OpenGL ES: implement compressed texture support.

SwANGLE does not support GL_EXT_texture_compression_s3tc.
However, it does support GL_EXT_texture_compression_dxt1,
GL_ANGLE_texture_compression_dxt3 and GL_ANGLE_texture_compression_dxt5,
which should be sufficient for Dawn's purposes.

Note that sRGB formats may be problematic for OpenGL ES in general,
but ANGLE does support them, so we can satisfy the requirements for
Dawn's texture_compression_bc and exercise the codepaths on ES.

glPixelStorei is not only unsupported for CompressedTexSubImage*D()
but causes asserts in ANGLE and validation errors elsewhere. The fix
is to scope the glPixelStorei() calls to the non-compressed codepath.

Bug: dawn:580
Change-Id: I68fa019eda2aee37a097e697cfc87bcdc28c1f12
Reviewed-by: Austin Eng <>
Reviewed-by: Corentin Wallez <>
Commit-Queue: Stephen White <>
4 files changed
tree: 0bff74acfaebbf0af664e2c62a870a181ba84b37
  1. .clang-format
  2. .gitattributes
  3. .gitignore
  4. .gn
  7. CMakeLists.txt
  9. DEPS
  12. OWNERS
  14. README.chromium
  16. build_overrides/
  17. codereview.settings
  18. dawn.json
  19. dawn_wire.json
  20. docs/
  21. examples/
  22. generator/
  23. infra/
  24. scripts/
  25. src/
  26. third_party/
  27. tools/

Dawn, a WebGPU implementation

Dawn is an open-source and cross-platform implementation of the work-in-progress WebGPU standard. More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL. Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
    • The webgpu.h version that Dawn implements.
    • A C++ wrapper for the webgpu.h.
  • A “native” implementation of WebGPU using platforms' GPU APIs:
    • D3D12 on Windows 10
    • Metal on macOS and iOS
    • Vulkan on Windows, Linux, ChromeOS, Android and Fuchsia
    • OpenGL as best effort where available
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers

Helpful links:

Documentation table of content

Developer documentation:

User documentation: (TODO, figure out what overlaps with the webgpu.h docs)




Apache 2.0 Public License, please see LICENSE.


This is not an officially supported Google product.