swung0x48
10315e71f3
- MobileGL/MG_Test/Wire, 42 gtest cases in five binaries, ctest label `unit`, registered only when MOBILEGL_BUILD_DISAGGREGATED is ON so the default configuration is untouched. - FdPassingTest is the one the earlier branch could not have had: it forks a child that creates a shared segment, fills 64 KiB with a pattern and hands the descriptor over SCM_RIGHTS; the parent adopts it, maps it read-only and compares every byte. Everything in Feat/CS-Delta-IPC ran in one process, which is why `out->fd = -1` survived unnoticed. It also pins that a too-small sideband buffer is refused before the datagram is consumed (so no descriptor is dropped), that an empty sideband still carries its fd, and that a receive with no offer times out. The `spawn` SocketDoorbell is covered in the same file because it rides the same kind of socket: a parked waiter woken through NotifyIfParked, a clean timeout, and a wakeup that arrives before anyone parks being remembered and then consumed exactly once. - RingTest: control-page size/alignment/cache-line layout, a non-power-of-two capacity refused, payload alignment, 200 records driven through a 256-byte ring so the wrap filler path runs repeatedly and no record ever straddles the boundary, backpressure (full ring refuses, applied alone frees nothing, retired frees), a record larger than the ring refused, the generation bump refused while records are in flight and accepted once quiesced, a corrupt header refused instead of dispatched, and a 20000-record two-thread producer/consumer run checking order, content and the final cursor equality. - FramingTest: byte-at-a-time reassembly of two frames, the magic reading "MGLF" on the wire, empty payloads, a bad magic and an oversized length each latching the reader dead (the old code hung silently instead), the send-side cap, and the buffer-too-small contract keeping the message so the retry still finds it. - InProcessTransportTest: both directions, ordering, buffer-too-small, poll and timeout, shutdown draining queued messages before it closes, a blocked receiver woken by a send and by a shutdown, the frame cap, descriptor hand-off with its sideband, and three condvar doorbell cases - a parked waiter woken through NotifyIfParked, an already-true condition that must never park, and a clean timeout. - ProtocolSmokeTest: a Hello built and read back through the committed generated header, a Welcome carrying the four segment announcements, the same buffer travelling across the transport unchanged, a truncated buffer failing verification rather than being read, and the CtrlMsg / SegmentKind / LogLevel / FatalCode tag values frozen - they are wire numbers, so if that test has to be edited the schema change was a wire break. - CI: a `flatc-check` job in test.yml that checks out only the flatbuffers submodule, builds the pinned flatc through scripts/gen_protocol.py into the runner temp directory, regenerates and runs `git diff --exit-code` on protocol_generated.h. It needs no MobileGL build, so it does not depend on build-linux (plan B section 8.1 / earlier section 7.1: the committed header plus a CI regeneration check, and no flatc in the default build graph). - Verified: `ctest -L unit` is green in both configurations - 1382 cases with the option OFF and 1424 with it ON (the same 1382 plus these 42); the nm gate is 0 matches OFF and 93 ON; regeneration of protocol_generated.h is byte-identical, and the flatc-check gate goes red on a hand-edited header and green again after a clean regeneration.
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.