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>
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 fromdawn.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/samplesdawn_native
: native implementation of WebGPU, one subfolder per backenddawn_wire
: client-server implementation of WebGPUinclude
: public headers for Dawntests
: internal Dawn testsend2end
: WebGPU tests performing GPU operationsunittests
: unittests and by extension tests not using the GPUvalidation
: 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.