36c3e0f546
Existing implementation uses single `GlobalMutex` for
- EGL calls
- GL calls for Contexts with concurrent access.
This CL introduces abstract `egl::ContextMutex` with two
implementations:
- SingleContextMutex;
- SharedContextMutex<Mutex>;
Note:
`std::mutex` is used in this commit. It is very easy to change mutex
type either at compile-time or at run-time (single type per Display).
When Context:
- is not Shared;
- does not use `EGLImage`s;
- does not use EGL_DISPLAY_TEXTURE_SHARE_GROUP_ANGLE
- does not use EGL_DISPLAY_SEMAPHORE_SHARE_GROUP_ANGLE
then it will be using `SingleContextMutex` with minimal overhead.
Before such Context is used as `shareContext` or uses `EGLImage`
its mutex replaced by `SharedContextMutex<Mutex>`.
The `GlobalMutex` is only used for EGL calls, while `egl::ContextMutex`
implementations for GL calls. Because some EGL calls use Context,
explicit `egl::ContextMutex` lock is required. This is implemented by
generating "egl_context_mutex_autogen.h" header, and insertion of
`ANGLE_EGL_SCOPED_CONTEXT_LOCK()` macro before `ANGLE_EGL_VALIDATE()`
in each EGL entry point. Implementation in "egl_context_lock_impl.h"
returns lock for required APIs. Special cases of `egl::ContextMutex`
lock handled separately. `std::unique_lock<>` is not used for
performance reasons.
`egl::ContextMutex` explicitly locked when capturing EGL calls.
Fixes EGLImage problem:
|
||
|---|---|---|
| android | ||
| build_overrides | ||
| doc | ||
| extensions | ||
| gni | ||
| include | ||
| infra | ||
| samples | ||
| scripts | ||
| src | ||
| third_party | ||
| tools | ||
| util | ||
| .clang-format | ||
| .gitattributes | ||
| .gitignore | ||
| .gn | ||
| .style.yapf | ||
| .vpython | ||
| .vpython3 | ||
| .yapfignore | ||
| AUTHORS | ||
| Android.mk | ||
| BUILD.gn | ||
| CONTRIBUTORS | ||
| DEPS | ||
| DIR_METADATA | ||
| LICENSE | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.chromium | ||
| README.md | ||
| WATCHLISTS | ||
| additional_readme_paths.json | ||
| codereview.settings | ||
| dotfile_settings.gni | ||
README.md
ANGLE - Almost Native Graphics Layer Engine
The goal of ANGLE is to allow users of multiple operating systems to seamlessly run WebGL and other OpenGL ES content by translating OpenGL ES API calls to one of the hardware-supported APIs available for that platform. ANGLE currently provides translation from OpenGL ES 2.0, 3.0 and 3.1 to Vulkan, desktop OpenGL, OpenGL ES, Direct3D 9, and Direct3D 11. Future plans include ES 3.2, translation to Metal and MacOS, Chrome OS, and Fuchsia support.
Level of OpenGL ES support via backing renderers
| Direct3D 9 | Direct3D 11 | Desktop GL | GL ES | Vulkan | Metal | |
|---|---|---|---|---|---|---|
| OpenGL ES 2.0 | complete | complete | complete | complete | complete | complete |
| OpenGL ES 3.0 | complete | complete | complete | complete | complete | |
| OpenGL ES 3.1 | incomplete | complete | complete | complete | ||
| OpenGL ES 3.2 | in progress | in progress | in progress |
Additionally, OpenGL ES 1.1 is implemented in the front-end using OpenGL ES 3.0 features. This version of the specification is thus supported on all platforms specified above that support OpenGL ES 3.0 with known issues.
Platform support via backing renderers
| Direct3D 9 | Direct3D 11 | Desktop GL | GL ES | Vulkan | Metal | |
|---|---|---|---|---|---|---|
| Windows | complete | complete | complete | complete | complete | |
| Linux | complete | complete | ||||
| Mac OS X | complete | complete | ||||
| iOS | complete | |||||
| Chrome OS | complete | planned | ||||
| Android | complete | complete | ||||
| GGP (Stadia) | complete | |||||
| Fuchsia | complete |
ANGLE v1.0.772 was certified compliant by passing the OpenGL ES 2.0.3 conformance tests in October 2011.
ANGLE has received the following certifications with the Vulkan backend:
- OpenGL ES 2.0: ANGLE 2.1.0.d46e2fb1e341 (Nov, 2019)
- OpenGL ES 3.0: ANGLE 2.1.0.f18ff947360d (Feb, 2020)
- OpenGL ES 3.1: ANGLE 2.1.0.f5dace0f1e57 (Jul, 2020)
ANGLE also provides an implementation of the EGL 1.5 specification.
ANGLE is used as the default WebGL backend for both Google Chrome and Mozilla Firefox on Windows platforms. Chrome uses ANGLE for all graphics rendering on Windows, including the accelerated Canvas2D implementation and the Native Client sandbox environment.
Portions of the ANGLE shader compiler are used as a shader validator and translator by WebGL implementations across multiple platforms. It is used on Mac OS X, Linux, and in mobile variants of the browsers. Having one shader validator helps to ensure that a consistent set of GLSL ES shaders are accepted across browsers and platforms. The shader translator can be used to translate shaders to other shading languages, and to optionally apply shader modifications to work around bugs or quirks in the native graphics drivers. The translator targets Desktop GLSL, Vulkan GLSL, Direct3D HLSL, and even ESSL for native GLES2 platforms.
Sources
ANGLE repository is hosted by Chromium project and can be browsed online or cloned with
git clone https://chromium.googlesource.com/angle/angle
Building
View the Dev setup instructions.
Contributing
-
Join our Google group to keep up to date.
-
Join us on Slack in the #angle channel. You can follow the instructions on the Chromium developer page for the steps to join the Slack channel. For Googlers, please follow the instructions on this document to use your google or chromium email to join the Slack channel.
-
File bugs in the issue tracker (preferably with an isolated test-case).
-
Choose an ANGLE branch to track in your own project.
-
Read ANGLE development documentation.
-
Become a code contributor.
-
Use ANGLE's coding standard.
-
Learn how to build ANGLE for Chromium development.
-
Get help on debugging ANGLE.
-
Go through ANGLE's orientation and sift through starter projects. If you decide to take on any task, write a comment so you can get in touch with us, and more importantly, set yourself as the "owner" of the bug. This avoids having multiple people accidentally working on the same issue.
-
Read about WebGL on the Khronos WebGL Wiki.
-
Learn about the initial ANGLE implementation details in the OpenGL Insights chapter on ANGLE (this is not the most up-to-date ANGLE implementation details, it is listed here for historical reference only) and this ANGLE presentation.
-
Learn about the past, present, and future of the ANGLE implementation in this presentation.
-
Watch a short presentation on the Vulkan back-end.
-
Track the dEQP test conformance
-
Read design docs on the Vulkan back-end
-
Read about ANGLE's testing infrastructure
-
View information on ANGLE's supported extensions
-
If you use ANGLE in your own project, we'd love to hear about it!