Files
webgpufundamentals/webgpu/webgpu-simple-triangle-storage-buffer-split.html
Gregg Tavares dcfd514975 Revert "Use direct attachment binding"
This reverts commit bdce233195.
2026-02-04 12:17:44 -08:00

230 lines
6.5 KiB
HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
<title>WebGPU Multiple Triangles w/split Storage Buffers</title>
<style>
@import url(resources/webgpu-lesson.css);
html, body {
margin: 0; /* remove the default margin */
height: 100%; /* make the html,body fill the page */
}
canvas {
display: block; /* make the canvas act like a block */
width: 100%; /* make the canvas fill its container */
height: 100%;
}
</style>
</head>
<body>
<canvas></canvas>
</body>
<script type="module">
// A random number between [min and max)
// With 1 argument it will be [0 to min)
// With no arguments it will be [0 to 1)
const rand = (min, max) => {
if (min === undefined) {
min = 0;
max = 1;
} else if (max === undefined) {
max = min;
min = 0;
}
return min + Math.random() * (max - min);
};
async function main() {
const adapter = await navigator.gpu?.requestAdapter();
const device = await adapter?.requestDevice();
if (!device) {
fail('need a browser that supports WebGPU');
return;
}
// Get a WebGPU context from the canvas and configure it
const canvas = document.querySelector('canvas');
const context = canvas.getContext('webgpu');
const presentationFormat = navigator.gpu.getPreferredCanvasFormat();
context.configure({
device,
format: presentationFormat,
});
const module = device.createShaderModule({
code: /* wgsl */ `
struct OurStruct {
color: vec4f,
offset: vec2f,
};
struct OtherStruct {
scale: vec2f,
};
struct VSOutput {
@builtin(position) position: vec4f,
@location(0) color: vec4f,
}
@group(0) @binding(0) var<storage, read> ourStructs: array<OurStruct>;
@group(0) @binding(1) var<storage, read> otherStructs: array<OtherStruct>;
@vertex fn vs(
@builtin(vertex_index) vertexIndex : u32,
@builtin(instance_index) instanceIndex: u32
) -> VSOutput {
let pos = array(
vec2f( 0.0, 0.5), // top center
vec2f(-0.5, -0.5), // bottom left
vec2f( 0.5, -0.5) // bottom right
);
let otherStruct = otherStructs[instanceIndex];
let ourStruct = ourStructs[instanceIndex];
var vsOut: VSOutput;
vsOut.position = vec4f(
pos[vertexIndex] * otherStruct.scale + ourStruct.offset, 0.0, 1.0);
vsOut.color = ourStruct.color;
return vsOut;
}
@fragment fn fs(vsOut: VSOutput) -> @location(0) vec4f {
return vsOut.color;
}
`,
});
const pipeline = device.createRenderPipeline({
label: 'split storage buffer pipeline',
layout: 'auto',
vertex: {
module,
},
fragment: {
module,
targets: [{ format: presentationFormat }],
},
});
const kNumObjects = 100;
// create 2 storage buffers
const staticStorageUnitSize =
4 * 4 + // color is 4 32bit floats (4bytes each)
2 * 4 + // offset is 2 32bit floats (4bytes each)
2 * 4; // padding
const storageUnitSize =
2 * 4; // scale is 2 32bit floats (4bytes each)
const staticStorageBufferSize = staticStorageUnitSize * kNumObjects;
const storageBufferSize = storageUnitSize * kNumObjects;
const staticStorageBuffer = device.createBuffer({
label: 'static storage for objects',
size: staticStorageBufferSize,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST,
});
const storageBuffer = device.createBuffer({
label: 'changing storage for objects',
size: storageBufferSize,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST,
});
const staticStorageValues = new Float32Array(staticStorageBufferSize / 4);
const storageValues = new Float32Array(storageBufferSize / 4);
// offsets to the various uniform values in float32 indices
const kColorOffset = 0;
const kOffsetOffset = 4;
const kScaleOffset = 0;
const objectInfos = [];
for (let i = 0; i < kNumObjects; ++i) {
const staticOffset = i * (staticStorageUnitSize / 4);
// These are only set once so set them now
staticStorageValues.set([rand(), rand(), rand(), 1], staticOffset + kColorOffset); // set the color
staticStorageValues.set([rand(-0.9, 0.9), rand(-0.9, 0.9)], staticOffset + kOffsetOffset); // set the offset
objectInfos.push({
scale: rand(0.2, 0.5),
});
}
device.queue.writeBuffer(staticStorageBuffer, 0, staticStorageValues);
const bindGroup = device.createBindGroup({
label: 'bind group for objects',
layout: pipeline.getBindGroupLayout(0),
entries: [
{ binding: 0, resource: staticStorageBuffer },
{ binding: 1, resource: storageBuffer },
],
});
const renderPassDescriptor = {
label: 'our basic canvas renderPass',
colorAttachments: [
{
// view: <- to be filled out when we render
clearValue: [0.3, 0.3, 0.3, 1],
loadOp: 'clear',
storeOp: 'store',
},
],
};
function render() {
// Get the current texture from the canvas context and
// set it as the texture to render to.
renderPassDescriptor.colorAttachments[0].view =
context.getCurrentTexture().createView();
const encoder = device.createCommandEncoder();
const pass = encoder.beginRenderPass(renderPassDescriptor);
pass.setPipeline(pipeline);
// Set the uniform values in our JavaScript side Float32Array
const aspect = canvas.width / canvas.height;
objectInfos.forEach(({scale}, ndx) => {
const offset = ndx * (storageUnitSize / 4);
storageValues.set([scale / aspect, scale], offset + kScaleOffset); // set the scale
});
device.queue.writeBuffer(storageBuffer, 0, storageValues);
pass.setBindGroup(0, bindGroup);
pass.draw(3, kNumObjects); // call our vertex shader 3 times for several instances
pass.end();
const commandBuffer = encoder.finish();
device.queue.submit([commandBuffer]);
}
const observer = new ResizeObserver(entries => {
for (const entry of entries) {
const canvas = entry.target;
const width = entry.contentBoxSize[0].inlineSize;
const height = entry.contentBoxSize[0].blockSize;
canvas.width = Math.max(1, Math.min(width, device.limits.maxTextureDimension2D));
canvas.height = Math.max(1, Math.min(height, device.limits.maxTextureDimension2D));
// re-render
render();
}
});
observer.observe(canvas);
}
function fail(msg) {
alert(msg);
}
main();
</script>
</html>