swung0x48
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Completes the uniform-block reflection chain: glGetUniformIndices, glGetActiveUniformName and glGetActiveUniformBlockiv were already implemented; glGetActiveUniformsiv was the last stub. Supports all 8 GL 3.3 Core pnames: * GL_UNIFORM_TYPE / SIZE / NAME_LENGTH / BLOCK_INDEX / OFFSET / ARRAY_STRIDE come straight from glslang's TObjectReflection (the same reflection the existing uniform queries use). * GL_UNIFORM_IS_ROW_MAJOR from the member's TType layout qualifier, guarded by isMatrix() so a scalar in a layout(row_major) block does not wrongly report 1. * GL_UNIFORM_MATRIX_STRIDE is derived: glslang exposes no matrix stride, so it is computed from the std140 rule (each column/row vector rounded up to a vec4), which matches the std140 layout MobileGL's SPIR-V path emits. Evaluates to 16 for every GL 3.3 float matrix. The -1-vs-0 distinction is handled explicitly: OFFSET / ARRAY_STRIDE / MATRIX_STRIDE / BLOCK_INDEX return -1 for a default-block uniform (glslang gives arrayStride 0 there, so it is gated on block membership), while ARRAY_STRIDE / MATRIX_STRIDE return 0 for a non-array / non-matrix member that IS in a block. Errors: GL_INVALID_VALUE for uniformCount<0, any index >= active uniform count, or a never-generated program name; GL_INVALID_OPERATION for a live shader name; GL_INVALID_ENUM for an unaccepted pname (e.g. the GL 4.2 GL_UNIFORM_ATOMIC_COUNTER_BUFFER_INDEX). All validation runs before any write, so params is untouched on error. There is no "not linked" error -- an unlinked program has zero active uniforms, so any index raises GL_INVALID_VALUE. Also fix GetActiveUniformArraySize, which returned glslang's TObjectReflection.size verbatim: that field only carries the element count for a non-block array and reports 1 for a block array member, so GL_UNIFORM_SIZE (and glGetActiveUniform's size out-param, and glGetProgramResourceiv's GL_ARRAY_SIZE) wrongly reported 1 for an array inside a UBO. Take the count from the TType instead, which is authoritative for both cases. Covered by 3 ProgramTest cases (std140 block with scalar/array/mat4 + a default-block sampler, a row_major variant, and the six error cases) that link real shaders and assert every pname value.
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 3.3 (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 3.3 (Core Profile). - Current development focus:
MG_StateandMG_ImplforOpenGL 3.3 (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 |
VK_ICD_FILENAMES |
Select the Vulkan ICD used by the Vulkan loader. | Path to an ICD JSON file | Loader default |
Notice
- MobileGL is not production-ready currently.
- Some
OpenGL 3.3 (Core Profile)features are still missing or under development.
License
This project is distributed under GNU LGPL v3.0. See the LICENSE file in the repository for detailed information.