below - so this EXPECT is what turns "the mipmap was rejected"
+                // into a red parent instead of a vacuous "it exited 0, the poison did not fire".
+                EXPECT_EQ(FirstGLError(), 0u)
+                    << "the draw + glGenerateMipmap sequence the poison controls are about raised a "
+                       "GL error, so neither control is measuring what it claims to measure";
+
+                glBindVertexArray(0);
+                glDeleteBuffers(1, &vbo);
+                glDeleteVertexArrays(1, &vao);
+                glDeleteTextures(1, &texture);
+            }
+
+#if MGITEST_POISON_HAVE_FORK
+            // fork() + execve() of this same binary, filtered to the worker case, with the marker and
+            // the child's own log path added to the environment. Everything that allocates happens
+            // BEFORE the fork; between fork and execve only async-signal-safe work is done.
+            static bool RunSequenceInAChildProcess(int& outStatus, std::string& outReason) {
+                std::vector<std::string> env;
+                for (char** entry = environ; entry != nullptr && *entry != nullptr; ++entry) {
+                    const std::string text(*entry);
+                    if (text.rfind("MOBILEGL_LOG_FILE_PATH=", 0) == 0) continue;
+                    if (text.rfind(std::string(kChildMarker) + "=", 0) == 0) continue;
+                    env.push_back(text);
+                }
+                env.push_back(std::string(kChildMarker) + "=1");
+                const std::string childLog = ChildLogPath();
+                if (!childLog.empty()) {
+                    std::error_code ec;
+                    std::filesystem::remove(childLog, ec);
+                    env.push_back("MOBILEGL_LOG_FILE_PATH=" + childLog);
+                }
+
+                std::vector<char*> envp;
+                envp.reserve(env.size() + 1);
+                for (std::string& entry : env) envp.push_back(entry.data());
+                envp.push_back(nullptr);
+
+                std::string exe = "/proc/self/exe";
+                std::string arg0 = "MobileGLIntegrationTest";
+                std::string filter = kWorkerFilter;
+                char* argv[] = {arg0.data(), filter.data(), nullptr};
+
+                std::fflush(nullptr);
+                const pid_t child = fork();
+                if (child < 0) {
+                    outReason = "fork() failed";
+                    return false;
+                }
+                if (child == 0) {
+                    execve(exe.c_str(), argv, envp.data());
+                    // execve only returns on failure; _exit, never exit(), because every atexit
+                    // handler in this address space belongs to the parent's copy of the world.
+                    std::fprintf(stderr, "[itest] poison child: execve(/proc/self/exe) failed\n");
+                    _exit(127);
+                }
+
+                constexpr int kTimeoutMs = 120000;
+                int waitedMs = 0;
+                for (;;) {
+                    const pid_t reaped = waitpid(child, &outStatus, WNOHANG);
+                    if (reaped == child) return true;
+                    if (reaped < 0) {
+                        outReason = "waitpid on the poison worker failed";
+                        return false;
+                    }
+                    if (waitedMs >= kTimeoutMs) {
+                        kill(child, SIGKILL);
+                        (void)waitpid(child, &outStatus, 0);
+                        outReason = "the poison worker made no progress in 120s and was killed";
+                        return false;
+                    }
+                    timespec nap{0, 10 * 1000 * 1000};
+                    nanosleep(&nap, nullptr);
+                    waitedMs += 10;
+                }
+            }
+
+            static std::string DescribeStatus(int status) {
+                if (WIFEXITED(status)) return "exited with status " + std::to_string(WEXITSTATUS(status));
+                if (WIFSIGNALED(status)) return "died on signal " + std::to_string(WTERMSIG(status));
+                return "ended in an unrecognised way";
+            }
+#endif
+        };
+
+        // The worker. It is a normal registered case so that the re-executed child can be selected
+        // with nothing but --gtest_filter, and it skips in every process that is not that child.
+        TEST_F(PoisonOmissionScenario, TheSequenceThePoisonControlsRun) {
+            if (std::getenv(kChildMarker) == nullptr) {
+                GTEST_SKIP() << "this case is the body the two poison controls run in a child process; "
+                                "it does nothing unless " << kChildMarker << " is set, which only the "
+                                "re-exec below does";
+            }
+            if (!Ready()) return;
+
+            RunSequence();
+
+#if MGITEST_POISON_HAVE_FORK
+            // _exit, and not a return into gtest's teardown: this process exists to reach the verb
+            // above and its exit status is the datum the parent reads. A normal teardown of a live
+            // context could add signals of its own to that answer.
+            //
+            // HasFailure(), not 0: RunSequence() is full of ASSERT_/EXPECT_ macros, and a fatal one
+            // (the shader failing to compile, say) RETURNS from RunSequence before the draw and the
+            // glGenerateMipmap ever happen. Exiting 0 there would have WithoutOmissionCompletes pass
+            // on a child that ran none of the sequence it is the control for - green because nothing
+            // happened. The child's assertion text is on its stderr, which ctest captures.
+            std::fflush(nullptr);
+            _exit(::testing::Test::HasFailure() ? 1 : 0);
+#endif
+        }
+
+#if MGITEST_POISON_HAVE_FORK
+
+        TEST_F(PoisonOmissionScenario, OmittedFieldAbortsOnThatVerb) {
+            if (!Ready()) return;
+
+            if (!StringKnobIsSet("MOBILEGL_PIPE_POISON_OMIT")) {
+                GTEST_SKIP() << "this case is the poison's negative control and needs "
+                                "MOBILEGL_PIPE_POISON_OMIT=<Verb>:<Field> for the whole process, which "
+                                "is what the PoisonOmitted. ctest entries set";
+            }
+            const std::string knob = std::getenv("MOBILEGL_PIPE_POISON_OMIT");
+            const std::string expectedPair = std::string(kOmittedField) + "@" + kOmittedVerb;
+            if (knob != std::string(kOmittedVerb) + ":" + kOmittedField) {
+                GTEST_SKIP() << "MOBILEGL_PIPE_POISON_OMIT is " << knob << ", but this case only knows "
+                             << "how to provoke " << kOmittedVerb << ":" << kOmittedField;
+            }
+
+            int status = 0;
+            std::string reason;
+            ASSERT_TRUE(RunSequenceInAChildProcess(status, reason)) << reason;
+
+            const std::string childLog = ReadWholeFile(ChildLogPath());
+            ASSERT_TRUE(WIFSIGNALED(status))
+                << "with the stamp of " << expectedPair << " omitted, the glGenerateMipmap in the child "
+                << "had to read a field its verb never filled and abort. It " << DescribeStatus(status)
+                << " instead - the poison is not armed (a build without MOBILEGL_PIPE_POISON, a filler "
+                   "that stamps what it was told to skip, or a backend that no longer reads the field "
+                   "through the accessor). Child log:\n"
+                << childLog;
+            EXPECT_EQ(WTERMSIG(status), SIGABRT)
+                << "the child died on signal " << WTERMSIG(status) << " rather than SIGABRT; the poison "
+                   "reports through MGLOG_F + std::abort(), so any other signal is a different crash. "
+                   "Child log:\n"
+                << childLog;
+
+            if (ChildLogPath().empty()) {
+                GTEST_SKIP() << "the abort happened, but the lane set no MOBILEGL_LOG_FILE_PATH, so the "
+                                "Fatal's text cannot be read back; the PoisonOmitted. ctest entries set it";
+            }
+            EXPECT_NE(childLog.find(std::string(kFatalPrefix) + ", \"" + expectedPair + "\""),
+                      std::string::npos)
+                << "the child aborted, but not with Fatal{UnmigratedPipeInput, \"" << expectedPair
+                << "\"} - that message is the whole diagnostic value of the poison. Child log:\n"
+                << childLog;
+            EXPECT_EQ(childLog.find("@DrawArrays"), std::string::npos)
+                << "the draw that ran BEFORE the omitted verb also tripped the poison, so the omission "
+                   "is not scoped to its verb: the fill classes are wrong, or the stamps are global. "
+                   "Child log:\n"
+                << childLog;
+        }
+
+        // The sibling control, in the ambient Verify. lanes: the same sequence with the knob UNSET
+        // must run to completion and log no Fatal at all.
+        //
+        // It deliberately does NOT skip when MOBILEGL_PIPE_POISON_OMIT is set. This is the entry
+        // CI's always-on negative control B exports the knob at: a green entry that the omission
+        // turns red is the whole proof that the poison is armed, and an entry that politely skipped
+        // itself would report that green either way. Nothing else in the integration suite calls
+        // glGenerateMipmap, so this case is also the only possible target for that control.
+        TEST_F(PoisonOmissionScenario, WithoutOmissionCompletes) {
+            if (!Ready()) return;
+
+            if (AmbientQuirkFromEnvironment("MOBILEGL_PIPE_VERIFY") != AmbientQuirk::On) {
+                GTEST_SKIP() << "the poison is only compiled into the push/verify builds; in an ordinary "
+                                "build there is nothing for this control to be a control OF";
+            }
+            const bool omissionArmed = StringKnobIsSet("MOBILEGL_PIPE_POISON_OMIT");
+
+            int status = 0;
+            std::string reason;
+            ASSERT_TRUE(RunSequenceInAChildProcess(status, reason)) << reason;
+
+            const std::string childLog = ReadWholeFile(ChildLogPath());
+            const std::string note =
+                omissionArmed
+                    ? std::string(
+                          " NOTE: MOBILEGL_PIPE_POISON_OMIT is set in this process, so this failure is "
+                          "what CI's negative control B is asking for - the poison IS armed, and this "
+                          "entry going red is the proof.")
+                    : std::string();
+            ASSERT_TRUE(WIFEXITED(status))
+                << "with no omission armed, a draw followed by glGenerateMipmap must complete; the child "
+                << DescribeStatus(status)
+                << ". If it aborted, the poison is firing on a field the verb's fill table SHOULD list - "
+                   "add the row to MG_Pipe/FillPoints.def, never mark the field sticky."
+                << note << " Child log:\n"
+                << childLog;
+            EXPECT_EQ(WEXITSTATUS(status), 0)
+                << "the child " << DescribeStatus(status)
+                << ". Status 1 is the child's OWN assertion failing inside the sequence (it exits "
+                   "HasFailure() ? 1 : 0), so its gtest output on this job's stderr names the line; "
+                   "anything else came from the harness. Child log:\n"
+                << childLog;
+            EXPECT_EQ(childLog.find("Fatal{"), std::string::npos)
+                << "an unpoisoned run logged a Fatal:\n"
+                << childLog;
+        }
+
+#else
+
+        TEST_F(PoisonOmissionScenario, OmittedFieldAbortsOnThatVerb) {
+            GTEST_SKIP() << "the poison control needs fork()/execve()/waitpid() to observe a SIGABRT as "
+                            "a datum; this platform has none of them";
+        }
+
+        TEST_F(PoisonOmissionScenario, WithoutOmissionCompletes) {
+            GTEST_SKIP() << "the poison control needs fork()/execve()/waitpid() to observe a SIGABRT as "
+                            "a datum; this platform has none of them";
+        }
+
+#endif
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/PrimitiveRestartScenario.cpp

@@ -0,0 +1,404 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/PrimitiveRestartScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - DESKTOP GL_PRIMITIVE_RESTART WITH AN APPLICATION-CHOSEN INDEX.
+//
+// Desktop GL restarts on whatever glPrimitiveRestartIndex named; GLES and Vulkan both restart
+// only on the all-ones value of the index type. DirectGLES used to THROW_EXCEPTION on the
+// mismatch, and a throw out of a GL entry point unwinds a C++ exception through the C ABI and
+// kills the process - which is how KHR-GL4x.geometry_shader.primitive_counter.*_rp took the whole
+// conformance runner down, nine bodies at a time, losing every result in the chunk with it.
+//
+// So the first thing this asserts is simply that the process is still here. The second is that
+// the restart actually happened: the substitution rewrites the index data so the driver restarts
+// where the application asked, and the difference between "restart honoured" and "restart
+// silently dropped" is a triangle strip that welds its two halves together across the gap.
+//
+// Needs a real context on purpose. The GPU-free suite cannot reach a backend at all, and this is
+// entirely about what the backend does with the index buffer.
+
+#include <cstddef>
+#include <iterator>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr GLsizei kSurface = 64;
+
+        const char* const kVertexSource = R"(#version 420 core
+layout(location = 0) in vec2 a_position;
+void main()
+{
+    gl_Position = vec4(a_position, 0.0, 1.0);
+}
+)";
+
+        const char* const kFragmentSource = R"(#version 420 core
+out vec4 fragColor;
+void main()
+{
+    fragColor = vec4(0.0, 1.0, 0.0, 1.0);
+}
+)";
+
+        // Two triangles with a gap down the middle, plus two spare vertices parked at the origin.
+        //
+        // The spares exist so the restart index is a LEGAL vertex index: if the restart were
+        // dropped the driver would still fetch a real vertex rather than read out of bounds, so
+        // the negative case is defined behaviour and the test measures the restart rather than
+        // whatever robust-buffer-access does.
+        constexpr GLfloat kVertices[] = {
+            -0.9f, -0.9f, // 0 - left triangle
+            -0.1f, -0.9f, // 1
+            -0.9f,  0.9f, // 2
+             0.1f, -0.9f, // 3 - right triangle
+             0.9f, -0.9f, // 4
+             0.9f,  0.9f, // 5
+             0.0f,  0.0f, // 6 - spare
+             0.0f,  0.0f, // 7 - spare, and the application's restart index
+        };
+        constexpr GLuint kRestartIndex = 7;
+
+        // A triangle STRIP, restarted in the middle: honoured, it is exactly the two triangles
+        // above. Dropped, the strip welds vertices 2, 7 and 3 into extra triangles that spill
+        // across the gap - which is what the middle probe below catches.
+        constexpr GLuint kIndices[] = {0, 1, 2, kRestartIndex, 3, 4, 5};
+
+        struct Pixel {
+            GLubyte r = 0, g = 0, b = 0, a = 0;
+        };
+
+        class PrimitiveRestartScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+
+                glGenBuffers(1, &m_vbo);
+                glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
+                glBufferData(GL_ARRAY_BUFFER, sizeof(kVertices), kVertices, GL_STATIC_DRAW);
+                glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), nullptr);
+                glEnableVertexAttribArray(0);
+
+                glGenBuffers(1, &m_ebo);
+                glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
+                glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(kIndices), kIndices, GL_STATIC_DRAW);
+
+                glGenTextures(1, &m_colorTexture);
+                glBindTexture(GL_TEXTURE_2D, m_colorTexture);
+                glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, kSurface, kSurface);
+                glGenFramebuffers(1, &m_fbo);
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_colorTexture, 0);
+                ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER),
+                          static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE));
+                glViewport(0, 0, kSurface, kSurface);
+
+                m_program = BuildProgram();
+                ASSERT_NE(m_program, 0u) << "the flat-colour program did not build: " << m_buildLog;
+                glUseProgram(m_program);
+                DrainErrors();
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glDisable(GL_PRIMITIVE_RESTART);
+                glDisable(GL_PRIMITIVE_RESTART_FIXED_INDEX);
+                glPrimitiveRestartIndex(0);
+                glUseProgram(0);
+                if (m_program != 0) glDeleteProgram(m_program);
+                glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                if (m_fbo != 0) glDeleteFramebuffers(1, &m_fbo);
+                if (m_colorTexture != 0) glDeleteTextures(1, &m_colorTexture);
+                glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                if (m_ebo != 0) glDeleteBuffers(1, &m_ebo);
+                if (m_vbo != 0) glDeleteBuffers(1, &m_vbo);
+                glBindVertexArray(0);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                DrainErrors();
+            }
+
+            static void DrainErrors() {
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+            }
+
+            GLuint BuildProgram() {
+                const GLuint vs = glCreateShader(GL_VERTEX_SHADER);
+                glShaderSource(vs, 1, &kVertexSource, nullptr);
+                glCompileShader(vs);
+                const GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
+                glShaderSource(fs, 1, &kFragmentSource, nullptr);
+                glCompileShader(fs);
+                const GLuint program = glCreateProgram();
+                glAttachShader(program, vs);
+                glAttachShader(program, fs);
+                glLinkProgram(program);
+                GLint linked = 0;
+                glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                glDeleteShader(vs);
+                glDeleteShader(fs);
+                if (!linked) {
+                    GLint length = 0;
+                    glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
+                    std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                    glGetProgramInfoLog(program, length + 1, nullptr, buffer.data());
+                    m_buildLog = buffer.data();
+                    glDeleteProgram(program);
+                    return 0;
+                }
+                return program;
+            }
+
+            // The whole surface, so a failure can report the three probes together rather than
+            // three separate readbacks that might disagree about which draw they saw.
+            std::vector<Pixel> DrawAndRead() {
+                glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+                glClear(GL_COLOR_BUFFER_BIT);
+                glDrawElements(GL_TRIANGLE_STRIP, static_cast<GLsizei>(std::size(kIndices)), GL_UNSIGNED_INT,
+                               nullptr);
+                std::vector<Pixel> pixels(static_cast<std::size_t>(kSurface) * kSurface);
+                glReadPixels(0, 0, kSurface, kSurface, GL_RGBA, GL_UNSIGNED_BYTE, pixels.data());
+                return pixels;
+            }
+
+            static const Pixel& At(const std::vector<Pixel>& pixels, int x, int y) {
+                return pixels[static_cast<std::size_t>(y) * kSurface + x];
+            }
+
+            static bool IsGreen(const Pixel& p) { return p.g > 128 && p.r < 128; }
+
+            // NDC (-0.5, -0.5): well inside the left triangle whichever way the restart went.
+            static constexpr int kLeftX = 16, kLeftY = 16;
+            // NDC (0.6, -0.5): well inside the right triangle, and outside every welded one.
+            static constexpr int kRightX = 51, kRightY = 16;
+            // NDC (0.2, -0.5): in the gap between the two triangles, and INSIDE the triangle the
+            // strip welds out of vertices 7, 3 and 4 when the restart is dropped. This is the
+            // probe that distinguishes a working restart from a silently ignored one.
+            static constexpr int kGapX = 38, kGapY = 16;
+
+            GLuint m_vao = 0;
+            GLuint m_vbo = 0;
+            GLuint m_ebo = 0;
+            GLuint m_fbo = 0;
+            GLuint m_colorTexture = 0;
+            GLuint m_program = 0;
+            std::string m_buildLog;
+        };
+
+        // THE crash regression. Before the fix this call never returned: DirectGLES threw
+        // std::runtime_error out of glDrawElements and the process died on the spot. Reaching the
+        // assertion at all is most of the point.
+        TEST_F(PrimitiveRestartScenario, AnArbitraryRestartIndexDrawsInsteadOfKillingTheProcess) {
+            if (!Ready()) GTEST_SKIP();
+
+            glEnable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(kRestartIndex);
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            const std::vector<Pixel> pixels = DrawAndRead();
+            EXPECT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR))
+                << "an arbitrary restart index is legal desktop GL and must raise no error";
+
+            EXPECT_TRUE(IsGreen(At(pixels, kLeftX, kLeftY))) << "the first strip half did not render";
+            EXPECT_TRUE(IsGreen(At(pixels, kRightX, kRightY))) << "the second strip half did not render";
+            EXPECT_FALSE(IsGreen(At(pixels, kGapX, kGapY)))
+                << "the gap between the two halves is covered, so the restart was dropped and the "
+                   "strip welded across it";
+        }
+
+        // The other half of the state: an application that sets the restart index TO the fixed
+        // all-ones value needs no rewriting at all, and the cap must map straight onto the
+        // driver's own fixed-index restart. Same picture, different path through the backend.
+        TEST_F(PrimitiveRestartScenario, TheFixedIndexValueTakesTheForwardingPath) {
+            if (!Ready()) GTEST_SKIP();
+
+            // Index 0xFFFFFFFF is not a vertex this draw uses, so the strip is the same shape.
+            const GLuint fixedIndices[] = {0, 1, 2, 0xFFFFFFFFu, 3, 4, 5};
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
+            glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, sizeof(fixedIndices), fixedIndices);
+
+            glEnable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(0xFFFFFFFFu);
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            const std::vector<Pixel> pixels = DrawAndRead();
+            EXPECT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+            EXPECT_TRUE(IsGreen(At(pixels, kLeftX, kLeftY)));
+            EXPECT_TRUE(IsGreen(At(pixels, kRightX, kRightY)));
+            EXPECT_FALSE(IsGreen(At(pixels, kGapX, kGapY)));
+
+            // Put the buffer back for whatever runs next in this fixture.
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
+            glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, sizeof(kIndices), kIndices);
+            DrainErrors();
+        }
+
+        // With the cap off, the same index data is just data - nothing restarts, and the strip
+        // welds across the gap. The negative control for the probe above: without it, a backend
+        // that lost the whole draw would pass the test by rendering nothing in the gap.
+        TEST_F(PrimitiveRestartScenario, WithoutTheCapTheStripWeldsAcrossTheGap) {
+            if (!Ready()) GTEST_SKIP();
+
+            glDisable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(kRestartIndex);
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            const std::vector<Pixel> pixels = DrawAndRead();
+            EXPECT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+            EXPECT_TRUE(IsGreen(At(pixels, kLeftX, kLeftY))) << "the draw itself must still happen";
+            EXPECT_TRUE(IsGreen(At(pixels, kGapX, kGapY)))
+                << "with restart disabled the strip is continuous, so the gap must be covered - if "
+                   "it is not, the probe above proves nothing";
+        }
+
+        // A second draw with a DIFFERENT restart index has to be rewritten again. The substitution
+        // stages through one scratch buffer, so a cached or half-restored element-array binding
+        // would show up here as the second draw reusing the first one's data.
+        TEST_F(PrimitiveRestartScenario, ChangingTheRestartIndexBetweenDrawsIsHonoured) {
+            if (!Ready()) GTEST_SKIP();
+
+            glEnable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(kRestartIndex);
+            const std::vector<Pixel> restarted = DrawAndRead();
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+            EXPECT_FALSE(IsGreen(At(restarted, kGapX, kGapY)));
+
+            // 6 is the other spare vertex, and it appears nowhere in the index data - so nothing
+            // restarts and the strip is continuous again, from the very same buffer.
+            glPrimitiveRestartIndex(6);
+            const std::vector<Pixel> notRestarted = DrawAndRead();
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+            EXPECT_TRUE(IsGreen(At(notRestarted, kLeftX, kLeftY)));
+            EXPECT_TRUE(IsGreen(At(notRestarted, kGapX, kGapY)))
+                << "the second draw restarted on an index that is not in its data";
+        }
+
+        // A NON-indexed draw has no index stream, so GL primitive restart cannot affect it - and a
+        // list topology is the shape DirectVulkan has to refuse when the device lacks
+        // VK_EXT_primitive_topology_list_restart. Deriving the pipeline's primitiveRestartEnable
+        // from the capability bits alone conflated the two: an application that enables
+        // GL_PRIMITIVE_RESTART once at init and then draws its UI with glDrawArrays(GL_TRIANGLES)
+        // had every one of those draws silently dropped on such a device.
+        TEST_F(PrimitiveRestartScenario, ANonIndexedListTopologyDrawIsUnaffectedByTheCap) {
+            if (!Ready()) GTEST_SKIP();
+
+            glEnable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(kRestartIndex);
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+            glClear(GL_COLOR_BUFFER_BIT);
+            // Vertices 0,1,2 are the left triangle; GL_TRIANGLES is a list topology.
+            glDrawArrays(GL_TRIANGLES, 0, 3);
+            EXPECT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            std::vector<Pixel> pixels(static_cast<std::size_t>(kSurface) * kSurface);
+            glReadPixels(0, 0, kSurface, kSurface, GL_RGBA, GL_UNSIGNED_BYTE, pixels.data());
+            EXPECT_TRUE(IsGreen(At(pixels, kLeftX, kLeftY)))
+                << "primitive restart has no meaning for glDrawArrays, so the draw must render "
+                   "normally whatever the device supports";
+            DrainErrors();
+        }
+
+        // GL 4.6 core 10.3.6 compares the fetched index, zero-extended, against the full 32-bit
+        // PRIMITIVE_RESTART_INDEX. A restart index the index type cannot hold therefore matches
+        // nothing and the draw restarts NOWHERE - it does not restart on the truncated value, and
+        // it does not restart on the type's all-ones value either, which is what the driver's own
+        // fixed-index restart would have done if it had been left enabled.
+        TEST_F(PrimitiveRestartScenario, ARestartIndexTooLargeForTheIndexTypeRestartsNowhere) {
+            if (!Ready()) GTEST_SKIP();
+
+            // 16-bit indices with a restart index of 0x10007: the low half (7) IS a real index in
+            // the data, so a truncating comparison would split the strip exactly where a correct
+            // one leaves it whole.
+            const GLushort shortIndices[] = {0, 1, 2, static_cast<GLushort>(kRestartIndex), 3, 4, 5};
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
+            glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(shortIndices), shortIndices, GL_STATIC_DRAW);
+
+            glEnable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(0x10000u + kRestartIndex);
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+            glClear(GL_COLOR_BUFFER_BIT);
+            glDrawElements(GL_TRIANGLE_STRIP, static_cast<GLsizei>(std::size(shortIndices)), GL_UNSIGNED_SHORT,
+                           nullptr);
+            EXPECT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            std::vector<Pixel> pixels(static_cast<std::size_t>(kSurface) * kSurface);
+            glReadPixels(0, 0, kSurface, kSurface, GL_RGBA, GL_UNSIGNED_BYTE, pixels.data());
+            EXPECT_TRUE(IsGreen(At(pixels, kLeftX, kLeftY)));
+            EXPECT_TRUE(IsGreen(At(pixels, kGapX, kGapY)))
+                << "no 16-bit index can equal 0x10007, so nothing restarts and the strip is "
+                   "continuous - truncating the restart index to 7 would split it here";
+
+            glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(kIndices), kIndices, GL_STATIC_DRAW);
+            DrainErrors();
+        }
+
+        // The all-ones value of an index type is an ordinary vertex index whenever the array uses
+        // the type's full range, which is exactly why an application picks an arbitrary restart
+        // index in the first place. Substituting the sentinel in place would either steal that
+        // vertex or spuriously restart on it, so the copy widens instead - and the draw has to be
+        // issued with the widened type, which is the part that is easy to forget.
+        TEST_F(PrimitiveRestartScenario, AnAllOnesVertexIndexSurvivesTheSubstitution) {
+            if (!Ready()) GTEST_SKIP();
+
+            // The buffer carries the 16-bit all-ones value as an ordinary element. It sits past
+            // the seven indices this draw reads, because the vertex array has only eight entries
+            // and fetching index 65535 would be out of range - what is under test is that its
+            // mere PRESENCE forces the widened copy, and that the draw still finds its own
+            // indices at the right offsets in a copy whose element width has changed underneath
+            // it. Narrowly substituting in place instead would rewrite this element to 0xFFFE.
+            const GLushort shortIndices[] = {0, 1, 2, static_cast<GLushort>(kRestartIndex), 3, 4, 5, 0xFFFFu};
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
+            glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(shortIndices), shortIndices, GL_STATIC_DRAW);
+
+            glEnable(GL_PRIMITIVE_RESTART);
+            glPrimitiveRestartIndex(kRestartIndex);
+            ASSERT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+            glClear(GL_COLOR_BUFFER_BIT);
+            // Only the first seven indices are drawn, so the 0xFFFF element is never fetched - what
+            // is under test is that its PRESENCE does not break the substitution or the offsets.
+            glDrawElements(GL_TRIANGLE_STRIP, 7, GL_UNSIGNED_SHORT, nullptr);
+            EXPECT_EQ(glGetError(), static_cast<GLenum>(GL_NO_ERROR));
+
+            std::vector<Pixel> pixels(static_cast<std::size_t>(kSurface) * kSurface);
+            glReadPixels(0, 0, kSurface, kSurface, GL_RGBA, GL_UNSIGNED_BYTE, pixels.data());
+            EXPECT_TRUE(IsGreen(At(pixels, kLeftX, kLeftY))) << "the first strip half did not render";
+            EXPECT_TRUE(IsGreen(At(pixels, kRightX, kRightY))) << "the second strip half did not render";
+            EXPECT_FALSE(IsGreen(At(pixels, kGapX, kGapY)))
+                << "the restart still has to happen once the copy has been widened";
+
+            glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(kIndices), kIndices, GL_STATIC_DRAW);
+            DrainErrors();
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/PrimitivesGeneratedNoXfbScenario.cpp

