1878323 - WebGPU demo (https://gs-max.vercel.app/) doesnt draw anything on the screen

Status: NEW

(Core :: Graphics: WebGPU, defect, P3)

Description

[Mayank Bansal]

https://gs-max.vercel.app/

20:24:53.063 New shader set! page-51d11a44ad5f3ae1.js:1:651
20:24:53.063 Canvas resized to 450, 450 page-51d11a44ad5f3ae1.js:1:2906
20:24:53.064
Encountered one or more errors while creating shader module
20:24:53.064
WebGPU compilation info for shader module (1 error(s), 0 warning(s), 0 info)
20:24:53.064

Shader validation error:
┌─ :30:21
│
30 │ output.pos = vec4(pos[VertexIndex], 0.0, 1.0);
│ ^^^^^^^^^^^^^^^^ naga::Expression [5]

20:24:53.064 Error matching ShaderStages(VERTEX) shader requirements against the pipeline, caused by: Shader module is invalid
20:24:53.085 In a set_pipeline command, caused by: Render pipeline Id(0,1,d3d12) is invalid
20:24:53.085 Command encoder is invalid
20:24:57.178 New shader set! 2 page-51d11a44ad5f3ae1.js:1:651

​

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Bob Hood [:bhood]]

WebGPU is unreleased tech. Dropping Severity to S3 to remove from org tracking.

Comment 3

[Erich Gubler [:ErichDonGubler]]

NI'ing for root cause investigation, no promises on ETA.

Comment 4

[Erich Gubler [:ErichDonGubler]]

The first shader this page loads:

@group(0) @binding(0) var mySampler: sampler;
@group(0) @binding(1) var myTexture : texture_2d<f32>;

struct VertexOutput {
  @builtin(position) pos: vec4f,
  @location(0) fragUV: vec2f,
}
  
const pos = array(
  vec2( 1.0,  1.0),
  vec2( 1.0, -1.0),
  vec2(-1.0, -1.0),
  vec2( 1.0,  1.0),
  vec2(-1.0, -1.0),
  vec2(-1.0,  1.0),
);

const uv = array(
  vec2(1.0, 0.0),
  vec2(1.0, 1.0),
  vec2(0.0, 1.0),
  vec2(1.0, 0.0),
  vec2(0.0, 1.0),
  vec2(0.0, 0.0),
);

@vertex
fn vert_main(@builtin(vertex_index) VertexIndex : u32) -> VertexOutput {
  var output: VertexOutput;
  output.pos = vec4(pos[VertexIndex], 0.0, 1.0);
  output.fragUV = uv[VertexIndex];
  return output;
}

@fragment
fn frag_main(@location(0) fragUV : vec2f) -> @location(0) vec4f {
  return textureSample(myTexture, mySampler, fragUV);
}

…appear to be blocked on Naga disallowing dynamic index accesses into const arrays:

cargo run -p naga-cli -- in.wgsl
    Finished dev [unoptimized + debuginfo] target(s) in 0.21s
     Running `target\debug\naga.exe in.wgsl`
error:
   ┌─ in.wgsl:30:21
   │
30 │   output.pos = vec4(pos[VertexIndex], 0.0, 1.0);
   │                     ^^^^^^^^^^^^^^^^ naga::Expression [5]

Entry point vert_main at Vertex is invalid:
        Expression [5] is invalid
        The expression [4] may only be indexed by a constant
error: process didn't exit successfully: `target\debug\naga.exe in.wgsl` (exit code: 0xffffffff)

Upstream issue: wgpu#4337