Do not track global texture usage in PassResourceUsage.

The global resource usage was used for two things:
 - Validating that the texture had the required usage, but this was
removed in a previous commit in favor of checking the texture's usage at
the encoding entrypoint.
 - Skipping laz-clearing of the texture if it was used as
RenderAttachment. This was incorrect and would skip clearing of all of
the texture's subresource as long as one of them was used as

This commit make PassTextureUsage exactly a
SubresourceStorage<TextureUsage> and fixes the logic for skipping
the clearing or RenderAttachment. It also adds a regression test for the
lazy clearing fix.

Bug: dawn:635
Change-Id: I5d984febb3e5a5f9ae15b632cac68e294555c4e6
Commit-Queue: Corentin Wallez <>
Reviewed-by: Stephen White <>
Auto-Submit: Corentin Wallez <>
13 files changed
tree: ffdc3838650a2d5ec7b9da340f08b4acc6e1cfb8
  1. .clang-format
  2. .gitattributes
  3. .gitignore
  4. .gn
  7. CMakeLists.txt
  9. DEPS
  11. OWNERS
  13. README.chromium
  15. build_overrides/
  16. codereview.settings
  17. dawn.json
  18. dawn_wire.json
  19. docs/
  20. examples/
  21. generator/
  22. infra/
  23. scripts/
  24. src/
  25. third_party/
  26. 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.