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dawn / dawn / 59e7fad99b033da37fc4281d441546d33a236497
commit59e7fad99b033da37fc4281d441546d33a236497[log] [tgz]
authorCorentin Wallez <cwallez@chromium.org>Thu Aug 16 15:32:35 2018 +0200
committerCorentin Wallez <corentin@wallez.net>Mon Aug 20 07:24:55 2018 -0400
tree636cfae240836ea64be852fd721ec8e22a3c9574
parentd273d33a63b9847facdf6b3e4073ffd3cd6f2c28 [diff]
BUILD.gn: Remove use of exec_script

Chromium's BUILD files try to avoid uses of exec_script when possible
because they slow down every GN invocation. In preparation for building
Dawn inside Chromium, the calls to exec_script for the code generator
are removed.

In GN, the generator now outputs a "JSON tarball", a dictionnary mapping
filenames to content. This allows us to use the "depfile" feature of GN
to avoid the exec_script call to gather the script's inputs.

Outputs of the generator are now listed in the BUILD.gn files. To keep
it in sync with the generator, GN outputs a file containing "expected
outputs" that is checked by the code generator.

Finally the dawn_generator GN template doesn't create a target anymore,
but users are expected to gather outputs using get_target_outputs.
3 files changed
tree: 636cfae240836ea64be852fd721ec8e22a3c9574
  1. build_overrides/
  2. examples/
  3. generator/
  4. scripts/
  5. src/
  6. third_party/
  7. .appveyor.yml
  8. .clang-format
  9. .gitignore
  10. .gitmodules
  11. .gn
  12. .travis.yml
  13. AUTHORS
  14. BUILD.gn
  15. CMakeLists.txt
  16. CONTRIBUTING.md
  17. dawn.json
  18. DEPS
  19. LICENSE
  20. OWNERS
  21. README.chromium
  22. 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://github.com/google/nxt-standalone.git 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.

License

Please see LICENSE.

Disclaimer

This is not an officially supported Google product.