swung0x48
f1b04edfc6
CONTRACT-P7 §3.2's `vertex-layout` and `vertex-format-conversion` rows.
BuildWireVertexInput answered eight different conditions with one `false`, and the single
caller answered that with a P7-marked MagmaWireFatal. So a Magma split session that met a
GL_FIXED array, a dvec on a device with native fp64, or any format without
VK_FORMAT_FEATURE_VERTEX_BUFFER_BIT did not decline the draw: it killed the process. The
monolith arm on the same device has always masked the attribute out and then declined the
draw loudly and once.
The split is by what the reason is ABOUT, not by severity. `buffer-window` is a statement
about the RECORD - an enabled attribute the program reads whose slot lies outside the
window set_vertex_buffers published - so it stays a named Fatal through the hook; it is
what caught the Redmi VAO hash collision fixed in 376c04be. Every other reason is a
statement about what Vulkan can express on this device, and those now set
unsupportedAttribMask and continue, with the monolith arm's own pre-flight in WireDraw.inc
declining the draw when a masked bit is one the program actually reads.
The contract says "the other six"; there are seven. `offset-overflow` post-dates the
audit's count and is an arithmetic guard rather than a shape one. It is masked with the
rest: an attribute whose base offsets cannot be added is one Vulkan cannot fetch, the
monolith arm never computes that sum at all, and masking is strictly safer than a Fatal
for a number no application can reach on purpose.
unsupportedAttribMask now enters the wire layout hash, for the reason the monolith entry's
hash already carries it: two VAOs can otherwise agree on every binding, attribute and
divisor and differ only in which enabled attribute was masked, and a blind hash would hand
one of them the other's pipeline. Omitting it was safe only while the mask was always zero.
vertex-format-conversion becomes a decline for a narrower reason: the converter is only
ever asked for a conversion BuildWireVertexInput already chose, so a refusal means the two
disagree - a defect on this side, not a peer's malformed record.
@P7 census: 15 sites / 4 files -> 13 / 3. Renderer/WireDraw.inc leaves the list entirely.
fatal_census.py unchanged at 79 abort sites / 43 family words / 0 unmarked, as expected:
wave 0 already funnelled these, so retiring a MagmaWireFatal CALL moves no abort count.
New MagmaVertexLayoutScenario, DirectVulkan only (Espryt hands GL_FIXED to a driver that
supports it, so the same name would assert a different fact there). DataType::Fixed32 has
no arm in ToVkVertexFormat at all, which makes it the one unmappable shape reachable on
host lavapipe - §2.5 records that no other P7-marked refusal is. One case has the program
READ the array and asserts the draw declines; the other leaves it enabled but unread and
asserts the draw lands, which is what stops the first being satisfied by "decline every
draw that mentions GL_FIXED". Registered on all three transports and picked up by the
ambient monolith DirectVulkan discovery, so the A/B is direct.
RED-ONCE: `format-map` put back on the protocol verdict reds the three split arms with
`Subprocess aborted` / `Fatal{UnmigratedVerb, "Magma:vertex-layout-buffer-window"}` while
the monolith control stays green - exactly the divergence this closes. Restored: 10/10.
The gating Magma lanes grow with the new entries: split 73 -> 75, spawn 52 -> 54, tcp
54 -> 56. Growth only.
Open for the integrator: the honest family word for buffer-window is ProtocolCorruption,
and MGPipeFatalFamily carries only UnmigratedVerb and RoleViolation. Adding a third costs
a row there plus an adapter arm, and §3.3 keeps the three Magma funnels on UnmigratedVerb
deliberately so the refusal census stays comparable to P5b. Flagged, not decided.
MobileGL
A desktop OpenGL implementation
MobileGL is a free and open-source project that implements a desktop OpenGL API. The goal is to provide a complete desktop OpenGL implementation with a state management layer and multi-backend support.
Note
Status: In development. Parts of the codebase are incomplete. Current short-term target: OpenGL 4.2 (Core Profile).
Project positioning
MobileGL is an implementation of a desktop OpenGL library. It aims to provide:
- Full OpenGL state management.
- A front-end that exposes OpenGL functions.
- Multiple independent backend implementations, where each backend targets a specific graphics API and remains fully isolated from others.
This project is intended as an implementation/translation layer.
Key components
The repository is organized into following top-level modules:
- MG_State — state tracking and management logic for Graphics APIs.
- MG_Impl — front-end implementations of Graphics APIs that interact with
MG_StateandMG_Backend. - MG_Backend — per-backend translation layer that maps front-end Graphics APIs' semantics and state into concrete backend API calls (e.g. OpenGL ES, Vulkan).
- MG_Util and other utility modules.
Third-party components
MobileGL reuses several open-source projects:
- SPIRV-Cross by KhronosGroup - Apache License 2.0: github
- glslang by KhronosGroup - Various Licenses: github
- DiligentCore by Diligent Graphics - Apache License 2.0: github
- flat_hash_map by Malte Skarupke - Boost Software License 1.0: github
Refer to each component's repository for exact license texts. Any bundled third-party code in this repository is included under the upstream project's license.
Compatibility & target
- Short-term target:
OpenGL 4.2 (Core Profile). - Current development focus:
- Performance improvement
MG_StateandMG_ImplforOpenGL 4.2 (Core Profile)Direct (Vulkan)backendDirect (OpenGL ES)backend
Build Instructions
We currently provide no releases and no precompiled binaries.
