This repository contains the implementation of Dawn, which is itself composed of two main libraries (dawn_native and dawn_wire), along with support libraries, tests, and samples. Dawn makes heavy use of code-generation based on the dawn.json
file that describes the native WebGPU API. It is used to generate the API headers, C++ wrapper, parts of the client-server implementation, and more!
dawn.json
: contains a description of the native WebGPU in JSON form. It is the data model that's used by the code generators.dawn_wire.json
: contains additional information used to generate dawn_wire
files, such as commands in addition to regular WebGPU commands.examples
: a small collection of samples using the native WebGPU API. They were mostly used when bringing up Dawn for the first time, and to test the WGPUSwapChain
object.generator
: directory containg the code generators and their templates. Generators are based on Jinja2 and parse data-models from JSON files.dawn_json_generator.py
: the main code generator that outputs the WebGPU headers, C++ wrapper, client-server implementation, etc.templates
: Jinja2 templates for the generator, with subdirectories for groups of templates that are all used in the same library.infra
: configuration file for the commit-queue infrastructure.scripts
: contains a grab-bag of files that are used for building Dawn, in testing, etc.src
:dawn
: root directory for Dawn codecommon
: helper code that is allowed to be used by Dawn's core libraries, dawn_native
and dawn_wire
. Also allowed for use in all other Dawn targets.fuzzers
: various fuzzers for Dawn that are running in Clusterfuzz.native
: code for the implementation of WebGPU on top of graphics APIs. Files in this folder are the “frontend” while subdirectories are “backends”.<backend>
: code for the implementation of the backend on a specific graphics API, for example d3d12
, metal
or vulkan
.wire
: code for an implementation of WebGPU as a client-server architecture.utils
: helper code to use Dawn used by tests and samples but disallowed for dawn_native
and dawn_wire
.platform
: definition of interfaces for dependency injection in dawn_native
or dawn_wire
.include
: public headers with subdirectories for each library. Note that some headers are auto-generated and not present directly in the directory.tests
:end2end
: tests for the execution of the WebGPU API and require a GPU to run.perf_tests
: benchmarks for various aspects of Dawn.unittests
: code unittests of internal classes, but also by extension WebGPU API tests that don't require a GPU to run.validation
: WebGPU validation tests not using the GPU (frontend tests)white_box
: tests using the GPU that need to access the internals of dawn_native
or dawn_wire
.third_party
: directory where dependencies live as well as their buildfiles.dawn_native
)The largest library in Dawn is dawn_native
which implements the WebGPU API by translating to native graphics APIs such as D3D12, Metal or Vulkan. It is composed of a frontend that does all the state-tracking and validation, and backends that do the actual translation to the native graphics APIs.
dawn_native
hosts the spirv-val for validation of SPIR-V shaders and uses SPIRV-Cross shader translator to convert SPIR-V shaders to an equivalent shader for use in the native graphics API (HLSL for D3D12, MSL for Metal or Vulkan SPIR-V for Vulkan).
dawn_wire
)A second library that implements both a client that takes WebGPU commands and serializes them into a buffer, and a server that deserializes commands from a buffer, validates they are well-formed and calls the relevant WebGPU commands. Some server to client communication also happens so the API's callbacks work properly.
Note that dawn_wire
is meant to do as little state-tracking as possible so that the client can be lean and defer most of the heavy processing to the server side where the server calls into dawn_native
.
dawn_proc
)Normally libraries implementing webgpu.h
should implement function like wgpuDeviceCreateBuffer
but instead dawn_native
and dawn_wire
implement the dawnProcTable
which is a structure containing all the WebGPU functions Dawn implements. Then a dawn_proc
library contains a static version of this dawnProcTable
and for example forwards wgpuDeviceCreateBuffer
to the procTable.deviceCreateBuffer
function pointer. This is useful in two ways:
dawn_native
and dawn_wire
, which is useful to test boths paths with the same binary in our infrastructure.wgpuGetProcAddress
repeatedly.When the WebGPU API evolves, a lot of places in Dawn have to be updated, so to reduce efforts, Dawn relies heavily on code generation for things like headers, proc tables and de/serialization. For more information, see codegen.md.