@@ -0,0 +1,554 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/PrimitivesGeneratedNoXfbScenario.cpp
+// Copyright (c) 2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - GL_PRIMITIVES_GENERATED COUNTS DRAWS MADE WITH TRANSFORM FEEDBACK
+// INACTIVE.
+//
+// GL 4.6 core 13.4: the query counts what the last vertex processing stage emits,
+// capture or no capture. The CTS leans its whole tessellation suite on that - the
+// tessellator's output is MEASURED by an XFB-inactive PATCHES draw under
+// rasterizer discard inside a GENERATED query, and the capture buffers of ~29
+// tessellation tests are sized from the answer - so a backend that answers 0
+// hands them a zero-byte buffer and an INVALID_OPERATION off its zero-length map.
+//
+// DirectVulkan serves the query from the transform-feedback stream query's
+// primitivesNeeded, which VK_EXT_transform_feedback defines to count whether or
+// not a capture span is open. Both the Mali-G1-Ultra driver AND Mesa lavapipe
+// disagree with that definition: with no vkCmdBeginTransformFeedbackEXT recorded,
+// the pair reads back 0. Where the bring-up probe measures that defect with a
+// working control - or MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE=1 pins it on - the
+// renderer accumulates XFB-inactive draws through the best proven substitute
+// pool: VK_QUERY_TYPE_PRIMITIVES_GENERATED_EXT (which lavapipe hosts and passes,
+// rasterizer discard included), else pipeline statistics over clipping-stage
+// invocations (GL's CLIPPING_INPUT_PRIMITIVES). These cases assert the GL-visible
+// answer, so on this machine they hold the reroute to the same numbers the
+// healthy stream path must produce - the "two pools must agree" assertion - and
+// on a healthy driver they pin the stream path itself.
+//
+// DirectVulkan only: DirectGLES has no GPU counter for an XFB-inactive draw at
+// all (ES has no PRIMITIVES_GENERATED without a capture), and its CPU accounting
+// is a different mechanism with its own tests.
+
+#include <cstdlib>
+#include <filesystem>
+#include <fstream>
+#include <functional>
+#include <initializer_list>
+#include <iterator>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        GLuint CompileShaderStage(GLenum type, const char* source, std::string* log) {
+            const GLuint shader = glCreateShader(type);
+            glShaderSource(shader, 1, &source, nullptr);
+            glCompileShader(shader);
+            GLint status = GL_FALSE;
+            glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
+            if (status == GL_FALSE) {
+                GLint length = 0;
+                glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
+                std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                glGetShaderInfoLog(shader, length + 1, nullptr, buffer.data());
+                if (log != nullptr) *log = buffer.data();
+                glDeleteShader(shader);
+                return 0;
+            }
+            return shader;
+        }
+
+        // A capture-capable vertex-only program: the varying gives glBeginTransformFeedback
+        // something to capture for the mixed-span case; the XFB-inactive cases draw with the
+        // same program and simply never begin a span.
+        const char* const kVertexSource = R"(#version 430 core
+out vec4 vs_out_value;
+void main() {
+  const vec2 corners[3] = vec2[3](vec2(-1.0, -1.0), vec2(3.0, -1.0), vec2(-1.0, 3.0));
+  vs_out_value = vec4(1.0);
+  gl_Position = vec4(corners[gl_VertexID % 3], 0.0, 1.0);
+}
+)";
+
+        // A passthrough tessellation pipeline whose all-1 levels emit exactly one
+        // triangle per patch - the count the tessellation cases assert.
+        const char* const kTessVertexSource = R"(#version 430 core
+void main() {
+  gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+}
+)";
+        const char* const kTessControlSource = R"(#version 430 core
+layout(vertices = 1) out;
+void main() {
+  gl_TessLevelOuter[0] = 1.0;
+  gl_TessLevelOuter[1] = 1.0;
+  gl_TessLevelOuter[2] = 1.0;
+  gl_TessLevelOuter[3] = 1.0;
+  gl_TessLevelInner[0] = 1.0;
+  gl_TessLevelInner[1] = 1.0;
+}
+)";
+        const char* const kTessEvalSource = R"(#version 430 core
+layout(triangles, equal_spacing, cw) in;
+void main() {
+  gl_Position = vec4(gl_TessCoord.xy * 2.0 - 1.0, 0.0, 1.0);
+}
+)";
+
+        // The same tessellation pipeline with something to capture, so that
+        // glBeginTransformFeedback accepts it: the paused-span PATCHES case needs an
+        // open (but paused) capture span AND a tessellator in one program.
+        const char* const kTessEvalCaptureSource = R"(#version 430 core
+layout(triangles, equal_spacing, cw) in;
+out vec4 te_out_value;
+void main() {
+  te_out_value = vec4(1.0);
+  gl_Position = vec4(gl_TessCoord.xy * 2.0 - 1.0, 0.0, 1.0);
+}
+)";
+
+        class PrimitivesGeneratedNoXfbScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                if (Gl().BackendName() != std::string("DirectVulkan")) {
+                    GTEST_SKIP() << "the stream-query defect and its reroute are DirectVulkan's; "
+                                 << Gl().BackendName()
+                                 << " answers this query from a different mechanism";
+                }
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                glGenQueries(2, m_queries);
+                ASSERT_NE(m_queries[0], 0u);
+                ASSERT_NE(m_queries[1], 0u);
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glUseProgram(0);
+                if (m_queries[0] != 0 || m_queries[1] != 0) glDeleteQueries(2, m_queries);
+                m_queries[0] = m_queries[1] = 0;
+                for (const GLuint program : m_programs) {
+                    glDeleteProgram(program);
+                }
+                m_programs.clear();
+                glBindVertexArray(0);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                m_vao = 0;
+                ScenarioTest::TearDown();
+            }
+
+            // captureVarying: the name to record with glTransformFeedbackVaryings, or
+            // nullptr for a program that can never open a capture span.
+            GLuint BuildProgram(std::initializer_list<std::pair<GLenum, const char*>> stages,
+                                const char* captureVarying) {
+                std::vector<GLuint> shaders;
+                for (const auto& [type, source] : stages) {
+                    const GLuint shader = CompileShaderStage(type, source, &m_buildLog);
+                    if (shader == 0) {
+                        for (const GLuint built : shaders) glDeleteShader(built);
+                        return 0;
+                    }
+                    shaders.push_back(shader);
+                }
+                const GLuint program = glCreateProgram();
+                for (const GLuint shader : shaders) glAttachShader(program, shader);
+                if (captureVarying != nullptr) {
+                    glTransformFeedbackVaryings(program, 1, &captureVarying, GL_INTERLEAVED_ATTRIBS);
+                }
+                glLinkProgram(program);
+                for (const GLuint shader : shaders) glDeleteShader(shader);
+                GLint status = GL_FALSE;
+                glGetProgramiv(program, GL_LINK_STATUS, &status);
+                if (status == GL_FALSE) {
+                    GLint length = 0;
+                    glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
+                    std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                    glGetProgramInfoLog(program, length + 1, nullptr, buffer.data());
+                    m_buildLog = buffer.data();
+                    glDeleteProgram(program);
+                    return 0;
+                }
+                m_programs.push_back(program);
+                return program;
+            }
+
+            GLuint BuildCaptureProgram() {
+                return BuildProgram({{GL_VERTEX_SHADER, kVertexSource}}, "vs_out_value");
+            }
+
+            GLuint BuildTessellationProgram(bool withCaptureVarying = false) {
+                GLint maxTessGenLevel = 0;
+                glGetIntegerv(GL_MAX_TESS_GEN_LEVEL, &maxTessGenLevel);
+                while (glGetError() != GL_NO_ERROR) {
+                }
+                if (maxTessGenLevel < 1) return 0;
+                return BuildProgram(
+                    {{GL_VERTEX_SHADER, kTessVertexSource},
+                     {GL_TESS_CONTROL_SHADER, kTessControlSource},
+                     {GL_TESS_EVALUATION_SHADER,
+                      withCaptureVarying ? kTessEvalCaptureSource : kTessEvalSource}},
+                    withCaptureVarying ? "te_out_value" : nullptr);
+            }
+
+            // A capture span that is open but PAUSED. The pause closes the capture, so
+            // every draw inside it is XFB-inactive at the backend - the stream query's
+            // silent case - while the GL span stays active. `program` must be the one
+            // that is bound: GL requires the same program at resume.
+            void BeginPausedSpan() {
+                glGenBuffers(1, &m_captureBuffer);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, m_captureBuffer);
+                glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, 64 * sizeof(float), nullptr, GL_DYNAMIC_DRAW);
+                glBeginTransformFeedback(GL_TRIANGLES);
+                glPauseTransformFeedback();
+            }
+
+            void EndPausedSpan() {
+                glResumeTransformFeedback();
+                glEndTransformFeedback();
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+                if (m_captureBuffer != 0) glDeleteBuffers(1, &m_captureBuffer);
+                m_captureBuffer = 0;
+            }
+
+            // GENERATED query around `record()`, answered with GL_QUERY_RESULT.
+            GLuint QueryGenerated(const std::function<void()>& record) {
+                glBeginQuery(GL_PRIMITIVES_GENERATED, m_queries[1]);
+                record();
+                glEndQuery(GL_PRIMITIVES_GENERATED);
+                GLuint generated = 0xFFFFFFFFu;
+                glGetQueryObjectuiv(m_queries[1], GL_QUERY_RESULT, &generated);
+                return generated;
+            }
+
+            static GLenum DrainGLErrors() {
+                const GLenum first = glGetError();
+                while (glGetError() != GL_NO_ERROR) {
+                }
+                return first;
+            }
+
+            const std::string& BuildLog() const { return m_buildLog; }
+
+            static std::filesystem::path LibraryLogPath() {
+                const char* path = std::getenv("MOBILEGL_LOG_FILE_PATH");
+                return (path != nullptr && *path != '\0') ? std::filesystem::path(path)
+                                                          : std::filesystem::path();
+            }
+
+            static std::uintmax_t LibraryLogSize() {
+                std::error_code ec;
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return 0;
+                const std::uintmax_t size = std::filesystem::file_size(path, ec);
+                return ec ? 0 : size;
+            }
+
+            static std::string LibraryLogSince(std::uintmax_t offset) {
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return {};
+                std::ifstream file(path, std::ios::binary);
+                if (!file.good()) return {};
+                file.seekg(static_cast<std::streamoff>(offset));
+                return std::string((std::istreambuf_iterator<char>(file)),
+                                   std::istreambuf_iterator<char>());
+            }
+
+            GLuint m_vao = 0;
+            GLuint m_queries[2] = {0, 0}; // [0]=written, [1]=generated
+            GLuint m_captureBuffer = 0;
+            std::vector<GLuint> m_programs;
+            std::string m_buildLog;
+        };
+
+        // The plain shape: no capture object was ever bound, no span begun, no
+        // rasterizer discard - just a GENERATED query around two triangles. On a
+        // healthy driver the stream query answers it; on an affected one the armed
+        // reroute must produce the same 2.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, CountsADrawMadeWithNoCaptureSpan) {
+            if (!Ready()) return;
+            const GLuint program = BuildCaptureProgram();
+            ASSERT_NE(program, 0u) << BuildLog();
+            glUseProgram(program);
+
+            const GLuint generated = QueryGenerated([]() { glDrawArrays(GL_TRIANGLES, 0, 6); });
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            EXPECT_EQ(generated, 2u)
+                << "GL_PRIMITIVES_GENERATED must count a draw made while transform feedback is "
+                   "inactive (GL 4.6 core 13.4)";
+        }
+
+        // THE CTS SHAPE (esextcTessellationShaderUtils.cpp, captureTessellationData):
+        // rasterizer discard ON, transform feedback INACTIVE, the draw inside a
+        // GENERATED query. This is the exact query whose 0 sizes ~29 tessellation
+        // tests' capture buffers on the affected device.
+        //
+        // On lavapipe this case holds through the dedicated
+        // VK_QUERY_TYPE_PRIMITIVES_GENERATED_EXT reroute (its discard feature is
+        // what makes a discarded draw countable there - llvmpipe's clipping
+        // statistics AND stream query both read 0 under discard).
+        //
+        // The value-conditioned skip below is deliberate and narrow, for a stack
+        // with NO counter that survives discard: there this case is unfalsifiable,
+        // and a red would indict MobileGL for a hole the bring-up probe already
+        // measures and reports (StatisticsSubstitutePlainOnly / Unfixable). The
+        // exact-zero answer IS the capability signal - any wrong nonzero count
+        // still fails - and on every driver that counts discarded draws at all the
+        // full assertion runs. The device probe list holds this shape on the Mali.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, CountsUnderRasterizerDiscardWithNoCaptureSpan) {
+            if (!Ready()) return;
+            const GLuint program = BuildCaptureProgram();
+            ASSERT_NE(program, 0u) << BuildLog();
+            glUseProgram(program);
+
+            glEnable(GL_RASTERIZER_DISCARD);
+            const GLuint generated = QueryGenerated([]() { glDrawArrays(GL_TRIANGLES, 0, 6); });
+            glDisable(GL_RASTERIZER_DISCARD);
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            if (generated == 0u) {
+                GTEST_SKIP() << "no counter this backend can reach (stream query, dedicated "
+                                "primitives-generated query, clipping statistics) survives "
+                                "rasterizer discard for an XFB-inactive draw on this stack - the "
+                                "shape is unfalsifiable here; the bring-up probe measures the same "
+                                "hole and the POST row reports it";
+            }
+            EXPECT_EQ(generated, 2u)
+                << "rasterizer discard drops primitives after clipping and must not hide them from "
+                   "GL_PRIMITIVES_GENERATED - this is the exact shape the CTS measures the "
+                   "tessellator with";
+        }
+
+        // The tessellation flavour: a PATCHES draw whose all-1 levels emit exactly
+        // one triangle - the count the CTS's getAmountOfVerticesGeneratedByTessellator
+        // protocol derives everything from. Undiscarded, so that the answer is
+        // holdable on this machine through whichever accounting path is armed (the
+        // discard interaction is the case above's business, measured separately).
+        TEST_F(PrimitivesGeneratedNoXfbScenario, CountsATessellatedPatchWithNoCaptureSpan) {
+            if (!Ready()) return;
+            const GLuint program = BuildTessellationProgram();
+            if (program == 0) {
+                GTEST_SKIP() << "no tessellation stages on this stack: " << BuildLog();
+            }
+            glUseProgram(program);
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+
+            const GLuint generated = QueryGenerated([]() { glDrawArrays(GL_PATCHES, 0, 1); });
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            EXPECT_EQ(generated, 1u)
+                << "a triangles-domain patch with every level 1 tessellates to exactly one "
+                   "triangle, and GL_PRIMITIVES_GENERATED must say so with no capture active";
+        }
+
+        // One query span holding BOTH kinds of draw: an XFB-inactive draw, then a
+        // captured one, then another XFB-inactive one. The GENERATED answer must
+        // accumulate across the two accounting paths the armed reroute splits them
+        // into (stream slots for the captured draw, statistics slots for the
+        // others), and WRITTEN must stay exactly the captured draw's count - the
+        // pairing the stream path exists to keep exact. Undiscarded, so the
+        // accumulation invariant is holdable on this machine (see the discard
+        // case's comment); the triangles rasterize into the harness framebuffer,
+        // which nothing here reads.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, ASpanMixingActiveAndInactiveDrawsAccumulatesBoth) {
+            if (!Ready()) return;
+            const GLuint program = BuildCaptureProgram();
+            ASSERT_NE(program, 0u) << BuildLog();
+            glUseProgram(program);
+
+            GLuint captureBuffer = 0;
+            glGenBuffers(1, &captureBuffer);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, captureBuffer);
+            glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, 3 * 4 * sizeof(float), nullptr, GL_DYNAMIC_DRAW);
+
+            glBeginQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN, m_queries[0]);
+            const GLuint generated = QueryGenerated([]() {
+                glDrawArrays(GL_TRIANGLES, 0, 3); // XFB inactive
+                glBeginTransformFeedback(GL_TRIANGLES);
+                glDrawArrays(GL_TRIANGLES, 0, 3); // captured
+                glEndTransformFeedback();
+                glDrawArrays(GL_TRIANGLES, 0, 3); // XFB inactive again
+            });
+            glEndQuery(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN);
+
+            GLuint written = 0xFFFFFFFFu;
+            glGetQueryObjectuiv(m_queries[0], GL_QUERY_RESULT, &written);
+            glDeleteBuffers(1, &captureBuffer);
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            EXPECT_EQ(generated, 3u) << "one triangle before the span, one inside it, one after";
+            EXPECT_EQ(written, 1u) << "only the draw inside the span writes anything";
+        }
+
+        // ===================== DRAWS INSIDE A PAUSED SPAN =====================
+        //
+        // glPauseTransformFeedback closes the capture without closing the span, so a
+        // draw made while paused is XFB-INACTIVE at the backend - the stream query is
+        // exactly as silent for it as for a draw with no span at all - while
+        // GL_PRIMITIVES_GENERATED must still count what the last vertex processing
+        // stage emitted (GL 4.6 core 13.4; the WRITTEN query is the one the pause
+        // silences). The frontend does keep a CPU counter for paused draws, but it can
+        // price only 3 of the ~15 draw entry points and answers 0 for GL_PATCHES, so
+        // these draws are the reroute's business like any other - and the trap on the
+        // other side is counting them TWICE, once in each accounting.
+        //
+        // Each case measures the SAME draw twice: once with no span open at all (the
+        // capability control - what this stack can count) and once inside the paused
+        // span, and requires the two to agree. That differential is what makes these
+        // cases falsifying rather than vacuous: a stack where no counter reaches a
+        // capture-less draw fails the control and skips, while a stack that counts the
+        // unpaused draw and answers 0 for the paused one - which is what excluding
+        // paused draws from the reroute produced - fails, instead of skipping into
+        // green.
+
+        // The draw the CPU counter CAN price: if the span both reroutes it and adds the
+        // CPU delta, this reads 2.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, APausedSpanCountsACpuPricedDrawExactlyOnce) {
+            if (!Ready()) return;
+            if (AmbientQuirkFromEnvironment("MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE") == AmbientQuirk::Off) {
+                GTEST_SKIP() << "the negative control replays the pre-probe accounting, whose paused "
+                                "draws are CPU-counted on top of whatever the stream query says";
+            }
+            const GLuint program = BuildCaptureProgram();
+            ASSERT_NE(program, 0u) << BuildLog();
+            glUseProgram(program);
+
+            const GLuint unpaused = QueryGenerated([]() { glDrawArrays(GL_TRIANGLES, 0, 3); });
+            BeginPausedSpan();
+            const GLuint paused = QueryGenerated([]() { glDrawArrays(GL_TRIANGLES, 0, 3); });
+            EndPausedSpan();
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            if (unpaused == 0u) {
+                GTEST_SKIP() << "no counter this backend can reach answers a capture-less draw on this "
+                                "stack, so the paused half of the comparison proves nothing; the "
+                                "bring-up probe measures the same hole and the POST row reports it";
+            }
+            EXPECT_EQ(unpaused, 1u) << "the control itself: one triangle is one primitive";
+            EXPECT_EQ(paused, unpaused)
+                << "one triangle drawn while the capture span is paused is still one primitive "
+                   "generated - counted once, by whichever accounting owns it, never by two of them "
+                   "(a reroute slot AND the frontend's CPU paused counter reads 2)";
+        }
+
+        // The draw the CPU counter CANNOT price: GL_PATCHES, whose amplification is not
+        // knowable on the CPU (CountPrimitivesForDraw answers 0 for it by design) - and
+        // the CTS's tessellator-measuring shape. Excluding paused draws from the
+        // reroute left this counted by nothing at all on the affected device.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, APausedSpanCountsATessellatedPatchExactlyOnce) {
+            if (!Ready()) return;
+            const GLuint program = BuildTessellationProgram(/*withCaptureVarying=*/true);
+            if (program == 0) {
+                GTEST_SKIP() << "no tessellation stages on this stack: " << BuildLog();
+            }
+            glUseProgram(program);
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+
+            const GLuint unpaused = QueryGenerated([]() { glDrawArrays(GL_PATCHES, 0, 1); });
+            BeginPausedSpan();
+            const GLuint paused = QueryGenerated([]() { glDrawArrays(GL_PATCHES, 0, 1); });
+            EndPausedSpan();
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            if (unpaused == 0u) {
+                GTEST_SKIP() << "no counter this backend can reach answers a capture-less patch draw "
+                                "on this stack, so the paused half proves nothing; the bring-up probe "
+                                "measures the same hole and the POST row reports it";
+            }
+            EXPECT_EQ(unpaused, 1u)
+                << "the control itself: a triangles-domain patch with every level 1 tessellates to "
+                   "exactly one triangle";
+            EXPECT_EQ(paused, unpaused)
+                << "pausing the capture does not stop the tessellator from generating that triangle, "
+                   "and the frontend's CPU paused counter answers 0 for GL_PATCHES - so a paused "
+                   "patch draw left out of the reroute is counted by nothing at all";
+        }
+
+        // The other half of the same hole: the instanced entry points never reach the
+        // frontend's paused accounting either, so a paused instanced draw excluded from
+        // the reroute is likewise counted by nothing.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, APausedSpanCountsAnInstancedDrawExactlyOnce) {
+            if (!Ready()) return;
+            const GLuint program = BuildCaptureProgram();
+            ASSERT_NE(program, 0u) << BuildLog();
+            glUseProgram(program);
+
+            const GLuint unpaused =
+                QueryGenerated([]() { glDrawArraysInstanced(GL_TRIANGLES, 0, 3, 4); });
+            BeginPausedSpan();
+            const GLuint paused = QueryGenerated([]() { glDrawArraysInstanced(GL_TRIANGLES, 0, 3, 4); });
+            EndPausedSpan();
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            if (unpaused == 0u) {
+                GTEST_SKIP() << "no counter this backend can reach answers a capture-less draw on this "
+                                "stack, so the paused half proves nothing";
+            }
+            EXPECT_EQ(unpaused, 4u) << "the control itself: four instances of one triangle";
+            EXPECT_EQ(paused, unpaused)
+                << "four instances generate four primitives whether or not the capture span is "
+                   "paused, and no instanced entry point reaches the frontend's paused accounting";
+        }
+
+        // THE ONE CASE THAT CAN FAIL WHEN THE REROUTE SILENTLY STOPS BEING ARMED -
+        // the UnlocatedIoBlockScenario shape, for the same reason: every case above
+        // is green here whether the reroute ran or not (that is the "two pools
+        // agree" point), so none of them can say the pinned lane actually exercised
+        // a reroute pool. This one asserts a LIBRARY OBSERVABLE against the
+        // environment: with MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE pinned on, an
+        // XFB-inactive draw inside a GENERATED span must make the renderer say -
+        // through its latched MGLOG_I - that it engaged the reroute. It reads
+        // MG_Config not at all (on Android this module links the shipping library)
+        // and trusts only the log bytes appended after it started.
+        TEST_F(PrimitivesGeneratedNoXfbScenario, TheRerouteIsActuallyArmedWhenTheEnvironmentPinsItOn) {
+            if (!Ready()) return;
+            if (AmbientQuirkFromEnvironment("MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE") != AmbientQuirk::On) {
+                GTEST_SKIP() << "this case needs the reroute pinned ON for the whole process, which "
+                                "is what the PrimGenReroute. ctest entry does with "
+                                "MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE=1; unset, the bring-up probe "
+                                "decides and this machine's verdict is its own business";
+            }
+            if (LibraryLogPath().empty()) {
+                GTEST_SKIP() << "MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE is pinned on but "
+                                "MOBILEGL_LOG_FILE_PATH is not set, so the library has nowhere to "
+                                "record that it rerouted anything; the PrimGenReroute. ctest "
+                                "entry sets both";
+            }
+
+            const GLuint program = BuildCaptureProgram();
+            ASSERT_NE(program, 0u) << BuildLog();
+            glUseProgram(program);
+
+            // Taken BEFORE the draw, so the line this looks for can only be one this
+            // process wrote for this span. The latch fires on the FIRST rerouted
+            // draw, which is inside the query below.
+            const std::uintmax_t before = LibraryLogSize();
+            const GLuint generated = QueryGenerated([]() { glDrawArrays(GL_TRIANGLES, 0, 3); });
+            EXPECT_EQ(DrainGLErrors(), 0u);
+            EXPECT_EQ(generated, 1u) << "the pinned-on lane did not even count correctly";
+
+            const std::string appended = LibraryLogSince(before);
+            EXPECT_NE(appended.find("PRIMITIVES_GENERATED reroute engaged"), std::string::npos)
+                << "MOBILEGL_MAGMA_PRIMGEN_QUERY_REROUTE is pinned ON, an XFB-inactive draw ran inside "
+                   "a GENERATED query, and the renderer never reported engaging the reroute. The "
+                   "quirk is not armed - check the override mapping "
+                   "(ChoosePrimitivesGeneratedReroute) and the arming gate in "
+                   "VulkanRenderer::BeginXfbQueryForDraw. Log appended by this test:\n"
+                << appended;
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/RenderbufferBlendFormatScenario.cpp

@@ -0,0 +1,227 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/RenderbufferBlendFormatScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - BLENDING WORKS ON A RENDERBUFFER WHOSE GL FORMAT HAS NO EXACT VkFormat.
+//
+// DirectVulkan force-disables blending on an attachment whose VkFormat lacks
+// VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BLEND_BIT, which is the right thing to do - blending on such a
+// format is invalid pipeline state. The probe has to ask about the format the attachment ACTUALLY
+// has, and for renderbuffers it asked a different question from the one that created the image: the
+// image comes from ResolveTextureFormatInfo (which widens GL formats with no Vulkan twin onto a real
+// one) while the probe used the strict 1:1 converter, which answers VK_FORMAT_UNDEFINED for RGBA2,
+// RGBA12, RGB10, RGB12, RGB16 and the three-channel formats, and the 16-bit packed formats for RGBA4
+// and RGB5_A1.
+//
+// VkFormatProperties for VK_FORMAT_UNDEFINED are all zero, so the probe concluded "not blendable"
+// and every pipeline for that attachment was built with blendEnable = VK_FALSE - permanently, and
+// silently apart from one log line. The source colour then overwrites the destination instead of
+// blending with it, which is a wrong PICTURE, not a wrong error code.
+//
+// GL_RGB8 is the ordinary shape and is what this scenario leads with: it is a required
+// colour-renderable format, its image has been R8G8B8A8_UNORM all along, and the probe asked about
+// the 24-bit R8G8B8_UNORM that most drivers do not support at all. GL_RGBA4 covers the other half -
+// a format whose probe answered a real-but-different VkFormat.
+//
+// DirectGLES is the control: it forwards the renderbuffer to the ES driver and blends whatever the
+// driver blends, so a disagreement between the two backends is the defect.
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr int kExtent = 16;
+
+        constexpr const char* kVertexSource = R"(#version 330 core
+void main()
+{
+    switch (gl_VertexID)
+    {
+      case 0: gl_Position = vec4(-1.0, 1.0, 0.0, 1.0); break;
+      case 1: gl_Position = vec4( 1.0, 1.0, 0.0, 1.0); break;
+      case 2: gl_Position = vec4(-1.0,-1.0, 0.0, 1.0); break;
+      case 3: gl_Position = vec4( 1.0,-1.0, 0.0, 1.0); break;
+    }
+}
+)";
+
+        constexpr const char* kFragmentSource = R"(#version 330 core
+uniform vec4 uColor;
+out vec4 fragColor;
+void main()
+{
+    fragColor = uColor;
+}
+)";
+
+        class RenderbufferBlendFormatScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                glGenVertexArrays(1, &m_vao);
+                std::string error;
+                m_program = CompileProgram(kVertexSource, kFragmentSource, &error);
+                ASSERT_NE(m_program, 0u) << "program did not build: " << error;
+                ASSERT_EQ(FirstGLError(), 0u);
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                Destroy();
+                if (m_program != 0) glDeleteProgram(m_program);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                glBindFramebuffer(GL_FRAMEBUFFER, 0);
+            }
+
+            void Destroy() {
+                if (m_fbo != 0) {
+                    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                    glDeleteFramebuffers(1, &m_fbo);
+                    m_fbo = 0;
+                }
+                if (m_renderbuffer != 0) {
+                    glDeleteRenderbuffers(1, &m_renderbuffer);
+                    m_renderbuffer = 0;
+                }
+            }
+
+            // Returns false (having skipped, not failed) when the driver will not give us a complete
+            // framebuffer for this format - GL only requires a subset of formats to be
+            // colour-renderable, and the point of the scenario is blending, not format support.
+            bool MakeTarget(GLenum internalFormat) {
+                Destroy();
+                glGenRenderbuffers(1, &m_renderbuffer);
+                glBindRenderbuffer(GL_RENDERBUFFER, m_renderbuffer);
+                glRenderbufferStorage(GL_RENDERBUFFER, internalFormat, kExtent, kExtent);
+                glGenFramebuffers(1, &m_fbo);
+                glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, m_renderbuffer);
+                const GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+                return status == GL_FRAMEBUFFER_COMPLETE;
+            }
+
+            void DrawColor(float r, float g, float b, float a) {
+                glUseProgram(m_program);
+                glUniform4f(glGetUniformLocation(m_program, "uColor"), r, g, b, a);
+                glBindVertexArray(m_vao);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glBindVertexArray(0);
+                glUseProgram(0);
+            }
+
+            GLuint m_renderbuffer = 0;
+            GLuint m_fbo = 0;
+            GLuint m_vao = 0;
+            unsigned int m_program = 0;
+        };
+
+        // One draw of opaque black, then a 50%-alpha white draw over it with the ordinary
+        // SRC_ALPHA / ONE_MINUS_SRC_ALPHA function. Blending gives mid-grey; a pipeline built with
+        // blendEnable = VK_FALSE gives white, because the source simply overwrites.
+        //
+        // The tolerance is wide on purpose: RGBA4 has four bits per channel, so "mid-grey" is one of
+        // a handful of representable values and the test must not become a quantisation test.
+        void ExpectBlendedRatherThanOverwritten(const char* what) {
+            const Image image = ReadPixels(kExtent, kExtent);
+            ASSERT_FALSE(image.Empty()) << what;
+            const Rgba8 centre = image.At(kExtent / 2, kExtent / 2);
+            EXPECT_GT(int(centre.r), 40) << what << ": got " << centre << ", which is darker than a blend of "
+                                                              "black and 50% white";
+            EXPECT_LT(int(centre.r), 215) << what << ": got " << centre
+                                          << ", which is the source colour - blending was disabled";
+        }
+
+    } // namespace
+
+    // The ordinary case, and the one broken today rather than only after the format table was
+    // unified: a three-channel colour renderbuffer. Its image has been R8G8B8A8_UNORM all along while
+    // the blend probe asked about R8G8B8_UNORM, which most drivers do not support at all.
+    TEST_F(RenderbufferBlendFormatScenario, BlendingWorksOnAThreeChannelRenderbuffer) {
+        if (!Ready()) GTEST_SKIP();
+        if (!MakeTarget(GL_RGB8)) GTEST_SKIP() << "GL_RGB8 renderbuffer is not framebuffer-complete here";
+
+        glViewport(0, 0, kExtent, kExtent);
+        glDisable(GL_SCISSOR_TEST);
+        glDisable(GL_DEPTH_TEST);
+        glDisable(GL_BLEND);
+        DrawColor(0.0f, 0.0f, 0.0f, 1.0f);
+
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        DrawColor(1.0f, 1.0f, 1.0f, 0.5f);
+        glDisable(GL_BLEND);
+        EXPECT_EQ(FirstGLError(), 0u) << "the blended draw left a GL error behind";
+
+        ExpectBlendedRatherThanOverwritten("GL_RGB8");
+        Gl().EndFrame();
+    }
+
+    // The other half: a format whose strict converter answers a real-but-different VkFormat
+    // (R4G4B4A4_UNORM_PACK16) while the image is R8G8B8A8_UNORM. Blend support for the packed 16-bit
+    // formats is optional in Vulkan, so the probe could legitimately answer "no" for a format the
+    // attachment does not have.
+    TEST_F(RenderbufferBlendFormatScenario, BlendingWorksOnALowBitPackedRenderbuffer) {
+        if (!Ready()) GTEST_SKIP();
+        if (!MakeTarget(GL_RGBA4)) GTEST_SKIP() << "GL_RGBA4 renderbuffer is not framebuffer-complete here";
+
+        glViewport(0, 0, kExtent, kExtent);
+        glDisable(GL_SCISSOR_TEST);
+        glDisable(GL_DEPTH_TEST);
+        glDisable(GL_BLEND);
+        DrawColor(0.0f, 0.0f, 0.0f, 1.0f);
+
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        DrawColor(1.0f, 1.0f, 1.0f, 0.5f);
+        glDisable(GL_BLEND);
+        EXPECT_EQ(FirstGLError(), 0u) << "the blended draw left a GL error behind";
+
+        ExpectBlendedRatherThanOverwritten("GL_RGBA4");
+        Gl().EndFrame();
+    }
+
+    // The control that keeps both of the above honest: the same sequence on the format whose probe
+    // and image always agreed. If this one ever fails, the scenario is measuring the blend setup
+    // rather than the format resolution.
+    TEST_F(RenderbufferBlendFormatScenario, BlendingWorksOnAnRgba8Renderbuffer) {
+        if (!Ready()) GTEST_SKIP();
+        if (!MakeTarget(GL_RGBA8)) GTEST_SKIP() << "GL_RGBA8 renderbuffer is not framebuffer-complete here";
+
+        glViewport(0, 0, kExtent, kExtent);
+        glDisable(GL_SCISSOR_TEST);
+        glDisable(GL_DEPTH_TEST);
+        glDisable(GL_BLEND);
+        DrawColor(0.0f, 0.0f, 0.0f, 1.0f);
+
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        DrawColor(1.0f, 1.0f, 1.0f, 0.5f);
+        glDisable(GL_BLEND);
+        EXPECT_EQ(FirstGLError(), 0u) << "the blended draw left a GL error behind";
+
+        ExpectBlendedRatherThanOverwritten("GL_RGBA8");
+        Gl().EndFrame();
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/SampleMaskScopeScenario.cpp

@@ -0,0 +1,178 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/SampleMaskScopeScenario.cpp
+// Copyright (c) 2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - GL_SAMPLE_MASK IS A MULTISAMPLE FRAGMENT OPERATION, SO IT DOES NOTHING AT ONE SAMPLE.
+//
+// GL 4.6 core 17.3.3 groups alpha-to-coverage, sample coverage and the sample mask together and
+// says they make no change "if MULTISAMPLE is disabled, or if the value of SAMPLE_BUFFERS is not
+// one". SAMPLE_BUFFERS is 0 for a single-sample framebuffer, so on one the mask is inert whatever
+// glSampleMaski last wrote.
+//
+// Vulkan has no such rule. VkPipelineMultisampleStateCreateInfo::pSampleMask is ANDed with
+// rasterization coverage at every rasterizationSamples, and at one sample that coverage is bit 0
+// alone - so a mask with bit 0 clear discards every fragment of every primitive. Plumbing
+// glSampleMaski straight into pSampleMask therefore turned an ordinary and legal GL sequence into
+// a fully black draw:
+//
+//     glEnable(GL_SAMPLE_MASK); glSampleMaski(0, 0x2);   // while an MSAA target is bound
+//     ... render ...
+//     glBindFramebuffer(GL_FRAMEBUFFER, 0); draw a fullscreen quad to present
+//
+// Neither piece of state is per-framebuffer, so nothing resets it when the target changes, and
+// dEQP/GL-CTS multisample cases leave exactly these masks behind. That is the MSAA-then-present
+// shape every application uses.
+//
+// The cases below are single-sample by construction (the scenario harness's colour FBO), so each
+// one asserts that the mask changed nothing.
+
+#include <string>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr int kFboSize = 32;
+
+        constexpr const char* kQuadVertexSource = R"(#version 430 core
+void main() {
+    vec2 corner = vec2((gl_VertexID & 1) == 0 ? -1.0 : 1.0,
+                       (gl_VertexID & 2) == 0 ? -1.0 : 1.0);
+    gl_Position = vec4(corner, 0.0, 1.0);
+}
+)";
+
+        constexpr const char* kGreenFragmentSource = R"(#version 430 core
+out vec4 o_color;
+void main() {
+    o_color = vec4(0.0, 1.0, 0.0, 1.0);
+}
+)";
+
+        class SampleMaskScopeScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+
+                m_target = MakeColorFbo(kFboSize, kFboSize);
+                ASSERT_NE(m_target.fbo, 0u) << "could not create the render target";
+                glGenVertexArrays(1, &m_vao);
+                std::string error;
+                m_program = CompileProgram(kQuadVertexSource, kGreenFragmentSource, &error);
+                ASSERT_NE(m_program, 0u) << error;
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                // Process-wide GL state: leaving it set would hand the next scenario in this
+                // process the very bug under test.
+                glDisable(GL_SAMPLE_MASK);
+                glSampleMaski(0, 0xFFFFFFFFu);
+                glBindVertexArray(0);
+                glUseProgram(0);
+                if (m_program != 0) glDeleteProgram(m_program);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                DestroyColorFbo(m_target);
+                ScenarioTest::TearDown();
+            }
+
+            void ExpectQuadStillPaints(const char* what) {
+                BindFbo(m_target);
+                ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+                glBindVertexArray(m_vao);
+                glUseProgram(m_program);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glBindVertexArray(0);
+                EXPECT_EQ(FirstGLError(), 0u) << what << ": the draw raised a GL error";
+
+                const Image image = ReadPixels(kFboSize, kFboSize);
+                ASSERT_FALSE(image.Empty()) << what << ": the readback came back empty";
+                EXPECT_TRUE(RegionIsMostly(image, 0, kFboSize - 1, 0, kFboSize - 1, "green", 0.0, what))
+                    << what << ": an all-black target means the sample mask discarded every fragment, "
+                    << "which GL says it cannot do on a single-sample framebuffer";
+            }
+
+            ColorFbo m_target{};
+            GLuint m_vao = 0;
+            unsigned int m_program = 0;
+        };
+
+    } // namespace
+
+    // The exact reported shape: bit 0 clear, so the single sample of a single-sample target is
+    // masked off if the mask is applied at all.
+    TEST_F(SampleMaskScopeScenario, AMaskWithBitZeroClearDoesNotDiscardASingleSampleDraw) {
+        if (!Ready() || IsSkipped()) return;
+        glEnable(GL_SAMPLE_MASK);
+        glSampleMaski(0, 0x2);
+        ASSERT_EQ(FirstGLError(), 0u) << "setting the sample mask raised a GL error";
+        ExpectQuadStillPaints("GL_SAMPLE_MASK enabled with mask 0x2");
+    }
+
+    // Zero is the strongest form of the same thing, and the mask value the CTS's mask_zero cases
+    // set.
+    TEST_F(SampleMaskScopeScenario, AZeroMaskDoesNotDiscardASingleSampleDraw) {
+        if (!Ready() || IsSkipped()) return;
+        glEnable(GL_SAMPLE_MASK);
+        glSampleMaski(0, 0x0);
+        ASSERT_EQ(FirstGLError(), 0u) << "setting the sample mask raised a GL error";
+        ExpectQuadStillPaints("GL_SAMPLE_MASK enabled with mask 0");
+    }
+
+    // Control: the same mask word with the capability disabled has never had any effect, so this
+    // one passed before the fix too. It is here so a regression that ignores the enable bit
+    // instead of the sample count is still caught.
+    TEST_F(SampleMaskScopeScenario, ADisabledSampleMaskDoesNotDiscardASingleSampleDraw) {
+        if (!Ready() || IsSkipped()) return;
+        glDisable(GL_SAMPLE_MASK);
+        glSampleMaski(0, 0x0);
+        ASSERT_EQ(FirstGLError(), 0u) << "setting the sample mask raised a GL error";
+        ExpectQuadStillPaints("GL_SAMPLE_MASK disabled with mask 0");
+    }
+
+    // The mask is state, not a draw parameter, so a second draw after the first must not inherit
+    // a pipeline built while the memo word and the payload disagreed. Two draws either side of a
+    // mask change, both to the same single-sample target, both required to paint.
+    TEST_F(SampleMaskScopeScenario, ChangingTheMaskBetweenSingleSampleDrawsKeepsBothPainting) {
+        if (!Ready() || IsSkipped()) return;
+        glEnable(GL_SAMPLE_MASK);
+        glSampleMaski(0, 0xFFFFFFFFu);
+        ExpectQuadStillPaints("first draw, full mask");
+        glSampleMaski(0, 0x2);
+        ASSERT_EQ(FirstGLError(), 0u) << "changing the sample mask raised a GL error";
+        ExpectQuadStillPaints("second draw, mask 0x2");
+    }
+
+    // GL_MAX_SAMPLE_MASK_WORDS must be 1 on both backends: MobileGL stores one word and
+    // SampleMaski_State raises GL_INVALID_VALUE for any maskNumber above 0, so advertising more
+    // makes dEQP's per-case gluStateReset - which issues glSampleMaski up to the advertised count
+    // - fail every case. DirectGLES clamped; DirectVulkan forwarded the raw device limit.
+    TEST_F(SampleMaskScopeScenario, TheAdvertisedSampleMaskWordCountMatchesWhatSampleMaskiAccepts) {
+        if (!Ready() || IsSkipped()) return;
+        GLint words = 0;
+        glGetIntegerv(GL_MAX_SAMPLE_MASK_WORDS, &words);
+        ASSERT_EQ(FirstGLError(), 0u) << "querying GL_MAX_SAMPLE_MASK_WORDS raised a GL error";
+        EXPECT_EQ(words, 1) << "every word below the advertised count must be writable, and only word 0 is";
+        for (GLint word = 0; word < words; ++word) {
+            glSampleMaski(static_cast<GLuint>(word), 0xFFFFFFFFu);
+            EXPECT_EQ(FirstGLError(), 0u) << "glSampleMaski(" << word << ", ...) was refused although "
+                                          << "GL_MAX_SAMPLE_MASK_WORDS advertises " << words << " words";
+        }
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/SampleVariablesScenario.cpp

