swung0x48
519445f946
P3b/P4b R-5 (and R-3's cheap half), landing under the P7 program (PLAN-PH-P34B-P7.md
1.2, wave 2-D package D2).
The rule had SIX statements and nothing compared them, and two of the four prose ones
were wrong in the same way: MG_Pipe/MGPipe.h and MG_Backend/DirectGLES/Managers.h both
said "THREE OF THEM HAVE A DEPENDENCY" (there are six rows) and both said "the mirror
pairs (10 without 11, ...) are all fine" - when 10-without-11 is precisely D-K2's FOURTH
row (ID-14/ID-15), refused by the server and withheld by the client, with PipeFill.cpp
saying so out loud: "The brief's original 'bit 10 without 11 is fine' is WITHDRAWN for
P4a as built." Neither wrong comment could fail anything; Managers.h's copy sits in the
header of the file that implements the refusal.
The rows, once, in MG_Pipe/SubsystemDeps.def (X-macro, FatalFamilies.def's convention),
expanded by MGPipe.h into kMGPipeSubsystemDependencies[] / MGPipeSubsystemRequires() /
MGPipeSubsystemDependenciesAreSet() with four static_asserts. Six rows: 8->7, 9->10,
10->{7,11}, 11->10, 12->none (a ROW, not an absence), 13->7. Bits 8 and 13 are the two
the old comment did not know about; bit 13's row lived fifteen lines further down in the
same header, which is how "THREE OF THEM" survived two phases.
THE TWO READERS DO NOT YET READ IT, deliberately: MG_Impl/Pipe/PipeFill.cpp is the
contract package's file for the whole phase (TextureEmit.h states that rule) and
MG_Backend/DirectGLES/Managers.cpp belongs to wave 2-D package D1 while it is in flight.
Switching them is two one-line changes for the integrator. The anti-drift property does
not wait: MG_Test/Backend/DirectGLES/SubsystemDepsTest.cpp is the first thing in the tree
that calls BOTH readers at the same mask - sweeping the phase constants, the two
documented refusal lanes and one mask per row - and compares each against the .def. It
lives in that binary because that binary links both sides.
Both comparisons are one-directional, each for a measured reason. The server resolvers
also fold in the family's own bit and D-C3's wire-caps refusal, so a resolver may say NO
for its own reasons but never YES where the table refuses. MGPipeP4aFamilyEmits is a
QUADRUPLE and the first version of this case asserted equality and reddened at 0x1fff on
the sampler and program families because a bare unit binary registers no consumer - the
assertion being wrong, not the product, and recorded in the note because the temptation
to assert equality here is strong.
Red-once (R-16), twice: dropping the fourth row from the .def fails at COMPILE time
(MGPipe.h's static_asserts); making the server's ResolveSamplerSubsystemArm stop checking
bit 10 (throwaway, reverted) reds the runtime case and names the mask - 0x9ff, which is
exactly the lane CMakeLists.txt already pins for G12.
R-3's cheap half: CONTRACT-P5.md claimed the image-access, sampler-view-target and
draw-buffer encodings as contract by pointing at package-header LINE RANGES, and all
three had drifted (ImageEmit.h:146-159 no longer holds the encoding at all). All three
rows now state the encoding by enumerator and function name, and the two confusable
siblings are named. The remaining half - MGPSamplerView::Target still has no Count bound,
no ...IsValid and no Fatal for an out-of-range value - is stated in the row rather than
closed, being an MG_Pipe change outside this package's footprint.
Managers.h:690-695's copy of the wrong prose is NOT corrected here: it is package D1's
file, and its two defects are named in notes/p34b/espryt-d2.md so the integrator can take
them in one line.
G1 after this change: pull .text 10822147 = 0xa52203, nm --defined-only identical to
~/w7/p7-before/pull-syms.txt (30570 symbols) - the new inline constexpr table does not
reach the pull build.
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.