If you want to try the project right now, you’ll need to build it yourself:
-
Clone the repository:
git clone https://github.com/MobileGL-Dev/MobileGL.git -
Initialize and update all submodules recursively:
git submodule update --init --recursive -
Follow glslang’s own documentation for its required initiation.
-
Configure and build the project with CMake:
cmake -B build cmake --build buildor do it in a modern way:
cmake -S . -B build -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ cmake --build buildAlternatively, you can use platform-specific build commands as needed.
Build For macOS
On macOS, MobileGL can be built as a dylib that exposes the normal OpenGL/CGL/NSOpenGL entry points and routes them to the DirectVulkan backend. This is useful for running applications such as Minecraft through their stock GLFW/LWJGL OpenGL path while MobileGL is injected before context creation.
Prerequisites:
- macOS with Clang and Ninja.
- Vulkan loader and MoltenVK installed. With Homebrew, the MoltenVK ICD is commonly located at
/opt/homebrew/etc/vulkan/icd.d/MoltenVK_icd.json.
Configure and build:
cmake -S . -B build-macos-magma \
-G Ninja \
-DCMAKE_BUILD_TYPE=Release \
-DMOBILEGL_BACKEND_TYPE=DirectVulkan \
-DMOBILEGL_BUILD_TEST=OFF \
-DMOBILEGL_BUILD_BENCHMARK=OFF
cmake --build build-macos-magma --target MobileGL -j8
The dylib will be generated at:
build-macos-magma/libMobileGL.dylib
To run Minecraft by MobileGL from a launcher like PrismLauncher, keep the stock LWJGL/GLFW natives and add a wrapper command to the instance settings:
env DYLD_INSERT_LIBRARIES=/absolute/path/to/MobileGL/build-macos-magma/libMobileGL.dylib MOBILEGL_BACKEND_TYPE=DirectVulkan VK_ICD_FILENAMES=/opt/homebrew/etc/vulkan/icd.d/MoltenVK_icd.json
Also make sure the JVM arguments include:
-XstartOnFirstThread
DYLD_INSERT_LIBRARIES must be active before GLFW creates its OpenGL context. After startup, the Minecraft F3 screen should report MobileGL and the Direct (Vulkan) backend if the injection worked.
Build Options
| Option | Description | Default |
|---|---|---|
MOBILEGL_BUILD_TEST |
Build MobileGL tests (requires Clang) | ON |
MOBILEGL_BUILD_BENCHMARK |
Build MobileGL benchmarks (requires Clang) | ON |
MOBILEGL_FORCE_RELEASE_OPT |
Enable O3 and LTO in Debug build | ON |
MOBILEGL_ENABLE_TRACY |
Enable Tracy profiler for performance analysis | OFF |
Notes:
- The project requires C++23.
MG_TestandMG_Benchmarkcan only be built with Clang, not GCC. To enforce Clang, add-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++to your command.- On Android, tests and benchmarks are always disabled.
Environment Variables
MobileGL supports runtime configuration via environment variables.
Supported Keys
| Variable | Description | Allowed Values | Default |
|---|---|---|---|
MOBILEGL_BACKEND_TYPE |
Select active backend implementation at startup. | DirectGLES, DirectVulkan |
DirectGLES |
MOBILEGL_DISABLE_TIMERQUERY |
Disable GPU timer-query exposure and use. | 0, 1 |
0 |
MOBILEGL_ESPRYT_USE_ANGLE |
Load ANGLE EGL/GLES libraries. | 0, 1 |
0 |
MOBILEGL_MAGMA_DISABLE_SUBGROUP |
Disable Vulkan shader subgroup support. | 0, 1 |
0 |
MOBILEGL_ADVERTISE_FP64 |
Advertise GL_ARB_gpu_shader_fp64. GLSL double/dvec/dmat compile and run either way - they are narrowed to 32 bits - so this only changes whether an application is told it has 64-bit precision, which it does not. |
0, 1 |
0 |
MOBILEGL_MAGMA_R11G11B10F_FALLBACK |
Use Magma's R11G11B10F format fallback. | 0, 1 |
0 |
MOBILEGL_MAGMA_FRAMESINFLIGHT |
Set Magma frames in flight. | Integer 1–64 |
3 |
MOBILEGL_ESPRYT_AVOID_SAMPLER_MIPMAP_MIN_FILTER |
Avoid sampler mipmap minification filters. | 0, 1 |
0 |
MOBILEGL_COHERENT_AS_FLUSH |
Treat persistent GL_MAP_FLUSH_EXPLICIT_BIT maps as coherent (app-compat for engines like Flywheel that never flush them). |
0, 1 |
0 |
MOBILEGL_ESPRYT_FORCE_DS_READBACK_EMULATION |
Always emulate depth/stencil glReadPixels/glGetTexImage by shader sampling on Espryt, instead of using the driver's own depth/stencil readback where it has one. |
0, 1 |
0 |
VK_ICD_FILENAMES |
Select the Vulkan ICD used by the Vulkan loader. | Path to an ICD JSON file | Loader default |
License
This project is distributed under GNU LGPL v3.0. See the LICENSE file in the repository for detailed information.