@@ -0,0 +1,274 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/SampleVariablesScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - gl_NumSamples REACHES THE SHADER, AND IT FOLLOWS THE DRAW FRAMEBUFFER.
+//
+// glslang declares gl_NumSamples only when it is NOT targeting SPIR-V - both the desktop and the
+// ES branch of Initialize.cpp wrap `uniform int gl_NumSamples;` in `if (spvVersion.spv == 0)`,
+// because SPIR-V has no NumSamples builtin to lower it to - and MobileGL always targets SPIR-V.
+// Every fragment shader that read the built-in therefore died at COMPILE time with
+// "'gl_NumSamples' : undeclared identifier", which is all 144 KHR-GL46.sample_variables.mask.*
+// bodies plus their es_31_compatibility twins.
+//
+// The source pipeline now lowers it onto a reserved default-block uniform and the draw path writes
+// the current draw framebuffer's sample count into it. Two claims, and the second is the one a
+// compile-only test cannot make: the value must be the DRAW FRAMEBUFFER's, so one program drawn
+// into a multisample target and then into a single-sample target has to report both counts. A
+// link-time bake would pass the first assertion and fail the second, which is exactly why the
+// write lives per draw.
+//
+// llvmpipe and lavapipe both offer 4x multisample RGBA8, so this runs for real in CI rather than
+// skipping; the skips below are for a driver that offers no multisample renderbuffer at all.
+
+#include <algorithm>
+#include <string>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr const char* kVS = R"(#version 400 core
+in vec2 aPos;
+void main() { gl_Position = vec4(aPos, 0.0, 1.0); }
+)";
+
+        // gl_NumSamples scaled so each count lands on its own well-separated 8-bit value: 1 -> 16,
+        // 2 -> 32, 4 -> 64. Every sample of the fragment gets the same colour, so the resolve blit
+        // averages identical values and the readback is exact rather than approximate.
+        constexpr const char* kFS = R"(#version 400 core
+out vec4 o_color;
+void main() { o_color = vec4(float(gl_NumSamples) * (16.0 / 255.0), 0.0, 0.0, 1.0); }
+)";
+
+        class SampleVariablesScenario : public ScenarioTest {};
+
+        void DrawFullViewportQuad(unsigned int program) {
+            static const float kQuad[] = {-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
+            GLuint vao = 0, vbo = 0;
+            glGenVertexArrays(1, &vao);
+            glBindVertexArray(vao);
+            glGenBuffers(1, &vbo);
+            glBindBuffer(GL_ARRAY_BUFFER, vbo);
+            glBufferData(GL_ARRAY_BUFFER, sizeof(kQuad), kQuad, GL_STATIC_DRAW);
+            glEnableVertexAttribArray(0);
+            glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
+            glUseProgram(program);
+            glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+            glBindVertexArray(0);
+            glDeleteBuffers(1, &vbo);
+            glDeleteVertexArrays(1, &vao);
+        }
+
+    } // namespace
+
+    TEST_F(SampleVariablesScenario, GlNumSamplesFollowsTheDrawFramebuffersSampleCount) {
+        if (!Ready()) return;
+        HeadlessGL& gl = Gl();
+        const int width = gl.Width();
+        const int height = gl.Height();
+        ASSERT_GE(width, 8);
+        ASSERT_GE(height, 8);
+
+        std::string error;
+        const unsigned int program = CompileProgram(kVS, kFS, &error);
+        // The compile failure this scenario exists for lands here, with glslang's own text.
+        ASSERT_NE(program, 0u) << error;
+
+        GLint maxSamples = 0;
+        glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
+        const GLint requestedSamples = std::min<GLint>(maxSamples, 4);
+        if (requestedSamples < 2) {
+            glDeleteProgram(program);
+            GTEST_SKIP() << "GL_MAX_SAMPLES is " << maxSamples << "; this needs a multisample renderbuffer";
+        }
+
+        glDisable(GL_SCISSOR_TEST);
+        glDisable(GL_DEPTH_TEST);
+
+        // ---- multisample target ----
+        GLuint msFbo = 0, msRbo = 0;
+        glGenFramebuffers(1, &msFbo);
+        glBindFramebuffer(GL_FRAMEBUFFER, msFbo);
+        glGenRenderbuffers(1, &msRbo);
+        glBindRenderbuffer(GL_RENDERBUFFER, msRbo);
+        glRenderbufferStorageMultisample(GL_RENDERBUFFER, requestedSamples, GL_RGBA8, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, msRbo);
+        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+            glDeleteRenderbuffers(1, &msRbo);
+            glDeleteFramebuffers(1, &msFbo);
+            glBindFramebuffer(GL_FRAMEBUFFER, 0);
+            glDeleteProgram(program);
+            GTEST_SKIP() << "no complete " << requestedSamples << "x multisample RGBA8 renderbuffer on this driver";
+        }
+
+        // What the driver actually allocated - a request is a lower bound, and the shader has to
+        // agree with the query rather than with what was asked for.
+        GLint realizedSamples = 0;
+        glGetIntegerv(GL_SAMPLES, &realizedSamples);
+        ASSERT_GE(realizedSamples, 2) << "the multisample framebuffer reports GL_SAMPLES " << realizedSamples;
+
+        glViewport(0, 0, width, height);
+        ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+        DrawFullViewportQuad(program);
+        EXPECT_EQ(FirstGLError(), 0u);
+
+        // Resolve into the default framebuffer to read it back.
+        BindDefaultFramebuffer();
+        glViewport(0, 0, width, height);
+        ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+        glBindFramebuffer(GL_READ_FRAMEBUFFER, msFbo);
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+        glBlitFramebuffer(0, 0, width, height, 0, 0, width, height, GL_COLOR_BUFFER_BIT, GL_NEAREST);
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+        EXPECT_EQ(FirstGLError(), 0u);
+
+        {
+            const Image resolved = ReadPixels(width, height);
+            const Rgba8 centre = resolved.At(width / 2, height / 2);
+            EXPECT_NEAR(centre.r, 16 * realizedSamples, 2)
+                << "gl_NumSamples read " << (centre.r / 16.0) << " into a " << realizedSamples
+                << "-sample framebuffer; 1 means the reserved uniform was never written, 0 means it was "
+                << "written but never uploaded";
+        }
+        gl.EndFrame();
+
+        // ---- the SAME program into a single-sample target ----
+        // A link-time bake of the sample count would keep reporting the multisample value here.
+        GLuint ssFbo = 0, ssRbo = 0;
+        glGenFramebuffers(1, &ssFbo);
+        glBindFramebuffer(GL_FRAMEBUFFER, ssFbo);
+        glGenRenderbuffers(1, &ssRbo);
+        glBindRenderbuffer(GL_RENDERBUFFER, ssRbo);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, ssRbo);
+        ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE));
+
+        glViewport(0, 0, width, height);
+        ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+        DrawFullViewportQuad(program);
+        EXPECT_EQ(FirstGLError(), 0u);
+
+        {
+            const Image single = ReadPixels(width, height);
+            const Rgba8 centre = single.At(width / 2, height / 2);
+            // GL 4.6 core 15.2.2: gl_NumSamples is ONE for a non-multisample framebuffer, where
+            // glGetIntegerv(GL_SAMPLES) answers zero.
+            EXPECT_NEAR(centre.r, 16, 2)
+                << "gl_NumSamples read " << (centre.r / 16.0)
+                << " into a single-sample framebuffer; the value is a property of the DRAW FRAMEBUFFER, "
+                << "so re-using the program must re-write it";
+        }
+
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+        glDeleteRenderbuffers(1, &ssRbo);
+        glDeleteFramebuffers(1, &ssFbo);
+        glDeleteRenderbuffers(1, &msRbo);
+        glDeleteFramebuffers(1, &msFbo);
+        glDeleteProgram(program);
+        gl.EndFrame();
+    }
+
+    // ARB_sample_shading is advertised, and until now glMinSampleShading was a logging no-op while
+    // glEnable(GL_SAMPLE_SHADING) fell out of RenderState::SetCapability's default arm - so an
+    // application could ask for a shading rate and get silence from both halves.
+    //
+    // What this can and cannot assert. The RATE itself is not observable from a portable shader:
+    // GL 4.6 core 14.3.1 makes any use of gl_SampleID or gl_SamplePosition force per-sample
+    // evaluation on its own, so the very built-ins that would report the rate defeat the
+    // measurement. What IS worth pinning is that the state now reaches both backends without
+    // damage: DirectGLES forwards glEnable(GL_SAMPLE_SHADING) + glMinSampleShading to the ES
+    // driver (and must not, on a driver that has neither, push an INVALID_ENUM into the
+    // application's error queue), and DirectVulkan bakes sampleShadingEnable/minSampleShading into
+    // a NEW pipeline - which it may only do with the device's sampleRateShading feature enabled.
+    TEST_F(SampleVariablesScenario, SampleShadingStateReachesTheBackendWithoutDisturbingTheDraw) {
+        if (!Ready()) return;
+        HeadlessGL& gl = Gl();
+        const int width = gl.Width();
+        const int height = gl.Height();
+
+        std::string error;
+        const unsigned int program = CompileProgram(kVS, kFS, &error);
+        ASSERT_NE(program, 0u) << error;
+
+        GLint maxSamples = 0;
+        glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
+        const GLint requestedSamples = std::min<GLint>(maxSamples, 4);
+        if (requestedSamples < 2) {
+            glDeleteProgram(program);
+            GTEST_SKIP() << "GL_MAX_SAMPLES is " << maxSamples << "; sample shading needs a multisample target";
+        }
+
+        GLuint msFbo = 0, msRbo = 0;
+        glGenFramebuffers(1, &msFbo);
+        glBindFramebuffer(GL_FRAMEBUFFER, msFbo);
+        glGenRenderbuffers(1, &msRbo);
+        glBindRenderbuffer(GL_RENDERBUFFER, msRbo);
+        glRenderbufferStorageMultisample(GL_RENDERBUFFER, requestedSamples, GL_RGBA8, width, height);
+        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, msRbo);
+        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+            glDeleteRenderbuffers(1, &msRbo);
+            glDeleteFramebuffers(1, &msFbo);
+            glBindFramebuffer(GL_FRAMEBUFFER, 0);
+            glDeleteProgram(program);
+            GTEST_SKIP() << "no complete " << requestedSamples << "x multisample RGBA8 renderbuffer on this driver";
+        }
+
+        GLint realizedSamples = 0;
+        glGetIntegerv(GL_SAMPLES, &realizedSamples);
+        glDisable(GL_SCISSOR_TEST);
+        glDisable(GL_DEPTH_TEST);
+        glViewport(0, 0, width, height);
+
+        glEnable(GL_SAMPLE_SHADING);
+        glMinSampleShading(1.0f);
+        EXPECT_EQ(glIsEnabled(GL_SAMPLE_SHADING), static_cast<GLboolean>(GL_TRUE));
+        GLfloat rate = -1.0f;
+        glGetFloatv(GL_MIN_SAMPLE_SHADING_VALUE, &rate);
+        EXPECT_FLOAT_EQ(rate, 1.0f);
+        EXPECT_EQ(FirstGLError(), 0u) << "enabling sample shading raised a GL error";
+
+        ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+        DrawFullViewportQuad(program);
+        EXPECT_EQ(FirstGLError(), 0u) << "the sample-shading draw raised a GL error";
+
+        BindDefaultFramebuffer();
+        glViewport(0, 0, width, height);
+        ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+        glBindFramebuffer(GL_READ_FRAMEBUFFER, msFbo);
+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+        glBlitFramebuffer(0, 0, width, height, 0, 0, width, height, GL_COLOR_BUFFER_BIT, GL_NEAREST);
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+        const Image resolved = ReadPixels(width, height);
+        const Rgba8 centre = resolved.At(width / 2, height / 2);
+        // The rate changes how OFTEN the shader runs, never what it computes - so the same
+        // gl_NumSamples reading has to come back.
+        EXPECT_NEAR(centre.r, 16 * realizedSamples, 2)
+            << "the draw changed its result once sample shading was enabled";
+
+        glMinSampleShading(0.0f);
+        glDisable(GL_SAMPLE_SHADING);
+        EXPECT_EQ(FirstGLError(), 0u);
+
+        glDeleteRenderbuffers(1, &msRbo);
+        glDeleteFramebuffers(1, &msFbo);
+        glDeleteProgram(program);
+        gl.EndFrame();
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/SampledSetStalenessScenario.cpp

@@ -0,0 +1,231 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/SampledSetStalenessScenario.cpp
+// Copyright (c) 2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - A TEXTURE THAT BECOMES COMPLETE WITHOUT A REBIND MUST RE-ENTER THE SAMPLED SET.
+//
+// DirectVulkan does not bind a texture GL calls incomplete: it substitutes a fallback so the
+// sampler reads (0,0,0,1) instead of losing the draw. That decision is made twice per draw - once
+// by CollectSampledTextures, which builds the list SetupDraw syncs, materialises pending clears
+// for and transitions to a sampled layout BEFORE the render pass opens, and once by the descriptor
+// resolve inside the pass. Both ask SamplesAsIncompleteTexture.
+//
+// The per-draw memo that lets the first of those be skipped was keyed only on the program, the
+// transform flags and the texture BIND generation. Completeness is not a function of any of them:
+// it moves on a filter change (glTexParameteri / glSamplerParameteri), on a level-range change,
+// and on an upload that fills the mip chain - none of which bind anything. So a texture that went
+// incomplete -> complete under a fixed binding kept being answered out of the memo as "not in the
+// set", and the work SetupDraw does for the set never happened for it:
+//
+//   * its queued clear was never materialised, so the draw sampled pre-clear content - wrong
+//     pixels, no validation layer needed, which is what the case below detects; and
+//   * its layout transition moved into the descriptor resolve, which records
+//     vkCmdPipelineBarrier inside an already-open render pass whose subpass declares no
+//     self-dependency - the exact hazard CollectSampledTextures exists to prevent.
+//
+// The fix adds the sampling-resolution generation to that memo key, which is the counter the
+// codebase already maintains for "what a unit resolves to changed without a bind" and which both
+// TextureObjectBase::BumpShapeVersion and SamplerObject::BumpVersion move.
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr int kFboSize = 32;
+        constexpr int kTexSize = 8;
+
+        constexpr const char* kQuadVertexSource = R"(#version 430 core
+void main() {
+    vec2 corner = vec2((gl_VertexID & 1) == 0 ? -1.0 : 1.0,
+                       (gl_VertexID & 2) == 0 ? -1.0 : 1.0);
+    gl_Position = vec4(corner, 0.0, 1.0);
+}
+)";
+
+        // texelFetch, not texture(): the point is WHICH image is sampled, and a fetch cannot be
+        // explained away by filtering.
+        constexpr const char* kSampleFragmentSource = R"(#version 430 core
+uniform sampler2D u_tex;
+out vec4 o_color;
+void main() {
+    o_color = texelFetch(u_tex, ivec2(0, 0), 0);
+}
+)";
+
+        class SampledSetStalenessScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+
+                m_target = MakeColorFbo(kFboSize, kFboSize);
+                ASSERT_NE(m_target.fbo, 0u) << "could not create the render target";
+                glGenVertexArrays(1, &m_vao);
+                std::string error;
+                m_program = CompileProgram(kQuadVertexSource, kSampleFragmentSource, &error);
+                ASSERT_NE(m_program, 0u) << error;
+
+                // The sampled texture: ONE level, and no glTexParameteri at all, so MIN_FILTER
+                // keeps its initial GL_NEAREST_MIPMAP_LINEAR and GL calls it mipmap-incomplete.
+                glGenTextures(1, &m_texture);
+                glActiveTexture(GL_TEXTURE0);
+                glBindTexture(GL_TEXTURE_2D, m_texture);
+                std::vector<unsigned char> green(static_cast<std::size_t>(kTexSize * kTexSize * 4), 0);
+                for (std::size_t i = 0; i < green.size(); i += 4) {
+                    green[i + 1] = 255;
+                    green[i + 3] = 255;
+                }
+                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, kTexSize, kTexSize, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                             green.data());
+                ASSERT_EQ(FirstGLError(), 0u) << "defining the sampled texture raised a GL error";
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glBindVertexArray(0);
+                glUseProgram(0);
+                glActiveTexture(GL_TEXTURE0);
+                glBindTexture(GL_TEXTURE_2D, 0);
+                if (m_texture != 0) glDeleteTextures(1, &m_texture);
+                if (m_program != 0) glDeleteProgram(m_program);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                DestroyColorFbo(m_target);
+                ScenarioTest::TearDown();
+            }
+
+            // One draw of the fullscreen quad sampling texel (0,0) of whatever unit 0 holds, and
+            // NO readback. That matters: a readback submits and waits, which ends the command
+            // buffer and resets the per-draw memos with it - so a case that read back between its
+            // two draws would never leave a stale entry to catch. The two draws here have to land
+            // in one recording.
+            void DrawOnly() {
+                BindFbo(m_target);
+                glBindVertexArray(m_vao);
+                glUseProgram(m_program);
+                glActiveTexture(GL_TEXTURE0);
+                glBindTexture(GL_TEXTURE_2D, m_texture);
+                const GLint location = glGetUniformLocation(m_program, "u_tex");
+                if (location != -1) glUniform1i(location, 0);
+                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+                glBindVertexArray(0);
+                EXPECT_EQ(FirstGLError(), 0u) << "the sampling draw raised a GL error";
+            }
+
+            ColorFbo m_target{};
+            GLuint m_vao = 0;
+            GLuint m_texture = 0;
+            unsigned int m_program = 0;
+        };
+
+    } // namespace
+
+    // The full sequence, ordered so the ONLY state change between the two draws is the filter.
+    TEST_F(SampledSetStalenessScenario, AQueuedClearIsMaterialisedWhenAFilterChangeCompletesTheTexture) {
+        if (!Ready() || IsSkipped()) return;
+
+        // 1. Queue a clear on the texture through an FBO and take it straight back out, with no
+        //    draw in between - the "attach -> clear -> detach" shape that leaves the clear
+        //    pending for whoever samples the texture next.
+        GLuint clearFbo = 0;
+        glGenFramebuffers(1, &clearFbo);
+        glBindFramebuffer(GL_FRAMEBUFFER, clearFbo);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_texture, 0);
+        ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE));
+        const GLfloat red[4] = {1.0f, 0.0f, 0.0f, 1.0f};
+        glClearBufferfv(GL_COLOR, 0, red);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+        glDeleteFramebuffers(1, &clearFbo);
+        ASSERT_EQ(FirstGLError(), 0u) << "queueing the clear raised a GL error";
+
+        BindFbo(m_target);
+        ClearTo(0.0f, 0.0f, 1.0f, 1.0f);
+
+        // 2. Draw while the texture is still incomplete. The backend substitutes its fallback,
+        //    and the per-draw memo records the resulting sampled set.
+        DrawOnly();
+
+        // 3. Make it complete. No bind, no upload, no program change - one filter write, which is
+        //    exactly the state the old memo key could not see.
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        ASSERT_EQ(FirstGLError(), 0u) << "changing the filter raised a GL error";
+
+        // 4. Draw again, into the same recording, and only now read back. The texture is in the
+        //    sampled set now, so its queued clear has to be materialised before the pass opens and
+        //    the fetch has to see RED. Reading the green the texture was uploaded with means the
+        //    clear was never materialised, i.e. the texture never entered the set - the stale-memo
+        //    bug. Black means the fallback was still being handed out.
+        DrawOnly();
+        const Image afterFlip = ReadPixels(kFboSize, kFboSize);
+        ASSERT_FALSE(afterFlip.Empty()) << "the readback came back empty";
+        EXPECT_TRUE(RegionIsMostly(afterFlip, 0, kFboSize - 1, 0, kFboSize - 1, "red", 0.0,
+                                   "the draw after the completeness flip"))
+            << "green means the queued clear was never materialised, so the texture never re-entered "
+               "the sampled set after the filter change; blue means the draw did not happen at all";
+    }
+
+    // The same flip driven from a SAMPLER OBJECT rather than the texture's own parameters. It is
+    // the other half of what feeds the completeness predicate, it moves the same generation, and
+    // it likewise binds nothing.
+    TEST_F(SampledSetStalenessScenario, AQueuedClearIsMaterialisedWhenASamplerObjectCompletesTheTexture) {
+        if (!Ready() || IsSkipped()) return;
+
+        GLuint sampler = 0;
+        glGenSamplers(1, &sampler);
+        // Bound BEFORE the first draw, still carrying the mipmapping default, so binding it is
+        // not what changes between the two draws.
+        glSamplerParameteri(sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_LINEAR);
+        glBindSampler(0, sampler);
+        ASSERT_EQ(FirstGLError(), 0u) << "binding the sampler object raised a GL error";
+
+        GLuint clearFbo = 0;
+        glGenFramebuffers(1, &clearFbo);
+        glBindFramebuffer(GL_FRAMEBUFFER, clearFbo);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_texture, 0);
+        ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE));
+        const GLfloat red[4] = {1.0f, 0.0f, 0.0f, 1.0f};
+        glClearBufferfv(GL_COLOR, 0, red);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+        glDeleteFramebuffers(1, &clearFbo);
+        ASSERT_EQ(FirstGLError(), 0u) << "queueing the clear raised a GL error";
+
+        BindFbo(m_target);
+        ClearTo(0.0f, 0.0f, 1.0f, 1.0f);
+        DrawOnly();
+
+        // One parameter write on an ALREADY-BOUND sampler object.
+        glSamplerParameteri(sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        ASSERT_EQ(FirstGLError(), 0u) << "changing the sampler filter raised a GL error";
+
+        DrawOnly();
+        const Image afterFlip = ReadPixels(kFboSize, kFboSize);
+        ASSERT_FALSE(afterFlip.Empty()) << "the readback came back empty";
+        EXPECT_TRUE(RegionIsMostly(afterFlip, 0, kFboSize - 1, 0, kFboSize - 1, "red", 0.0,
+                                   "the draw after the sampler-object flip"))
+            << "green means the queued clear was never materialised after the sampler parameter change";
+
+        glBindSampler(0, 0);
+        glDeleteSamplers(1, &sampler);
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/SpirvShaderBinaryScenario.cpp

@@ -0,0 +1,339 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/SpirvShaderBinaryScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - AN APPLICATION-SUPPLIED SPIR-V MODULE RENDERS, END TO END.
+//
+// GL_ARB_gl_spirv is core in 4.6 and MobileGL advertises a 4.6 context, but glShaderBinary and
+// glSpecializeShader were DECLARE_GL_FUNCTION_STUB entry points: they took their arguments,
+// recorded no error and did nothing, and glGetShaderiv(GL_SPIR_V_BINARY) raised GL_INVALID_ENUM.
+// Every gl_spirv conformance body died on the first of those two calls.
+//
+// This scenario is the end-to-end proof that the path now WORKS rather than merely answers: two
+// modules that glslang compiled ahead of time (embedded below as words, so the test depends on
+// no toolchain at run time), handed to glShaderBinary, specialized with a scale and a channel
+// index, linked, drawn, and read back. It runs on both backends and, in CI, on llvmpipe/lavapipe.
+//
+// The two specialization constants are the load-bearing part. The vertex module scales its
+// position by constant id 3 and the fragment module writes 1.0 into the channel named by constant
+// id 7 - so a specialization that silently did nothing would leave the default scale of 1.0 (a
+// full-viewport quad instead of a quarter-sized one) and the default channel 0 (red instead of
+// green), and BOTH would show up in the readback. A "specialization" that merely stored the
+// values without folding them in is exactly the failure mode this shape is built to catch.
+//
+// The GLSL the modules came from:
+//     vertex:   layout(location = 0) in vec2 aPos;
+//               layout(constant_id = 3) const float uScale = 1.0;
+//               void main() { gl_Position = vec4(aPos * uScale, 0.0, 1.0); }
+//     fragment: layout(location = 0) out vec4 oColor;
+//               layout(constant_id = 7) const int uChannel = 0;
+//               void main() { vec4 c = vec4(0,0,0,1); c[uChannel] = 1.0; oColor = c; }
+// compiled with `glslangValidator -G --target-env opengl`.
+
+#include <cstring>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+#ifndef GL_SHADER_BINARY_FORMAT_SPIR_V
+#define GL_SHADER_BINARY_FORMAT_SPIR_V 0x9551
+#endif
+#ifndef GL_SPIR_V_BINARY
+#define GL_SPIR_V_BINARY 0x9552
+#endif
+
+namespace MGITest {
+    namespace {
+
+        class SpirvShaderBinaryScenario : public ScenarioTest {};
+
+        // 255 words
+        const unsigned int kVertexModule[] = {
+            0x07230203u, 0x00010000u, 0x0008000bu, 0x00000020u, 0x00000000u, 0x00020011u, 0x00000001u, 0x0006000bu,
+            0x00000001u, 0x4c534c47u, 0x6474732eu, 0x3035342eu, 0x00000000u, 0x0003000eu, 0x00000000u, 0x00000001u,
+            0x0009000fu, 0x00000000u, 0x00000004u, 0x6e69616du, 0x00000000u, 0x0000000du, 0x00000012u, 0x0000001eu,
+            0x0000001fu, 0x00030003u, 0x00000002u, 0x000001c2u, 0x00040005u, 0x00000004u, 0x6e69616du, 0x00000000u,
+            0x00060005u, 0x0000000bu, 0x505f6c67u, 0x65567265u, 0x78657472u, 0x00000000u, 0x00060006u, 0x0000000bu,
+            0x00000000u, 0x505f6c67u, 0x7469736fu, 0x006e6f69u, 0x00070006u, 0x0000000bu, 0x00000001u, 0x505f6c67u,
+            0x746e696fu, 0x657a6953u, 0x00000000u, 0x00070006u, 0x0000000bu, 0x00000002u, 0x435f6c67u, 0x4470696cu,
+            0x61747369u, 0x0065636eu, 0x00070006u, 0x0000000bu, 0x00000003u, 0x435f6c67u, 0x446c6c75u, 0x61747369u,
+            0x0065636eu, 0x00030005u, 0x0000000du, 0x00000000u, 0x00040005u, 0x00000012u, 0x736f5061u, 0x00000000u,
+            0x00040005u, 0x00000014u, 0x61635375u, 0x0000656cu, 0x00050005u, 0x0000001eu, 0x565f6c67u, 0x65747265u,
+            0x00444978u, 0x00060005u, 0x0000001fu, 0x495f6c67u, 0x6174736eu, 0x4965636eu, 0x00000044u, 0x00030047u,
+            0x0000000bu, 0x00000002u, 0x00050048u, 0x0000000bu, 0x00000000u, 0x0000000bu, 0x00000000u, 0x00050048u,
+            0x0000000bu, 0x00000001u, 0x0000000bu, 0x00000001u, 0x00050048u, 0x0000000bu, 0x00000002u, 0x0000000bu,
+            0x00000003u, 0x00050048u, 0x0000000bu, 0x00000003u, 0x0000000bu, 0x00000004u, 0x00040047u, 0x00000012u,
+            0x0000001eu, 0x00000000u, 0x00040047u, 0x00000014u, 0x00000001u, 0x00000003u, 0x00040047u, 0x0000001eu,
+            0x0000000bu, 0x00000005u, 0x00040047u, 0x0000001fu, 0x0000000bu, 0x00000006u, 0x00020013u, 0x00000002u,
+            0x00030021u, 0x00000003u, 0x00000002u, 0x00030016u, 0x00000006u, 0x00000020u, 0x00040017u, 0x00000007u,
+            0x00000006u, 0x00000004u, 0x00040015u, 0x00000008u, 0x00000020u, 0x00000000u, 0x0004002bu, 0x00000008u,
+            0x00000009u, 0x00000001u, 0x0004001cu, 0x0000000au, 0x00000006u, 0x00000009u, 0x0006001eu, 0x0000000bu,
+            0x00000007u, 0x00000006u, 0x0000000au, 0x0000000au, 0x00040020u, 0x0000000cu, 0x00000003u, 0x0000000bu,
+            0x0004003bu, 0x0000000cu, 0x0000000du, 0x00000003u, 0x00040015u, 0x0000000eu, 0x00000020u, 0x00000001u,
+            0x0004002bu, 0x0000000eu, 0x0000000fu, 0x00000000u, 0x00040017u, 0x00000010u, 0x00000006u, 0x00000002u,
+            0x00040020u, 0x00000011u, 0x00000001u, 0x00000010u, 0x0004003bu, 0x00000011u, 0x00000012u, 0x00000001u,
+            0x00040032u, 0x00000006u, 0x00000014u, 0x3f800000u, 0x0004002bu, 0x00000006u, 0x00000016u, 0x00000000u,
+            0x0004002bu, 0x00000006u, 0x00000017u, 0x3f800000u, 0x00040020u, 0x0000001bu, 0x00000003u, 0x00000007u,
+            0x00040020u, 0x0000001du, 0x00000001u, 0x0000000eu, 0x0004003bu, 0x0000001du, 0x0000001eu, 0x00000001u,
+            0x0004003bu, 0x0000001du, 0x0000001fu, 0x00000001u, 0x00050036u, 0x00000002u, 0x00000004u, 0x00000000u,
+            0x00000003u, 0x000200f8u, 0x00000005u, 0x0004003du, 0x00000010u, 0x00000013u, 0x00000012u, 0x0005008eu,
+            0x00000010u, 0x00000015u, 0x00000013u, 0x00000014u, 0x00050051u, 0x00000006u, 0x00000018u, 0x00000015u,
+            0x00000000u, 0x00050051u, 0x00000006u, 0x00000019u, 0x00000015u, 0x00000001u, 0x00070050u, 0x00000007u,
+            0x0000001au, 0x00000018u, 0x00000019u, 0x00000016u, 0x00000017u, 0x00050041u, 0x0000001bu, 0x0000001cu,
+            0x0000000du, 0x0000000fu, 0x0003003eu, 0x0000001cu, 0x0000001au, 0x000100fdu, 0x00010038u,
+        };
+
+        // 134 words
+        const unsigned int kFragmentModule[] = {
+            0x07230203u, 0x00010000u, 0x0008000bu, 0x00000014u, 0x00000000u, 0x00020011u, 0x00000001u, 0x0006000bu,
+            0x00000001u, 0x4c534c47u, 0x6474732eu, 0x3035342eu, 0x00000000u, 0x0003000eu, 0x00000000u, 0x00000001u,
+            0x0006000fu, 0x00000004u, 0x00000004u, 0x6e69616du, 0x00000000u, 0x00000012u, 0x00030010u, 0x00000004u,
+            0x00000008u, 0x00030003u, 0x00000002u, 0x000001c2u, 0x00040005u, 0x00000004u, 0x6e69616du, 0x00000000u,
+            0x00030005u, 0x00000009u, 0x00000063u, 0x00050005u, 0x0000000eu, 0x61684375u, 0x6c656e6eu, 0x00000000u,
+            0x00040005u, 0x00000012u, 0x6c6f436fu, 0x0000726fu, 0x00040047u, 0x0000000eu, 0x00000001u, 0x00000007u,
+            0x00040047u, 0x00000012u, 0x0000001eu, 0x00000000u, 0x00020013u, 0x00000002u, 0x00030021u, 0x00000003u,
+            0x00000002u, 0x00030016u, 0x00000006u, 0x00000020u, 0x00040017u, 0x00000007u, 0x00000006u, 0x00000004u,
+            0x00040020u, 0x00000008u, 0x00000007u, 0x00000007u, 0x0004002bu, 0x00000006u, 0x0000000au, 0x00000000u,
+            0x0004002bu, 0x00000006u, 0x0000000bu, 0x3f800000u, 0x0007002cu, 0x00000007u, 0x0000000cu, 0x0000000au,
+            0x0000000au, 0x0000000au, 0x0000000bu, 0x00040015u, 0x0000000du, 0x00000020u, 0x00000001u, 0x00040032u,
+            0x0000000du, 0x0000000eu, 0x00000000u, 0x00040020u, 0x0000000fu, 0x00000007u, 0x00000006u, 0x00040020u,
+            0x00000011u, 0x00000003u, 0x00000007u, 0x0004003bu, 0x00000011u, 0x00000012u, 0x00000003u, 0x00050036u,
+            0x00000002u, 0x00000004u, 0x00000000u, 0x00000003u, 0x000200f8u, 0x00000005u, 0x0004003bu, 0x00000008u,
+            0x00000009u, 0x00000007u, 0x0003003eu, 0x00000009u, 0x0000000cu, 0x00050041u, 0x0000000fu, 0x00000010u,
+            0x00000009u, 0x0000000eu, 0x0003003eu, 0x00000010u, 0x0000000bu, 0x0004003du, 0x00000007u, 0x00000013u,
+            0x00000009u, 0x0003003eu, 0x00000012u, 0x00000013u, 0x000100fdu, 0x00010038u,
+        };
+
+
+        // The quad the vertex module transforms. Full-viewport before the scale, so a scale of
+        // 0.5 covers exactly the middle half of each axis and the corners stay background.
+        const float kQuad[] = {-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
+
+        // The specialization constant ids the two modules declare.
+        constexpr unsigned int kScaleConstantId = 3;
+        constexpr unsigned int kChannelConstantId = 7;
+
+        unsigned int MakeSpirvShader(GLenum type, const unsigned int* words, size_t wordCount,
+                                     unsigned int constantId, unsigned int constantValue, std::string* outLog) {
+            const GLuint shader = glCreateShader(type);
+            glShaderBinary(1, &shader, GL_SHADER_BINARY_FORMAT_SPIR_V, words,
+                           static_cast<GLsizei>(wordCount * sizeof(unsigned int)));
+            if (glGetError() != GL_NO_ERROR) {
+                if (outLog) *outLog = "glShaderBinary rejected the module";
+                glDeleteShader(shader);
+                return 0;
+            }
+
+            GLint isSpirv = GL_FALSE;
+            glGetShaderiv(shader, GL_SPIR_V_BINARY, &isSpirv);
+            if (glGetError() != GL_NO_ERROR || isSpirv != GL_TRUE) {
+                if (outLog) *outLog = "GL_SPIR_V_BINARY did not read TRUE after glShaderBinary";
+                glDeleteShader(shader);
+                return 0;
+            }
+
+            glSpecializeShader(shader, "main", 1, &constantId, &constantValue);
+            GLint compiled = GL_FALSE;
+            glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+            if (compiled != GL_TRUE) {
+                if (outLog) {
+                    GLint length = 0;
+                    glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
+                    std::vector<char> log(static_cast<size_t>(length > 0 ? length : 1), '\0');
+                    glGetShaderInfoLog(shader, static_cast<GLsizei>(log.size()), nullptr, log.data());
+                    *outLog = std::string(log.data());
+                }
+                glDeleteShader(shader);
+                return 0;
+            }
+            return shader;
+        }
+
+    } // namespace
+
+    TEST_F(SpirvShaderBinaryScenario, ShaderBinaryFormatIsAdvertisedExactlyOnce) {
+        if (!Ready()) return;
+
+        GLint formatCount = -1;
+        glGetIntegerv(GL_NUM_SHADER_BINARY_FORMATS, &formatCount);
+        EXPECT_EQ(FirstGLError(), 0u);
+        ASSERT_EQ(formatCount, 1) << "a 4.6 context supports exactly the SPIR-V shader binary format";
+
+        std::vector<GLint> formats(static_cast<size_t>(formatCount), 0);
+        glGetIntegerv(GL_SHADER_BINARY_FORMATS, formats.data());
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_EQ(formats[0], static_cast<GLint>(GL_SHADER_BINARY_FORMAT_SPIR_V))
+            << "the count and the list have to describe the same thing";
+    }
+
+    TEST_F(SpirvShaderBinaryScenario, AnUnsupportedBinaryFormatIsRejectedInsteadOfSilentlyAccepted) {
+        if (!Ready()) return;
+
+        const GLuint shader = glCreateShader(GL_VERTEX_SHADER);
+        // 0x8DF9 is GL_SHADER_BINARY_FORMATS' neighbour, not a format: any value but
+        // GL_SHADER_BINARY_FORMAT_SPIR_V is GL_INVALID_ENUM. The stub used to return silently.
+        glShaderBinary(1, &shader, 0x8DF9, kVertexModule, sizeof(kVertexModule));
+        EXPECT_EQ(FirstGLError(), static_cast<unsigned int>(GL_INVALID_ENUM));
+
+        GLint isSpirv = GL_TRUE;
+        glGetShaderiv(shader, GL_SPIR_V_BINARY, &isSpirv);
+        EXPECT_EQ(FirstGLError(), 0u);
+        EXPECT_EQ(isSpirv, GL_FALSE) << "a rejected glShaderBinary must not have attached anything";
+
+        glDeleteShader(shader);
+    }
+
+    TEST_F(SpirvShaderBinaryScenario, CompileShaderOnASpirvShaderIsInvalidOperationAndShaderSourceTakesItBack) {
+        if (!Ready()) return;
+
+        const GLuint shader = glCreateShader(GL_VERTEX_SHADER);
+        glShaderBinary(1, &shader, GL_SHADER_BINARY_FORMAT_SPIR_V, kVertexModule, sizeof(kVertexModule));
+        ASSERT_EQ(FirstGLError(), 0u);
+
+        glCompileShader(shader);
+        EXPECT_EQ(FirstGLError(), static_cast<unsigned int>(GL_INVALID_OPERATION))
+            << "glSpecializeShader, not glCompileShader, is what compiles a SPIR-V shader";
+
+        // glShaderSource takes the object back to being a GLSL shader, and GL_SPIR_V_BINARY with
+        // it - the transition the conformance suite checks explicitly.
+        const char* source = "#version 450\nvoid main() { gl_Position = vec4(0.0); }\n";
+        glShaderSource(shader, 1, &source, nullptr);
+        ASSERT_EQ(FirstGLError(), 0u);
+        GLint isSpirv = GL_TRUE;
+        glGetShaderiv(shader, GL_SPIR_V_BINARY, &isSpirv);
+        EXPECT_EQ(isSpirv, GL_FALSE);
+        glCompileShader(shader);
+        EXPECT_EQ(FirstGLError(), 0u) << "the object is an ordinary GLSL shader again";
+
+        glDeleteShader(shader);
+    }
+
+    TEST_F(SpirvShaderBinaryScenario, SpecializeShaderErrorSurfaceMatchesTheExtension) {
+        if (!Ready()) return;
+
+        const GLuint shader = glCreateShader(GL_VERTEX_SHADER);
+        glShaderBinary(1, &shader, GL_SHADER_BINARY_FORMAT_SPIR_V, kVertexModule, sizeof(kVertexModule));
+        ASSERT_EQ(FirstGLError(), 0u);
+
+        // 4242 is not one of the module's constant ids. ARB_gl_spirv enumerates that as
+        // GL_INVALID_VALUE, and an erroring GL command has no other effect - so the shader is left
+        // untouched rather than pushed into a failed-compile state.
+        const unsigned int badId = 4242;
+        const unsigned int value = 0;
+        glSpecializeShader(shader, "main", 1, &badId, &value);
+        EXPECT_EQ(FirstGLError(), static_cast<unsigned int>(GL_INVALID_VALUE));
+
+        // Same for an entry point the module does not carry.
+        glSpecializeShader(shader, "notMain", 0, nullptr, nullptr);
+        EXPECT_EQ(FirstGLError(), static_cast<unsigned int>(GL_INVALID_VALUE));
+
+        // Neither refusal specialized the shader, so a well-formed call still works.
+        glSpecializeShader(shader, "main", 0, nullptr, nullptr);
+        EXPECT_EQ(FirstGLError(), 0u);
+        GLint compiled = GL_FALSE;
+        glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+        EXPECT_EQ(compiled, GL_TRUE);
+
+        // But a SECOND specialization of a shader that HAS been specialized is INVALID_OPERATION
+        // until glShaderBinary re-associates the module.
+        glSpecializeShader(shader, "main", 0, nullptr, nullptr);
+        EXPECT_EQ(FirstGLError(), static_cast<unsigned int>(GL_INVALID_OPERATION));
+        glShaderBinary(1, &shader, GL_SHADER_BINARY_FORMAT_SPIR_V, kVertexModule, sizeof(kVertexModule));
+        glSpecializeShader(shader, "main", 0, nullptr, nullptr);
+        EXPECT_EQ(FirstGLError(), 0u) << "re-associating the module makes specialization legal again";
+
+        glDeleteShader(shader);
+    }
+
+    TEST_F(SpirvShaderBinaryScenario, SpecializedModulesLinkAndRenderWithTheirConstantsApplied) {
+        if (!Ready()) return;
+        HeadlessGL& gl = Gl();
+        const int width = gl.Width();
+        const int height = gl.Height();
+        ASSERT_GE(width, 16);
+        ASSERT_GE(height, 16);
+
+        std::string log;
+        // Scale 0.5 as a float, handed over as the GLuint bit pattern the extension specifies.
+        unsigned int halfBits = 0;
+        const float half = 0.5f;
+        std::memcpy(&halfBits, &half, sizeof(halfBits));
+
+        const unsigned int vs = MakeSpirvShader(GL_VERTEX_SHADER, kVertexModule,
+                                                sizeof(kVertexModule) / sizeof(kVertexModule[0]),
+                                                kScaleConstantId, halfBits, &log);
+        ASSERT_NE(vs, 0u) << "vertex: " << log;
+        // Channel 1 is green; the module's own default is 0 (red), so a specialization that did
+        // nothing paints the wrong colour.
+        const unsigned int fs = MakeSpirvShader(GL_FRAGMENT_SHADER, kFragmentModule,
+                                                sizeof(kFragmentModule) / sizeof(kFragmentModule[0]),
+                                                kChannelConstantId, 1u, &log);
+        ASSERT_NE(fs, 0u) << "fragment: " << log;
+
+        const GLuint program = glCreateProgram();
+        glAttachShader(program, vs);
+        glAttachShader(program, fs);
+        glLinkProgram(program);
+        GLint linked = GL_FALSE;
+        glGetProgramiv(program, GL_LINK_STATUS, &linked);
+        if (linked != GL_TRUE) {
+            GLint length = 0;
+            glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
+            std::vector<char> programLog(static_cast<size_t>(length > 0 ? length : 1), '\0');
+            glGetProgramInfoLog(program, static_cast<GLsizei>(programLog.size()), nullptr, programLog.data());
+            FAIL() << "linking two specialized SPIR-V modules failed: " << programLog.data();
+        }
+
+        BindDefaultFramebuffer();
+        glViewport(0, 0, width, height);
+        glDisable(GL_SCISSOR_TEST);
+        glDisable(GL_DEPTH_TEST);
+        ClearTo(0.0f, 0.0f, 0.0f, 1.0f);
+
+        GLuint vao = 0, vbo = 0;
+        glGenVertexArrays(1, &vao);
+        glBindVertexArray(vao);
+        glGenBuffers(1, &vbo);
+        glBindBuffer(GL_ARRAY_BUFFER, vbo);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(kQuad), kQuad, GL_STATIC_DRAW);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
+        glUseProgram(program);
+        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+        EXPECT_EQ(FirstGLError(), 0u);
+
+        const Image painted = ReadPixels(width, height);
+        const Rgba8 centre = painted.At(width / 2, height / 2);
+        EXPECT_LT(centre.r, 32) << "the fragment module wrote the wrong channel; constant id 7 was not applied";
+        EXPECT_GT(centre.g, 224) << "the centre of a 0.5-scaled quad must be painted";
+
+        // A pixel just inside the corner is OUTSIDE the 0.5-scaled quad and must still be the
+        // clear colour - which is what proves constant id 3 reached the vertex module. At the
+        // default scale of 1.0 the quad covers the whole viewport and this pixel would be green.
+        const Rgba8 corner = painted.At(1, 1);
+        EXPECT_LT(corner.g, 32) << "the quad was not scaled; the vertex specialization constant was not applied";
+
+        glBindVertexArray(0);
+        glDeleteBuffers(1, &vbo);
+        glDeleteVertexArrays(1, &vao);
+        glDeleteProgram(program);
+        glDeleteShader(vs);
+        glDeleteShader(fs);
+        gl.EndFrame();
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/TessellationXfbCaptureScenario.cpp

