BZLZHH
33ff177bb2
First wave of the advertised-extension CTS campaign (targeted caselist: the
glcts groups of every extension both backends advertise, 4867 cases across the
KHR-GL41..46 namespaces). All frontend, shared by both backends:
- Non-square float matrix uniforms actually upload: glUniformMatrix{2x3,3x2,
2x4,4x2,3x4,4x3}fv and the six glProgramUniformMatrix* twins were
validate-only no-ops; they now write column-at-a-time at the global UBO's
16-byte std140 column stride, honouring transpose. glUniformMatrix2fv had
the sibling bug - mat2 written as 4 contiguous floats put column 1 at byte
8 instead of 16. The readback path only ever un-padded mat3, so
glGetUniformfv is fixed for mat2, mat3x2 (previously mis-gathered) and
every non-square shape, with the bounds check widened to the padded span.
- glBindBufferRange validates offset/size at last: size <= 0, offset < 0,
SSBO and UBO offset alignment, transform-feedback offset AND size
multiples of 4 - all before any state write (a negative offset used to
reach Range1D unchecked). glBindBuffersRange inherits per element, with
the ARB_multi_bind up-front [first, first+count) checks added to the
BindBuffersBase/Range and BindSamplers prologues.
- BufferSubData's second, wrong mapped-overlap test deleted (it rejected
every write at or after a mapped range's start, mapped or not); the state
layer's assert relaxed to the same half-open intersection the frontend
checks. BufferStorage error precedence fixed: no-bound-buffer now beats
bad-size/flags.
- glSamplerParameteri accepts the full GL_NEVER..GL_ALWAYS compare-func
range (NEVER/LESS/EQUAL were rejected by a wrong lower bound).
glBindSampler's unit gate uses GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS instead
of the frontend array capacity, shared with glBindSamplers by construction.
- Getters: GL_MAX_SHADER_STORAGE_BLOCK_SIZE in glGetIntegerv; atomic-counter
buffer limits; all 11 per-unit GL_TEXTURE_BINDING_* plus GL_SAMPLER_BINDING
in glGetIntegeri_v; GL_VERTEX_ATTRIB_BINDING/_RELATIVE_OFFSET across the
vertex-attrib query family; glGetFloati_v/glGetDoublei_v implemented (were
stubs); KHR_debug limits raised to spec floors.
- glCreateShader records INVALID_ENUM for an unknown type (it previously
handed out a usable name with no error at all); glCreateShaderProgramv
validates count up front. glDispatchCompute/Indirect validate work-group
counts, offset alignment and indirect-buffer presence.
- glVertexAttribIFormat & friends take a positive integer-type whitelist -
GL_FLOAT/GL_HALF_FLOAT/GL_DOUBLE/GL_FIXED no longer slip through as
integer attributes.
Gate (headless Mesa, default config = async on): 570/570 unit at default and
with the kill switch; ext caselist Espryt 76.29% -> 77.87% (+81 fixed, 6
crashes -> 0, the whole list now runs in one glcts process), Magma 75.94% ->
77.58% (+80 fixed, 0 newly broken); KHR-GL33 full mustpass lost nothing
(9884/9886, the 2 known Mesa-drift failures); retrace smoke clean (the
bsl-GLES miss is the documented golden drift, bit-identical on the pristine
baseline). The 4 DirectGLES direct_state_access.renderbuffers_storage* cases
that turned red are a PRE-EXISTING GL_FRAMEBUFFER_SRGB cross-test leak,
A/B-proven on an unpatched 2e6fc1ff build - wave 1 removed the two accidental
maskers (a crash partition and a failing case whose error path reset the
state). Fixing the leak itself is queued.
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
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_USE_ANGLE |
Load ANGLE EGL/GLES libraries. | 0, 1 |
0 |
MOBILEGL_DISABLE_SUBGROUP |
Disable Vulkan shader subgroup support. | 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_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 |
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.