swung0x48
e460536119
Six pure-state entry points that were stubs or empty // TODO bodies, all backed by new
context state and read back through glGet*.
* glHint: Hint_State was an empty TODO. Store the 4 GL 3.3 core hint targets (LINE_SMOOTH,
POLYGON_SMOOTH, TEXTURE_COMPRESSION, FRAGMENT_SHADER_DERIVATIVE), default GL_DONT_CARE.
Validate target and mode (FASTEST/NICEST/DONT_CARE) -> GL_INVALID_ENUM otherwise. The
compatibility-only targets (GL_PERSPECTIVE_CORRECTION_HINT, GL_POINT_SMOOTH_HINT, GL_FOG_HINT,
GL_GENERATE_MIPMAP_HINT) are rejected. The glGetIntegerv hint cases, previously hardcoded to
GL_DONT_CARE, now read the stored value; glGetBooleanv on a hint is always GL_TRUE.
* glPointParameter{f,i,fv,iv}: the scalar _State bodies were empty TODOs and the *v forms were
stubs. Only the 2 core pnames are accepted: GL_POINT_FADE_THRESHOLD_SIZE (float, default 1.0,
GL_INVALID_VALUE if negative) and GL_POINT_SPRITE_COORD_ORIGIN (GL_LOWER_LEFT/GL_UPPER_LEFT,
default GL_UPPER_LEFT, GL_INVALID_ENUM on a bad value -- note the different error code from the
fade case). The compat pnames (POINT_SIZE_MIN/MAX, POINT_DISTANCE_ATTENUATION) are rejected. All
four forms funnel through one (pname, float) handler. glGetIntegerv(GL_POINT_FADE_THRESHOLD_SIZE)
was hardcoded to 1; it now rounds the stored float, glGetFloatv reads the float directly (keeping
the fractional part), and GL_POINT_SPRITE_COORD_ORIGIN gained a getter case (it had none).
* glPixelStoref: funnels into the existing glPixelStorei state, but converts per type -- boolean
pnames (PACK/UNPACK_SWAP_BYTES/LSB_FIRST) by a zero-test so 0.4 -> TRUE, integer pnames by
round-to-nearest. A blanket round would wrongly turn a fractional true flag into false.
* glGetDoublev: funnels through glGetFloatv and widens, writing exactly the pname's component count
(1/2/4) so a single-component query cannot overrun the caller's buffer. MobileGL stores no native
double state (depth range/clear are float), so widening from float matches its real resolution.
State added to RenderStateParameters + RenderState Set/Get + GLContext wrappers, following the
existing LineWidth/DepthRange pattern. Covered by 4 SanityTest cases (set-then-get round trips, the
core-vs-compat enum rejections, the two different error codes, and the glPixelStoref boolean
zero-test, which was verified to fail against a blanket-round implementation).
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.