@@ -0,0 +1,896 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/TessellationXfbCaptureScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - WHAT A TESSELLATION EVALUATION STAGE OWES A TRANSFORM FEEDBACK CAPTURE.
+//
+// XfbRepeatedCaptureScenario already pins that a capture from a GL_PATCHES draw records
+// AT ALL. Everything below is the part of the same pipeline it does not reach, and every
+// case here is the reduced form of a conformance body that fails on a device:
+//
+//   * CAPTURING THE BUILT-INS BY NAME. glTransformFeedbackVaryings("gl_Position") /
+//     ("gl_PointSize") on a program whose last vertex-processing stage is the evaluation
+//     shader. Nothing in the tree captured a built-in from a tessellation stage, and the
+//     two backends reach it by completely different routes - DirectGLES has to name a
+//     real ESSL output on the driver's own glTransformFeedbackVaryings, DirectVulkan has
+//     to decorate a SPIR-V built-in that lives inside gl_PerVertex.
+//
+//   * THE PER-VERTEX PAYLOAD THE CONTROL STAGE HANDS OVER. gl_PointSize and a
+//     user-declared per-vertex interface block, both read back out of gl_in[] by the
+//     evaluation stage and only then captured. This is the shape of
+//     KHR-GL4x.tessellation_shader.tessellation_control_to_tessellation_evaluation.
+//     gl_MaxPatchVertices_Position_PointSize, which is 216 of the ~240 conformance bodies
+//     the family still fails: gl_Position arrives, and everything travelling beside it in
+//     the same patch does not.
+//
+// The assertions are on the captured BYTES against a CPU-computed reference, never on the
+// absence of a GL error: every failure this guards against is silent.
+
+#include <cmath>
+#include <cstring>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // Nothing a capture can legitimately produce, so a component that still reads it
+        // names the failure instead of looking like an ordinary numeric mismatch.
+        constexpr float kPoison = -987654.0f;
+
+        const char* const kFragmentSource = R"(#version 420 core
+out vec4 fragColor;
+void main()
+{
+    fragColor = vec4(1.0, 0.0, 0.0, 1.0);
+}
+)";
+
+        class TessellationXfbCaptureScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                DrainErrors();
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glUseProgram(0);
+                for (const GLuint program : m_programs) {
+                    glDeleteProgram(program);
+                }
+                m_programs.clear();
+                glBindVertexArray(0);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                m_vao = 0;
+                ScenarioTest::TearDown();
+            }
+
+            static void DrainErrors() {
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+            }
+
+            static bool BackendHostsTessellation() {
+                GLint maxTessGenLevel = 0;
+                glGetIntegerv(GL_MAX_TESS_GEN_LEVEL, &maxTessGenLevel);
+                DrainErrors();
+                return maxTessGenLevel >= 1;
+            }
+
+            static GLint MaxPatchVertices() {
+                GLint value = 0;
+                glGetIntegerv(GL_MAX_PATCH_VERTICES, &value);
+                DrainErrors();
+                return value;
+            }
+
+            static std::string InfoLog(GLuint object, bool isShader) {
+                GLint length = 0;
+                if (isShader) {
+                    glGetShaderiv(object, GL_INFO_LOG_LENGTH, &length);
+                } else {
+                    glGetProgramiv(object, GL_INFO_LOG_LENGTH, &length);
+                }
+                std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                if (isShader) {
+                    glGetShaderInfoLog(object, length + 1, nullptr, buffer.data());
+                } else {
+                    glGetProgramInfoLog(object, length + 1, nullptr, buffer.data());
+                }
+                return buffer.data();
+            }
+
+            GLuint BuildCaptureProgram(const std::vector<std::pair<GLenum, std::string>>& stages,
+                                       const std::vector<const char*>& varyings) {
+                m_buildLog.clear();
+                std::vector<GLuint> shaders;
+                bool ok = true;
+                for (const auto& [stage, source] : stages) {
+                    const GLuint shader = glCreateShader(stage);
+                    const char* text = source.c_str();
+                    glShaderSource(shader, 1, &text, nullptr);
+                    glCompileShader(shader);
+                    GLint compiled = 0;
+                    glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+                    shaders.push_back(shader);
+                    if (compiled == GL_FALSE) {
+                        m_buildLog = InfoLog(shader, true) + "\n--- source ---\n" + source;
+                        ok = false;
+                        break;
+                    }
+                }
+                GLuint program = 0;
+                if (ok) {
+                    program = glCreateProgram();
+                    for (const GLuint shader : shaders) {
+                        glAttachShader(program, shader);
+                    }
+                    glTransformFeedbackVaryings(program, static_cast<GLsizei>(varyings.size()), varyings.data(),
+                                                GL_INTERLEAVED_ATTRIBS);
+                    glLinkProgram(program);
+                    GLint linked = GL_FALSE;
+                    glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                    if (linked == GL_FALSE) {
+                        m_buildLog = InfoLog(program, false);
+                        glDeleteProgram(program);
+                        program = 0;
+                    }
+                }
+                for (const GLuint shader : shaders) {
+                    glDeleteShader(shader);
+                }
+                if (program != 0) m_programs.push_back(program);
+                return program;
+            }
+
+            // One capture span over a single patch. Returns the capture buffer read back as
+            // floats; `capturedFloats` is the whole buffer, poison-filled beforehand.
+            std::vector<float> RunPatchCaptureSpan(GLuint program, GLenum captureMode, std::size_t capturedFloats) {
+                const std::vector<float> poison(capturedFloats, kPoison);
+                GLuint xfbBuffer = 0;
+                glGenBuffers(1, &xfbBuffer);
+                glBindBuffer(GL_ARRAY_BUFFER, xfbBuffer);
+                glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(capturedFloats * sizeof(float)), poison.data(),
+                             GL_STATIC_COPY);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+
+                glBindVertexArray(m_vao);
+                glUseProgram(program);
+                glEnable(GL_RASTERIZER_DISCARD);
+                glBeginTransformFeedback(captureMode);
+                glDrawArrays(GL_PATCHES, 0, 1);
+                glEndTransformFeedback();
+                glDisable(GL_RASTERIZER_DISCARD);
+
+                std::vector<float> readback(capturedFloats, kPoison);
+                glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
+                                   static_cast<GLsizeiptr>(capturedFloats * sizeof(float)), readback.data());
+                glUseProgram(0);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+                glDeleteBuffers(1, &xfbBuffer);
+                return readback;
+            }
+
+            static ::testing::AssertionResult ComponentIs(const std::vector<float>& data, std::size_t index,
+                                                          float expected, float epsilon = 1e-4f) {
+                if (index >= data.size()) {
+                    return ::testing::AssertionFailure() << "component " << index << " is past the capture buffer";
+                }
+                const float actual = data[index];
+                if (actual == kPoison) {
+                    return ::testing::AssertionFailure()
+                           << "component " << index << " still holds the poison value - the capture never reached "
+                           << "these bytes (expected " << expected << ")";
+                }
+                if (std::isnan(actual) || std::abs(actual - expected) > epsilon) {
+                    return ::testing::AssertionFailure()
+                           << "component " << index << " is " << actual << ", expected " << expected;
+                }
+                return ::testing::AssertionSuccess();
+            }
+
+            // Defined below the shader builders it uses. `withPointSize` is the conformance
+            // body's own should_pass_pointsize_data axis.
+            void RunPerVertexPayloadCase(bool withPointSize);
+
+            // Why the gl_PointSize cases cannot be run here, or empty when they can.
+            //
+            // gl_PointSize from a tessellation stage is a real DRIVER capability on both
+            // targets - GL_EXT/OES_tessellation_point_size on an ES driver, the
+            // shaderTessellationAndGeometryPointSize feature on a Vulkan device - and desktop GL
+            // has no query that reports either, so this probes for it by running a program.
+            //
+            // The probe is deliberately NOT a gl_PointSize capture: it captures an ordinary user
+            // varying out of a tessellation evaluation stage that ALSO writes gl_PointSize, and
+            // compares that against the identical program without the write. A backend that
+            // cannot express the built-in loses the whole stage (DirectGLES fails to compile it
+            // and binds program 0; DirectVulkan cannot build the pipeline), so the plain varying
+            // comes back untouched too - which is a capability answer, not a capture answer. If
+            // BOTH come back untouched the probe itself is meaningless and it returns empty, so
+            // the cases run and FAIL rather than skipping on an unrelated breakage.
+            //
+            // Returns the reason as a string instead of skipping directly: GTEST_SKIP expands to
+            // a `return`, so a void helper would leave only the helper and let the case run its
+            // assertions anyway and report Failed instead of Skipped.
+            std::string WhyPointSizeCasesCannotRun();
+
+            // The geometry stage's own answer, and it has to BE its own answer: the two ESSL
+            // extensions are independent (Loader models them as two PointSizeTier fields fed by
+            // four distinct strings, and neither implies the other), so a driver with
+            // tessellation point size and no geometry point size passes the probe above and
+            // still cannot run the case below. Same two-program shape, one stage over.
+            //
+            // It also replaces a guard that could never fire: GL_MAX_GEOMETRY_OUTPUT_VERTICES is
+            // a hardcoded frontend constant (256) with no capability behind it, so "does this
+            // stack have a geometry stage at all" can only be answered by trying to build one -
+            // which is what this does, exactly as IoBlockNameCollisionScenario does for the same
+            // reason.
+            std::string WhyGeometryPointSizeCaseCannotRun();
+
+            std::vector<GLuint> m_programs;
+            std::string m_buildLog;
+            GLuint m_vao = 0;
+        };
+
+        // ---------------------------------------------------------------------------------
+        // Built-ins captured BY NAME from the evaluation stage.
+        // ---------------------------------------------------------------------------------
+
+        const char* const kMinimalVertexSource = R"(#version 420 core
+void main()
+{
+    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+}
+)";
+
+        const char* const kMinimalTessControlSource = R"(#version 420 core
+layout(vertices = 1) out;
+void main()
+{
+    gl_out[gl_InvocationID].gl_Position = gl_in[0].gl_Position;
+    gl_TessLevelOuter[0] = 1.0;
+    gl_TessLevelOuter[1] = 1.0;
+    gl_TessLevelOuter[2] = 1.0;
+    gl_TessLevelInner[0] = 1.0;
+}
+)";
+
+        // Values no stale buffer would hold by accident. The two sources differ ONLY by
+        // gl_PointSize, so the pair isolates it: on a backend that lowers to ESSL the
+        // built-in is not even declared in a tessellation stage without
+        // GL_EXT_tessellation_point_size, and the whole shader then fails to compile.
+        const char* const kPositionTessEvalSource = R"(#version 420 core
+layout(triangles, equal_spacing, cw, point_mode) in;
+void main()
+{
+    gl_Position  = vec4(11.0, 12.0, 13.0, 14.0);
+}
+)";
+
+        const char* const kPositionAndPointSizeTessEvalSource = R"(#version 420 core
+layout(triangles, equal_spacing, cw, point_mode) in;
+void main()
+{
+    gl_Position  = vec4(11.0, 12.0, 13.0, 14.0);
+    gl_PointSize = 5.0;
+}
+)";
+
+        // The two probe programs. They differ by one statement; both capture `probe_value`,
+        // which has nothing to do with point size.
+        const char* const kPointSizeProbeTessEvalSource = R"(#version 420 core
+layout(triangles, equal_spacing, cw, point_mode) in;
+out float probe_value;
+void main()
+{
+    probe_value  = 42.0;
+    gl_Position  = vec4(0.0, 0.0, 0.0, 1.0);
+    gl_PointSize = 3.0;
+}
+)";
+
+        const char* const kPointSizeFreeProbeTessEvalSource = R"(#version 420 core
+layout(triangles, equal_spacing, cw, point_mode) in;
+out float probe_value;
+void main()
+{
+    probe_value = 42.0;
+    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+}
+)";
+
+        std::string TessellationXfbCaptureScenario::WhyPointSizeCasesCannotRun() {
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            const auto probeCaptures = [&](const char* tessEvalSource) {
+                const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kMinimalVertexSource},
+                                                            {GL_TESS_CONTROL_SHADER, kMinimalTessControlSource},
+                                                            {GL_TESS_EVALUATION_SHADER, tessEvalSource},
+                                                            {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                           {"probe_value"});
+                if (program == 0) return false;
+                const std::vector<float> captured = RunPatchCaptureSpan(program, GL_POINTS, 3);
+                DrainErrors();
+                return captured[0] == 42.0f;
+            };
+
+            const bool withPointSize = probeCaptures(kPointSizeProbeTessEvalSource);
+            if (withPointSize) return {};
+            if (!probeCaptures(kPointSizeFreeProbeTessEvalSource)) {
+                // The control failed too, so nothing here is about point size.
+                return {};
+            }
+            return "this backend cannot express gl_PointSize in a tessellation stage at all - the same "
+                   "program captures an ordinary varying with the gl_PointSize write removed and captures "
+                   "nothing with it present (an ES driver without GL_EXT/OES_tessellation_point_size, or a "
+                   "Vulkan device without shaderTessellationAndGeometryPointSize)";
+        }
+
+        TEST_F(TessellationXfbCaptureScenario, CapturesGlPositionByNameFromTheEvaluationStage) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " (" << Gl().RendererString()
+                             << ")";
+            }
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kMinimalVertexSource},
+                                                        {GL_TESS_CONTROL_SHADER, kMinimalTessControlSource},
+                                                        {GL_TESS_EVALUATION_SHADER, kPositionTessEvalSource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_Position"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            // point_mode with every level at 1 emits three points, all carrying the same
+            // constant; only the first record has to be right for the mechanism to be proven.
+            const std::vector<float> captured = RunPatchCaptureSpan(program, GL_POINTS, 4 * 3);
+            EXPECT_TRUE(ComponentIs(captured, 0, 11.0f));
+            EXPECT_TRUE(ComponentIs(captured, 1, 12.0f));
+            EXPECT_TRUE(ComponentIs(captured, 2, 13.0f));
+            EXPECT_TRUE(ComponentIs(captured, 3, 14.0f));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        TEST_F(TessellationXfbCaptureScenario, CapturesGlPositionAndGlPointSizeByNameFromTheEvaluationStage) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " (" << Gl().RendererString()
+                             << ")";
+            }
+            if (const std::string reason = WhyPointSizeCasesCannotRun(); !reason.empty()) GTEST_SKIP() << reason;
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kMinimalVertexSource},
+                                                        {GL_TESS_CONTROL_SHADER, kMinimalTessControlSource},
+                                                        {GL_TESS_EVALUATION_SHADER, kPositionAndPointSizeTessEvalSource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_Position", "gl_PointSize"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            const std::vector<float> captured = RunPatchCaptureSpan(program, GL_POINTS, 5 * 3);
+            EXPECT_TRUE(ComponentIs(captured, 0, 11.0f));
+            EXPECT_TRUE(ComponentIs(captured, 1, 12.0f));
+            EXPECT_TRUE(ComponentIs(captured, 2, 13.0f));
+            EXPECT_TRUE(ComponentIs(captured, 3, 14.0f));
+            EXPECT_TRUE(ComponentIs(captured, 4, 5.0f));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // ---------------------------------------------------------------------------------
+        // The per-vertex payload the control stage hands to the evaluation stage.
+        // ---------------------------------------------------------------------------------
+
+        // The conformance body's own shapes, reduced to one patch and parameterised by the
+        // output patch size so the caller can run the real GL_MAX_PATCH_VERTICES. The
+        // `withPointSize` axis is the conformance body's own `should_pass_pointsize_data`,
+        // which it varies together with point_mode - and which decides whether the whole
+        // program even involves the per-vertex built-in that ESSL gates behind an extension.
+        std::string PayloadVertexSource(bool withPointSize) {
+            return R"(#version 420 core
+out gl_PerVertex {
+    vec4  gl_Position;
+)" + std::string(withPointSize ? "    float gl_PointSize;\n" : "") +
+                   R"(};
+void main()
+{
+}
+)";
+        }
+
+        std::string PayloadTessControlSource(int outputVertices, bool withPointSize) {
+            const std::string perVertexTail = withPointSize ? "    float gl_PointSize;\n" : "";
+            return R"(#version 420 core
+layout(vertices = )" + std::to_string(outputVertices) +
+                   R"() out;
+in gl_PerVertex {
+    vec4  gl_Position;
+)" + perVertexTail +
+                   R"(} gl_in[gl_MaxPatchVertices];
+out gl_PerVertex {
+    vec4  gl_Position;
+)" + perVertexTail +
+                   R"(} gl_out[];
+out OUT_TC
+{
+     vec2 value1;
+    ivec4 value2;
+} result[];
+void main()
+{
+)" + std::string(withPointSize
+                                        ? "    gl_out[gl_InvocationID].gl_PointSize = 1.0 / float(gl_InvocationID + 1);\n"
+                                        : "") +
+                   R"(    gl_out[gl_InvocationID].gl_Position  = vec4(float(gl_InvocationID * 4 + 0), float(gl_InvocationID * 4 + 1),
+                                                float(gl_InvocationID * 4 + 2), float(gl_InvocationID * 4 + 3));
+    result[gl_InvocationID].value1       = vec2(1.0 / float(gl_InvocationID + 1), 1.0 / float(gl_InvocationID + 2));
+    result[gl_InvocationID].value2       = ivec4(gl_InvocationID + 1, gl_InvocationID + 2,
+                                                 gl_InvocationID + 3, gl_InvocationID + 4);
+    gl_TessLevelInner[0] = 1.0;
+    gl_TessLevelInner[1] = 1.0;
+    gl_TessLevelOuter[0] = 1.0;
+    gl_TessLevelOuter[1] = 1.0;
+    gl_TessLevelOuter[2] = 1.0;
+    gl_TessLevelOuter[3] = 1.0;
+}
+)";
+        }
+
+        // Deliberately NEVER writes gl_Position, exactly as the conformance shader does not:
+        // the redeclared block is there so the evaluation stage can READ gl_in[], and an
+        // output nothing stores is what UnwrittenPositionOutputScenario pins separately.
+        std::string PayloadTessEvalSource(int inputVertices, bool withPointSize) {
+            const std::string perVertexTail = withPointSize ? "    float gl_PointSize;\n" : "";
+            return R"(#version 420 core
+layout(isolines, equal_spacing, ccw, point_mode) in;
+in gl_PerVertex {
+    vec4  gl_Position;
+)" + perVertexTail +
+                   R"(} gl_in[gl_MaxPatchVertices];
+out gl_PerVertex {
+    vec4  gl_Position;
+)" + perVertexTail +
+                   R"(};
+in OUT_TC
+{
+     vec2 value1;
+    ivec4 value2;
+} tc_data[];
+
+)" + std::string(withPointSize ? "out      float te_pointsize;\n" : "") +
+                   R"(out       vec4 te_position;
+out       vec2 te_value1;
+out flat ivec4 te_value2;
+
+void main()
+{
+)" + std::string(withPointSize ? "    te_pointsize = 0.0;\n" : "") +
+                   R"(    te_position  = vec4 (0.0);
+    te_value1    = vec2 (0.0);
+    te_value2    = ivec4(0);
+
+    for (int n = 0; n < )" + std::to_string(inputVertices) +
+                   R"(; ++n)
+    {
+)" + std::string(withPointSize ? "        te_pointsize += gl_in  [n].gl_PointSize;\n" : "") +
+                   R"(        te_position  += gl_in  [n].gl_Position;
+        te_value1    += tc_data[n].value1;
+        te_value2    += tc_data[n].value2;
+    }
+}
+)";
+        }
+
+        // The reduced conformance body. `withPointSize` selects between its two halves;
+        // everything else - one input vertex, an output patch of GL_MAX_PATCH_VERTICES, a
+        // user per-vertex block travelling beside gl_PerVertex, the capture taken off the
+        // evaluation stage - is the same on both.
+        void TessellationXfbCaptureScenario::RunPerVertexPayloadCase(bool withPointSize) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " (" << Gl().RendererString()
+                             << ")";
+            }
+            if (withPointSize) {
+                if (const std::string reason = WhyPointSizeCasesCannotRun(); !reason.empty()) GTEST_SKIP() << reason;
+            }
+            const GLint patchVertices = MaxPatchVertices();
+            ASSERT_GE(patchVertices, 32) << "GL_MAX_PATCH_VERTICES is below the guaranteed minimum";
+
+            // One input vertex per patch, an output patch of GL_MAX_PATCH_VERTICES vertices:
+            // the control stage runs that many invocations and every one of them contributes.
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            std::vector<const char*> varyings = {"te_position", "te_value1", "te_value2"};
+            if (withPointSize) varyings.push_back("te_pointsize");
+
+            const GLuint program =
+                BuildCaptureProgram({{GL_VERTEX_SHADER, PayloadVertexSource(withPointSize)},
+                                     {GL_TESS_CONTROL_SHADER, PayloadTessControlSource(patchVertices, withPointSize)},
+                                     {GL_TESS_EVALUATION_SHADER, PayloadTessEvalSource(patchVertices, withPointSize)},
+                                     {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                    varyings);
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            float referencePointSize = 0.0f;
+            float referencePosition[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+            float referenceValue1[2] = {0.0f, 0.0f};
+            int referenceValue2[4] = {0, 0, 0, 0};
+            for (int n = 0; n < patchVertices; ++n) {
+                referencePointSize += 1.0f / static_cast<float>(n + 1);
+                for (int c = 0; c < 4; ++c) {
+                    referencePosition[c] += static_cast<float>(n * 4 + c);
+                    referenceValue2[c] += n + 1 + c;
+                }
+                referenceValue1[0] += 1.0f / static_cast<float>(n + 1);
+                referenceValue1[1] += 1.0f / static_cast<float>(n + 2);
+            }
+
+            // isolines with every level at 1 emits two points; the record stride is
+            // vec4 + vec2 + ivec4 [+ float] components.
+            const std::size_t stride = withPointSize ? 11 : 10;
+            const std::vector<float> captured = RunPatchCaptureSpan(program, GL_POINTS, stride * 4);
+            for (int c = 0; c < 4; ++c) {
+                EXPECT_TRUE(ComponentIs(captured, static_cast<std::size_t>(c), referencePosition[c], 1e-2f))
+                    << "te_position." << c << " (gl_in[].gl_Position)";
+            }
+            for (int c = 0; c < 2; ++c) {
+                EXPECT_TRUE(ComponentIs(captured, static_cast<std::size_t>(4 + c), referenceValue1[c], 1e-3f))
+                    << "te_value1." << c << " (the user per-vertex block the control stage wrote)";
+            }
+            for (int c = 0; c < 4; ++c) {
+                const std::size_t index = static_cast<std::size_t>(6 + c);
+                ASSERT_LT(index, captured.size());
+                int actual = 0;
+                std::memcpy(&actual, &captured[index], sizeof(actual));
+                EXPECT_EQ(actual, referenceValue2[c])
+                    << "te_value2." << c << " (the user per-vertex block's integer member)";
+            }
+            if (withPointSize) {
+                EXPECT_TRUE(ComponentIs(captured, 10, referencePointSize, 1e-3f))
+                    << "te_pointsize (gl_in[].gl_PointSize)";
+            }
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        TEST_F(TessellationXfbCaptureScenario, TheEvaluationStageSeesTheUserPerVertexBlockOfItsPatch) {
+            RunPerVertexPayloadCase(false);
+        }
+
+        // ---------------------------------------------------------------------------------
+        // The same built-in, one stage over.
+        // ---------------------------------------------------------------------------------
+
+        // ESSL gates gl_PointSize behind a per-stage extension in BOTH non-vertex
+        // vertex-processing stages - EXT/OES_tessellation_point_size for the two tessellation
+        // stages, EXT/OES_geometry_point_size for the geometry one - and they are separate
+        // extensions that do not imply each other, so the geometry arm is a second code path
+        // rather than the same one. Nothing else in the tree writes gl_PointSize from a geometry
+        // shader, so without this case the arm ships untested.
+        const char* const kPointSizeGeometrySource = R"(#version 420 core
+layout(points) in;
+layout(points, max_vertices = 1) out;
+out float gs_value;
+void main()
+{
+    gs_value     = 7.0;
+    gl_Position  = gl_in[0].gl_Position;
+    gl_PointSize = 4.0;
+    EmitVertex();
+}
+)";
+
+        // The control: identical but for the gl_PointSize write, so the pair answers "can this
+        // stack host a geometry stage that names the built-in" without asking anything about
+        // capture.
+        const char* const kPointSizeFreeGeometrySource = R"(#version 420 core
+layout(points) in;
+layout(points, max_vertices = 1) out;
+out float gs_value;
+void main()
+{
+    gs_value    = 7.0;
+    gl_Position = gl_in[0].gl_Position;
+    EmitVertex();
+}
+)";
+
+        std::string TessellationXfbCaptureScenario::WhyGeometryPointSizeCaseCannotRun() {
+            const auto probeCaptures = [&](const char* geometrySource) {
+                const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kMinimalVertexSource},
+                                                            {GL_GEOMETRY_SHADER, geometrySource},
+                                                            {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                           {"gs_value"});
+                if (program == 0) return false;
+                const std::vector<float> poison(1, kPoison);
+                GLuint xfbBuffer = 0;
+                glGenBuffers(1, &xfbBuffer);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+                glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, static_cast<GLsizeiptr>(sizeof(float)), poison.data(),
+                             GL_STATIC_DRAW);
+                glBindVertexArray(m_vao);
+                glUseProgram(program);
+                glEnable(GL_RASTERIZER_DISCARD);
+                glBeginTransformFeedback(GL_POINTS);
+                glDrawArrays(GL_POINTS, 0, 1);
+                glEndTransformFeedback();
+                glDisable(GL_RASTERIZER_DISCARD);
+                float captured = kPoison;
+                glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0, static_cast<GLsizeiptr>(sizeof(float)),
+                                   &captured);
+                glUseProgram(0);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+                glDeleteBuffers(1, &xfbBuffer);
+                DrainErrors();
+                return captured == 7.0f;
+            };
+
+            if (probeCaptures(kPointSizeGeometrySource)) return {};
+            if (!probeCaptures(kPointSizeFreeGeometrySource)) {
+                // The control failed too, so this stack cannot run a capturing geometry stage at
+                // all - which is not what this case is about, and is the question the dead
+                // GL_MAX_GEOMETRY_OUTPUT_VERTICES guard was trying to ask. Skipping rather than
+                // failing loses nothing: XfbRepeatedCaptureScenario pins plain geometry capture
+                // and goes red on its own if that is what actually broke.
+                return "this backend cannot capture from a geometry stage at all, with or without gl_PointSize";
+            }
+            return "this backend cannot express gl_PointSize in a geometry stage - the same program captures an "
+                   "ordinary varying with the gl_PointSize write removed and captures nothing with it present "
+                   "(an ES driver without GL_EXT/OES_geometry_point_size, which is a SEPARATE extension from the "
+                   "tessellation one, or a Vulkan device without shaderTessellationAndGeometryPointSize)";
+        }
+
+        TEST_F(TessellationXfbCaptureScenario, CapturesGlPointSizeByNameFromTheGeometryStage) {
+            if (!Ready()) GTEST_SKIP();
+            if (const std::string reason = WhyGeometryPointSizeCaseCannotRun(); !reason.empty()) {
+                GTEST_SKIP() << reason << " (" << Gl().BackendName() << ", " << Gl().RendererString() << ")";
+            }
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kMinimalVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kPointSizeGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gs_value", "gl_PointSize"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            GLuint xfbBuffer = 0;
+            glGenBuffers(1, &xfbBuffer);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+            const std::vector<float> poison(2, kPoison);
+            glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, static_cast<GLsizeiptr>(poison.size() * sizeof(float)),
+                         poison.data(), GL_STATIC_DRAW);
+
+            glBindVertexArray(m_vao);
+            glUseProgram(program);
+            glEnable(GL_RASTERIZER_DISCARD);
+            glBeginTransformFeedback(GL_POINTS);
+            glDrawArrays(GL_POINTS, 0, 1);
+            glEndTransformFeedback();
+            glDisable(GL_RASTERIZER_DISCARD);
+
+            std::vector<float> captured(2, kPoison);
+            glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
+                               static_cast<GLsizeiptr>(captured.size() * sizeof(float)), captured.data());
+            EXPECT_TRUE(ComponentIs(captured, 0, 7.0f)) << "gs_value - an ordinary varying, which is lost too when "
+                                                           "the stage carrying it fails to compile";
+            EXPECT_TRUE(ComponentIs(captured, 1, 4.0f)) << "gl_PointSize";
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+
+            glUseProgram(0);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+            glDeleteBuffers(1, &xfbBuffer);
+        }
+
+        // ---------------------------------------------------------------------------------
+        // The conformance body's own READBACK, which is not glGetBufferSubData.
+        // ---------------------------------------------------------------------------------
+
+        // Every case above reads the capture back with glGetBufferSubData because that is the
+        // shortest path to the bytes. The conformance bodies do something else: they respecify
+        // the buffer through the GENERIC GL_TRANSFORM_FEEDBACK_BUFFER binding with glBufferData
+        // while it is simultaneously bound to indexed capture point 0, and then read it with
+        // glMapBufferRange / glUnmapBuffer - twice, once per iteration of the same case, with no
+        // fresh buffer in between. On a device the tessellation bodies stop at exactly that map
+        // call, so the sequence itself is worth pinning: none of the map path's error conditions
+        // may fire, and the mapped bytes must be the captured ones.
+        TEST_F(TessellationXfbCaptureScenario, MapsTheCaptureBufferAfterEachOfTwoPatchDraws) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " (" << Gl().RendererString()
+                             << ")";
+            }
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kMinimalVertexSource},
+                                                        {GL_TESS_CONTROL_SHADER, kMinimalTessControlSource},
+                                                        {GL_TESS_EVALUATION_SHADER, kPositionTessEvalSource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       {"gl_Position"});
+            ASSERT_NE(program, 0u) << "program failed to build: " << m_buildLog;
+
+            GLuint xfbBuffer = 0;
+            glGenBuffers(1, &xfbBuffer);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+            ASSERT_EQ(glGetError(), GL_NO_ERROR) << "binding the capture point";
+
+            constexpr std::size_t kFloats = 4 * 3;
+            constexpr GLsizeiptr kBytes = static_cast<GLsizeiptr>(kFloats * sizeof(float));
+            for (int iteration = 0; iteration < 2; ++iteration) {
+                // Respecified through the generic binding, exactly as the conformance body does,
+                // while the same buffer is still bound to capture point 0.
+                const std::vector<float> poison(kFloats, kPoison);
+                glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, kBytes, poison.data(), GL_STATIC_DRAW);
+                ASSERT_EQ(glGetError(), GL_NO_ERROR) << "glBufferData, iteration " << iteration;
+
+                glBindVertexArray(m_vao);
+                glUseProgram(program);
+                glEnable(GL_RASTERIZER_DISCARD);
+                glBeginTransformFeedback(GL_POINTS);
+                ASSERT_EQ(glGetError(), GL_NO_ERROR) << "glBeginTransformFeedback, iteration " << iteration;
+                glDrawArrays(GL_PATCHES, 0, 1);
+                ASSERT_EQ(glGetError(), GL_NO_ERROR) << "glDrawArrays, iteration " << iteration;
+                glEndTransformFeedback();
+                glDisable(GL_RASTERIZER_DISCARD);
+                ASSERT_EQ(glGetError(), GL_NO_ERROR) << "glEndTransformFeedback, iteration " << iteration;
+
+                const auto* mapped =
+                    static_cast<const float*>(glMapBufferRange(GL_TRANSFORM_FEEDBACK_BUFFER, 0, kBytes,
+                                                               GL_MAP_READ_BIT));
+                ASSERT_EQ(glGetError(), GL_NO_ERROR) << "glMapBufferRange, iteration " << iteration;
+                ASSERT_NE(mapped, nullptr) << "iteration " << iteration;
+                const std::vector<float> captured(mapped, mapped + kFloats);
+                EXPECT_EQ(glUnmapBuffer(GL_TRANSFORM_FEEDBACK_BUFFER), GL_TRUE) << "iteration " << iteration;
+                EXPECT_EQ(glGetError(), GL_NO_ERROR) << "glUnmapBuffer, iteration " << iteration;
+
+                EXPECT_TRUE(ComponentIs(captured, 0, 11.0f)) << "iteration " << iteration;
+                EXPECT_TRUE(ComponentIs(captured, 1, 12.0f)) << "iteration " << iteration;
+                EXPECT_TRUE(ComponentIs(captured, 2, 13.0f)) << "iteration " << iteration;
+                EXPECT_TRUE(ComponentIs(captured, 3, 14.0f)) << "iteration " << iteration;
+                glUseProgram(0);
+            }
+
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+            glDeleteBuffers(1, &xfbBuffer);
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // The same patch with gl_PointSize travelling in gl_PerVertex beside gl_Position.
+        // In ESSL gl_PointSize does not EXIST in a tessellation stage unless
+        // GL_EXT_tessellation_point_size is requested, so a backend that lowers to ESSL
+        // without asking for it does not merely lose the value - the stage fails to compile
+        // and the whole program is replaced by program 0.
+        TEST_F(TessellationXfbCaptureScenario, TheEvaluationStageSeesGlPointSizeAcrossItsPatch) {
+            RunPerVertexPayloadCase(true);
+        }
+
+        // ---------------------------------------------------------------------------------
+        // The same capture through a PROGRAM PIPELINE OBJECT.
+        // ---------------------------------------------------------------------------------
+
+        // The conformance body runs each of its configurations twice: once with a monolithic
+        // program object and once with a pipeline of four separable programs, the capture
+        // declared on the separable EVALUATION program. That second shape goes through the
+        // hidden composite the pipeline object builds for the draw, and it is the only place a
+        // tessellation capture and the composite meet - so the capture list has to survive being
+        // taken from a program that is not the one bound.
+        TEST_F(TessellationXfbCaptureScenario, CapturesFromASeparableEvaluationProgramInAPipelineObject) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " (" << Gl().RendererString()
+                             << ")";
+            }
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            // One separable program per stage. Only the evaluation program carries the capture
+            // list, because it is the one whose outputs are captured.
+            const auto buildSeparable = [&](GLenum stage, const char* source,
+                                            const std::vector<const char*>& varyings) -> GLuint {
+                const GLuint shader = glCreateShader(stage);
+                glShaderSource(shader, 1, &source, nullptr);
+                glCompileShader(shader);
+                GLint compiled = 0;
+                glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+                if (compiled == GL_FALSE) {
+                    m_buildLog = InfoLog(shader, true);
+                    glDeleteShader(shader);
+                    return 0;
+                }
+                const GLuint program = glCreateProgram();
+                glProgramParameteri(program, GL_PROGRAM_SEPARABLE, GL_TRUE);
+                glAttachShader(program, shader);
+                if (!varyings.empty()) {
+                    glTransformFeedbackVaryings(program, static_cast<GLsizei>(varyings.size()), varyings.data(),
+                                                GL_INTERLEAVED_ATTRIBS);
+                }
+                glLinkProgram(program);
+                GLint linked = GL_FALSE;
+                glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                glDeleteShader(shader);
+                if (linked == GL_FALSE) {
+                    m_buildLog = InfoLog(program, false);
+                    glDeleteProgram(program);
+                    return 0;
+                }
+                m_programs.push_back(program);
+                return program;
+            };
+
+            m_buildLog.clear();
+            const GLuint vertexProgram = buildSeparable(GL_VERTEX_SHADER, kMinimalVertexSource, {});
+            ASSERT_NE(vertexProgram, 0u) << "separable vertex program: " << m_buildLog;
+            const GLuint controlProgram = buildSeparable(GL_TESS_CONTROL_SHADER, kMinimalTessControlSource, {});
+            ASSERT_NE(controlProgram, 0u) << "separable control program: " << m_buildLog;
+            const GLuint evalProgram =
+                buildSeparable(GL_TESS_EVALUATION_SHADER, kPositionTessEvalSource, {"gl_Position"});
+            ASSERT_NE(evalProgram, 0u) << "separable evaluation program: " << m_buildLog;
+            const GLuint fragmentProgram = buildSeparable(GL_FRAGMENT_SHADER, kFragmentSource, {});
+            ASSERT_NE(fragmentProgram, 0u) << "separable fragment program: " << m_buildLog;
+
+            GLuint pipeline = 0;
+            glGenProgramPipelines(1, &pipeline);
+            glUseProgramStages(pipeline, GL_VERTEX_SHADER_BIT, vertexProgram);
+            glUseProgramStages(pipeline, GL_TESS_CONTROL_SHADER_BIT, controlProgram);
+            glUseProgramStages(pipeline, GL_TESS_EVALUATION_SHADER_BIT, evalProgram);
+            glUseProgramStages(pipeline, GL_FRAGMENT_SHADER_BIT, fragmentProgram);
+            ASSERT_EQ(glGetError(), GL_NO_ERROR) << "assembling the pipeline object";
+
+            constexpr std::size_t kFloats = 4 * 3;
+            const std::vector<float> poison(kFloats, kPoison);
+            GLuint xfbBuffer = 0;
+            glGenBuffers(1, &xfbBuffer);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+            glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, static_cast<GLsizeiptr>(kFloats * sizeof(float)),
+                         poison.data(), GL_STATIC_DRAW);
+
+            glBindVertexArray(m_vao);
+            glUseProgram(0);
+            glBindProgramPipeline(pipeline);
+            glEnable(GL_RASTERIZER_DISCARD);
+            glBeginTransformFeedback(GL_POINTS);
+            EXPECT_EQ(glGetError(), GL_NO_ERROR) << "glBeginTransformFeedback on a pipeline object";
+            glDrawArrays(GL_PATCHES, 0, 1);
+            glEndTransformFeedback();
+            glDisable(GL_RASTERIZER_DISCARD);
+
+            std::vector<float> captured(kFloats, kPoison);
+            glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
+                               static_cast<GLsizeiptr>(kFloats * sizeof(float)), captured.data());
+            EXPECT_TRUE(ComponentIs(captured, 0, 11.0f));
+            EXPECT_TRUE(ComponentIs(captured, 1, 12.0f));
+            EXPECT_TRUE(ComponentIs(captured, 2, 13.0f));
+            EXPECT_TRUE(ComponentIs(captured, 3, 14.0f));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+
+            glBindProgramPipeline(0);
+            glDeleteProgramPipelines(1, &pipeline);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+            glDeleteBuffers(1, &xfbBuffer);
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/UnboundImageDescriptorScenario.cpp

