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chromium / angle / angle / chromium/2808
commitc9bde92635e8dfa84961b86192af4ecda90de4d9[log] [tgz]
authorJamie Madill <jmadill@chromium.org>Sun Jul 24 21:58:50 2016
committerCommit Bot <commit-bot@chromium.org>Mon Jul 25 06:18:06 2016
treeb5924c79031ba51c52d5f8ad00d6604ccc6ad2ef
parentce1ed238a5949ddb895e94cb6ae5478b150d97a8 [diff]
D3D11: Allow gl_PointCoord when not rendering points.

ANGLE D3D11 uses a geometry shader to expand points into quads.
This led to an edge case with gl_PointCoord. When the user references
gl_PointCoord in the fragment shader but renders with GL_TRIANGLES or
other non-point primitives, gl_PointCoord is undefined, but ANGLE
would produce a link error. This would break some very odd edge-case
shaders (e.g. a shader that is used with both points and triangles).

We can fix this by simply adding a dummy PointCoord value to our
vertex shader is all cases. If the user renders points, we ignore the
PointCoord value passed to the geometry shader. If they render tris
or lines and use PointCoord, the shader signatures will match, and
PointCoord will even have a sane value of (0.5, 0.5).

BUG=angleproject:1380

Change-Id: I322155cd3801d0241cabc9bb639a5aaa502831b3
Reviewed-on: https://chromium-review.googlesource.com/362779
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
3 files changed
tree: b5924c79031ba51c52d5f8ad00d6604ccc6ad2ef
  1. build/
  2. doc/
  3. extensions/
  4. include/
  5. infra/
  6. samples/
  7. scripts/
  8. src/
  9. third_party/
  10. util/
  11. .clang-format
  12. .gitattributes
  13. .gitignore
  14. angle.isolate
  15. angle_on_all_platforms.isolate
  16. AUTHORS
  17. BUILD.gn
  18. codereview.settings
  19. CONTRIBUTORS
  20. DEPS
  21. DEPS.chromium
  22. LICENSE
  23. README.chromium
  24. 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 to desktop OpenGL, Direct3D 9, and Direct3D 11. Support for translation from OpenGL ES 3.0 to all of these APIs is nearing completion, and future plans include enabling validated ES-to-ES support.

Direct3D 9Direct3D 11Desktop GLGL ES
OpenGL ES 2.0completecompletecompleteplanned
OpenGL ES 3.0nearing completionnearing completionplanned
[Level of OpenGL ES support via backing renderers]
Direct3D 9Direct3D 11Desktop GL
Windows***
Linux*
Mac OS Xin progress
[Platform support via backing renderers]

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. For generating a Windows Store version of ANGLE view the Windows Store instructions

Contributing