Make Unstruct resolvable to its Struct counterpart

[reczkok]

Unstructs could be used with raw WGSL vertex functions to generate attributes with proper locations (given every property is decorated with the location attribute).

const Vertex = d.unstruct({
 position: d.location(0, d.vec3f), // or d.float32x3
 color: d.location(1, d.unorm8x4),
});

const shader = /* wgsl */ `
 @vertex
 fn vert(v: Vertex) -> @builtin(position) pos: vec4f {
  ....
 }`;

const resolved = tgpu.resolve({
 template: shader,
 externals: { Vertex },
});

it would resolve to:

struct Vertex_0 {
 @location(0) postion: vec3f,
 @location(1) color: vec4f,
}

@vertex
fn vert(v:Vertex_0) -> @builtin(position) pos: vec4f {
  ....
}

Structs and Unstructs still need to be separate because buffers created with Unstructs as their schemas can't be used as storage or uniforms - they can be used as local variables tho.
We can assume a default representation for each format (eg. rgba16unorm -> vec4f). Potentially that could allows us to combine it with vertexLayouts to unwrap to appropriate GPUVertexBufferLayout entry and have just one sot (the struct).

const vLayout = tgpu.vertexLayout(n => d.disarrayOf(Vertex, n))

const vertexShader = device.createRenderPipeline({
  layout: device.createPipelineLayout({
    bindGroupLayouts: [root.unwrap(layout)],
  }),
  vertex: {
    module: device.createShaderModule({
      code: shader,
    }),
    buffers: [
      root.unwrap(vLayout) 
    ],
  },
...
});

[iwoplaza]

This could be a really nice improvement, creating a new point of integration for vanilla WebGPU projects (with unwrapping vertex layouts and resolving an external unstruct with attributes) and for full-TypeGPU projects (reduced duplication, which usually involved creating an unstruct, and its struct counterpart manually).

[iwoplaza]

@mhawryluk Thoughts? 🧠

[mhawryluk]

sure, I don't see why not 🚀