9b7a965667
This proves a flag in msl::PipelineOptions that attempts to write all Metal vertex entry points to use a vertex pulling technique. It does this by: 1) Forcing the _buffer_sizes structure to be generated for all vertex entry points. The structure has additional buffer_size members that contain the byte sizes of the vertex buffers. 2) Adding new args to vertex entry points for the vertex id and/or the instance id and for the bound buffers. If there is an existing @builtin(vertex_index) or @builtin(instance_index) param, then no duplicate arg is created. 3) Adding code at the beginning of the function for vertex entry points to compare the vertex id or instance id against the lengths of all the bound buffers, and force an early-exit if the bounds are violated. 4) Extracting the raw bytes from the vertex buffer(s) and unpacking those bytes into the bound attributes with the expected types. 5) Replacing the varyings input and instead using the unpacked attributes to fill any structs-as-args that are rebuilt in the entry point. A new naga test is added which exercises this flag and demonstrates the effect of the transform. The msl generated by this test passes validation. Eventually this transformation will be the default, always-on behavior for Metal pipelines, though the flag may remain so that naga translation tests can be run with and without the tranformation. |
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| .. | ||
| .cargo | ||
| fuzz | ||
| hlsl-snapshots | ||
| src | ||
| tests | ||
| xtask | ||
| .gitattributes | ||
| .gitignore | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| README.md | ||
Naga
The shader translation library for the needs of wgpu.
Supported end-points
| Front-end | Status | Feature | Notes |
|---|---|---|---|
| SPIR-V (binary) | ✅ | spv-in | |
| WGSL | ✅ | wgsl-in | Fully validated |
| GLSL | 🆗 | glsl-in | GLSL 440+ and Vulkan semantics only |
| Back-end | Status | Feature | Notes |
|---|---|---|---|
| SPIR-V | ✅ | spv-out | |
| WGSL | 🆗 | wgsl-out | |
| Metal | ✅ | msl-out | |
| HLSL | ✅ | hlsl-out | Shader Model 5.0+ (DirectX 11+) |
| GLSL | 🆗 | glsl-out | GLSL 330+ and GLSL ES 300+ |
| AIR | |||
| DXIL/DXIR | |||
| DXBC | |||
| DOT (GraphViz) | 🆗 | dot-out | Not a shading language |
✅ = Primary support — 🆗 = Secondary support — 🚧 = Unsupported, but support in progress
Conversion tool
Naga can be used as a CLI, which allows testing the conversion of different code paths.
First, install naga-cli from crates.io or directly from GitHub.
# release version
cargo install naga-cli
# development version
cargo install naga-cli --git https://github.com/gfx-rs/wgpu.git
Then, you can run naga command.
naga my_shader.wgsl # validate only
naga my_shader.spv my_shader.txt # dump the IR module into a file
naga my_shader.spv my_shader.metal --flow-dir flow-dir # convert the SPV to Metal, also dump the SPIR-V flow graph to `flow-dir`
naga my_shader.wgsl my_shader.vert --profile es310 # convert the WGSL to GLSL vertex stage under ES 3.20 profile
As naga includes a default binary target, you can also use cargo run without installation. This is useful when you develop naga itself or investigate the behavior of naga at a specific commit (e.g. wgpu might pin a different version of naga than the HEAD of this repository).
cargo run my_shader.wgsl
Development workflow
The main instrument aiding the development is the good old cargo test --all-features --workspace,
which will run the unit tests and also update all the snapshots. You'll see these
changes in git before committing the code.
If working on a particular front-end or back-end, it may be convenient to
enable the relevant features in Cargo.toml, e.g.
default = ["spv-out"] #TEMP!
This allows IDE basic checks to report errors there unless your IDE is sufficiently configurable already.
Finally, when changes to the snapshots are made, we should verify that the produced shaders are indeed valid for the target platforms they are compiled for:
cargo xtask validate spv # for Vulkan shaders, requires SPIRV-Tools installed
cargo xtask validate msl # for Metal shaders, requires XCode command-line tools installed
cargo xtask validate glsl # for OpenGL shaders, requires GLSLang installed
cargo xtask validate dot # for dot files, requires GraphViz installed
cargo xtask validate wgsl # for WGSL shaders
cargo xtask validate hlsl dxc # for HLSL shaders via DXC
cargo xtask validate hlsl fxc # for HLSL shaders via FXC