swung0x48 3c2867d34d [MG_Backend, scripts, docs] (P7): in a disaggregated build the monolith arm blits and mips with the baked modules, and the ratchet's p7-magma bucket falls to 88
CONTRACT-P7 §5.2's (B'), which §4.2 needs.

WHAT MOVES. In a disaggregated build the monolith arm now drives the SAME baked
modules the wire arm does:
  * InitializeBlitResources / InitializeDepthMipmapResources return true - there is
    nothing to build on any transport;
  * TryBlitToDefaultFramebufferWithShader turns its two BlitImageBindings into
    WireImages and calls BlitWireColorToDefault (WireColorBlit.inc);
  * GenerateDepthMipmapWithShader loops GenerateWireDepthMipLevel
    (WireDepthMipmap.inc) and hands the image back in the finalLayout its caller
    promised;
  * GetOrCreateBlitPipeline, the three GLSL strings, the eight kHidden* ids and the
    frontend members of BlitResources / DepthMipmapResources compile out.
The `#else` is the pull build's code, statement for statement.

WHY AN `#if` AND NOT A RUNTIME BRANCH - this is the whole of §4.2. P5f fv already
gave both initializers a non-monolith early return, and the ratchet counted the
symbols anyway, because a reference is a reference whether or not the branch runs.
And the MEMBER has to go with the construction: a SharedPtr member's destructor is
itself a reference to ~ProgramObject.

THE BUCKET TABLE (scripts/link_ratchet.py --bucket, build-split):

  bucket             before   after   a6
  p6-core                11      11    6
  p7-magma              101      88  101
  p3b-p4b-espryt         13      18   14
  both-backends          61      56   60
  total                 186     173  184

p3b-p4b-espryt's +5 is not a regression: those five MOVED out of both-backends
because DirectVulkan stopped referring to them and only DirectGLES still does.
Thirteen symbols went away outright, and they are exactly the three classes §4.2
names: ProgramObject::{AllocateLifetimeId, AttachShader, Link, ~ProgramObject},
SamplerObject::{SetLodRange, SetWrapR, SetWrapS, SetWrapT} and
ShaderObject::{Compile, DropCompileNode, JoinPendingCompile, ReleaseCompileNode,
SetShaderSource}. Re-baselined in this commit with --write-baseline; the 7 `# P13`
annotations carried over.

§4.2's "down to 0" DOES NOT HOLD, and the gap is not (B') left half-done - it is
that 88 of the 101 were never about the hidden programs. 62 come from
UniformManager.cpp.o and 14 more from VkSamplerManager.cpp.o: the MONOLITH
descriptor binder and sampler cache reading the application's own GL texture and
sampler objects (TextureObjectBase 35, TextureObjectWithOneMipmap 20 with its
vtable and typeinfo, SamplerObject's fourteen getters). Under a transport
SetupDraw branches to SetupWireDraw and not one of those lines runs - but that
branch is a RUNTIME one, which ID-P7-5 deliberately leaves to the optimisation
phase. notes/p7/magma-b2.md §4.3 names all eleven referring-object groups and what
each is.

NONE OF THEM IS ANNOTATED `# P13`, on purpose: that mark is for a symbol that
cannot fall without moving pull `.text`, and nothing above has shown that.
UniformManager's and VkSamplerManager's monolith arms are pull-build code, and
`#if`-ing them is the same operation this commit performed on VulkanRenderer.cpp.
They are wave 3's work, not P13's boundary problem, and marking them P13 early
would record an untried thing as a tried-and-impossible one.

Gates: integration-gpu 1705 (every monolith `DirectVulkan.` entry is in there),
integration-magma-split 93, -spawn 72, -tcp 74, integration-magma-full-split 524,
ctest -L unit 2423, all green; fatal_census 79 abort sites / 44 family words / 0
unmarked; spawn_lane_parity green; link_ratchet --assert-monotone unchanged at 173
against the re-baselined file, and --self-test OK.

RETRACE, which is this slice's load-bearing reading because the monolith arm
changed implementation: OpenRA.DirectVulkan (monolith) ssim 1.000000,
mismatchPixels 0, twice; OpenRA.DirectVulkan.SPLIT ssim 1.000000, 0. The whole
DirectVulkan matrix is 39/40 monolith and 38/39 split, and both reds are the SAME
case, minecraft-1.21.4-fabric-iris-iterationrp-in-world (ssim 0.027915), which is
PRE-EXISTING - it fails identically on ~/w7/p7-magma-b (this branch's parent),
because it needs CONTRACT-P7 §2.4's three iterationRP knobs and those are exported
by the CI job rather than by the ctest entry.

G1 pull .text 0xa52203, nm --defined-only identical to p7-before/pull-syms.txt
(30570 lines, 0 diffs).

Device debt: the monolith arm in the Android disaggregated package now runs the
baked blit, and its ROTATE_90/180/270 geometry has never executed - every surface
on this host is IDENTITY. notes/p7/magma-b2.md §5 lists it with the package's three
other device items.
2026-09-22 18:29:22 -04:00

MobileGL

C++ GNU LGPL 3.0 Development

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:

  1. MG_State — state tracking and management logic for Graphics APIs.
  2. MG_Impl — front-end implementations of Graphics APIs that interact with MG_State and MG_Backend.
  3. 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).
  4. MG_Util and other utility modules.

Third-party components

MobileGL reuses several open-source projects:

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_State and MG_Impl for OpenGL 4.2 (Core Profile)
    • Direct (Vulkan) backend
    • Direct (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:

  1. Clone the repository:

    git clone https://github.com/MobileGL-Dev/MobileGL.git
    
  2. Initialize and update all submodules recursively:

    git submodule update --init --recursive
    
  3. Follow glslang’s own documentation for its required initiation.

  4. Configure and build the project with CMake:

    cmake -B build
    cmake --build build
    

    or do it in a modern way:

    cmake -S . -B build -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
    cmake --build build
    

    Alternatively, 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_Test and MG_Benchmark can 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.

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