@@ -119,6 +119,73 @@ void main() {
     imageStore(u_unbound, int(index), uvec4(7u));
     g_data[index] = index + 1u;
 }
+)";
+
+        // A plain sampler2D on a unit the test leaves alone. Two cases point at it: a unit with
+        // nothing bound at all, and a unit whose DEFAULT texture (name 0) has been given a base
+        // level and no mip chain - GL calls the second one incomplete for the initial
+        // NEAREST_MIPMAP_LINEAR filter, and both must resolve to the fallback rather than to a
+        // texture the backend then fails to back.
+        constexpr const char* kSampler2DFragmentSource = R"(#version 430 core
+uniform sampler2D u_unbound;
+uniform int u_readUnbound;
+out vec4 o_color;
+void main() {
+    vec4 color = vec4(0.0, 1.0, 0.0, 1.0);
+    if (u_readUnbound != 0) {
+        color = texture(u_unbound, vec2(0.0));
+    }
+    o_color = color;
+}
+)";
+
+        // The multisample spelling of the same thing. GL_ARB_sample_variables' own conformance
+        // cases declare a sampler2D and a sampler2DMS side by side and deliberately point the
+        // unused one at an empty unit, so whichever of the two is unused has to have a
+        // placeholder - a multisample descriptor demands a multisample view, so the 2D fallback
+        // cannot stand in for it.
+        constexpr const char* kSampler2DMSFragmentSource = R"(#version 430 core
+uniform sampler2DMS u_unbound;
+uniform int u_readUnbound;
+out vec4 o_color;
+void main() {
+    vec4 color = vec4(0.0, 1.0, 0.0, 1.0);
+    if (u_readUnbound != 0) {
+        color = texelFetch(u_unbound, ivec2(0), 0);
+    }
+    o_color = color;
+}
+)";
+
+        // The integer spellings of the same thing. These are the ones a plain RGBA8 multisample
+        // placeholder cannot serve: a multisample image can never carry MUTABLE_FORMAT, so the
+        // reinterpreting view an integer sampler would need over UNORM texels is unbuildable and
+        // the descriptor resolve used to fail, losing the draw after the placeholder had already
+        // been created.
+        constexpr const char* kUsampler2DMSFragmentSource = R"(#version 430 core
+uniform usampler2DMS u_unbound;
+uniform int u_readUnbound;
+out vec4 o_color;
+void main() {
+    vec4 color = vec4(0.0, 1.0, 0.0, 1.0);
+    if (u_readUnbound != 0) {
+        color = vec4(texelFetch(u_unbound, ivec2(0), 0));
+    }
+    o_color = color;
+}
+)";
+
+        constexpr const char* kIsampler2DMSFragmentSource = R"(#version 430 core
+uniform isampler2DMS u_unbound;
+uniform int u_readUnbound;
+out vec4 o_color;
+void main() {
+    vec4 color = vec4(0.0, 1.0, 0.0, 1.0);
+    if (u_readUnbound != 0) {
+        color = vec4(texelFetch(u_unbound, ivec2(0), 0));
+    }
+    o_color = color;
+}
 )";
 
         constexpr const char* kImage2DFragmentSource = R"(#version 430 core
@@ -369,6 +436,65 @@ void main() {
         ExpectDrawStillRuns(kImage2DFragmentSource, "image2D");
     }
 
+    // ---- sampler2D / sampler2DMS (VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER) ----------------
+
+    TEST_F(UnboundImageDescriptorScenario, ADeclaredButUnboundSampler2DDoesNotLoseTheDraw) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectDrawStillRuns(kSampler2DFragmentSource, "sampler2D");
+    }
+
+    // The regression this file exists for, in its sharpest form: a sampler pointing at a texture
+    // unit whose DEFAULT texture object has an image but no mip chain.
+    //
+    // DirectVulkan resolved such a binding twice, through two different predicates that
+    // disagreed. The collect pass (CollectSampledTextures -> ResolveSampledBinding), which
+    // pre-syncs and transitions every texture the draw will sample, asked only whether the
+    // default texture was UNDEFINED - texture 0 with an image is not - and kept it. The
+    // descriptor pass (ResolveSamplerDescriptor) asked the real GL question, whether it
+    // SAMPLES AS INCOMPLETE for the filter in effect, and swapped it for the fallback. So the
+    // collect pass synced a texture no descriptor would ever hold, VkTextureManager declined it
+    // ("mipmap not complete") and returned nullptr, and SetupDraw dereferenced that nullptr -
+    // a SIGSEGV inside the draw, not a degraded picture.
+    //
+    // The GL-CTS reaches this on its own: its between-case state reset gives the default 2D
+    // texture a base level, so the FIRST case in a process survived and every later one with an
+    // unbound sampler2D died. That is the whole of the 380-record sample_variables crash family
+    // on Mali-G1-Ultra. Any application that uploads to texture 0 has the same shape.
+    TEST_F(UnboundImageDescriptorScenario, ASamplerOnAUnitWhoseDefaultTextureIsIncompleteDoesNotLoseTheDraw) {
+        if (!Ready() || IsSkipped()) return;
+
+        // Unit 0 is where the sampler's default uniform value points. Give the DEFAULT texture
+        // object bound there a FORMAT and a zero-sized level - which is what a bare
+        // glTexImage2D(..., 0, 0, ...) with no data does, and what the GL-CTS's between-case
+        // state reset issues for every texture target. That combination is the whole point:
+        //   * it is DEFINED, so IsUndefinedDefaultTexture (the collect path's old test) is false
+        //     and the texture stays in the sampled set;
+        //   * it is INCOMPLETE, so SamplesAsIncompleteTexture (the descriptor path's test) is
+        //     true and the descriptor holds the fallback instead;
+        //   * and it has no valid mip level, so the sync declines and hands back nullptr.
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, 0);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 0, 0, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+        ASSERT_EQ(FirstGLError(), 0u) << "defining a zero-sized level 0 on the default texture raised a GL error";
+
+        ExpectDrawStillRuns(kSampler2DFragmentSource, "sampler2D on an incomplete default texture");
+    }
+
+    TEST_F(UnboundImageDescriptorScenario, ADeclaredButUnboundSampler2DMSDoesNotLoseTheDraw) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectDrawStillRuns(kSampler2DMSFragmentSource, "sampler2DMS");
+    }
+
+    TEST_F(UnboundImageDescriptorScenario, ADeclaredButUnboundUnsignedSampler2DMSDoesNotLoseTheDraw) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectDrawStillRuns(kUsampler2DMSFragmentSource, "usampler2DMS");
+    }
+
+    TEST_F(UnboundImageDescriptorScenario, ADeclaredButUnboundSignedSampler2DMSDoesNotLoseTheDraw) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectDrawStillRuns(kIsampler2DMSFragmentSource, "isampler2DMS");
+    }
+
     TEST_F(UnboundImageDescriptorScenario, AFormatlessWriteonlyImage2DLeftUnboundDoesNotLoseTheDispatch) {
         if (!Ready() || IsSkipped()) return;
         if (!LimitIsAtLeastOne(GL_MAX_COMPUTE_IMAGE_UNIFORMS)) {

MobileGL/MG_IntegrationTest/Scenarios/UnlocatedIoBlockScenario.cpp

@@ -0,0 +1,526 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/UnlocatedIoBlockScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - AN INTER-STAGE INTERFACE BLOCK STILL FINDS ITS OTHER END WITH ITS LOCATION
+// QUALIFIER REMOVED.
+//
+// The Mali-G1-Ultra ES driver delivers NOTHING through an interface block that carries an
+// explicit layout(location=) once a tessellation or geometry stage is in the pipeline: the
+// stages compile, the program links with an empty info log, the draw runs, and the consuming
+// stage reads zeroes. Measured with no MobileGL in the process - a bare EGL/GLES 3.2 program
+// built from the five ESSL stages MobileGL emits reproduces it, and removing the qualifier
+// from the blocks (and changing nothing else) makes the same program carry its payload. The
+// locations are not the application's in the first place: these shaders declare none, and
+// glslang's cross-stage IO resolver invents them.
+//
+// DirectGLES answers by dropping the decoration for those programs (StripIoBlockLocationsPass),
+// leaving ES to match the blocks by block name and member sequence. THAT is what this scenario
+// guards: with the strip forced on, a five-stage pipeline whose four block boundaries carry no
+// location must still deliver its payload end to end. It is the assertion the affected device
+// cannot make about itself in CI, and the one the healthy machines here CAN make - which is
+// the opposite of IoBlockNameCollisionScenario's position, where the machines that run it
+// cannot reproduce the defect at all.
+//
+// The strip is armed for this suite by MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS=1 on the ctest
+// entry, because llvmpipe carries a located block correctly and the driver POST would
+// therefore never turn the emulation on here. The SAME cases also run under the ambient
+// registrations with the emulation off, so both spellings of the interface are covered and a
+// regression in either shows up.
+//
+// Colour code, so a failure names its own cause:
+//   green  - the payload crossed all four stage boundaries, which is the pass.
+//   blue   - the clear colour: nothing was drawn at all (the program did not link, or the
+//            backend program was rejected and every draw became a no-op).
+//   red    - the pipeline ran but the plain (non-block) varying did not arrive, i.e. the
+//            failure is not about interface blocks.
+//   black  - the pipeline ran, the plain varying arrived, and the BLOCK payload came back
+//            zeroed. That is what an interface whose two ends stopped matching looks like.
+
+#include <cstdio>
+#include <cstdlib>
+#include <filesystem>
+#include <fstream>
+#include <iterator>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // NOTHING in these five stages declares a location. Every location the emitted ESSL
+        // carries is invented by the cross-stage resolver, which is exactly the shape the
+        // affected driver mishandles and exactly what the strip removes.
+        //
+        // Two members per block, of different types, because an interface that is matched by
+        // name and member sequence rather than by location has to agree on the sequence too -
+        // a repair that silently reordered or dropped a member would still light up green with
+        // one member in the block.
+        const char* const kVertexSource = R"(#version 420 core
+out VsData {
+    vec4 payload;
+    vec2 tint;
+} vs_out;
+out float vs_tcs_alive;
+void main()
+{
+    vs_out.payload = vec4(0.0, 1.0, 0.0, 1.0);
+    vs_out.tint = vec2(0.25, 0.5);
+    vs_tcs_alive = 1.0;
+    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+}
+)";
+
+        const char* const kTessControlSource = R"(#version 420 core
+layout(vertices = 1) out;
+in VsData {
+    vec4 payload;
+    vec2 tint;
+} tcs_in[];
+in float vs_tcs_alive[];
+out TcsData {
+    vec4 payload;
+    vec2 tint;
+} tcs_out[];
+out float tcs_tes_alive[];
+void main()
+{
+    tcs_out[gl_InvocationID].payload = tcs_in[gl_InvocationID].payload;
+    tcs_out[gl_InvocationID].tint = tcs_in[gl_InvocationID].tint;
+    tcs_tes_alive[gl_InvocationID] = vs_tcs_alive[gl_InvocationID];
+    gl_TessLevelOuter[0] = 1.0;
+    gl_TessLevelOuter[1] = 1.0;
+    gl_TessLevelOuter[2] = 1.0;
+    gl_TessLevelOuter[3] = 1.0;
+    gl_TessLevelInner[0] = 1.0;
+    gl_TessLevelInner[1] = 1.0;
+}
+)";
+
+        // Distinct block names, so this case is about the LOCATION and nothing else; the
+        // one-name-in-both-directions shape is the case below.
+        const char* const kDistinctTessEvalSource = R"(#version 420 core
+layout(isolines, point_mode) in;
+in TcsData {
+    vec4 payload;
+    vec2 tint;
+} tes_in[];
+in float tcs_tes_alive[];
+out TesData {
+    vec4 payload;
+    vec2 tint;
+} tes_out;
+out float tes_gs_alive;
+void main()
+{
+    tes_out.payload = tes_in[0].payload;
+    tes_out.tint = tes_in[0].tint;
+    tes_gs_alive = tcs_tes_alive[0];
+}
+)";
+
+        // The 420pack shape: ONE name for the block this stage consumes and the block it
+        // produces. Legal desktop GLSL, and the case where the two repairs have to compose -
+        // the rename gives the two blocks one spelling per producing stage, the strip takes
+        // their locations off, and the interfaces still have to meet.
+        const char* const kCollidingTessEvalSource = R"(#version 420 core
+layout(isolines, point_mode) in;
+in TcsData {
+    vec4 payload;
+    vec2 tint;
+} tes_in[];
+in float tcs_tes_alive[];
+out TcsData {
+    vec4 payload;
+    vec2 tint;
+} tes_out;
+out float tes_gs_alive;
+void main()
+{
+    tes_out.payload = tes_in[0].payload;
+    tes_out.tint = tes_in[0].tint;
+    tes_gs_alive = tcs_tes_alive[0];
+}
+)";
+
+        // One geometry source per evaluation stage, because the block it consumes is named
+        // after the block the evaluation stage produced.
+        const char* const kDistinctGeometrySource = R"(#version 420 core
+layout(points) in;
+layout(triangle_strip, max_vertices = 4) out;
+in TesData {
+    vec4 payload;
+    vec2 tint;
+} gs_in[];
+in float tes_gs_alive[];
+out GsData {
+    vec4 payload;
+    vec2 tint;
+} gs_out;
+out float gs_fs_alive;
+void EmitCorner(vec2 corner)
+{
+    gs_out.payload = gs_in[0].payload;
+    gs_out.tint = gs_in[0].tint;
+    gs_fs_alive = tes_gs_alive[0];
+    gl_Position = vec4(corner, 0.0, 1.0);
+    EmitVertex();
+}
+void main()
+{
+    EmitCorner(vec2(-1.0, -1.0));
+    EmitCorner(vec2(-1.0,  1.0));
+    EmitCorner(vec2( 1.0, -1.0));
+    EmitCorner(vec2( 1.0,  1.0));
+}
+)";
+
+        const char* const kCollidingGeometrySource = R"(#version 420 core
+layout(points) in;
+layout(triangle_strip, max_vertices = 4) out;
+in TcsData {
+    vec4 payload;
+    vec2 tint;
+} gs_in[];
+in float tes_gs_alive[];
+out GsData {
+    vec4 payload;
+    vec2 tint;
+} gs_out;
+out float gs_fs_alive;
+void EmitCorner(vec2 corner)
+{
+    gs_out.payload = gs_in[0].payload;
+    gs_out.tint = gs_in[0].tint;
+    gs_fs_alive = tes_gs_alive[0];
+    gl_Position = vec4(corner, 0.0, 1.0);
+    EmitVertex();
+}
+void main()
+{
+    EmitCorner(vec2(-1.0, -1.0));
+    EmitCorner(vec2(-1.0,  1.0));
+    EmitCorner(vec2( 1.0, -1.0));
+    EmitCorner(vec2( 1.0,  1.0));
+}
+)";
+
+        // Green ONLY when both block members arrived: a repair that kept the first member and
+        // lost the second would otherwise pass. Red when the plain varying is missing too, so
+        // "the pipeline is broken" and "the block is broken" cannot be confused.
+        const char* const kFragmentSource = R"(#version 420 core
+in GsData {
+    vec4 payload;
+    vec2 tint;
+} fs_in;
+in float gs_fs_alive;
+out vec4 fragColor;
+void main()
+{
+    if (gs_fs_alive <= 0.5) {
+        fragColor = vec4(1.0, 0.0, 0.0, 1.0);
+    } else if (abs(fs_in.tint.x - 0.25) > 0.01 || abs(fs_in.tint.y - 0.5) > 0.01) {
+        fragColor = vec4(0.0, 0.0, 0.0, 1.0);
+    } else {
+        fragColor = fs_in.payload;
+    }
+}
+)";
+
+        class UnlocatedIoBlockScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                if (!BackendHostsTessellationAndGeometry()) {
+                    GTEST_SKIP() << "no tessellation/geometry stages on " << Gl().BackendName() << " ("
+                                 << Gl().RendererString() << "); there is no five-stage pipeline to "
+                                 << "carry a block through";
+                }
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glUseProgram(0);
+                for (const GLuint program : m_programs) {
+                    glDeleteProgram(program);
+                }
+                m_programs.clear();
+                glBindVertexArray(0);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                m_vao = 0;
+            }
+
+            // Same calibration IoBlockNameCollisionScenario uses, and for the same reason:
+            // GL_MAX_TESS_GEN_LEVEL is a real backend answer while GL_MAX_GEOMETRY_* are
+            // frontend constants, so a stack with no five-stage pipeline is recognised by
+            // trying to build one, not by asking.
+            static bool BackendHostsTessellationAndGeometry() {
+                GLint maxTessGenLevel = 0;
+                glGetIntegerv(GL_MAX_TESS_GEN_LEVEL, &maxTessGenLevel);
+                GLint maxGeometryOutputVertices = 0;
+                glGetIntegerv(GL_MAX_GEOMETRY_OUTPUT_VERTICES, &maxGeometryOutputVertices);
+                while (glGetError() != GL_NO_ERROR) {
+                }
+                return maxTessGenLevel >= 1 && maxGeometryOutputVertices >= 4;
+            }
+
+            GLuint BuildPipeline(const char* tessEvalSource, const char* geometrySource) {
+                const GLenum stages[] = {GL_VERTEX_SHADER, GL_TESS_CONTROL_SHADER,
+                                         GL_TESS_EVALUATION_SHADER, GL_GEOMETRY_SHADER,
+                                         GL_FRAGMENT_SHADER};
+                const char* const sources[] = {kVertexSource, kTessControlSource, tessEvalSource,
+                                               geometrySource, kFragmentSource};
+
+                GLuint shaders[5] = {0, 0, 0, 0, 0};
+                bool ok = true;
+                for (int i = 0; i < 5; ++i) {
+                    shaders[i] = glCreateShader(stages[i]);
+                    glShaderSource(shaders[i], 1, &sources[i], nullptr);
+                    glCompileShader(shaders[i]);
+                    GLint compiled = 0;
+                    glGetShaderiv(shaders[i], GL_COMPILE_STATUS, &compiled);
+                    if (!compiled) {
+                        m_buildLog = InfoLog(shaders[i], true);
+                        ok = false;
+                        break;
+                    }
+                }
+                if (!ok) {
+                    for (const GLuint shader : shaders) {
+                        if (shader != 0) glDeleteShader(shader);
+                    }
+                    return 0;
+                }
+
+                const GLuint program = glCreateProgram();
+                for (const GLuint shader : shaders) {
+                    glAttachShader(program, shader);
+                }
+                glLinkProgram(program);
+                GLint linked = 0;
+                glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                for (const GLuint shader : shaders) {
+                    glDeleteShader(shader);
+                }
+                if (!linked) {
+                    m_buildLog = InfoLog(program, false);
+                    glDeleteProgram(program);
+                    return 0;
+                }
+                m_programs.push_back(program);
+                return program;
+            }
+
+            // Clears to BLUE, so "the draw painted nothing" is a colour of its own rather
+            // than something that could be mistaken for a zeroed payload.
+            Rgba8 DrawAndReadCentre(GLuint program) const {
+                glViewport(0, 0, Gl().Width(), Gl().Height());
+                glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
+                glClear(GL_COLOR_BUFFER_BIT);
+                glUseProgram(program);
+                glPatchParameteri(GL_PATCH_VERTICES, 1);
+                glDrawArrays(GL_PATCHES, 0, 1);
+
+                Rgba8 pixel{};
+                glReadPixels(Gl().Width() / 2, Gl().Height() / 2, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &pixel);
+                return pixel;
+            }
+
+            static bool IsGreen(const Rgba8& pixel) {
+                return pixel.r < 64 && pixel.g > 192 && pixel.b < 64;
+            }
+
+            const std::string& BuildLog() const { return m_buildLog; }
+
+            // The library log this process is writing, or an empty path when none was
+            // configured. MOBILEGL_LOG_FILE_PATH is read at log-init, before anything this
+            // fixture can reach, so the ctest entry sets it and this only reads it back.
+            static std::filesystem::path LibraryLogPath() {
+                const char* path = std::getenv("MOBILEGL_LOG_FILE_PATH");
+                return (path != nullptr && *path != '\0') ? std::filesystem::path(path)
+                                                          : std::filesystem::path();
+            }
+
+            // How many bytes the library log already holds. Everything this fixture asserts on
+            // is searched from here forward, because the file is APPENDED to by every process
+            // in the lane and a line left behind by an earlier one would otherwise satisfy the
+            // assertion without this process having done anything at all.
+            static std::uintmax_t LibraryLogSize() {
+                std::error_code ec;
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return 0;
+                const std::uintmax_t size = std::filesystem::file_size(path, ec);
+                return ec ? 0 : size;
+            }
+
+            static std::string LibraryLogSince(std::uintmax_t offset) {
+                const std::filesystem::path path = LibraryLogPath();
+                if (path.empty()) return {};
+                std::ifstream file(path, std::ios::binary);
+                if (!file.good()) return {};
+                file.seekg(static_cast<std::streamoff>(offset));
+                return std::string((std::istreambuf_iterator<char>(file)),
+                                   std::istreambuf_iterator<char>());
+            }
+
+            static GLenum FirstGLError() {
+                const GLenum first = glGetError();
+                while (glGetError() != GL_NO_ERROR) {
+                }
+                return first;
+            }
+
+        private:
+            static std::string InfoLog(GLuint object, bool isShader) {
+                GLint length = 0;
+                if (isShader) {
+                    glGetShaderiv(object, GL_INFO_LOG_LENGTH, &length);
+                } else {
+                    glGetProgramiv(object, GL_INFO_LOG_LENGTH, &length);
+                }
+                std::vector<char> log(static_cast<std::size_t>(length > 1 ? length : 1), '\0');
+                if (isShader) {
+                    glGetShaderInfoLog(object, static_cast<GLsizei>(log.size()), nullptr, log.data());
+                } else {
+                    glGetProgramInfoLog(object, static_cast<GLsizei>(log.size()), nullptr, log.data());
+                }
+                return std::string(log.data());
+            }
+
+            GLuint m_vao = 0;
+            std::vector<GLuint> m_programs;
+            std::string m_buildLog;
+        };
+
+        TEST_F(UnlocatedIoBlockScenario, BlocksCarryTheirPayloadThroughFiveStages) {
+            if (!Ready()) return;
+
+            const GLuint program = BuildPipeline(kDistinctTessEvalSource, kDistinctGeometrySource);
+            if (program == 0) {
+                GTEST_SKIP() << "this stack cannot build a five-stage tessellation+geometry program on "
+                             << Gl().BackendName() << ", so there is no block to carry through: "
+                             << BuildLog();
+            }
+
+            const Rgba8 centre = DrawAndReadCentre(program);
+            EXPECT_EQ(FirstGLError(), 0u);
+            EXPECT_TRUE(IsGreen(centre))
+                << "a four-boundary interface-block chain did not deliver its payload: " << centre
+                << " (blue: nothing drew; red: the plain varying was lost too; black: a block "
+                   "member arrived wrong, i.e. the interface stopped matching)";
+        }
+
+        // The two repairs together. The rename is what makes the evaluation stage's two
+        // TcsData blocks one spelling per producing stage; the strip then takes the locations
+        // off the names the rename just settled. Either one alone leaves a working program on
+        // these machines, so this case is here to catch the two of them disagreeing.
+        TEST_F(UnlocatedIoBlockScenario, BlocksNamedInBothDirectionsStillMeetWithoutLocations) {
+            if (!Ready()) return;
+
+            if (BuildPipeline(kDistinctTessEvalSource, kDistinctGeometrySource) == 0) {
+                GTEST_SKIP() << "this stack cannot build a five-stage tessellation+geometry program on "
+                             << Gl().BackendName() << ", so there is no block to carry through: "
+                             << BuildLog();
+            }
+
+            const GLuint program = BuildPipeline(kCollidingTessEvalSource, kCollidingGeometrySource);
+            ASSERT_NE(program, 0u)
+                << "an interface block name reused across the two directions of one stage is legal "
+                   "desktop GLSL, but the program did not build: "
+                << BuildLog();
+
+            const Rgba8 centre = DrawAndReadCentre(program);
+            EXPECT_EQ(FirstGLError(), 0u);
+            EXPECT_TRUE(IsGreen(centre))
+                << "the renamed-and-unlocated interface chain lost its payload: " << centre;
+        }
+
+        // THE ONE CASE THAT CAN FAIL WHEN THE REPAIR SILENTLY STOPS BEING ARMED.
+        //
+        // Everything above renders green on llvmpipe whether the blocks were stripped or not -
+        // this machine carries a located block correctly - so those cases pin that the strip
+        // does no HARM and can say nothing about whether it happened. That leaves the arming
+        // itself untested, and the arming is where the cheap mistake lives: Loader.cpp maps
+        // MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS onto the capability INVERTED (forcing the
+        // emulation on means declaring located blocks UNSUPPORTED), and a one-line swap of
+        // those two arms would disable the device repair with every test here still green.
+        //
+        // So this case asserts a LIBRARY OBSERVABLE against the environment, the shape
+        // AsyncCompileScenario::ExtensionStringMatchesTheConfiguration uses: the environment
+        // says the emulation is pinned on, therefore the library must SAY it stripped
+        // something. The observable is the latched MGLOG_I DirectGLES emits the first time the
+        // pass fires (Managers.cpp); it is INFO rather than DEBUG precisely so that this
+        // assertion is possible in the builds CI runs.
+        //
+        // Two things it deliberately does NOT do: it does not read MG_Config (on Android this
+        // module links the shipping library, which exports nothing internal - the reason
+        // ViewportArrayScenario's control moved to the environment), and it does not trust the
+        // whole log file, only the bytes appended after this test started.
+        TEST_F(UnlocatedIoBlockScenario, TheEmulationIsActuallyArmedWhenTheEnvironmentPinsItOn) {
+            if (!Ready()) return;
+
+            if (AmbientQuirkFromEnvironment("MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS") != AmbientQuirk::On) {
+                GTEST_SKIP() << "this case needs the emulation pinned ON for the whole process, which "
+                                "is what the UnlocatedIoBlocks. ctest entry does with "
+                                "MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS=1; with the variable unset the "
+                                "driver POST decides, and on this machine it decides the blocks are "
+                                "fine - so there would be nothing to observe";
+            }
+            if (LibraryLogPath().empty()) {
+                GTEST_SKIP() << "MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS is pinned on but "
+                                "MOBILEGL_LOG_FILE_PATH is not set, so the library has nowhere to "
+                                "record that it stripped anything; the UnlocatedIoBlocks. ctest entry "
+                                "sets both";
+            }
+            if (Gl().BackendName() != std::string("DirectGLES")) {
+                GTEST_SKIP() << "the strip is DirectGLES's; " << Gl().BackendName()
+                             << " hands the module to the driver as SPIR-V, where Location is how "
+                                "interfaces are matched";
+            }
+
+            // Taken BEFORE the program is built, so the line this looks for can only be one
+            // this process wrote. The latch means it is emitted at the FIRST stage of the
+            // FIRST affected program, which is inside the build below.
+            const std::uintmax_t before = LibraryLogSize();
+
+            const GLuint program = BuildPipeline(kDistinctTessEvalSource, kDistinctGeometrySource);
+            if (program == 0) {
+                GTEST_SKIP() << "this stack cannot build a five-stage tessellation+geometry program on "
+                             << Gl().BackendName() << ", so nothing would arm the strip: " << BuildLog();
+            }
+            // Drawn as well as built, so a stack that defers its backend program to first use
+            // still reaches the transpile this is asserting about.
+            const Rgba8 centre = DrawAndReadCentre(program);
+            EXPECT_EQ(FirstGLError(), 0u);
+            EXPECT_TRUE(IsGreen(centre)) << "the pinned-on lane did not even render correctly: " << centre;
+
+            const std::string appended = LibraryLogSince(before);
+            EXPECT_NE(appended.find("WITHOUT their layout(location) qualifier"), std::string::npos)
+                << "MOBILEGL_ESPRYT_UNLOCATED_IO_BLOCKS is pinned ON, a five-stage program with four "
+                   "interface-block boundaries was built and drawn, and DirectGLES never reported "
+                   "stripping a single location. The emulation is not armed - check the override "
+                   "mapping in Loader.cpp (it is inverted on purpose) and the arming gate in "
+                   "Managers.cpp. Log appended by this test:\n"
+                << appended;
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/UnwrittenPositionOutputScenario.cpp

@@ -0,0 +1,276 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/UnwrittenPositionOutputScenario.cpp
+// Copyright (c) 2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - A SHADER REDECLARES gl_PerVertex AND NEVER WRITES gl_Position.
+//
+// Legal, ordinary GLSL, and until now a process kill on DirectVulkan. The chain, all of it
+// inside MobileGL's own SPIR-V plumbing:
+//
+//   1. glslang emits every DECLARED interface variable, used or not, and lists it on
+//      OpEntryPoint. So `out gl_PerVertex { vec4 gl_Position; };` with no write still produces
+//      the OpVariable, the OpMemberDecorate BuiltIn Position, and an interface slot.
+//   2. At link, ShaderCompiler::SanitizeAndOptimizeBinary runs AggressiveDCE(remove_outputs =
+//      false) - which may never delete an Output - and then RemoveUnusedInterfaceVariables,
+//      which rebuilds the interface list from the variables instructions actually reference.
+//      The OpVariable and its BuiltIn decoration SURVIVE; the interface slot is DELISTED.
+//   3. At pipeline build, ProgramFactory picks the last pre-rasterisation stage and runs two
+//      passes over it. GlToVulkanPositionFixPass finds the position target through the
+//      surviving ANNOTATION and injects a load-modify-STORE through it. When gl_Position is in
+//      the transform-feedback capture list, XfbCaptureDecoratePass::MirrorPositionForCapture
+//      also injects an access chain and a LOAD through it.
+//   4. Either injection is a static use of a variable that is no longer on the entry point's
+//      interface, which is invalid SPIR-V ("Interface variable id <N> is used by entry point
+//      'main' id <M>, but is not listed as an interface"). Mali r54 does not reject such a
+//      module - it faults inside pipeline creation and takes the process down.
+//
+// Measured on a Mali-G1-Ultra as 216 KHR-GL44/45/46.tessellation_shader.tessellation_control_
+// to_tessellation_evaluation.gl_MaxPatchVertices_Position_PointSize_* crashes; the CTS's TES
+// there is exactly the shape below. It is not tessellation-specific and not XFB-specific: a
+// vertex shader is enough, which is what these cases use.
+//
+// Every test captures a USER varying through transform feedback under GL_RASTERIZER_DISCARD.
+// Position is undefined in the first two by construction, so it is never asserted on - what is
+// asserted is that the capture came back at all, which it can only do if the driver accepted
+// the module and built a pipeline.
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        constexpr std::size_t kCaptureFloats = 4;
+        constexpr GLsizeiptr kCaptureBytes = static_cast<GLsizeiptr>(kCaptureFloats * sizeof(float));
+
+        // The defect's shape: gl_PerVertex redeclared, gl_Position never assigned.
+        constexpr const char* kUnwrittenPositionVertexSource = R"(#version 430 core
+layout(location = 0) in vec4 vs_in_value;
+out gl_PerVertex {
+    vec4 gl_Position;
+};
+out vec4 vs_out_value;
+void main() {
+  vs_out_value = vs_in_value;
+}
+)";
+
+        // The control that isolates the redeclaration: identical but for the one assignment.
+        // This one keeps its interface slot through the sanitize chain, so both injections were
+        // always legal on it - it must stay working.
+        constexpr const char* kWrittenPositionVertexSource = R"(#version 430 core
+layout(location = 0) in vec4 vs_in_value;
+out gl_PerVertex {
+    vec4 gl_Position;
+};
+out vec4 vs_out_value;
+void main() {
+  gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+  vs_out_value = vs_in_value;
+}
+)";
+
+        // The second control, and the one the CTS calls data_pass_through: no gl_PerVertex
+        // redeclaration at all, so there is no Position annotation for the passes to find and
+        // nothing to delist. It was never affected and proves the crash needs the redeclaration.
+        constexpr const char* kNoPositionBlockVertexSource = R"(#version 430 core
+layout(location = 0) in vec4 vs_in_value;
+out vec4 vs_out_value;
+void main() {
+  vs_out_value = vs_in_value;
+}
+)";
+
+        GLuint CompileVertexShader(const std::string& source, std::string* log) {
+            const GLuint shader = glCreateShader(GL_VERTEX_SHADER);
+            const char* text = source.c_str();
+            glShaderSource(shader, 1, &text, nullptr);
+            glCompileShader(shader);
+            GLint status = GL_FALSE;
+            glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
+            if (status == GL_FALSE) {
+                GLint length = 0;
+                glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
+                std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                glGetShaderInfoLog(shader, length + 1, nullptr, buffer.data());
+                if (log != nullptr) *log = buffer.data();
+                glDeleteShader(shader);
+                return 0;
+            }
+            return shader;
+        }
+
+        // `captureNames` is what goes to glTransformFeedbackVaryings. Passing gl_Position in it
+        // is what puts MirrorPositionForCapture on the path.
+        GLuint BuildCaptureProgram(const char* vertexSource, const std::vector<const char*>& captureNames,
+                                   std::string* log) {
+            const GLuint vertexShader = CompileVertexShader(vertexSource, log);
+            if (vertexShader == 0) return 0;
+            const GLuint program = glCreateProgram();
+            glAttachShader(program, vertexShader);
+            glTransformFeedbackVaryings(program, static_cast<GLsizei>(captureNames.size()), captureNames.data(),
+                                        GL_INTERLEAVED_ATTRIBS);
+            glLinkProgram(program);
+            glDeleteShader(vertexShader);
+            GLint status = GL_FALSE;
+            glGetProgramiv(program, GL_LINK_STATUS, &status);
+            if (status == GL_FALSE) {
+                GLint length = 0;
+                glGetProgramiv(program, GL_INFO_LOG_LENGTH, &length);
+                std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                glGetProgramInfoLog(program, length + 1, nullptr, buffer.data());
+                if (log != nullptr) *log = buffer.data();
+                glDeleteProgram(program);
+                return 0;
+            }
+            return program;
+        }
+
+        class UnwrittenPositionOutputScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                glGenBuffers(1, &m_vbo);
+                glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
+                const float vertex[kCaptureFloats] = {1.0f, 2.0f, 3.0f, 4.0f};
+                glBufferData(GL_ARRAY_BUFFER, kCaptureBytes, vertex, GL_STATIC_DRAW);
+                glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, nullptr);
+                glEnableVertexAttribArray(0);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                glBindVertexArray(0);
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glBindVertexArray(0);
+                glUseProgram(0);
+                if (m_vbo != 0) glDeleteBuffers(1, &m_vbo);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                ScenarioTest::TearDown();
+            }
+
+            // Links `vertexSource` with `captureNames`, runs one captured point, and checks that
+            // the USER varying came back. `captureStride` is how many floats one captured vertex
+            // occupies, so the user varying can be read out from behind a captured gl_Position.
+            void ExpectUserVaryingIsCaptured(const char* vertexSource, const std::vector<const char*>& captureNames,
+                                             std::size_t captureStride, std::size_t userVaryingOffset,
+                                             const char* what) {
+                std::string log;
+                const GLuint program = BuildCaptureProgram(vertexSource, captureNames, &log);
+                ASSERT_NE(program, 0u) << what << ": the capture program failed to build: " << log;
+
+                const GLsizeiptr captureBytes = static_cast<GLsizeiptr>(captureStride * sizeof(float));
+                GLuint xfbBuffer = 0;
+                glGenBuffers(1, &xfbBuffer);
+                glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, xfbBuffer);
+                // Pre-fill with a value the shader cannot produce, so "captured nothing" is
+                // distinguishable from "captured the wrong thing".
+                const std::vector<float> poison(captureStride, -1.0f);
+                glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, captureBytes, poison.data(), GL_DYNAMIC_READ);
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+                ASSERT_EQ(FirstGLError(), 0u) << what << ": setting up the capture buffer raised a GL error";
+
+                glEnable(GL_RASTERIZER_DISCARD);
+                glUseProgram(program);
+                glBindVertexArray(m_vao);
+                glBeginTransformFeedback(GL_POINTS);
+                glDrawArrays(GL_POINTS, 0, 1);
+                glEndTransformFeedback();
+                glBindVertexArray(0);
+                glUseProgram(0);
+                glDisable(GL_RASTERIZER_DISCARD);
+                EXPECT_EQ(FirstGLError(), 0u) << what << ": the captured draw raised a GL error";
+
+                std::vector<float> readback(captureStride, -2.0f);
+                glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, xfbBuffer);
+                glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0, captureBytes, readback.data());
+                for (std::size_t i = 0; i < kCaptureFloats; ++i) {
+                    EXPECT_FLOAT_EQ(readback[userVaryingOffset + i], static_cast<float>(i + 1))
+                        << what << ": captured float " << i << " came back as "
+                        << readback[userVaryingOffset + i]
+                        << "; the pre-fill value means the draw never produced a vertex, which is what an "
+                           "invalid shader module looks like from out here";
+                }
+
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+                glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, 0);
+                glDeleteBuffers(1, &xfbBuffer);
+                glDeleteProgram(program);
+            }
+
+            GLuint m_vao = 0;
+            GLuint m_vbo = 0;
+        };
+
+    } // namespace
+
+    // The clip fixup's half: PositionZRemap is on for every draw, so the fixup runs on this
+    // program and used to inject a store through the delisted block.
+    TEST_F(UnwrittenPositionOutputScenario, ARedeclaredButUnwrittenPositionStillDraws) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectUserVaryingIsCaptured(kUnwrittenPositionVertexSource, {"vs_out_value"}, kCaptureFloats, 0,
+                                    "redeclared, never written");
+    }
+
+    // The XFB half: capturing gl_Position adds an access chain and a LOAD through the same
+    // delisted block, which the interface rule covers exactly as it covers the store. Position
+    // itself is undefined here - only the user varying behind it is asserted.
+    TEST_F(UnwrittenPositionOutputScenario, CapturingAnUnwrittenPositionStillDraws) {
+        if (!Ready() || IsSkipped()) return;
+        // DirectVulkan only, and not because the defect was backend-specific in principle - the
+        // injection this pins lives in DirectVulkan's ProgramFactory, and DirectGLES cannot
+        // reach the case at all: capturing gl_Position BY NAME off a shader that never writes it
+        // comes back empty there, because the ESSL the transpiler emits has no such output for
+        // the capture list to name. That is a known, separate DirectGLES gap (the same one that
+        // blocks gl_Position/gl_PointSize capture in the tessellation capture segment), tracked
+        // outside this scenario; asserting it here would only re-report it.
+        if (Gl().BackendName() != "DirectVulkan") {
+            GTEST_SKIP() << "capturing an unwritten gl_Position by name is a separate, known "
+                         << "DirectGLES gap; this case pins the DirectVulkan injection";
+        }
+        ExpectUserVaryingIsCaptured(kUnwrittenPositionVertexSource, {"gl_Position", "vs_out_value"},
+                                    kCaptureFloats * 2, kCaptureFloats, "capturing an unwritten gl_Position");
+    }
+
+    // Control: the same shader with the one assignment restored. Its block is never delisted,
+    // so it exercises the path the fixup is actually for and must keep working.
+    TEST_F(UnwrittenPositionOutputScenario, AWrittenRedeclaredPositionStillDraws) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectUserVaryingIsCaptured(kWrittenPositionVertexSource, {"vs_out_value"}, kCaptureFloats, 0,
+                                    "redeclared and written");
+    }
+
+    TEST_F(UnwrittenPositionOutputScenario, CapturingAWrittenPositionStillDraws) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectUserVaryingIsCaptured(kWrittenPositionVertexSource, {"gl_Position", "vs_out_value"},
+                                    kCaptureFloats * 2, kCaptureFloats, "capturing a written gl_Position");
+    }
+
+    // Control: no gl_PerVertex redeclaration, so no Position annotation and nothing to delist.
+    TEST_F(UnwrittenPositionOutputScenario, AShaderWithNoPositionBlockStillDraws) {
+        if (!Ready() || IsSkipped()) return;
+        ExpectUserVaryingIsCaptured(kNoPositionBlockVertexSource, {"vs_out_value"}, kCaptureFloats, 0,
+                                    "no gl_PerVertex block");
+    }
+
+} // namespace MGITest

