Impl 3DTexture copy splitter for empty first row on D3D12 - 2

If the copy region generated from 2D texture copy splitter has an
empty first row due to alignment adjustment and we simply extend
it to all copied depth slices, the copy region will be incorrect
for 3D texture copy.

If there is an empty first row and the copy height is odd, we can
split the copy region into two:
  - copy0: copy the first depth slice
  - copy1: copy the rest depth slices because there is no empty
    row after alignment adjustment

This method resolves the remaining problem when copy height is 1.
It also is an optimization for other odd copy height cases, say
copy height is 3, 5, 7, etc.

This change implements the special situation when the copy region
generated from 2D texture copy splitter has an empty first row and
its copy height is odd.

Bug: dawn:547
Change-Id: Idf4f4a9b87f783c5328463e0f4182429a7e809f1
Reviewed-by: Austin Eng <>
Commit-Queue: Yunchao He <>
2 files changed
tree: 29b2d08649e8eaf447a14bf708b3a7ad547c35fd
  1. .clang-format
  2. .gitattributes
  3. .gitignore
  4. .gn
  5. .vscode/
  8. 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.