GL: Support clip and cull distance redeclarations

* Fixed gl_PerVertex qualifier string.
* Updated ValidateClipCullDistanceTraverser to output
redeclared array sizes and maximum constant indices.
* Made DeclarePerVertexBlocks available for non-Vulkan
* Updated DeclarePerVertexBlocks to remove gl_ClipDistance
and gl_CullDistance redeclarations.
* Enabled DeclarePerVertexBlocks for ESSL output when
gl_ClipDistance or gl_CullDistance are redeclared.
* Updated ESSL output to use 3.10 shading language version,
when the context has GL_EXT_clip_cull_distance enabled.
* Updated ESSL output to enable GL_EXT_shader_io_blocks
when gl_ClipDistance or gl_CullDistance are redeclared.
* Updated extension exposure conditions.
* Fixed typos in ParseContext.

Bug: angleproject:7763
Change-Id: Ib87368a1953ad546a407d634d8b00f71cf92c40c
Reviewed-by: Geoff Lang <>
Commit-Queue: Alexey Knyazev <>
Reviewed-by: Shahbaz Youssefi <>
13 files changed
tree: eafb985f1a6b55fb2be2d05eb473911dca8ca14e
  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. .style.yapf
  19. .vpython
  20. .vpython3
  21. .yapfignore
  22. additional_readme_paths.json
  26. codereview.settings
  28. DEPS
  30. dotfile_settings.gni
  32. OWNERS
  34. README.chromium

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 9Direct3D 11Desktop GLGL ESVulkanMetal
OpenGL ES 2.0completecompletecompletecompletecompletecomplete
OpenGL ES 3.0completecompletecompletecompletein progress
OpenGL ES 3.1incompletecompletecompletecomplete
OpenGL ES 3.2in progressin progressin progress

Platform support via backing renderers

Direct3D 9Direct3D 11Desktop GLGL ESVulkanMetal
Mac OS Xcompletein progress
iOSin progress
Chrome OScompleteplanned
GGP (Stadia)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.


ANGLE repository is hosted by Chromium project and can be browsed online or cloned with

git clone


View the Dev setup instructions.