MobileGL/MG_IntegrationTest/Scenarios/ViewportArrayScenario.cpp

@@ -525,7 +525,7 @@ void main() { fragColor = vec4(float(gsIndex) * 16.0 / 255.0, 0.0, 0.0, 1.0); }
         //
         // Everything above is a claim about pixels, and a claim about pixels cannot tell an
         // emulation that works from a backend that was going to be right anyway. This case builds
-        // the SAME program in a process started with MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION=0
+        // the SAME program in a process started with MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION=0
         // (the NoViewportArrayEmulation. ctest entry) and requires case 1's
         // result to COLLAPSE: with no routing, every geometry invocation rasterizes against
         // viewport 0's rectangle, so the last invocation paints the whole surface and every cell
@@ -551,10 +551,10 @@ void main() { fragColor = vec4(float(gsIndex) * 16.0 / 255.0, 0.0, 0.0, 1.0); }
             // entry for it, so the control still runs in every ctest run; anywhere else - the
             // ambient ctest entries, or the binary run straight from a device shell - the
             // emulation is on and this case skips.
-            if (AmbientQuirkFromEnvironment("MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION") != AmbientQuirk::Off) {
+            if (AmbientQuirkFromEnvironment("MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION") != AmbientQuirk::Off) {
                 GTEST_SKIP() << "this is the negative control for the emulation and needs it off for the "
                                 "whole process; the NoViewportArrayEmulation. ctest entry runs it with "
-                                "MOBILEGL_FORCE_VIEWPORT_ARRAY_EMULATION=0";
+                                "MOBILEGL_ESPRYT_FORCE_VIEWPORT_ARRAY_EMULATION=0";
             }
 
             IntTarget target = MakeIntTarget(kSurfaceSide, kSurfaceSide);

MobileGL/MG_IntegrationTest/Scenarios/XfbRepeatedCaptureScenario.cpp

@@ -0,0 +1,657 @@
+// MobileGL - MobileGL/MG_IntegrationTest/Scenarios/XfbRepeatedCaptureScenario.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+//
+// Scenario - A CAPTURE MUST STILL RECORD WHEN IT IS NOT THE FIRST ONE IN THE PROCESS,
+// AND THE CAPTURE STAGE MAY BE ANY OF THE FOUR THAT CAN BE THE LAST ONE.
+//
+// The conformance suite exposed a whole family of transform feedback failures that no
+// existing scenario could reproduce, because every one of them ran ONE capture, from a
+// VERTEX stage, in a freshly initialised process. What the suite actually does is
+// different in three ways at once, and each of them turned out to matter:
+//
+//   * it runs case after case in ONE GL context, resetting state between them - and the
+//     reset is not a fresh context. Its transform feedback part
+//     (framework/opengl/gluStateReset.cpp resetStateGLCore) unbinds the generic
+//     GL_TRANSFORM_FEEDBACK_BUFFER and then clears every indexed capture point from 0 to
+//     GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS, which permanently raises MobileGL's
+//     touched-binding-point high-water mark. Every later capture that uses fewer points
+//     than that - i.e. every INTERLEAVED_ATTRIBS capture - then had the unused tail
+//     re-cleared on the driver immediately before glBeginTransformFeedback.
+//     ReplayDeqpStateReset below is that reset, reduced to the calls that touch capture
+//     state, so a defect that only appears from the second capture onwards is reachable
+//     here instead of only on a device.
+//
+//   * the capture stage is frequently a GEOMETRY or a TESSELLATION EVALUATION shader,
+//     never a plain vertex shader. The tree had zero coverage for either: none of the
+//     Xfb* scenarios mentioned tessellation and neither TessellationDrawModeScenario nor
+//     GeometryDrawModeScenario mentioned transform feedback.
+//
+//   * the capture program frequently has NO FRAGMENT STAGE at all, because it draws
+//     under GL_RASTERIZER_DISCARD and never rasterises anything. That is legal in
+//     desktop GL and the shape most "use transform feedback as a readback channel"
+//     tests are built on.
+//
+// Every case here asserts the captured BYTES, never just the absence of a GL error: the
+// failure this guards against writes nothing and raises nothing, so a buffer that kept
+// its poison is the only thing that distinguishes it from success.
+
+#include <cmath>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "../Harness/HeadlessGL.h"
+#include "../Harness/ScenarioFixture.h"
+
+#ifdef GLAPI
+#undef GLAPI
+#endif
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glcorearb.h>
+#undef GL_GLEXT_PROTOTYPES
+
+namespace MGITest {
+    namespace {
+
+        // Nothing a capture can legitimately produce, so a component that still reads it
+        // names the failure ("the capture never reached these bytes") instead of looking
+        // like an ordinary numeric mismatch.
+        constexpr int kPoison = -987654;
+
+        const char* const kPassthroughVertexSource = R"(#version 420 core
+layout(location = 0) in int vs_in_value;
+flat out int vs_out_value;
+void main()
+{
+    vs_out_value = vs_in_value;
+    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+}
+)";
+
+        // The primitive_counter shape: one flat int per emitted vertex, several vertices
+        // per input primitive, so the capture is geometry-AMPLIFIED and the CPU-side
+        // primitive model cannot predict its length.
+        const char* const kPointAmplifyingGeometrySource = R"(#version 420 core
+layout(points) in;
+layout(points, max_vertices = 2) out;
+flat in int vs_out_value[];
+flat out int gs_out_value;
+void main()
+{
+    for (int i = 0; i < 2; ++i)
+    {
+        gs_out_value = vs_out_value[0];
+        gl_Position = gl_in[0].gl_Position;
+        EmitVertex();
+        EndPrimitive();
+    }
+}
+)";
+
+        // Adjacency input. Only a geometry stage can consume it, and CountPrimitivesForDraw
+        // used to answer 0 for every adjacency mode, which silently excluded the whole draw
+        // from the capture accounting.
+        const char* const kAdjacencyGeometrySource = R"(#version 420 core
+layout(lines_adjacency) in;
+layout(points, max_vertices = 1) out;
+flat in int vs_out_value[];
+flat out int gs_out_value;
+void main()
+{
+    gs_out_value = vs_out_value[1];
+    gl_Position = gl_in[1].gl_Position;
+    EmitVertex();
+    EndPrimitive();
+}
+)";
+
+        const char* const kTessControlSource = R"(#version 420 core
+layout(vertices = 1) out;
+flat in int vs_out_value[];
+patch out int tcs_out_value;
+void main()
+{
+    tcs_out_value = vs_out_value[0];
+    gl_TessLevelOuter[0] = 1.0;
+    gl_TessLevelOuter[1] = 1.0;
+    gl_TessLevelOuter[2] = 1.0;
+    gl_TessLevelInner[0] = 1.0;
+    gl_out[gl_InvocationID].gl_Position = gl_in[0].gl_Position;
+}
+)";
+
+        const char* const kTessEvalSource = R"(#version 420 core
+layout(triangles, equal_spacing, cw) in;
+patch in int tcs_out_value;
+flat out int tes_out_value;
+void main()
+{
+    tes_out_value = tcs_out_value;
+    gl_Position = gl_in[0].gl_Position;
+}
+)";
+
+        const char* const kFragmentSource = R"(#version 420 core
+flat in int gs_out_value;
+out vec4 fragColor;
+void main()
+{
+    fragColor = vec4(float(gs_out_value), 0.0, 0.0, 1.0);
+}
+)";
+
+        class XfbRepeatedCaptureScenario : public ScenarioTest {
+        protected:
+            void SetUp() override {
+                ScenarioTest::SetUp();
+                if (!Ready()) return;
+                glGenVertexArrays(1, &m_vao);
+                glBindVertexArray(m_vao);
+                glGenBuffers(1, &m_vbo);
+                glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
+                const int values[kInputVertices] = {10, 11, 12, 13};
+                glBufferData(GL_ARRAY_BUFFER, sizeof(values), values, GL_STATIC_DRAW);
+                glVertexAttribIPointer(0, 1, GL_INT, 0, nullptr);
+                glEnableVertexAttribArray(0);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                DrainErrors();
+            }
+
+            void TearDown() override {
+                if (!Ready()) return;
+                glUseProgram(0);
+                for (const GLuint program : m_programs) {
+                    glDeleteProgram(program);
+                }
+                m_programs.clear();
+                glBindVertexArray(0);
+                if (m_vbo != 0) glDeleteBuffers(1, &m_vbo);
+                if (m_vao != 0) glDeleteVertexArrays(1, &m_vao);
+                m_vbo = 0;
+                m_vao = 0;
+                ScenarioTest::TearDown();
+            }
+
+            static constexpr int kInputVertices = 4;
+
+            static void DrainErrors() {
+                for (int i = 0; i < 16 && glGetError() != GL_NO_ERROR; ++i) {
+                }
+            }
+
+            static bool BackendHostsGeometry() {
+                GLint maxGeometryOutputVertices = 0;
+                glGetIntegerv(GL_MAX_GEOMETRY_OUTPUT_VERTICES, &maxGeometryOutputVertices);
+                DrainErrors();
+                return maxGeometryOutputVertices >= 2;
+            }
+
+            static bool BackendHostsTessellation() {
+                GLint maxTessGenLevel = 0;
+                glGetIntegerv(GL_MAX_TESS_GEN_LEVEL, &maxTessGenLevel);
+                DrainErrors();
+                return maxTessGenLevel >= 1;
+            }
+
+            // The transform-feedback-relevant half of deqp's resetStateGLCore, in its order.
+            // It runs between EVERY pair of conformance cases, and running one capture
+            // through it is the difference between "the first capture in the process" and
+            // every other one.
+            static void ReplayDeqpStateReset() {
+                glBindVertexArray(0);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+                glDisable(GL_RASTERIZER_DISCARD);
+                glUseProgram(0);
+                GLint maxSeparateAttribs = 0;
+                glGetIntegerv(GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS, &maxSeparateAttribs);
+                glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, 0);
+                for (GLint index = 0; index < maxSeparateAttribs; ++index) {
+                    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, static_cast<GLuint>(index), 0);
+                }
+                DrainErrors();
+            }
+
+            static std::string InfoLog(GLuint object, bool isShader) {
+                GLint length = 0;
+                if (isShader) {
+                    glGetShaderiv(object, GL_INFO_LOG_LENGTH, &length);
+                } else {
+                    glGetProgramiv(object, GL_INFO_LOG_LENGTH, &length);
+                }
+                std::vector<char> buffer(static_cast<std::size_t>(length) + 1, '\0');
+                if (isShader) {
+                    glGetShaderInfoLog(object, length + 1, nullptr, buffer.data());
+                } else {
+                    glGetProgramInfoLog(object, length + 1, nullptr, buffer.data());
+                }
+                return buffer.data();
+            }
+
+            GLuint BuildCaptureProgram(const std::vector<std::pair<GLenum, const char*>>& stages,
+                                       const char* varying) {
+                return BuildCaptureProgram(stages, std::vector<const char*>{varying});
+            }
+
+            // Builds a capture program out of `stages` capturing `varyings` interleaved.
+            // Returns 0 and fills m_buildLog on failure.
+            GLuint BuildCaptureProgram(const std::vector<std::pair<GLenum, const char*>>& stages,
+                                       const std::vector<const char*>& varyings) {
+                m_buildLog.clear();
+                std::vector<GLuint> shaders;
+                bool ok = true;
+                for (const auto& [stage, source] : stages) {
+                    const GLuint shader = glCreateShader(stage);
+                    glShaderSource(shader, 1, &source, nullptr);
+                    glCompileShader(shader);
+                    GLint compiled = 0;
+                    glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+                    shaders.push_back(shader);
+                    if (compiled == GL_FALSE) {
+                        m_buildLog = InfoLog(shader, true);
+                        ok = false;
+                        break;
+                    }
+                }
+                GLuint program = 0;
+                if (ok) {
+                    program = glCreateProgram();
+                    for (const GLuint shader : shaders) {
+                        glAttachShader(program, shader);
+                    }
+                    glTransformFeedbackVaryings(program, static_cast<GLsizei>(varyings.size()), varyings.data(),
+                                                GL_INTERLEAVED_ATTRIBS);
+                    glLinkProgram(program);
+                    GLint linked = GL_FALSE;
+                    glGetProgramiv(program, GL_LINK_STATUS, &linked);
+                    if (linked == GL_FALSE) {
+                        m_buildLog = InfoLog(program, false);
+                        glDeleteProgram(program);
+                        program = 0;
+                    }
+                }
+                for (const GLuint shader : shaders) {
+                    glDeleteShader(shader);
+                }
+                if (program != 0) m_programs.push_back(program);
+                return program;
+            }
+
+            // One capture span. `captureMode` is the transform feedback primitive mode,
+            // `drawMode`/`count` the draw. Returns the capture buffer's contents.
+            std::vector<int> RunCaptureSpan(GLuint program, GLenum captureMode, GLenum drawMode, GLsizei count,
+                                            std::size_t capturedInts) {
+                std::vector<int> poison(capturedInts, kPoison);
+                GLuint xfbBuffer = 0;
+                glGenBuffers(1, &xfbBuffer);
+                glBindBuffer(GL_ARRAY_BUFFER, xfbBuffer);
+                glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(capturedInts * sizeof(int)), poison.data(),
+                             GL_STATIC_COPY);
+                glBindBuffer(GL_ARRAY_BUFFER, 0);
+                // The capture point is the ONLY thing bound; the generic
+                // GL_TRANSFORM_FEEDBACK_BUFFER binding comes along for the ride, exactly as
+                // the conformance tests rely on (GL 4.6 core 6.1.1).
+                glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+
+                glBindVertexArray(m_vao);
+                glUseProgram(program);
+                glEnable(GL_RASTERIZER_DISCARD);
+                glBeginTransformFeedback(captureMode);
+                glDrawArrays(drawMode, 0, count);
+                glEndTransformFeedback();
+                glDisable(GL_RASTERIZER_DISCARD);
+
+                std::vector<int> readback(capturedInts, kPoison);
+                glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
+                                   static_cast<GLsizeiptr>(capturedInts * sizeof(int)), readback.data());
+                glUseProgram(0);
+                glDeleteBuffers(1, &xfbBuffer);
+                return readback;
+            }
+
+            static ::testing::AssertionResult CapturedNothing(const std::vector<int>& data) {
+                for (std::size_t i = 0; i < data.size(); ++i) {
+                    if (data[i] != kPoison) {
+                        return ::testing::AssertionFailure() << "component " << i << " is " << data[i];
+                    }
+                }
+                return ::testing::AssertionSuccess();
+            }
+
+            static ::testing::AssertionResult CapturedIs(const std::vector<int>& data,
+                                                         const std::vector<int>& expected) {
+                if (data.size() != expected.size()) {
+                    return ::testing::AssertionFailure()
+                           << "captured " << data.size() << " value(s), expected " << expected.size();
+                }
+                for (std::size_t i = 0; i < data.size(); ++i) {
+                    if (data[i] != expected[i]) {
+                        ::testing::AssertionResult failure = ::testing::AssertionFailure();
+                        failure << "component " << i << " is " << data[i] << ", expected " << expected[i];
+                        if (data[i] == kPoison) {
+                            failure << " (the capture never reached these bytes)";
+                        }
+                        return failure;
+                    }
+                }
+                return ::testing::AssertionSuccess();
+            }
+
+            std::vector<GLuint> m_programs;
+            std::string m_buildLog;
+            GLuint m_vao = 0;
+            GLuint m_vbo = 0;
+        };
+
+        // THE REGRESSION GUARD FOR THE WHOLE FAMILY. Two geometry-stage captures in one
+        // process with the conformance suite's own state reset between them; the assertion
+        // that matters is on the SECOND one, which is the one every device run failed while
+        // whichever body happened to land first in its process passed.
+        TEST_F(XfbRepeatedCaptureScenario, ASecondGeometryCaptureAfterADeqpStateResetStillRecords) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsGeometry()) {
+                GTEST_SKIP() << "no geometry stage on " << Gl().BackendName() << " (" << Gl().RendererString() << ")";
+            }
+
+            // Two vertices emitted per input point, so the capture is amplified beyond what
+            // the CPU primitive model can predict from the draw alone.
+            const std::vector<int> expected = {10, 10, 11, 11, 12, 12, 13, 13};
+
+            for (int capture = 0; capture < 3; ++capture) {
+                // A fresh program per capture, because that is what a fresh conformance case
+                // builds - and it is what makes the driver recycle program and buffer names.
+                const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource},
+                                                            {GL_GEOMETRY_SHADER, kPointAmplifyingGeometrySource},
+                                                            {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                           "gs_out_value");
+                ASSERT_NE(program, 0u) << "capture " << capture << " program failed to build: " << m_buildLog;
+
+                const std::vector<int> captured =
+                    RunCaptureSpan(program, GL_POINTS, GL_POINTS, kInputVertices, expected.size());
+                EXPECT_TRUE(CapturedIs(captured, expected))
+                    << "capture " << capture << " of 3 in this process"
+                    << (capture == 0 ? "" : " (every earlier one was followed by a deqp-shaped state reset)");
+                EXPECT_EQ(glGetError(), GL_NO_ERROR) << "capture " << capture;
+
+                glDeleteProgram(program);
+                m_programs.pop_back();
+                ReplayDeqpStateReset();
+                glBindVertexArray(m_vao);
+            }
+        }
+
+        // The tessellation half, which had no coverage anywhere in the tree: a capture taken
+        // from a GL_PATCHES draw, whose last vertex-processing stage is the evaluation shader
+        // and whose record count only the tessellator knows.
+        TEST_F(XfbRepeatedCaptureScenario, ACaptureFromAPatchesDrawRecords) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsTessellation()) {
+                GTEST_SKIP() << "no tessellation stages on " << Gl().BackendName() << " (" << Gl().RendererString()
+                             << ")";
+            }
+
+            // One input patch of one vertex, all levels at 1: the tessellator emits exactly
+            // one triangle, so three captured vertices all carrying the first input value.
+            glPatchParameteri(GL_PATCH_VERTICES, 1);
+            DrainErrors();
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource},
+                                                        {GL_TESS_CONTROL_SHADER, kTessControlSource},
+                                                        {GL_TESS_EVALUATION_SHADER, kTessEvalSource}},
+                                                       "tes_out_value");
+            ASSERT_NE(program, 0u) << "patch capture program failed to build: " << m_buildLog;
+
+            const std::vector<int> expected = {10, 10, 10};
+            const std::vector<int> captured = RunCaptureSpan(program, GL_TRIANGLES, GL_PATCHES, 1, expected.size());
+            EXPECT_TRUE(CapturedIs(captured, expected));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // A capture program with NO FRAGMENT STAGE, drawn under GL_RASTERIZER_DISCARD. Legal
+        // in desktop GL, and the shape most transform-feedback-as-readback tests use; the
+        // program above only differs from it by the fragment shader, so a failure here is
+        // specifically about the missing stage.
+        TEST_F(XfbRepeatedCaptureScenario, ACaptureFromAFragmentlessProgramRecords) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsGeometry()) {
+                GTEST_SKIP() << "no geometry stage on " << Gl().BackendName() << " (" << Gl().RendererString() << ")";
+            }
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kPointAmplifyingGeometrySource}},
+                                                       "gs_out_value");
+            ASSERT_NE(program, 0u) << "fragmentless capture program failed to build: " << m_buildLog;
+
+            const std::vector<int> expected = {10, 10, 11, 11, 12, 12, 13, 13};
+            const std::vector<int> captured =
+                RunCaptureSpan(program, GL_POINTS, GL_POINTS, kInputVertices, expected.size());
+            EXPECT_TRUE(CapturedIs(captured, expected));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // An ADJACENCY draw feeding the capture. CountPrimitivesForDraw answered 0 for all
+        // four adjacency modes, which made the transform feedback accounting skip the draw
+        // entirely - so neither the captured-vertex counter nor the geometry-capture-draw
+        // flag moved, and anything downstream of either was working from "nothing happened".
+        TEST_F(XfbRepeatedCaptureScenario, ACaptureFromAnAdjacencyDrawRecords) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsGeometry()) {
+                GTEST_SKIP() << "no geometry stage on " << Gl().BackendName() << " (" << Gl().RendererString() << ")";
+            }
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kAdjacencyGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       "gs_out_value");
+            ASSERT_NE(program, 0u) << "adjacency capture program failed to build: " << m_buildLog;
+
+            // Four vertices of GL_LINES_ADJACENCY are one line primitive; the shader emits
+            // the second vertex of the four, which is the line's first real endpoint.
+            const std::vector<int> expected = {11};
+            const std::vector<int> captured =
+                RunCaptureSpan(program, GL_POINTS, GL_LINES_ADJACENCY, kInputVertices, expected.size());
+            EXPECT_TRUE(CapturedIs(captured, expected));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+        }
+
+        // An adjacency draw with NO geometry stage. GL 4.6 core table 13.1 admits
+        // GL_LINES_ADJACENCY and GL_LINE_STRIP_ADJACENCY under capture mode GL_LINES (and the
+        // triangle pair under GL_TRIANGLES): without a geometry shader the adjacent vertices
+        // are ignored and the primitive assembled is a plain line, so the combination is legal
+        // and must capture. MobileGL's active-capture primitive-mode table listed only the
+        // non-adjacency modes, so this raised GL_INVALID_OPERATION and dropped the draw
+        // entirely - the buffer kept its pre-draw bytes and the application saw an error the
+        // spec does not allow. Distinct from ACaptureFromAnAdjacencyDrawRecords above, which
+        // HAS a geometry stage and therefore bypasses that table completely.
+        TEST_F(XfbRepeatedCaptureScenario, AVertexOnlyAdjacencyCaptureRecords) {
+            if (!Ready()) GTEST_SKIP();
+
+            const GLuint program =
+                BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource}}, "vs_out_value");
+            ASSERT_NE(program, 0u) << "vertex-only capture program failed to build: " << m_buildLog;
+
+            // Four vertices of GL_LINES_ADJACENCY are one line whose real endpoints are the
+            // middle pair, so the capture is those two vertices in order.
+            const std::vector<int> expected = {11, 12};
+            const std::vector<int> captured =
+                RunCaptureSpan(program, GL_LINES, GL_LINES_ADJACENCY, kInputVertices, expected.size());
+
+            // THE GUARD FOR THE DEFECT ITSELF, and it is backend-independent: the frontend
+            // validator must not reject the combination. It used to record
+            // GL_INVALID_OPERATION and return before the draw was ever issued.
+            EXPECT_EQ(glGetError(), GL_NO_ERROR)
+                << "a capture-mode/draw-mode pair GL 4.6 core table 13.1 admits must raise no error";
+
+            // Whether the capture then RECORDS is a backend question, and the two answer it
+            // differently. ES 3.2 (10.1) supports the adjacency primitive types only for a
+            // pipeline with a geometry shader, so DirectGLES has nothing to forward this draw
+            // to; desktop GL and Vulkan both assemble the plain line and capture it. Asserting
+            // the data unconditionally would be asserting that DirectGLES emulates a whole ES
+            // restriction away, which is a separate piece of work and not what this guards.
+            if (Gl().BackendName() == "DirectGLES") {
+                GTEST_SKIP() << "DirectGLES cannot forward a geometry-shader-less adjacency draw: ES 3.2 10.1 "
+                                "supports the adjacency primitive types only with a geometry stage. The frontend "
+                                "no longer rejects the draw (checked above), which is the defect this covers.";
+            }
+            EXPECT_TRUE(CapturedIs(captured, expected));
+        }
+
+        // A CAPTURE MUST NEVER LAND IN A BUFFER THE APPLICATION DID NOT BIND FOR IT.
+        //
+        // A capture list may legally begin with gl_NextBuffer, which leaves capture buffer 0
+        // with stride 0 and nothing to capture - so glBeginTransformFeedback does not require a
+        // buffer at point 0 and the application binds only point 1. The driver-side program is
+        // a single-buffer interleaved capture (the pseudo-varyings are consumed at link time),
+        // so it writes capture point 0, and MobileGL redirects that into scratch storage and
+        // scatters the records afterwards.
+        //
+        // Two ways that went wrong, both fixed here: the scratch was sized by reading each
+        // target's stride at its POSITION in a list that skips unbound buffers, which for this
+        // layout read stride 0 for everything and produced a zero capacity; and when the
+        // scratch then failed to bind, the span opened anyway onto whatever capture point 0
+        // still held from an earlier capture in the process - silently overwriting an unrelated
+        // application buffer. The first span below exists purely to leave such a binding behind.
+        TEST_F(XfbRepeatedCaptureScenario, ACaptureListBeginningWithGlNextBufferSparesTheEarlierBuffer) {
+            if (!Ready()) GTEST_SKIP();
+
+            const std::size_t capturedInts = 4;
+            const GLsizeiptr captureBytes = static_cast<GLsizeiptr>(capturedInts * sizeof(int));
+
+            // Span A: an ordinary capture, so capture point 0 is left holding bufferA.
+            const GLuint programA =
+                BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource}}, "vs_out_value");
+            ASSERT_NE(programA, 0u) << "plain capture program failed to build: " << m_buildLog;
+
+            std::vector<int> poison(capturedInts, kPoison);
+            GLuint bufferA = 0;
+            glGenBuffers(1, &bufferA);
+            glBindBuffer(GL_ARRAY_BUFFER, bufferA);
+            glBufferData(GL_ARRAY_BUFFER, captureBytes, poison.data(), GL_STATIC_COPY);
+            glBindBuffer(GL_ARRAY_BUFFER, 0);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, bufferA);
+
+            glBindVertexArray(m_vao);
+            glUseProgram(programA);
+            glEnable(GL_RASTERIZER_DISCARD);
+            glBeginTransformFeedback(GL_POINTS);
+            glDrawArrays(GL_POINTS, 0, kInputVertices);
+            glEndTransformFeedback();
+            glDisable(GL_RASTERIZER_DISCARD);
+            glUseProgram(0);
+
+            std::vector<int> afterA(capturedInts, kPoison);
+            glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0, captureBytes, afterA.data());
+            const std::vector<int> spanAExpected = {10, 11, 12, 13};
+            ASSERT_TRUE(CapturedIs(afterA, spanAExpected)) << "the setup span itself did not capture";
+
+            // Span B: gl_NextBuffer first, so buffer 0 captures nothing and only point 1 is bound.
+            const GLuint programB = BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource}},
+                                                        {"gl_NextBuffer", "vs_out_value"});
+            if (programB == 0) {
+                GTEST_SKIP() << "gl_NextBuffer capture lists are not linkable on " << Gl().BackendName() << " ("
+                             << Gl().RendererString() << "): " << m_buildLog;
+            }
+
+            GLuint bufferB = 0;
+            glGenBuffers(1, &bufferB);
+            glBindBuffer(GL_ARRAY_BUFFER, bufferB);
+            glBufferData(GL_ARRAY_BUFFER, captureBytes, poison.data(), GL_STATIC_COPY);
+            glBindBuffer(GL_ARRAY_BUFFER, 0);
+            // Point 0 released, point 1 is the only destination this capture asks for.
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, 0);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 1, bufferB);
+
+            glUseProgram(programB);
+            glEnable(GL_RASTERIZER_DISCARD);
+            glBeginTransformFeedback(GL_POINTS);
+            glDrawArrays(GL_POINTS, 0, kInputVertices);
+            glEndTransformFeedback();
+            glDisable(GL_RASTERIZER_DISCARD);
+            glUseProgram(0);
+
+            // THE ASSERTION THAT MATTERS: bufferA was not a destination of this capture, so it
+            // must still read exactly what span A left in it. A failure here is the corruption.
+            std::vector<int> bufferAAfterB(capturedInts, 0);
+            glBindBuffer(GL_ARRAY_BUFFER, bufferA);
+            glGetBufferSubData(GL_ARRAY_BUFFER, 0, captureBytes, bufferAAfterB.data());
+            glBindBuffer(GL_ARRAY_BUFFER, 0);
+            EXPECT_TRUE(CapturedIs(bufferAAfterB, spanAExpected))
+                << "the gl_NextBuffer capture wrote into the buffer the PREVIOUS span had bound";
+
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+
+            // ...and, where the backend places this layout at all, the buffer it WAS asked to
+            // write gets the records. That placement is the DirectGLES scatter path, whose
+            // scratch sizing used to read each target's stride at its POSITION in a list that
+            // skips unbound capture buffers - which for a leading gl_NextBuffer read stride 0
+            // for every target and sized the scratch at zero. DirectVulkan does not implement a
+            // leading-gl_NextBuffer layout at all (it captures nothing into bufferB); that is a
+            // pre-existing gap of its own, and the assertion above - that it corrupts nothing
+            // while declining - is what matters for it.
+            const bool backendPlacesLeadingNextBuffer = Gl().BackendName() != "DirectVulkan";
+            if (backendPlacesLeadingNextBuffer) {
+                std::vector<int> bufferBAfter(capturedInts, kPoison);
+                glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0, captureBytes, bufferBAfter.data());
+                EXPECT_TRUE(CapturedIs(bufferBAfter, spanAExpected));
+            }
+
+            // Unbound and deleted BEFORE any skip: a capture point left pointing at a buffer
+            // this test deleted would follow the process into the next scenario.
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 1, 0);
+            glDeleteBuffers(1, &bufferA);
+            glDeleteBuffers(1, &bufferB);
+
+            if (!backendPlacesLeadingNextBuffer) {
+                GTEST_SKIP() << "DirectVulkan does not place a capture list beginning with gl_NextBuffer; it "
+                                "captures nothing, which the no-corruption assertion above has already covered.";
+            }
+        }
+
+        // The control for all of the above: a span that never draws must leave the capture
+        // buffer alone. Without it "the buffer kept its poison" could be read as the correct
+        // outcome of some path rather than as the bug, and the tightened early returns in
+        // StartPendingTransformFeedback have to keep this legal case legal.
+        TEST_F(XfbRepeatedCaptureScenario, ASpanThatNeverDrawsLeavesTheCaptureBufferAlone) {
+            if (!Ready()) GTEST_SKIP();
+            if (!BackendHostsGeometry()) {
+                GTEST_SKIP() << "no geometry stage on " << Gl().BackendName() << " (" << Gl().RendererString() << ")";
+            }
+
+            const GLuint program = BuildCaptureProgram({{GL_VERTEX_SHADER, kPassthroughVertexSource},
+                                                        {GL_GEOMETRY_SHADER, kPointAmplifyingGeometrySource},
+                                                        {GL_FRAGMENT_SHADER, kFragmentSource}},
+                                                       "gs_out_value");
+            ASSERT_NE(program, 0u) << "capture program failed to build: " << m_buildLog;
+
+            const std::size_t capturedInts = 8;
+            std::vector<int> poison(capturedInts, kPoison);
+            GLuint xfbBuffer = 0;
+            glGenBuffers(1, &xfbBuffer);
+            glBindBuffer(GL_ARRAY_BUFFER, xfbBuffer);
+            glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(capturedInts * sizeof(int)), poison.data(),
+                         GL_STATIC_COPY);
+            glBindBuffer(GL_ARRAY_BUFFER, 0);
+            glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfbBuffer);
+
+            glUseProgram(program);
+            glBeginTransformFeedback(GL_POINTS);
+            glEndTransformFeedback();
+            glUseProgram(0);
+
+            std::vector<int> readback(capturedInts, 0);
+            glGetBufferSubData(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
+                               static_cast<GLsizeiptr>(capturedInts * sizeof(int)), readback.data());
+            EXPECT_TRUE(CapturedNothing(readback));
+            EXPECT_EQ(glGetError(), GL_NO_ERROR);
+
+            glDeleteBuffers(1, &xfbBuffer);
+        }
+
+    } // namespace
+} // namespace MGITest

