Dusk

The Dusk repository contains a series of examples which show usage of the Dawn native API. Each example is designed to be standalone so each example contains copies of all the required code for that example. This should make it easier to determine exactly what code is needed at any given point.

Note, the README.md files in each folder only talk about the new ideas and concepts provided in that example. So, looking at README.md files in earlier examples maybe needed to understand the concepts that were introduced earlier.

This is not an officially supported Google product.

Requirements

• depot_tools
• cmake
• ninja
• clang or gcc

Building

gclient sync --jobs=16
mkdir -p out/Debug
cd out/Debug
CC=clang CXX=clang++ cmake -GNinja ../..
ninja

Setup

Dawn has a lot of dependencies, in order to simplify things this repo is using the gclient command from depot_tools to handle the heavy lifting of checkout out all the needed dependencies.

In order to make gclient happy we require a git repo for our project and it needs to have an commit. Simply doing the following will get things setup for .gclient.

mkdir <project> && cd <project>
git init
touch README.md
git add .
git commit -m 'Initial commit'

Two files are needed for gclient. First copy in .gclient which is the basic gclient setup file. Then, copy in DEPS which is the dependency configuration file.

For our purposes a specific revision of Dawn is chosen (the tip-of-tree commit at random point in time). This is done such that every checkout will get the same version of Dawn and we can upgrade Dawn in a controlled fashion.

The recursedeps section tells gclient to go into the third_party/dawn folder and run the DEPS file found there. This will checkout all of the Dawn dependencies at the correct commit for Dawn (and recursively as needed).

The examples are using CMake for build configuration. The CMake is pretty standard, c++20 is used for a few of the newer features. The only things of note are, adding the third_party/dawn/include directory to the target_include_directories and when linking the executable we add the following to the target_link_libraries:

• webgpu_dawn
• webgpu_cpp
• webgpu_glfw
• glfw

The last two are only needed because GLFW is being used for the window management. If something else is providing the window, and code is written to create the needed surface, the last two libraries can be removed.

Examples

The following examples are provided:

• 01 - Adapter and Device Information
• 02 - Coloured Triangle
• 03 - Using an Index Buffer
• 04 - Rotating Cube

Doc Site

The documentation site is served by GitHub pages. The generate is Jekyll. There are current two parts to the docs site, the C and C++ API generator and the site itself.

C and C++ API Generator

The generator for the C and C++ API is scripts/api_doc_generator.rb. This script reads the dawn.json file in the third_party/dawn folder along with the src/api.yaml file and generates the API documentation.

Warning messages are emitted for items in the dawn.json file which are not found in the api.yaml file. This should help in making sure all the appropriate values are documented, and hopefully catch API changes in dawn.json during future upgrades.

Running the generator should just consist of:

./scripts/api_doc_generator.rb

Jekyll Site

The Jekyll site lives in the docs folder. In order to test the doc changes you'll need to install some RubyGems. This can be done with:

cd docs
bundle install

With the appropriate gems installed, the site can be run by executing (still in the docs folder):

jekyll serve

This should launch the site on localhosts:4000/Dusk/.