GPURenderBundleEncoder.setIndexBuffer size parameter defaults to 0

[0f-0b]

const adapter = await navigator.gpu.requestAdapter();
if (!adapter) {
  throw "no adapter";
}
const device = await adapter.requestDevice();
const buffer = device.createBuffer({ size: 2, usage: GPUBufferUsage.INDEX });
const encoder = device.createRenderBundleEncoder({ colorFormats: [] });
encoder.setIndexBuffer(buffer, "uint16");

$ deno run --unstable-webgpu a.ts
error: Uncaught (in promise) TypeError: size must be larger than 0
encoder.setIndexBuffer(buffer, "uint16");
        ^
    at GPURenderBundleEncoder.setIndexBuffer (ext:deno_webgpu/01_webgpu.js:4943:5)
    at …/a.ts:8:9
$ deno --version
deno 1.44.4+6ab1433 (canary, aarch64-apple-darwin)
v8 12.6.228.9
typescript 5.4.5

[Hajime-san]

I found some diff between deno's implementation and current spec around this issue.

• https://www.w3.org/TR/2024/WD-webgpu-20240813

GPURenderCommandsMixin

GPURenderCommandsMixin defines rendering commands common to GPURenderPassEncoder and GPURenderBundleEncoder.

GPURenderCommandsMixin assumes the presence of GPUObjectBase, GPUCommandsMixin, and GPUBindingCommandsMixin members on the same object. It must only be included by interfaces which also include those mixins.

• Rework encoder state and mixins gpuweb/gpuweb#2452

GPUDebugCommandsMixin

GPUDebugCommandsMixin is also common to GPURenderPassEncoder and GPUComputePassEncoder

GPUBindingCommandsMixin

The setBindGroup() method has two overloads, and the bindGroup argument to be nullable.

• https://www.w3.org/TR/2024/WD-webgpu-20240813/#gpubindingcommandsmixin

upstream wgpu

• The bind group in set_bind_group should be optional gfx-rs/wgpu#4738
• Add a function to clear bindgroups from passes and bundles, with stub backend implementations. gfx-rs/wgpu#5778 (comment)