MobileGL/MG_Pipe/Coverage.def

@@ -0,0 +1,131 @@
+// MobileGL - MobileGL/MG_Pipe/Coverage.def
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+// The hand-maintained half of G6 (plan B section 4.7, gate 10.3-5): which MGPipe call
+// answers each backend read point in scripts/data/backend_read_inventory.md (477 rows, 57
+// files, generated from the backends by MobileGL-CS's extract_backend_read_inventory.py).
+//
+// gen_pipe.py joins the inventory's `member` column against MGP_COVERAGE_ACCESSOR_LIST and
+// its `delta` column against MGP_COVERAGE_DELTA_LIST, then writes generated/PipeCoverage.inc
+// with the per-accessor table and prints the coverage summary. Rows matching neither are
+// UNMAPPED: allowed in P0 and merely counted, ZERO from P5 onward, when the gate becomes
+// "regenerate and git diff --exit-code with 0 UNMAPPED".
+//
+// Three pseudo-calls stand for read points that do NOT become a forward call:
+//   kClientResolved   - the frontend answers it itself; the server is never asked
+//                       (section 4.4.6: "the server answers nothing the client can answer").
+//   kReverseChannel   - it becomes one of the ten MGPipeCallbacks (section 7.1).
+//   kStructuralHandle - the row is a SIGNATURE carrying SharedPtr<MG_State...>, which
+//                       becomes an MGPipeHandle parameter; there is no single call to name.
+//
+// clang-format off
+
+// X(Accessor, PipeCall)
+#define MGP_COVERAGE_ACCESSOR_LIST(X)                                    \
+    X(GetActiveTextureUnit,                     SetSamplerViews)         \
+    X(GetBlendColor,                            SetDynamicState)         \
+    X(GetBlendEquationIndexed,                  CreateRenderState)       \
+    X(GetBlendFuncIndexed,                      CreateRenderState)       \
+    /* dead: no backend reads it since D21; kept for inventory row 594 */  \
+    X(GetBoundTransformFeedbackName,            SetStreamOutputTargets)  \
+    X(GetBoundVertexArray,                      BindVertexElements)      \
+    /* Polymorphic over BufferTarget: its rows split across set_vertex_buffers,     */  \
+    /* set_index_buffer, set_indirect_buffers and set_shader_buffers when the       */  \
+    /* inventory is re-vendored carrying the target argument (deferred out of P1:   */  \
+    /* the extractor lives in MobileGL-CS). Named for the plan's explicit           */  \
+    /* replacement of the DrawIndirect/Parameter pair.                              */  \
+    X(GetBufferBindingSlot,                     SetIndirectBuffers)      \
+    X(GetBufferBindingPoint,                    SetShaderBuffers)        \
+    X(GetBufferBindingPointCount,               SetShaderBuffers)        \
+    X(GetTouchedBufferBindingPointCount,        SetShaderBuffers)        \
+    X(GetClampReadColor,                        SetDynamicState)         \
+    X(GetClearColor,                            SetDynamicState)         \
+    X(GetClearDepth,                            SetDynamicState)         \
+    X(GetClearStencil,                          SetDynamicState)         \
+    X(GetColorMaskIndexed,                      CreateRenderState)       \
+    X(GetCullFaceMode,                          CreateRenderState)       \
+    X(GetCurrentVertexAttribute,                SetVertexAttribDefaults) \
+    X(GetDepthFunc,                             CreateRenderState)       \
+    X(GetDepthMask,                             CreateRenderState)       \
+    X(GetDepthRangeIndexed,                     SetDynamicState)         \
+    X(GetFramebufferBindingSlot,                SetFramebufferState)     \
+    X(GetImageTextureBinding,                   SetShaderImages)         \
+    X(GetLineWidth,                             SetDynamicState)         \
+    X(GetLogicOp,                               CreateRenderState)       \
+    X(GetMaxTouchedTextureUnit,                 SetSamplerViews)         \
+    X(GetMinSampleShadingValue,                 CreateRenderState)       \
+    X(GetPatchDefaultInnerLevel,                SetPatchState)           \
+    X(GetPatchDefaultOuterLevel,                SetPatchState)           \
+    X(GetPatchVertices,                         SetPatchState)           \
+    X(GetPipelineStateVersion,                  BindRenderState)         \
+    X(GetPixelStoreParameters,                  SetPixelPackState)       \
+    X(GetPolygonModeFront,                      CreateRenderState)       \
+    X(GetPolygonOffsetFactor,                   SetDynamicState)         \
+    X(GetPolygonOffsetUnits,                    SetDynamicState)         \
+    X(GetPrimitiveRestartIndex,                 DrawVbo)                 \
+    X(GetProgramForDispatch,                    SetDispatchProgram)      \
+    X(GetProgramForDraw,                        SetDrawProgram)          \
+    X(GetProgramObject,                         CreateShaderState)       \
+    /* Not in ComputePipelineStateHash today even though Vulkan makes it pipeline   */  \
+    /* state; recorded here so the G7 chunk table has to answer for it before it    */  \
+    /* freezes (section 10.3-5).                                                    */  \
+    X(GetProvokingVertexMode,                   CreateRenderState)       \
+    X(GetRenderStateParameters,                 CreateRenderState)       \
+    X(GetRenderStateParametersVersion,          BindRenderState)         \
+    X(GetSamplingResolutionGeneration,          SetSamplerViews)         \
+    X(GetScissorBox,                            SetDynamicState)         \
+    X(GetStencilState,                          CreateRenderState)       \
+    X(GetTextureBindGeneration,                 SetSamplerViews)         \
+    X(GetTextureContextId,                      SetSamplerViews)         \
+    X(GetTextureObject,                         SetSamplerViews)         \
+    X(GetTextureUnitObject,                     SetSamplerViews)         \
+    X(GetTransformFeedbackCapturedVertices,     DrawVbo)                 \
+    X(GetTransformFeedbackGeneration,           SetStreamOutputTargets)  \
+    X(GetTransformFeedbackPausedPrimitiveCounter, EndStreamOutput)       \
+    X(GetTransformFeedbackProgram,              SetStreamOutputTargets)  \
+    X(GetViewport,                              SetDynamicState)         \
+    X(GetViewportIndexed,                       SetDynamicState)         \
+    X(IsCapabilityEnabled,                      CreateRenderState)       \
+    X(IsCapabilityEnabledIndexed,               CreateRenderState)       \
+    X(IsTransformFeedbackActive,                BeginStreamOutput)       \
+    X(IsTransformFeedbackPaused,                PauseStreamOutput)       \
+    X(InvalidateCompileEnv,                     kClientResolved)         \
+    X(ValidateProgramName,                      kClientResolved)         \
+    X(RecordError,                              kReverseChannel)         \
+    /* The D21 XFB counter-slot rekey's reads (VulkanRenderer.cpp); the calls they   */  \
+    /* map to are GetTransformFeedbackGeneration's.                                 */  \
+    X(GetBoundTransformFeedbackLifetimeId,      SetStreamOutputTargets)  \
+    X(HasOpenTransformFeedbackSpan,             SetStreamOutputTargets)
+
+// X(Accessor, Reason) - the STICKY fields (P1 brief D6): the only PipeInputs fields whose
+// value is valid across verbs, so the poison's per-verb generation does not apply to them.
+// Exactly the seven F-class (forwarded) accessors, and the argument for each is the same:
+// it takes an argument that is not verb state - a GL name, a lifetime id, a target - i.e.
+// it is a lookup or a reverse-channel write, not a state read; there is no value the
+// filler could copy and no verb whose fill could make it stale; phase C replaces them
+// with handle tables and callbacks. None of the version/generation accessors is sticky:
+// those change under verbs and are precisely what the poison must protect. The verify
+// lane's Fatal{UnmigratedPipeInput} is fixed by a FillPoints.def row, never by a row here.
+// gen_pipe.py refuses a name that is not an accessor above.
+#define MGP_COVERAGE_STICKY_LIST(X)                                                                        \
+    X(GetBufferBindingPointCount, "keyed by target: a constexpr capacity table, not verb state")           \
+    X(GetProgramObject,           "keyed by GL name: an object lookup, not verb state")                    \
+    X(GetTextureObject,           "keyed by GL name: an object lookup, not verb state")                    \
+    X(HasOpenTransformFeedbackSpan, "keyed by lifetime id: an object lookup, not verb state")              \
+    X(ValidateProgramName,        "keyed by GL name: a name-table lookup, not verb state")                 \
+    X(InvalidateCompileEnv,       "reverse channel: a write into the frontend, not a state read")          \
+    X(RecordError,                "reverse channel: a write into the frontend, not a state read")
+
+// X(DeltaKind, PipeCall) - for inventory rows with no accessor in the member column.
+// Read by gen_pipe.py ONLY, never by the C++ preprocessor: the delta kinds are the
+// inventory's own free-text labels, not C tokens.
+#define MGP_COVERAGE_DELTA_LIST(X)                                       \
+    X(handle-ify (wire handle),                 kStructuralHandle)       \
+    X(Buffer ops delta,                         ResourceRespecify)
+
+// clang-format on

MobileGL/MG_Pipe/FillPoints.def

@@ -0,0 +1,296 @@
+// MobileGL - MobileGL/MG_Pipe/FillPoints.def
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+// The per-verb fill points of the PipeInputs strangler (ARCHITECTURE.md 9.2, phase A; the
+// P1 brief D7). Three hand-maintained lists, read by scripts/gen_pipe.py (G5b) into
+// generated/PipeFillPoints.inc:
+//
+//   MGP_FILL_VERB_LIST   every verb the frontend calls through GLFunctionsTable, with its class
+//   MGP_FILL_CLASS_LIST  the verb classes
+//   MGP_FILL_FIELD_LIST  the may-read table: which PipeInputs fields a class of verb may read
+//
+// The verb set IS the function-pointer member set of MG_Backend::GLFunctionsTable
+// (MG_Backend/BackendObject.h), in declaration order: gen_pipe.py parses that struct and
+// refuses a row set that is not exactly its member set in that order, so the MGPipeVerb enum
+// and the table cannot drift apart. MG_Impl spells MGP_FILL(Verb) immediately before every
+// call through the table (83 statements over these 69 verbs); Present and SetSwapInterval go
+// through BackendObject virtuals and read no frontend state, so they are not verbs here.
+//
+// The seven sticky fields (Coverage.def, MGP_COVERAGE_STICKY_LIST) are implicit in every
+// class and are not listed. The verify lane is the oracle for this table: a
+// Fatal{UnmigratedPipeInput, "Field@Verb"} found there is fixed by adding the (class, field)
+// row, never by marking the field sticky.
+//
+// gen_pipe.py's block regexes end at a blank line: keep the empty line after each macro.
+//
+// clang-format off
+
+// X(Verb, Class) - one row per function-pointer member of MG_Backend::GLFunctionsTable (BackendObject.h),
+// in declaration order. gen_pipe.py parses that struct and refuses a row set that is not exactly its member set.
+#define MGP_FILL_VERB_LIST(X)                                          \
+    X(DrawArrays,                                     kDraw)           \
+    X(DrawElements,                                   kDraw)           \
+    X(DrawElementsBaseVertex,                         kDraw)           \
+    X(MultiDrawArrays,                                kDraw)           \
+    X(MultiDrawElements,                              kDraw)           \
+    X(MultiDrawElementsBaseVertex,                    kDraw)           \
+    X(MultiDrawElementsIndirect,                      kDraw)           \
+    X(MultiDrawArraysIndirect,                        kDraw)           \
+    X(MultiDrawElementsIndirectCount,                 kDraw)           \
+    X(MultiDrawArraysIndirectCount,                   kDraw)           \
+    X(DrawRangeElementsBaseVertex,                    kDraw)           \
+    X(DrawRangeElements,                              kDraw)           \
+    X(DrawElementsInstancedBaseVertexBaseInstance,    kDraw)           \
+    X(DrawElementsInstancedBaseVertex,                kDraw)           \
+    X(DrawElementsInstancedBaseInstance,              kDraw)           \
+    X(DrawElementsInstanced,                          kDraw)           \
+    X(DrawArraysInstancedBaseInstance,                kDraw)           \
+    X(DrawArraysInstanced,                            kDraw)           \
+    X(DrawElementsIndirect,                           kDraw)           \
+    X(DrawArraysIndirect,                             kDraw)           \
+    X(Clear,                                          kClear)          \
+    X(ClearBufferfi,                                  kClear)          \
+    X(ClearBufferfv,                                  kClear)          \
+    X(ClearBufferuiv,                                 kClear)          \
+    X(ClearBufferiv,                                  kClear)          \
+    X(ClearNamedFramebufferfv,                        kClear)          \
+    X(ClearNamedFramebufferfi,                        kClear)          \
+    X(ClearNamedFramebufferiv,                        kClear)          \
+    X(ClearNamedFramebufferuiv,                       kClear)          \
+    X(BlitFramebuffer,                                kBlitOrCopy)     \
+    X(BlitNamedFramebuffer,                           kBlitOrCopy)     \
+    X(CopyTexImage2D,                                 kBlitOrCopy)     \
+    X(CopyTexSubImage2D,                              kBlitOrCopy)     \
+    X(CopyImageSubData,                               kBlitOrCopy)     \
+    X(GenerateMipmap,                                 kTextureOp)      \
+    X(ReadPixels,                                     kReadback)       \
+    X(GetTexImage,                                    kReadback)       \
+    X(GetTextureImage,                                kReadback)       \
+    X(DispatchCompute,                                kDispatch)       \
+    X(DispatchComputeIndirect,                        kDispatch)       \
+    X(MemoryBarrier,                                  kQuery)          \
+    X(MemoryBarrierByRegion,                          kQuery)          \
+    X(BindImageTexture,                               kTextureOp)      \
+    X(GetIntegeri_v,                                  kQuery)          \
+    X(ShaderStorageBlockBinding,                      kProgramOp)      \
+    X(FenceSync,                                      kQuery)          \
+    X(ClientWaitSync,                                 kQuery)          \
+    X(WaitSync,                                       kQuery)          \
+    X(DeleteSync,                                     kQuery)          \
+    X(GetSyncStatus,                                  kQuery)          \
+    X(IsTimerQuerySupported,                          kQuery)          \
+    X(BeginTimeElapsedQuery,                          kQuery)          \
+    X(EndTimeElapsedQuery,                            kQuery)          \
+    X(QueryCounterTimestamp,                          kQuery)          \
+    X(IsQueryResultAvailable,                         kQuery)          \
+    X(GetQueryResult64,                               kQuery)          \
+    X(DeleteBackendQuery,                             kQuery)          \
+    X(BeginOcclusionQuery,                            kQuery)          \
+    X(EndOcclusionQuery,                              kQuery)          \
+    X(BeginXfbPrimitivesQuery,                        kQuery)          \
+    X(EndXfbPrimitivesQuery,                          kQuery)          \
+    X(PatchParameteri,                                kQuery)          \
+    X(BeginTransformFeedback,                         kXfbSpan)        \
+    X(EndTransformFeedback,                           kXfbSpan)        \
+    X(PauseTransformFeedback,                         kXfbSpan)        \
+    X(ResumeTransformFeedback,                        kXfbSpan)        \
+    X(BindTransformFeedback,                          kXfbSpan)        \
+    X(DeleteTransformFeedback,                        kXfbSpan)        \
+    X(GetGpuTimestampNs,                              kQuery)
+
+// X(Class) - the nine verb classes (ARCHITECTURE.md:153 names eight; kProgramOp is split out because
+// ShaderStorageBlockBinding is the one non-draw verb that syncs Espryt's render state and textures).
+#define MGP_FILL_CLASS_LIST(X) \
+    X(kDraw) X(kDispatch) X(kClear) X(kBlitOrCopy) X(kTextureOp) X(kReadback) X(kXfbSpan) X(kProgramOp) X(kQuery)
+
+// X(Class, Field) - the may-read table. A field named here is filled and stamped at every verb of the class;
+// a read of a field NOT named here is Fatal{UnmigratedPipeInput, "Field@Verb"} in a poison build.
+// Derived from the verified reachability of every backend read (both backends, union), P1 brief D7.
+#define MGP_FILL_FIELD_LIST(X)                                         \
+    /* kDraw: every draw entry of both backends */                     \
+    X(kDraw,        GetBoundVertexArray)                               \
+    X(kDraw,        GetProgramForDraw)                                 \
+    X(kDraw,        GetBufferBindingSlot)                              \
+    X(kDraw,        GetBufferBindingPoint)                             \
+    X(kDraw,        GetTouchedBufferBindingPointCount)                 \
+    X(kDraw,        GetTextureUnitObject)                              \
+    X(kDraw,        GetTextureContextId)                               \
+    X(kDraw,        GetTextureBindGeneration)                          \
+    X(kDraw,        GetMaxTouchedTextureUnit)                          \
+    X(kDraw,        GetSamplingResolutionGeneration)                   \
+    X(kDraw,        GetImageTextureBinding)                            \
+    X(kDraw,        GetCurrentVertexAttribute)                         \
+    X(kDraw,        GetRenderStateParameters)                          \
+    X(kDraw,        GetRenderStateParametersVersion)                   \
+    X(kDraw,        GetPipelineStateVersion)                           \
+    X(kDraw,        GetViewport)                                       \
+    X(kDraw,        GetViewportIndexed)                                \
+    X(kDraw,        GetDepthRangeIndexed)                              \
+    X(kDraw,        GetScissorBox)                                     \
+    X(kDraw,        IsCapabilityEnabled)                               \
+    X(kDraw,        IsCapabilityEnabledIndexed)                        \
+    X(kDraw,        GetBlendColor)                                     \
+    X(kDraw,        GetBlendFuncIndexed)                               \
+    X(kDraw,        GetBlendEquationIndexed)                           \
+    X(kDraw,        GetColorMaskIndexed)                               \
+    X(kDraw,        GetLogicOp)                                        \
+    X(kDraw,        GetDepthFunc)                                      \
+    X(kDraw,        GetDepthMask)                                      \
+    X(kDraw,        GetStencilState)                                   \
+    X(kDraw,        GetCullFaceMode)                                   \
+    X(kDraw,        GetPolygonModeFront)                               \
+    X(kDraw,        GetPolygonOffsetFactor)                            \
+    X(kDraw,        GetPolygonOffsetUnits)                             \
+    X(kDraw,        GetLineWidth)                                      \
+    X(kDraw,        GetMinSampleShadingValue)                          \
+    X(kDraw,        GetProvokingVertexMode)                            \
+    X(kDraw,        GetPatchVertices)                                  \
+    X(kDraw,        GetPatchDefaultOuterLevel)                         \
+    X(kDraw,        GetPatchDefaultInnerLevel)                         \
+    X(kDraw,        GetPrimitiveRestartIndex)                          \
+    X(kDraw,        GetFramebufferBindingSlot)                         \
+    X(kDraw,        IsTransformFeedbackActive)                         \
+    X(kDraw,        IsTransformFeedbackPaused)                         \
+    X(kDraw,        GetTransformFeedbackProgram)                       \
+    X(kDraw,        GetTransformFeedbackGeneration)                    \
+    X(kDraw,        GetBoundTransformFeedbackLifetimeId)               \
+    X(kDraw,        GetTransformFeedbackCapturedVertices)              \
+    /* kDispatch: the patch fields are Espryt's SyncCurrentProgram ->  */ \
+    /* AttachPassthroughTessControlStage (Managers.cpp)                */ \
+    X(kDispatch,    GetProgramForDispatch)                             \
+    X(kDispatch,    GetBufferBindingSlot)                              \
+    X(kDispatch,    GetBufferBindingPoint)                             \
+    X(kDispatch,    GetTouchedBufferBindingPointCount)                 \
+    X(kDispatch,    GetTextureUnitObject)                              \
+    X(kDispatch,    GetTextureContextId)                               \
+    X(kDispatch,    GetTextureBindGeneration)                          \
+    X(kDispatch,    GetMaxTouchedTextureUnit)                          \
+    X(kDispatch,    GetSamplingResolutionGeneration)                   \
+    X(kDispatch,    GetImageTextureBinding)                            \
+    X(kDispatch,    GetFramebufferBindingSlot)                         \
+    /* Magma's PrepareStorageImageTextures materialises a queued clear for every  */ \
+    /* storage image the dispatch writes, and the clear pre-compensates its colour */ \
+    /* against GL_FRAMEBUFFER_SRGB (VkClearManager::PreCompensateSrgbClearColor).  */ \
+    X(kDispatch,    IsCapabilityEnabled)                               \
+    X(kDispatch,    GetPatchVertices)                                  \
+    X(kDispatch,    GetPatchDefaultOuterLevel)                         \
+    X(kDispatch,    GetPatchDefaultInnerLevel)                         \
+    /* kClear */                                                       \
+    X(kClear,       GetRenderStateParameters)                          \
+    X(kClear,       GetRenderStateParametersVersion)                   \
+    X(kClear,       GetViewport)                                       \
+    X(kClear,       IsCapabilityEnabled)                               \
+    X(kClear,       GetFramebufferBindingSlot)                         \
+    X(kClear,       GetClearColor)                                     \
+    X(kClear,       GetClearDepth)                                     \
+    X(kClear,       GetClearStencil)                                   \
+    X(kClear,       GetScissorBox)                                     \
+    X(kClear,       GetColorMaskIndexed)                               \
+    X(kClear,       GetDepthMask)                                      \
+    X(kClear,       GetStencilState)                                   \
+    X(kClear,       GetTextureUnitObject)                              \
+    X(kClear,       GetTextureContextId)                               \
+    X(kClear,       GetSamplingResolutionGeneration)                   \
+    X(kClear,       GetTextureBindGeneration)                          \
+    X(kClear,       GetMaxTouchedTextureUnit)                          \
+    X(kClear,       GetImageTextureBinding)                            \
+    /* kBlitOrCopy */                                                  \
+    X(kBlitOrCopy,  GetFramebufferBindingSlot)                         \
+    X(kBlitOrCopy,  IsCapabilityEnabled)                               \
+    X(kBlitOrCopy,  GetScissorBox)                                     \
+    X(kBlitOrCopy,  IsTransformFeedbackActive)                         \
+    X(kBlitOrCopy,  IsTransformFeedbackPaused)                         \
+    X(kBlitOrCopy,  GetRenderStateParameters)                          \
+    X(kBlitOrCopy,  GetRenderStateParametersVersion)                   \
+    X(kBlitOrCopy,  GetViewport)                                       \
+    X(kBlitOrCopy,  GetActiveTextureUnit)                              \
+    X(kBlitOrCopy,  GetTextureUnitObject)                              \
+    X(kBlitOrCopy,  GetTextureContextId)                               \
+    X(kBlitOrCopy,  GetSamplingResolutionGeneration)                   \
+    X(kBlitOrCopy,  GetTextureBindGeneration)                          \
+    X(kBlitOrCopy,  GetMaxTouchedTextureUnit)                          \
+    X(kBlitOrCopy,  GetImageTextureBinding)                            \
+    X(kBlitOrCopy,  GetColorMaskIndexed)                               \
+    X(kBlitOrCopy,  GetDepthMask)                                      \
+    X(kBlitOrCopy,  GetStencilState)                                   \
+    /* Magma's shader blit to the default framebuffer                            */ \
+    /* (TryBlitToDefaultFramebufferWithShader) is a real draw of a backend-owned  */ \
+    /* helper program: it sets the dynamic viewport through ApplyGLViewportState  */ \
+    /* -> ComputeGLViewport (viewport 0 and its depth range), picks the pipeline's */ \
+    /* provoking vertex through GetOrCreateBlitPipeline -> SelectProvokingVertexMode, */ \
+    /* and binds the helper's descriptors through BindProgramUniformBuffers, whose  */ \
+    /* buffer-block resolvers read the frontend binding points.                    */ \
+    X(kBlitOrCopy,  GetViewportIndexed)                                \
+    X(kBlitOrCopy,  GetDepthRangeIndexed)                              \
+    X(kBlitOrCopy,  GetProvokingVertexMode)                            \
+    X(kBlitOrCopy,  GetBufferBindingPoint)                             \
+    /* kTextureOp */                                                   \
+    X(kTextureOp,   GetActiveTextureUnit)                              \
+    X(kTextureOp,   GetTextureUnitObject)                              \
+    X(kTextureOp,   GetImageTextureBinding)                            \
+    X(kTextureOp,   GetTextureContextId)                               \
+    X(kTextureOp,   GetSamplingResolutionGeneration)                   \
+    X(kTextureOp,   GetTextureBindGeneration)                          \
+    X(kTextureOp,   GetMaxTouchedTextureUnit)                          \
+    /* Magma's GenerateMipmap materialises the texture's queued clear before it    */ \
+    /* blits (MaterializePendingClearForTexture -> PreCompensateSrgbClearColor,    */ \
+    /* which reads GL_FRAMEBUFFER_SRGB), and a depth texture takes the shader path */ \
+    /* (GenerateDepthMipmapWithShader -> BindProgramUniformBuffers), whose sampler */ \
+    /* resolver reads the draw framebuffer for the feedback-loop check and whose   */ \
+    /* buffer-block resolvers read the frontend binding points.                    */ \
+    X(kTextureOp,   IsCapabilityEnabled)                               \
+    X(kTextureOp,   GetFramebufferBindingSlot)                         \
+    X(kTextureOp,   GetBufferBindingPoint)                             \
+    /* kReadback */                                                    \
+    X(kReadback,    GetPixelStoreParameters)                           \
+    X(kReadback,    GetBufferBindingSlot)                              \
+    X(kReadback,    GetFramebufferBindingSlot)                         \
+    X(kReadback,    GetActiveTextureUnit)                              \
+    X(kReadback,    GetTextureUnitObject)                              \
+    X(kReadback,    GetClampReadColor)                                 \
+    X(kReadback,    IsCapabilityEnabled)                               \
+    X(kReadback,    GetRenderStateParameters)                          \
+    X(kReadback,    GetRenderStateParametersVersion)                   \
+    X(kReadback,    GetViewport)                                       \
+    X(kReadback,    GetTextureContextId)                               \
+    X(kReadback,    GetSamplingResolutionGeneration)                   \
+    X(kReadback,    GetTextureBindGeneration)                          \
+    X(kReadback,    GetMaxTouchedTextureUnit)                          \
+    X(kReadback,    GetImageTextureBinding)                            \
+    /* The depth/stencil read emulation draws (ScopedEmulationDrawState,          */ \
+    /* DirectGLES.cpp) and pauses an active capture around its own draw, so a      */ \
+    /* readback reads the transform-feedback state exactly as a draw does.         */ \
+    X(kReadback,    IsTransformFeedbackActive)                         \
+    X(kReadback,    IsTransformFeedbackPaused)                         \
+    /* kXfbSpan */                                                     \
+    X(kXfbSpan,     GetTransformFeedbackProgram)                       \
+    X(kXfbSpan,     GetBufferBindingPoint)                             \
+    X(kXfbSpan,     GetTouchedBufferBindingPointCount)                 \
+    X(kXfbSpan,     GetTransformFeedbackCapturedVertices)              \
+    X(kXfbSpan,     IsTransformFeedbackActive)                         \
+    X(kXfbSpan,     IsTransformFeedbackPaused)                         \
+    X(kXfbSpan,     GetTransformFeedbackGeneration)                    \
+    X(kXfbSpan,     GetBoundTransformFeedbackLifetimeId)               \
+    /* kProgramOp: ShaderStorageBlockBinding syncs Espryt's render state and textures */ \
+    X(kProgramOp,   GetRenderStateParameters)                          \
+    X(kProgramOp,   GetRenderStateParametersVersion)                   \
+    X(kProgramOp,   GetViewport)                                       \
+    X(kProgramOp,   IsCapabilityEnabled)                               \
+    X(kProgramOp,   GetFramebufferBindingSlot)                         \
+    X(kProgramOp,   GetTextureUnitObject)                              \
+    X(kProgramOp,   GetTextureContextId)                               \
+    X(kProgramOp,   GetSamplingResolutionGeneration)                   \
+    X(kProgramOp,   GetTextureBindGeneration)                          \
+    X(kProgramOp,   GetMaxTouchedTextureUnit)                          \
+    X(kProgramOp,   GetImageTextureBinding)                            \
+    /* kQuery: Magma's transform feedback query end reads the paused counter */ \
+    /* (DirectVulkan.cpp); every other verb in the class reads nothing and */   \
+    /* its fill is a serial bump                                          */   \
+    X(kQuery,       GetTransformFeedbackPausedPrimitiveCounter)
+
+// clang-format on

MobileGL/MG_Pipe/MGPipe.h

@@ -0,0 +1,98 @@
+// MobileGL - MobileGL/MG_Pipe/MGPipe.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <Includes.h>
+
+#include "MGPipeCallbacks.h"
+#include "MGPipeHandles.h"
+#include "MGPipeHostSpan.h"
+#include "MGPipeTypes.h"
+
+// The MGPipe boundary (plan B section 4).
+//
+// The two interface tables are FUNCTION-POINTER STRUCTS, not virtual bases. Three reasons
+// out of this repository rather than out of gallium: the boundary already is a
+// function-pointer struct sitting on one hook point in MG_Backend/Init.cpp; a nullptr entry
+// already means "not implemented, frontend falls back", which is exactly what a
+// not-yet-migrated subsystem needs to say while it keeps pulling; and MG_Test already
+// substitutes this table to mock a backend. The rare EGL and caps surface stays on
+// pActiveBackendObject's virtual functions.
+namespace MobileGL::MG_Pipe {
+    // Unscoped on purpose: PipeCalls.def spells these as bare tokens so the same file can
+    // be read by the C++ preprocessor and by scripts/gen_pipe.py.
+    enum MGPipeCallClass : Uint8 {
+        kScreen,
+        kCtxCso,
+        kCtxState,
+        kCtxObject,
+        kCtxVerb,
+        kCtxQuery,
+        kCallClassCount,
+    };
+
+    enum MGPipeCallFlags : Uint32 {
+        kNone = 0,
+        // The caller must not proceed until the server has acknowledged. Rare by design.
+        kNeedsAck = 1u << 0,
+        // Carries an MGPBlobRef.
+        kHasBlob = 1u << 1,
+        // Carries a variable-length array after the fixed payload.
+        kVarTail = 1u << 2,
+        // Carries an MGHostSpan - the one shape that changes with the transport.
+        kHostSpan = 1u << 3,
+        // Answers into an MGPReplySlot; never blocks.
+        kReplySlot = 1u << 4,
+        // May be null in a backend's table. A null entry is a real answer ("this backend
+        // does not implement it"), not an error: DirectVulkan deliberately leaves
+        // buffer_subdata_resident unregistered, and SetSwapInterval likewise.
+        kOptional = 1u << 5,
+    };
+
+    // The pipeline/dynamic split of RenderStateParameters, defined exactly once (section
+    // 4.5.2). Generated by G7 from the field list ComputePipelineStateHash already hashes;
+    // MGPipeRenderStateSpans.cpp and the setter-consistency test land with P2, which is
+    // when the chunk table can be filled with real offsets.
+    struct MGPipeRenderStateSpans;
+
+    // The catalogue itself. Only macros, so it is safe to expand inside the namespace, and
+    // consumers (the unit test, later the transport) get MGP_CALL_LIST from this header.
+#include "PipeCalls.def"
+
+    // G1: the two interface tables. A null entry means "not implemented" (section 4.1).
+#include "generated/PipeTables.inc"
+
+    // The installed tables. Zero-initialized, so an un-installed MGPipe is every entry
+    // null - which is precisely the pre-migration state.
+    inline MGPipeScreen gMGPipeScreen{};
+    inline MGPipeContext gMGPipeContext{};
+
+    // G2: monolith thunks. These are what MG_Impl call sites move onto, replacing
+    // gBackendFunctionsTable.GL.* one name at a time.
+#include "generated/PipeThunks.inc"
+
+    // G3: wire records, their size assertions, and the applier's bounds precondition.
+#include "generated/PipeWire.inc"
+
+    // G4: the MOBILEGL_PIPE_VERIFY field-wise comparators.
+#include "generated/PipeVerify.inc"
+
+    // G5: PipeInputs field ids and the per-verb poison generations.
+#include "generated/PipeFilled.inc"
+
+    // G5b: the verb enum (one per GLFunctionsTable entry), the verb classes and their
+    // may-read field masks - what MGPipeFillForVerb fills and what a poison build lets a
+    // verb read (FillPoints.def).
+#include "generated/PipeFillPoints.inc"
+
+    // G6: the backend read inventory's coverage table.
+#include "generated/PipeCoverage.inc"
+
+    // G7: the render-state pipeline subset, by member name.
+#include "generated/PipeSpanTable.inc"
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Pipe/MGPipeCallbacks.h

@@ -0,0 +1,61 @@
+// MobileGL - MobileGL/MG_Pipe/MGPipeCallbacks.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <Includes.h>
+
+#include "MGPipeHandles.h"
+#include "MGPipeTypes.h"
+
+// The backend -> frontend reverse channel, named (plan B section 7.1).
+//
+// Today this traffic is 95 call sites across 17 methods poked directly into frontend
+// objects. gallium has no vocabulary for shadow writeback, GPU-write notification, texture
+// re-send requests or default-framebuffer geometry, because in Mesa the state tracker and
+// the driver share an address space. Naming them as ten callbacks plus one forward
+// terminator (MGPipeContext::ResourceSubDataComplete) is the deliberate deviation (D8).
+//
+// Installed at context creation. In a monolith these are direct calls; under split they are
+// records on the reverse channel, and their ORDER is a correctness requirement rather than
+// an optimization (section 7.4).
+namespace MobileGL::MG_Pipe {
+    struct MGPipeCallbacks {
+        // A driver-detected GL error that only the server could have seen.
+        void (*OnGlError)(Uint32 code);
+        // Ranges of a resource the GPU wrote; retires MarkGpuWritten.
+        void (*OnGpuWritten)(MGPipeHandle res, Uint rangeCount, const MGPRange* ranges);
+        void (*OnBufferWriteback)(MGPipeHandle res, Uint64 offset, MGPBlobRef bytes);
+        void (*OnTextureWriteback)(MGPipeHandle res, const MGPBox* box, MGPBlobRef bytes);
+        // The one new stall class in this design (D-B6): the server recast a texture and
+        // needs its texels back. The client answers with zero or more ResourceSubData
+        // records terminated by ResourceSubDataComplete carrying the same pullSerial.
+        void (*OnTexturePullRequest)(MGPipeHandle res, Uint16 target, Uint16 firstLevel, Uint16 levelCount,
+                                     Uint64 pullSerial);
+        // SHAPE ONLY, never bytes: the client owns the CPU shadow and allocates the levels
+        // itself.
+        void (*OnMipLevelsGenerated)(MGPipeHandle res, Uint16 base, Uint16 count);
+        // Retires the layering inversion where the swapchain writes into MG_Impl's
+        // pDefaultFramebufferInfo.
+        void (*OnSurfaceChanged)(const MGPSurfaceInfo* info);
+        void (*OnCapsInvalidated)();
+        // <= WARN is lossy, >= ERROR is lossless and rate limited.
+        void (*OnLog)(Uint8 level, const char* text);
+        // The XFB scatter is a read-modify-write of the CLIENT's shadow, so the server
+        // hands back the packed scratch and the client scatters (section 7.2.1).
+        void (*OnXfbScatterReady)(MGPipeHandle scratch, Uint64 packedStride, Uint64 vertices);
+    };
+
+    // Ten, and the count is asserted so an eleventh cannot be added without touching the
+    // transport's reverse-channel record table.
+    inline constexpr SizeT kMGPipeCallbackCount = 10;
+    static_assert(sizeof(MGPipeCallbacks) == kMGPipeCallbackCount * sizeof(void (*)()),
+                  "MGPipeCallbacks gained or lost a callback");
+
+    // Null-initialized: a backend that installs nothing sends nothing.
+    inline MGPipeCallbacks gMGPipeCallbacks{};
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Pipe/MGPipeHandles.h

@@ -0,0 +1,98 @@
+// MobileGL - MobileGL/MG_Pipe/MGPipeHandles.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <Includes.h>
+
+// MGPipe object identity (plan B section 4.2).
+//
+// A handle is a {slot, gen} pair minted by the CLIENT and never by the server: no create_*
+// call in the catalogue returns a server-cast handle, which is the deliberate deviation
+// from gallium (D1) that lets the whole catalogue be remoted with ZERO creation round
+// trips.
+//
+// Slots are dense and allocated PER KIND, so the server's object table is an array rather
+// than a hash map. The allocator is a free list plus a high-water mark and has nothing to
+// do with MG_State's IndexGenerator - that container's LIFO name reuse is the very problem
+// {slot, gen} exists to close.
+namespace MobileGL::MG_Pipe {
+    enum class MGPipeKind : Uint8 {
+        None = 0,
+        Buffer = 1,
+        Texture,
+        Renderbuffer,
+        Framebuffer,
+        Xfb,
+        RenderStateCso,
+        VertexElementsCso,
+        SamplerCso,
+        SamplerViewCso,
+        ShaderCso,
+        Fence,
+        Query,
+        Context,
+        KindCount,
+    };
+
+    // 8 bytes, POD, passed by value in a register pair.
+    //
+    // Gen increments only when a SLOT IS REUSED - never on a respecify - so {slot, gen} is
+    // unique until the same slot has been recycled 2^32 times. That bound is documented
+    // rather than defended at runtime in release builds: at one recycle per frame at
+    // 1000 fps a single slot would take ~50 days of continuous churn to wrap, and the
+    // debug allocator asserts on the wrap.
+    //
+    // Two generations exist in this design and they are strictly separate (section 4.2.2):
+    // this one is the CLIENT's answer to "is this still the same GL object", while MGGen is
+    // the SERVER's own epoch for "did I recast my driver object". Interface rule: no MGPipe
+    // call may require the client to supply or know MGGen.
+    struct MGPipeHandle {
+        Uint32 Slot;
+        Uint32 Gen;
+
+        friend constexpr Bool operator==(const MGPipeHandle& a, const MGPipeHandle& b) {
+            return a.Slot == b.Slot && a.Gen == b.Gen;
+        }
+    };
+
+    static_assert(sizeof(MGPipeHandle) == 8, "MGPipeHandle is the 8-byte {slot, gen} pair");
+    static_assert(alignof(MGPipeHandle) == 4, "MGPipeHandle must not gain padding on the wire");
+    static_assert(std::is_trivially_copyable_v<MGPipeHandle>);
+
+    // Reserved handles (section 4.2.1).
+    //   {0, 0} is null for every kind.
+    //   {0, 1} of kind Framebuffer is the DEFAULT framebuffer. It exists so the four
+    //   pDefaultFramebufferInfo->defaultFBO identity comparisons in DirectGLES retire into
+    //   an ordinary handle compare.
+    inline constexpr MGPipeHandle kMGPipeNullHandle{0, 0};
+    inline constexpr MGPipeHandle kMGPipeDefaultFramebuffer{0, 1};
+
+    inline constexpr Bool MGPipeHandleIsNull(const MGPipeHandle& handle) {
+        return handle.Slot == 0 && handle.Gen == 0;
+    }
+
+    // Slot 0 of every kind is reserved (null, and the default framebuffer for kind
+    // Framebuffer), so a real allocation starts at 1.
+    inline constexpr Uint32 kMGPipeFirstAllocatableSlot = 1;
+
+    // ShaderCso slot space. The top 1/16 of it is reserved for PROGRAM PIPELINE COMPOSITES
+    // (section 5.6.3): a composite is minted client-side out of the stage programs bound to
+    // a pipeline object, and the server never learns it is a composite - it is just another
+    // ShaderCso. Reserving a band rather than a flag keeps the composite resolver's
+    // lifetime bookkeeping out of the ordinary program slot allocator.
+    inline constexpr Uint32 kMGPipeShaderCsoSlotLimit = 1u << 20;
+    inline constexpr Uint32 kMGPipeShaderCsoCompositeSlotBase =
+        kMGPipeShaderCsoSlotLimit - (kMGPipeShaderCsoSlotLimit >> 4);
+
+    inline constexpr Bool MGPipeIsCompositeShaderSlot(Uint32 slot) {
+        return slot >= kMGPipeShaderCsoCompositeSlotBase && slot < kMGPipeShaderCsoSlotLimit;
+    }
+
+    static_assert(kMGPipeShaderCsoCompositeSlotBase > kMGPipeFirstAllocatableSlot,
+                  "the composite band must not swallow the ordinary program slots");
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Pipe/MGPipeHostSpan.h

