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chromium / angle / angle / refs/heads/chromium/3688
commit82fddcb1f3e3daa72b5306fc2d1e324e4c90943c[log] [tgz]
authorShahbaz Youssefi <syoussefi@chromium.org>Fri Jan 18 19:27:43 2019
committerCommit Bot <commit-bot@chromium.org>Tue Jan 29 16:10:50 2019
tree0c383d9f9a79c0da8233f9b30ebef18b215753dc
parent4b2e00f4d1801c6aa00cb58f21c29735eb355bb2 [diff]
Vulkan: Implement GLsync and EGLSync fence syncs

That is required in GLES 3 for GLsync and EGL_KHR_fence_sync and
EGL_KHR_wait_sync (or EGL 1.5) for EGLSync.

The two constructs (GLsync and EGLSync) have similar semantics and share
the implementation on the Vulkan backend.

The implementation of a fence sync object is achieved through the
combined use of a vkEvent and the implicit vkFence inserted at the end
of every submission.  Imagine the following command buffer:

    glDraw      : Draw
    glCreateSync: Set Event  <-- insertion of fence sync
    glDraw      : Draw
                : Signal Fence <-- implicit fence at the end of submission
    glFlush     : Submit

Assume the serial S is associated to this submission.  The following
hold:

- If event is set, the fence sync is signaled
- If S is already finished, the fence sync is signaled
- If client is waiting on the sync and S is not yet flushed, there will
  be a deadlock (unless multi-threaded and another thread performs the
  flush).

The event is used to implement server waits (glWaitSync), as vkEvent is
the only entity the GPU can signal and wait on within the command
buffer.  The wait is inserted in the command graph without incurring a
flush, i.e. the wait can be within the same command buffer as event set.

The event however does not support CPU waits (glClientWaitSync).
vkFence is the only entity the CPU can wait on.  For client wait
therefore, the following algorithm is used:

- If the event is already set, there's no wait  ->  already signaled
- If timeout is zero, there's no wait  ->  timeout expired
- If S is not flushed, flush it to ensure forward progress.
- Wait until S is finished  ->  condition satisfied / timeout expired.

Bug: angleproject:2466
Change-Id: I678995a6139dd9533fa8ad361a3d292b202c52a4
Reviewed-on: https://chromium-review.googlesource.com/c/1422552
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
12 files changed
tree: 0c383d9f9a79c0da8233f9b30ebef18b215753dc
  1. android/
  2. build_overrides/
  3. doc/
  4. extensions/
  5. gni/
  6. include/
  7. infra/
  8. samples/
  9. scripts/
  10. src/
  11. third_party/
  12. tools/
  13. util/
  14. .clang-format
  15. .gitattributes
  16. .gitignore
  17. .gn
  18. additional_readme_paths.json
  19. AUTHORS
  20. BUILD.gn
  21. codereview.settings
  22. CONTRIBUTORS
  23. DEPS
  24. dotfile_settings.gni
  25. LICENSE
  26. OWNERS
  27. PRESUBMIT.py
  28. README.chromium
  29. README.md
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 and 3.0 to desktop OpenGL, OpenGL ES, Direct3D 9, and Direct3D 11. Support for translation from OpenGL ES to Vulkan is underway, and future plans include compute shader support (ES 3.1) and MacOS support.

Level of OpenGL ES support via backing renderers

Direct3D 9Direct3D 11Desktop GLGL ESVulkan
OpenGL ES 2.0completecompletecompletecompletein progress
OpenGL ES 3.0completecompletein progressnot started
OpenGL ES 3.1not startedin progressin progressnot started

Platform support via backing renderers

Direct3D 9Direct3D 11Desktop GLGL ESVulkan
Windowscompletecompletecompletecompletein progress
Linuxcompletein progress
Mac OS Xin progress
Chrome OScompleteplanned
Androidcompletein progress

ANGLE v1.0.772 was certified compliant by passing the ES 2.0.3 conformance tests in October 2011. ANGLE also provides an implementation of the EGL 1.4 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, 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