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dawn / dawn / 4408b7f20c405b098bd68436076fc89e306eced1
commit4408b7f20c405b098bd68436076fc89e306eced1[log] [tgz]
authorStephen White <senorblanco@chromium.org>Thu Nov 01 13:59:19 2018 +0000
committerCommit Bot service account <commit-bot@chromium.org>Thu Nov 01 13:59:19 2018 +0000
tree55022cb6f2da490c4c88747fccb7e2b7a19df6aa
parent61791eae36b8155219f6217b64b28eb4f54e3396 [diff]
D3D12 fix for register binding offsets.

When both the vert and frag shaders have a UBO binding, the D3D12
backend was using register offset 0 for both, causing a collision,
and the wrong constant value used in one of the shaders.

The fix is to use the binding offsets computed by the BindGroupLayout,
since they know about all of the bindings, not just the ones computed
for each shader. This made it necessary to defer shader compilation
until pipeline layout creation time (as is done in the Metal backend
for similar reasons).

Finally, those bindings offsets computed by the BGL include an offset
for the CBV, UAV and SRV subgroups, so we must add the same register
offset when assigning the BaseShaderRegister to the descriptor ranges
in the PipelineLayout constructor so that they match.

Bug: dawn:20

Change-Id: I18287bf1c06f06dd61288e12da64752f54634466
Reviewed-on: https://dawn-review.googlesource.com/c/1960
Reviewed-by: Stephen White <senorblanco@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Stephen White <senorblanco@chromium.org>
7 files changed
tree: 55022cb6f2da490c4c88747fccb7e2b7a19df6aa
  1. build_overrides/
  2. examples/
  3. generator/
  4. infra/
  5. scripts/
  6. src/
  7. third_party/
  8. .clang-format
  9. .gitignore
  10. .gn
  11. AUTHORS
  12. BUILD.gn
  13. codereview.settings
  14. CONTRIBUTING.md
  15. dawn.json
  16. DEPS
  17. LICENSE
  18. OWNERS
  19. PRESUBMIT.py
  20. README.chromium
  21. README.md
README.md

Dawn, a WebGPU implementation

Dawn (formerly NXT) is an open-source and cross-platform implementation of the work-in-progress WebGPU standard. It exposes a C/C++ API that maps almost one-to-one to the WebGPU IDL and can be managed as part of a larger system such as a Web browser.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
  • A “native” implementation of WebGPU using platforms' GPU APIs:
    • D3D12 on Windows 10
    • Metal on OSX (and eventually iOS)
    • Vulkan on Windows, Linux (eventually ChromeOS and Android too)
    • OpenGL as best effort where available
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers

Directory structure

  • dawn.json: description of the API used to drive code generators.
  • examples: examples showing how Dawn is used.
  • generator: code generator for files produces from dawn.json
    • templates: Jinja2 templates for the generator
  • scripts: scripts to support things like continuous testing, build files, etc.
  • src:
    • common: helper code shared between core Dawn libraries and tests/samples
    • dawn_native: native implementation of WebGPU, one subfolder per backend
    • dawn_wire: client-server implementation of WebGPU
    • include: public headers for Dawn
    • tests: internal Dawn tests
      • end2end: WebGPU tests performing GPU operations
      • unittests: unittests and by extension tests not using the GPU
        • validation: WebGPU validation tests not using the GPU (frontend tests)
    • utils: helper code to use Dawn used by tests and samples
  • third_party: directory where dependencies live as well as their buildfiles.

Building Dawn

Dawn uses the Chromium build system and dependency management so you need to [install depot_tools] and add it to the PATH. Then get the source as follows:

# Clone the repo as "dawn"
git clone https://dawn.googlesource.com/dawn dawn && cd dawn

# Bootstrap the gclient configuration
cp scripts/standalone.gclient .gclient

# Fetch external dependencies and toolchains with gclient
gclient sync

Then generate build files using gn args out/Debug or gn args out/Release. A text editor will appear asking build options, the most common option is is_debug=true/false; otherwise gn args out/Release --list shows all the possible options.

Then use ninja -C out/Release to build dawn and for example ./out/Release/dawn_end2end_tests to run the tests.

Contributing

Please read and follow CONTRIBUTING.md. Dawn doesn‘t have a formal coding style yet, except what’s defined by our clang format style. Overall try to use the same style and convention as code around your change.

If you find issues with Dawn, please feel free to report them on the bug tracker.

License

Please see LICENSE.

Disclaimer

This is not an officially supported Google product.