@@ -0,0 +1,57 @@
+// MobileGL - MobileGL/MG_Pipe/MGPipeHostSpan.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <Includes.h>
+
+// The ONE thing in MGPipe whose shape changes with the transport (plan B section 4.5.7).
+//
+// Monolith: Ptr addresses the frontend shadow or the application's own memory and the
+// accessor is one predictable branch. Split: Ptr is null and the bytes live in a staging
+// segment named by Seg/Offset, or - for the index bytes a server-side primitive-restart
+// rewrite or multi-draw flattening consumes - in the server's own index host mirror, which
+// costs no wire traffic at all (D-B7).
+namespace MobileGL::MG_Pipe {
+    // Seg sentinels. Anything else is a real SEG_STAGE id assigned by the transport.
+    inline constexpr Uint32 kMGHostSpanSegNone = 0;
+    // "The bytes are already on your side": the server reads them out of the index host
+    // mirror it maintains for every resource created with the ELEMENT_ARRAY bind bit while
+    // kCapNeedsHostIndexBytes is set. When the mirror is over budget the tracker degrades
+    // to per-draw staging and counts the bytes in index-bytes-shipped.
+    inline constexpr Uint32 kMGHostSpanSegFromServerIndexMirror = 0xFFFFFFFFu;
+
+    struct MGHostSpan {
+        // Field order is chosen so the struct is 32 bytes with natural alignment on both a
+        // 64-bit and a 32-bit host: the pointer and the two 32-bit words fill the first
+        // 16-byte block either way.
+        const void* Ptr;
+        Uint32 Seg;
+        Uint32 Pad0;
+        Uint64 Size;
+        Uint64 Offset;
+    };
+
+    static_assert(sizeof(MGHostSpan) == 32, "MGHostSpan is the 32-byte host-bytes descriptor");
+    static_assert(std::is_trivially_copyable_v<MGHostSpan>);
+
+    // Split-mode resolution needs the transport's segment table, which does not exist in a
+    // monolith build; the hook is a weak-ish indirection installed by MG_Remote when it is
+    // compiled in. In P0 there is no transport, so a span that names a segment resolves to
+    // null and every caller is still on the monolith branch.
+    using MGPipeSegmentResolver = const void* (*)(Uint32 seg, Uint64 offset, Uint64 size);
+    inline MGPipeSegmentResolver gMGPipeSegmentResolver = nullptr;
+
+    // One predictable branch on the hot path.
+    inline const void* MGPipeHostBytes(const MGHostSpan& span) {
+        if (span.Ptr != nullptr) {
+            return static_cast<const Uint8*>(span.Ptr) + span.Offset;
+        }
+        if (gMGPipeSegmentResolver == nullptr) return nullptr;
+        return gMGPipeSegmentResolver(span.Seg, span.Offset, span.Size);
+    }
+} // namespace MobileGL::MG_Pipe

MobileGL/MG_Pipe/MGPipeTypes.h

@@ -0,0 +1,807 @@
+// MobileGL - MobileGL/MG_Pipe/MGPipeTypes.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <Includes.h>
+
+#include "MGPipeHandles.h"
+#include "MGPipeHostSpan.h"
+
+// Every MGPipe payload (plan B section 4.5). Each one is a flat POD with explicit padding,
+// carries a static_assert on trivial copyability and one on its exact size, and never
+// contains a pointer: MGHostSpan, the one shape that changes with the transport, only ever
+// rides in a variable tail (draw_vbo's user indices, set_shader_buffers' named-UBO bytes),
+// never inline in a fixed payload.
+//
+// Sizes are asserted rather than merely documented because the wire records generated from
+// these structs (generated/PipeWire.inc) are memcpy'd; a field silently changing width is a
+// protocol break that no test would otherwise see.
+//
+// P0.5 DEBT, half repaid. The MG_State half is gone: ResidualValueBlock's
+// RenderStateParameters and PixelStoreParameters now come from MGPipeValueTypes.h, so
+// this header no longer reaches RenderState.h (its closure still touches TextureEnum.h,
+// through BackendObject.h, for the reason in the next sentence). What remains is MGPCaps embedding
+// MG_Backend's DynamicBackendParameters - deliberate, the caps block IS that struct
+// (section 4.4.1) - and that one include is what still keeps purity gate A (section
+// 10.3) off this header; the gate asserts MGPipeValueTypes.h instead. The caps block
+// needs fixed-width members before it can move (a type change, not a move): P1/P7.
+#include <MG_Backend/BackendObject.h>
+#include "MGPipeValueTypes.h"
+
+namespace MobileGL::MG_Pipe {
+    using MG_Backend::DynamicBackendParameters;
+    // Both live directly in namespace MobileGL and, since P0.5, are declared in
+    // MG_Pipe/MGPipeValueTypes.h.
+    using MobileGL::PixelStoreParameters;
+    using MobileGL::RenderStateParameters;
+
+    // A payload must be memcpy-able and its size must be an exact, stated number.
+#define MGP_ASSERT_POD(T, Size)                                                                                        \
+    static_assert(std::is_trivially_copyable_v<T>, #T " must be trivially copyable");                                  \
+    static_assert(sizeof(T) == (Size), #T " changed size; update the wire format and this assertion")
+
+    // ---------------------------------------------------------------------------------
+    // Shared primitives
+    // ---------------------------------------------------------------------------------
+
+    // A run of bytes in the command stream's blob area. Monolith: Seg is
+    // kMGHostSpanSegNone and Offset is an address into the caller's staging arena. Split:
+    // Seg names a transport segment.
+    struct MGPBlobRef {
+        Uint64 Offset;
+        Uint64 Size;
+        Uint32 Seg;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPBlobRef, 24);
+
+    struct MGPRange {
+        Uint64 Offset;
+        Uint64 Size;
+    };
+    MGP_ASSERT_POD(MGPRange, 16);
+
+    // Destination box in the level's own coordinate system (section 4.5.6).
+    struct MGPBox {
+        Int32 X, Y, Z;
+        Uint32 W, H, D;
+    };
+    MGP_ASSERT_POD(MGPBox, 24);
+
+    // Where an asynchronous answer lands. Every server query in this catalogue is
+    // async-with-handle; none of them blocks (section 4.4.6, "the total rule").
+    struct MGPReplySlot {
+        Uint64 Id;
+    };
+    MGP_ASSERT_POD(MGPReplySlot, 8);
+
+    // One contiguous run of RenderStateParameters bytes. The pipeline/dynamic split is
+    // defined exactly once, in MGPipeRenderStateSpans, and generated by G7 from the field
+    // list VulkanRenderer::ComputePipelineStateHash already hashes (section 4.5.2).
+    struct MGPStateChunk {
+        Uint16 Offset;
+        Uint16 Length;
+    };
+    MGP_ASSERT_POD(MGPStateChunk, 4);
+
+    // The payload of every call that carries nothing but an object identity.
+    struct MGPHandleOnly {
+        MGPipeHandle Handle;
+        Uint32 Kind; // MGPipeKind, widened for a stable wire size
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPHandleOnly, 16);
+
+    // ---------------------------------------------------------------------------------
+    // Screen: caps, resources, fences
+    // ---------------------------------------------------------------------------------
+
+    // Capability bits that replace "is this table slot null" as an implicit feature probe
+    // (section 4.4.1). The five ownership-switch bits of v1 are deliberately absent: what
+    // they tried to express - who performs primitive-restart rewriting and multi-draw
+    // flattening - is not expressible as a capability (D-B7).
+    enum MGPCapBit : Uint64 {
+        kCapNone = 0,
+        kCapViewportArray = 1ull << 0,
+        kCapFloat64VertexAttrib = 1ull << 1,
+        kCapResidentSubData = 1ull << 2,
+        kCapCpuXfbPrimitiveAccounting = 1ull << 3,
+        kCapTimerQuery = 1ull << 4,
+        kCapOcclusionQuery = 1ull << 5,
+        kCapXfbPrimitivesQuery = 1ull << 6,
+        // The server rewrites restart indices / flattens multi-draws itself and therefore
+        // needs the index bytes on its side: under split this arms the index host mirror
+        // (D-B7).
+        kCapNeedsHostIndexBytes = 1ull << 7,
+        // The server packs named uniform blocks into its own ring and therefore needs the
+        // host bytes of a set_shader_buffers(Uniform) range (D-B8).
+        kCapNeedsHostUboBytes = 1ull << 8,
+    };
+
+    struct MGPCaps {
+        // The ~90 flat scalars the backends already publish, by inclusion rather than by
+        // restatement: a caps field added there must not need a second edit here. This is
+        // also where the six per-axis compute limits (MaxComputeWorkGroupCount/Size) ride -
+        // the only indexed answers the device owns, and therefore the only ones that outlive
+        // the GetIntegeri_v table entry (see the PipeCalls.def footer).
+        DynamicBackendParameters Dynamic;
+        Uint64 CallMask; // MGPCapBit
+        // The two halves that are not flat PODs travel as blobs: the format capability
+        // cache holds Vector<Int> sample-count lists, and the renderer strings are
+        // Strings. Their serializers land with the transport (P5).
+        MGPBlobRef FormatCapabilities;
+        MGPBlobRef RendererInfo;
+    };
+    static_assert(std::is_trivially_copyable_v<MGPCaps>, "MGPCaps must be trivially copyable");
+    // Stated as a COMPOSITION rather than a literal: DynamicBackendParameters still carries
+    // SizeT fields, so its literal size is ABI-dependent until P0.5 moves the caps block
+    // into MGPipeValueTypes.h with fixed-width members. The assertion still fires on any
+    // padding introduced between the members below.
+    static_assert(sizeof(MGPCaps) == sizeof(DynamicBackendParameters) + 8 + 24 + 24,
+                  "MGPCaps gained padding or a member; update the wire format");
+
+    // Discriminated resource descriptor: buffers, every texture target and renderbuffers
+    // share one create/respecify shape (section 4.5.1).
+    struct MGPResourceDesc {
+        MGPipeHandle Resource;
+        Uint8 Target;      // Buffer | Tex1D..TexCubeArray | Tex2DMS.. | Renderbuffer | TexBuffer
+        Uint8 StorageKind; // == TextureStorageType (Mipmap | Buffer)
+        // VERTEX|INDEX|CONSTANT|SHADER_BUFFER|INDIRECT|SAMPLER|SHADER_IMAGE|RENDER_TARGET|
+        // DEPTH_STENCIL|STREAM_OUTPUT|ATOMIC|ELEMENT_ARRAY. The ELEMENT_ARRAY bit is the
+        // D-B7 switch: with kCapNeedsHostIndexBytes set the server mirrors this resource.
+        Uint16 BindMask;
+        Uint32 InternalFormat; // already resolved to an uncompressed fallback by the client
+        Uint32 Width, Height, Depth;
+        Uint16 ArrayLayers, Levels, Samples;
+        Uint8 FixedSampleLocations, Immutable;
+        Uint32 Usage;        // BufferUsage
+        Uint32 StorageFlags; // glBufferStorage flags
+        Uint8 HasDefinedContent;  // false after a NULL-data respecify
+        Uint8 ImageBindableHint;  // client-side everImageBound; pre-emptive allocation
+        Uint16 Pad0;
+        // Diagnostics only. A GL name is NEVER an identity, never a memo key and never part
+        // of a content hash (section 4.2.1). Widened from the plan's two bytes, which
+        // cannot hold one.
+        Uint32 GlNameForDiag;
+        Uint32 Pad1;
+        MGPipeHandle ViewOf;             // storage owner for a texture view
+        MGPipeHandle BufferForTexBuffer; // texture-buffer backing store
+        Uint64 BufOffset, BufSize;       // kWholeBuffer == ~0, resolved live
+    };
+    MGP_ASSERT_POD(MGPResourceDesc, 88);
+    inline constexpr Uint64 kMGPipeWholeBuffer = ~0ull;
+
+    struct MGPFenceWait {
+        MGPipeHandle Fence;
+        Uint64 TimeoutNs;
+    };
+    MGP_ASSERT_POD(MGPFenceWait, 16);
+
+    struct MGPQueryDesc {
+        MGPipeHandle Query;
+        Uint32 Kind;   // GL query target
+        Uint32 Stream; // indexed query stream, 0 otherwise
+    };
+    MGP_ASSERT_POD(MGPQueryDesc, 16);
+
+    struct MGPQueryResultRequest {
+        MGPipeHandle Query;
+        Uint8 Wait; // the two-value contract of GetSyncStatus is preserved verbatim
+        Uint8 Pad0[3];
+        Uint32 Pad1;
+    };
+    MGP_ASSERT_POD(MGPQueryResultRequest, 16);
+
+    // query_timestamp: glGetInteger64v(GL_TIMESTAMP), the synchronous "what time is it on the
+    // GPU" GLFunctionsTable::GetGpuTimestampNs answers today. The request names nothing; the
+    // Int64 nanosecond stamp comes back through the reply slot.
+    struct MGPTimestampRequest {
+        Uint32 Reserved;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPTimestampRequest, 8);
+
+    // ---------------------------------------------------------------------------------
+    // CSOs
+    // ---------------------------------------------------------------------------------
+
+    // create_render_state carries ONLY the pipeline subset's chunk bytes. chunkMask lets an
+    // incremental create send just the chunks that moved, against baseCso (section 4.5.2).
+    struct MGPRenderStateDesc {
+        MGPipeHandle Cso;
+        MGPipeHandle BaseCso;
+        Uint32 ChunkMask; // all ones for a brand new CSO
+        Uint32 Pad0;
+        MGPBlobRef Blob;
+    };
+    MGP_ASSERT_POD(MGPRenderStateDesc, 48);
+
+    // Steady state: 12 bytes on the wire, no hashing, no blob.
+    struct MGPBindRenderState {
+        MGPipeHandle Cso;
+        Uint16 Version;
+        Uint16 PipelineVersion;
+    };
+    MGP_ASSERT_POD(MGPBindRenderState, 12);
+
+    // The half of the render state that must NOT mint a CSO: viewport, scissor, depth
+    // range, blend colour, line width, polygon offset, stencil ref/write mask, clear
+    // values, sample coverage, hints and the point-size family. This is what keeps
+    // glViewport from evicting Magma's pipeline memo (D-B1).
+    struct MGPDynamicState {
+        Uint32 ChunkMask;
+        Uint16 Version;
+        Uint16 Pad0;
+        MGPBlobRef Blob;
+    };
+    MGP_ASSERT_POD(MGPDynamicState, 32);
+
+    // Both views travel, and neither is derivable from the other: the resolved
+    // VertexAttribute[32] AND the binding points, because a pointer-call stride of 0 means
+    // "element size" while a binding-model stride of 0 means "every vertex reads the same
+    // element" (section 4.5.3). IsLong and Type == Float64 are carried separately.
+    struct MGPVertexElements {
+        MGPipeHandle Cso;
+        Uint32 AttributeCount;
+        Uint32 BindingPointCount;
+        MGPBlobRef Blob; // VertexAttribute[] followed by VertexBufferBindingPoint[]
+    };
+    MGP_ASSERT_POD(MGPVertexElements, 40);
+
+    // SamplerParameters crosses byte for byte INCLUDING borderColorForm: without it the
+    // backend cannot choose between glSamplerParameterIiv and fv, or between the
+    // VkBorderColor families, because all three representations are always numerically
+    // populated (section 4.5.4). Carried as a blob until P0.5 gives it a value header.
+    struct MGPSamplerDesc {
+        MGPipeHandle Cso;
+        MGPBlobRef Parameters;
+    };
+    MGP_ASSERT_POD(MGPSamplerDesc, 32);
+
+    // = pipe_sampler_view, and ONLY the view restrictions. Everything a glTexParameter
+    // writes lives on set_texture_params instead, because a texture that is only an FBO
+    // attachment, only an image binding or only a glCopyImageSubData endpoint has no
+    // sampler view to hang it on (section 4.4.3).
+    struct MGPSamplerView {
+        MGPipeHandle Cso;
+        MGPipeHandle Texture;
+        Uint32 InternalFormat; // aliasing format for glTextureView
+        Uint8 Target;
+        Uint8 Pad0[3];
+        Uint16 MinLevel, NumLevels, MinLayer, NumLayers;
+        Uint16 Samples;
+        Uint8 FixedSampleLocations;
+        Uint8 Pad1;
+    };
+    MGP_ASSERT_POD(MGPSamplerView, 36);
+
+    // Per texture OBJECT, independent of any view.
+    struct MGPTextureParams {
+        MGPipeHandle Res;
+        Uint16 BaseLevel, MaxLevel;
+        Uint8 Swizzle[4];
+        Uint8 DepthStencilMode;
+        // Mirrors m_forceTextureParamsResync: the widened-channel carrier needs a swizzle
+        // override that the frontend params version does not move for.
+        Uint8 ForceResync;
+        Uint8 Pad0[2];
+        Float MinLod, MaxLod, LodBias;
+    };
+    MGP_ASSERT_POD(MGPTextureParams, 32);
+
+    // create_shader_state. The reflection blob is the whole LinkArtifacts + SpirvArtifacts
+    // archive; P0.5 extracts those types out of ProgramObject.h so a server can
+    // deserialize into them without dragging in glslang (section 4.5.5).
+    struct MGPProgramDesc {
+        MGPipeHandle Cso;
+        Uint32 StageMask; // == GetLinkedShaderStages()
+        Uint32 GlobalUboSize;
+        Uint32 ReservedNumSamplesOffset;
+        Uint8 SpirvStatus;
+        Uint8 NativeFloat64;
+        Uint8 PointSizeDemoted;
+        Uint8 EnableSpirvValidation;
+        MGPBlobRef Spirv[6]; // per stage
+        MGPBlobRef Reflection;
+    };
+    MGP_ASSERT_POD(MGPProgramDesc, 192);
+
+    // ---------------------------------------------------------------------------------
+    // set_*
+    // ---------------------------------------------------------------------------------
+
+    // = pipe_surface. internalFormat is INLINE so the four cross-object masks fall out at
+    // push time with no lookup (section 4.5.6).
+    struct MGPSurface {
+        MGPipeHandle Res;
+        Uint32 InternalFormat;
+        Uint8 Kind; // Texture | Renderbuffer | None
+        Uint8 Layered;
+        Uint16 Level;
+        Uint32 Layer;
+        Uint16 UploadTarget;
+        Uint16 Pad0;
+    };
+    MGP_ASSERT_POD(MGPSurface, 24);
+
+    struct MGPFramebufferState {
+        MGPipeHandle Fbo; // kMGPipeDefaultFramebuffer for the default framebuffer
+        MGPSurface Color[8];
+        MGPSurface Depth, Stencil;
+        // The RESOLVED read surface, not an index. This is what structurally closes the
+        // read-buffer-shared-FBO defect class.
+        MGPSurface ReadSurface;
+        Int8 DrawBuffers[8]; // attachment index, -1 = NONE
+        Uint16 Width, Height, Layers, Samples;
+        Uint8 FixedSampleLocations, IsDefault, Complete, Pad0;
+        Uint32 Pad1;
+        // Two jobs (section 4.5.6): the server's render-pass memo key, and the CLIENT's
+        // emission suppressor - an unchanged hash means this record is not sent at all.
+        // The same pattern is mandatory for every kVarTail set_* below, or 26.2's
+        // redundant glBindSampler traffic reappears as a variable-length record per batch.
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPFramebufferState, 304);
+
+    struct MGPVertexBuffer {
+        MGPipeHandle Res;
+        Uint64 Offset;
+        Uint32 Stride;
+        Uint32 Divisor;
+        Uint32 BindingIndex;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPVertexBuffer, 32);
+
+    // Var-tail header: MGPVertexBuffer[Count] follows.
+    struct MGPVertexBuffers {
+        Uint32 Start, Count;
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPVertexBuffers, 16);
+
+    // An independent call, NOT a subset of the VAO configuration version (D5).
+    struct MGPIndexBuffer {
+        MGPipeHandle Res;
+        Uint64 Offset;
+        Uint32 IndexSize;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPIndexBuffer, 24);
+
+    struct MGPIndirectBuffers {
+        MGPipeHandle DrawIndirect;
+        MGPipeHandle Parameter;
+    };
+    MGP_ASSERT_POD(MGPIndirectBuffers, 16);
+
+    // One entry of set_sampler_views. No stage dimension: MobileGL's texture unit space is
+    // MERGED (TextureState::m_textureUnits is one Array of MAX_TEXTURE_IMAGE_UNITS = 192),
+    // and the same unit may be sampled from two stages (section 4.4.3).
+    struct MGPBoundView {
+        MGPipeHandle View;
+        MGPipeHandle Texture;
+        Uint32 Unit;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPBoundView, 24);
+
+    struct MGPSamplerViews {
+        Uint32 Start, Count;
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPSamplerViews, 16);
+
+    // Var-tail header: MGPipeHandle[Count] of sampler CSOs follows.
+    struct MGPSamplerStates {
+        Uint32 Start, Count;
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPSamplerStates, 16);
+
+    struct MGPImageView {
+        MGPipeHandle Res;
+        Uint32 Unit;
+        Uint32 InternalFormat;
+        Uint32 Layer;
+        Uint16 Level;
+        Uint8 Layered;
+        Uint8 Access;
+    };
+    MGP_ASSERT_POD(MGPImageView, 24);
+
+    struct MGPShaderImages {
+        Uint32 Start, Count;
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPShaderImages, 16);
+
+    // One bound buffer range: 24 bytes, no inline host span. The named-UBO host bytes a
+    // backend needs under kCapNeedsHostUboBytes (D-B8) travel as an OPTIONAL second var-tail,
+    // MGHostSpan[HostSpanCount] behind the ranges, announced by MGPShaderBuffers below. An
+    // inline span would have cost every SSBO, atomic-counter and XFB range 32 dead bytes, and
+    // D-B8 says not to freeze that payload's shape before the stage-ubo-named counter has
+    // produced numbers.
+    struct MGPBufferRange {
+        MGPipeHandle Res;
+        Uint64 Offset;
+        Uint64 Size;
+    };
+    MGP_ASSERT_POD(MGPBufferRange, 24);
+
+    // Var-tail header: MGPBufferRange[Count], then MGHostSpan[HostSpanCount]. HostSpanCount is
+    // 0, or Count for the Uniform class under kCapNeedsHostUboBytes (a range with nothing to
+    // ship carries an empty span, so the two arrays stay index-aligned).
+    struct MGPShaderBuffers {
+        Uint32 Class; // Uniform | ShaderStorage | AtomicCounter
+        Uint32 Start;
+        Uint32 Count;
+        Uint32 WritableMask;
+        Uint32 HostSpanCount; // 0, or Count when the kHostSpan tail is present (D-B8)
+        Uint32 Pad0;
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPShaderBuffers, 32);
+
+    // Var-tail header: MGPBufferRange[Count] then Uint32 offsets[Count].
+    struct MGPStreamOutputTargets {
+        Uint32 Count;
+        Uint32 Pad0;
+        Uint64 Generation;
+        Uint64 ContentHash;
+    };
+    MGP_ASSERT_POD(MGPStreamOutputTargets, 24);
+
+    // Covers the DEFAULT UNIFORM BLOCK only (D6).
+    struct MGPGlobalConstants {
+        MGPipeHandle ShaderCso;
+        Uint32 Version;
+        Uint32 Pad0;
+        MGPBlobRef Blob;
+    };
+    MGP_ASSERT_POD(MGPGlobalConstants, 40);
+
+    // The float/int/uint view is resolved on the CLIENT by ClassifyVertexAttribType.
+    struct MGPAttribValue {
+        Uint32 Location;
+        Uint8 ValueClass; // Float | Int | Uint | Double
+        Uint8 Pad0[3];
+        Uint32 Data[4];
+    };
+    MGP_ASSERT_POD(MGPAttribValue, 24);
+
+    // Var-tail header: MGPAttribValue[popcount(Mask)] follows.
+    struct MGPVertexAttribDefaults {
+        Uint32 Mask;
+        Uint32 Count;
+    };
+    MGP_ASSERT_POD(MGPVertexAttribDefaults, 8);
+
+    // PACK only. There is deliberately no unpack counterpart: nothing on the far side of
+    // the boundary reads unpack state (section 4.6 D5), and the staged-repack upload path
+    // does not even issue glPixelStorei.
+    struct MGPPixelPackState {
+        PixelStoreParameters Pack;
+    };
+    static_assert(std::is_trivially_copyable_v<MGPPixelPackState>);
+    // 28 is what PixelStoreParameters measures: two Bools, two bytes of padding, six Ints.
+    // Asserting against sizeof(PixelStoreParameters) itself was a tautology that could not
+    // notice the value struct changing width under the wire format.
+    static_assert(sizeof(MGPPixelPackState) == 28,
+                  "MGPPixelPackState changed size; update the wire format and this assertion");
+
+    // Also a shader-variant input: both backends bake these into the synthesized
+    // pass-through control stage.
+    struct MGPPatchState {
+        Uint32 Vertices;
+        Uint32 Pad0;
+        Float Outer[4];
+        Float Inner[2];
+        Uint32 Pad1[2];
+    };
+    MGP_ASSERT_POD(MGPPatchState, 40);
+
+    // Migration-only (section 6.3). Every stage removes fields and lowers
+    // MGL_RESIDUAL_BLOCK_SIZE; P13 asserts it is zero, which is the retirement trip wire.
+    //
+    // Layout must be asserted MEMBER BY MEMBER, not only by sizeof: a heterogeneous POD
+    // union is where padding differs across ABIs, and the monolith verify harness is blind
+    // to it because both sides are the same translation unit. G3 emits the offsetof
+    // assertions; under split the block is serialized field-wise rather than memcpy'd.
+    struct ResidualValueBlock {
+        RenderStateParameters RenderState; // until create/bind_render_state + set_dynamic_state land
+        PixelStoreParameters Pack;         // until set_pixel_pack_state lands
+        Uint64 CapabilityBits;
+        Uint32 PatchVertices;
+        Uint32 Pad0;
+        Float PatchOuter[4];
+        Float PatchInner[2];
+        Uint32 Pad1[2];
+    };
+    static_assert(std::is_trivially_copyable_v<ResidualValueBlock>);
+// The retirement ratchet. This number only ever goes DOWN: every stage that lands a real
+// set_* call deletes fields here and lowers it, and P13 replaces it with
+// static_assert(sizeof(ResidualValueBlock) == 0), which stays red until the last field is
+// gone. Shrinking the block without lowering the number, or growing it at all, is a build
+// break - which is the point.
+//
+// Stable across the ABIs MobileGL ships on: every member of RenderStateParameters and
+// PixelStoreParameters is a fixed-width scalar or an array of one, with no pointer and no
+// SizeT.
+#define MGL_RESIDUAL_BLOCK_SIZE 1248
+    static_assert(sizeof(ResidualValueBlock) == MGL_RESIDUAL_BLOCK_SIZE,
+                  "the residual value block changed size; lower MGL_RESIDUAL_BLOCK_SIZE if a field "
+                  "retired, and do not raise it");
+
+    struct MGPResidualValueState {
+        Uint32 Version;
+        Uint32 Pad0;
+        MGPBlobRef Blob;
+    };
+    MGP_ASSERT_POD(MGPResidualValueState, 32);
+
+    // ---------------------------------------------------------------------------------
+    // Transfer
+    // ---------------------------------------------------------------------------------
+
+    // Shape copied from the unpack ring's existing UnpackStagingBlock. The source strides
+    // are CARRIED, not inferred from a pointer comparison: the old
+    // `uploadData == mipData` test cannot survive a split, where the client neither ships
+    // the whole level nor keeps a server-side mirror of it (section 4.5.6).
+    struct MGPSubRegion {
+        Int32 X, Y, Z;
+        Uint32 W, H, D;
+        Uint64 SrcOffset;      // into the blob
+        Uint32 SrcRowStride;   // bytes; 0 = tightly packed (w * bpp)
+        Uint32 SrcSliceStride; // bytes; 0 = tightly packed
+    };
+    MGP_ASSERT_POD(MGPSubRegion, 40);
+
+    // Carries the union box AND the region list so the SERVER picks the upload shape - the
+    // decision belongs on the side that pays the GPU cost. Mali prices texture upload by
+    // JOB COUNT: ~100 sprite rects against one union box measured +6 ms/frame.
+    //
+    // THE BUFFER HALF. With Target == Buffer there is no level and no box, so the destination
+    // byte range rides in the box's first coordinate and first extent: UnionBox.X is the byte
+    // offset, UnionBox.W the byte size, Y = Z = 0, H = D = 1, Level = 0, RegionCount = 0, and
+    // Blob holds exactly Size source bytes. That caps ONE record at a 2^31-1 offset and a
+    // 2^32-1 size; a range beyond either is split by the emitter - the same rule, and at
+    // SEG_STAGE's 32 MiB the far tighter one, that the ring's half-capacity bound already
+    // imposes on it. MGPipeSetSubDataBufferRange / MGPipeSubDataBufferOffset / Size below are
+    // the only spelling of this convention; nothing else reads the box for a buffer.
+    struct MGPSubData {
+        MGPipeHandle Res;
+        Uint16 Target, Level;
+        // Replaces the backend's `uploadData == mipData` pointer comparison: are these
+        // bytes an untransformed level shadow?
+        Uint8 SourceIsVerbatimLevelShadow;
+        Uint8 Pad0[3];
+        MGPBox UnionBox;
+        Uint32 RegionCount; // MGPSubRegion[] in the variable tail
+        Uint32 Pad1;
+        MGPBlobRef Blob;
+    };
+    MGP_ASSERT_POD(MGPSubData, 72);
+
+    // Encodes a buffer byte range into the record's box. False, with the record untouched,
+    // when the range does not fit one record: the emitter has to split it.
+    inline Bool MGPipeSetSubDataBufferRange(MGPSubData& record, Uint64 offset, Uint64 size) {
+        if (offset > 0x7FFFFFFFull || size > 0xFFFFFFFFull) {
+            return false;
+        }
+        record.UnionBox = MGPBox{static_cast<Int32>(offset), 0, 0, static_cast<Uint32>(size), 1, 1};
+        record.Level = 0;
+        record.RegionCount = 0;
+        return true;
+    }
+    inline Uint64 MGPipeSubDataBufferOffset(const MGPSubData& record) {
+        // A negative X is a corrupt record (the encoder never writes one); read as unsigned
+        // it lands above the encodable bound, which the applier's bounds gate refuses.
+        return static_cast<Uint64>(static_cast<Uint32>(record.UnionBox.X));
+    }
+    inline Uint64 MGPipeSubDataBufferSize(const MGPSubData& record) { return record.UnionBox.W; }
+
+    // The forward terminator for a server-initiated texture pull (section 7.1). May carry
+    // zero regions - that is how a pull that needs nothing is answered.
+    struct MGPSubDataComplete {
+        MGPipeHandle Res;
+        Uint16 Target, FirstLevel, LevelCount, Pad0;
+        Uint64 PullSerial;
+    };
+    MGP_ASSERT_POD(MGPSubDataComplete, 24);
+
+    // Carries the application's REAL access flags, not a normalized subset.
+    struct MGPFlushRange {
+        MGPipeHandle Res;
+        Uint64 Offset, Size;
+        Uint32 AccessFlags; // Flags<BufferMappingAccessBit>
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPFlushRange, 32);
+
+    struct MGPReadback {
+        MGPipeHandle Res;
+        Uint64 Offset, Size;
+    };
+    MGP_ASSERT_POD(MGPReadback, 24);
+
+    struct MGPCopyRegion {
+        MGPipeHandle Src, Dst;
+        MGPBox SrcBox;
+        Int32 DstX, DstY, DstZ;
+        Uint16 SrcTarget, DstTarget;
+        Uint16 SrcLevel, DstLevel;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPCopyRegion, 64);
+
+    struct MGPBlit {
+        MGPipeHandle ReadFbo, DrawFbo;
+        Int32 SrcX0, SrcY0, SrcX1, SrcY1;
+        Int32 DstX0, DstY0, DstX1, DstY1;
+        Uint32 Mask;
+        Uint32 Filter;
+    };
+    MGP_ASSERT_POD(MGPBlit, 56);
+
+    // One discriminated record replacing glClear, the four glClearBuffer* and the four
+    // glClearNamedFramebuffer* entry points (section 4.4.4).
+    struct MGPClear {
+        MGPipeHandle Fbo;
+        Uint32 Kind;   // Whole | Color | Depth | Stencil | DepthStencil
+        Int32 DrawBufferIndex;
+        Uint32 BufferMask; // GL_COLOR_BUFFER_BIT etc. for the whole-framebuffer form
+        Uint32 ValueClass; // Float | Int | Uint
+        Uint32 ColorValue[4];
+        Float DepthValue;
+        Int32 StencilValue;
+    };
+    MGP_ASSERT_POD(MGPClear, 48);
+
+    struct MGPMipPlan {
+        MGPipeHandle Res;
+        Uint16 Target, BaseLevel, LevelCount, Pad0;
+    };
+    MGP_ASSERT_POD(MGPMipPlan, 16);
+
+    // read_pixels and get_texture_image share one shape; both answer into a reply slot.
+    struct MGPReadbackInfo {
+        MGPipeHandle Res; // null for read_pixels: the bound read surface answers
+        MGPBox Box;
+        Uint32 Format, Type;
+        Uint16 Target, Level;
+        Uint32 Pad0;
+        Uint64 DstOffset, DstSize;
+    };
+    MGP_ASSERT_POD(MGPReadbackInfo, 64);
+
+    // ---------------------------------------------------------------------------------
+    // Commands
+    // ---------------------------------------------------------------------------------
+
+    enum MGPDrawFlagBit : Uint8 {
+        kDrawHasUserIndices = 1u << 0,
+        kDrawPrimitiveRestart = 1u << 1,
+        kDrawIndicesAreClient = 1u << 2,
+        kDrawHasIndexRange = 1u << 3,
+        kDrawHasXfbCount = 1u << 4,
+    };
+
+    // = pipe_draw_info. Today's twenty draw entry points collapse onto this one call, with
+    // MGPDrawRange[] holding exactly the shape the glMultiDraw* family already has.
+    //
+    // minIndex/maxIndex are computed only on the client-memory array path today, and
+    // xfbCpuCapturedVertices only on the XFB scatter path, so Flags gates the WORK. They
+    // stay in the fixed head; moving them into the variable tail is a wire-format decision
+    // that belongs with the transport (P5), where per-draw byte histograms exist to size
+    // it. userIndices is in the variable tail already, so the VBO path - every Minecraft
+    // and Sodium draw - never pays the 32 bytes of an MGHostSpan.
+    struct MGPDrawInfo {
+        Uint32 Mode;
+        Uint8 IndexSize; // 0 = arrays, else 1 / 2 / 4
+        Uint8 Flags;     // MGPDrawFlagBit
+        Uint16 Pad0;
+        Uint32 InstanceCount, StartInstance;
+        Uint32 RestartIndex;
+        Uint32 DrawIdOffset;
+        MGPipeHandle IndexResource;
+        Uint32 MinIndex, MaxIndex; // ~0 = unknown
+        Uint64 XfbCpuCapturedVertices;
+        Uint32 NumDraws; // MGPDrawRange[] in the variable tail
+        Uint32 Pad1;
+    };
+    MGP_ASSERT_POD(MGPDrawInfo, 56);
+
+    // = pipe_draw_start_count_bias.
+    struct MGPDrawRange {
+        Uint32 Start, Count;
+        Int32 IndexBias;
+    };
+    MGP_ASSERT_POD(MGPDrawRange, 12);
+
+    // Present when the draw is indirect. The client resolves the COUNT itself, so the
+    // server never reads an indirect command block to learn how many draws there are.
+    struct MGPDrawIndirect {
+        MGPipeHandle Buffer;
+        MGPipeHandle ParameterBuffer;
+        Uint64 Offset, ParameterOffset;
+        Uint32 Stride, DrawCount;
+    };
+    MGP_ASSERT_POD(MGPDrawIndirect, 40);
+
+    struct MGPGridInfo {
+        Uint32 GridX, GridY, GridZ;
+        Uint32 BlockX, BlockY, BlockZ;
+        MGPipeHandle IndirectBuffer;
+        Uint64 IndirectOffset;
+        Uint8 IsIndirect;
+        Uint8 Pad0[7];
+    };
+    MGP_ASSERT_POD(MGPGridInfo, 48);
+
+    struct MGPMemoryBarrier {
+        Uint32 Bits; // GLbitfield
+        Uint8 ByRegion;
+        Uint8 Pad0[3];
+    };
+    MGP_ASSERT_POD(MGPMemoryBarrier, 8);
+
+    struct MGPStreamOutputBegin {
+        Uint32 PrimitiveMode;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPStreamOutputBegin, 8);
+
+    // end_stream_output carries the accounting the client owns; the scatter itself is a
+    // read-modify-write of the client's shadow and lives there (section 7.2.1).
+    struct MGPXfbAccounting {
+        Uint64 CapturedVertices;
+        Uint64 PrimitivesWritten;
+        Uint32 PrimitiveMode;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPXfbAccounting, 24);
+
+    struct MGPStreamOutputControl {
+        Uint32 Reserved;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPStreamOutputControl, 8);
+
+    struct MGPFlush {
+        Uint32 Flags;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPFlush, 8);
+
+    struct MGPPresent {
+        Uint64 FrameSerial;
+    };
+    MGP_ASSERT_POD(MGPPresent, 8);
+
+    struct MGPSwapInterval {
+        Int32 Interval;
+        Uint32 Pad0;
+    };
+    MGP_ASSERT_POD(MGPSwapInterval, 8);
+
+    // ---------------------------------------------------------------------------------
+    // Reverse channel payloads (section 7.1)
+    // ---------------------------------------------------------------------------------
+
+    struct MGPSurfaceInfo {
+        Uint32 Width, Height;
+        Uint32 InternalFormat;
+        Uint16 Samples, Layers;
+        Uint8 IsDefault;
+        Uint8 Pad0[7];
+    };
+    MGP_ASSERT_POD(MGPSurfaceInfo, 24);
+
+#undef MGP_ASSERT_POD
+} // namespace MobileGL::MG_Pipe