Wrong code in website?

[iampi31415]

const device = await adapter.requestDevice();
if (!device) throw Error("Couldn’t request WebGPU logical device.");

Should take into account:

GPUAdapter.requestDevice() will never return null, and it will reject only if the request is invalid, i.e. it exceeds the capabilities of the GPUAdapter.

I think device.lost.then(()=>...) needs to replace that code.

MDN

[surma]

Oh they must have changed the API!

[iampi31415]

In case you change it I add two typos (bold):

Adapters, in turn, are the translation layer from operation system’s native graphics API to WebGPU.

The attribute allows you to tell the GPU what the the size of a workgroup for this shader should be.

This explains what we see an unused field with the value 0 in the DevTools console.

It was a very nice article.

---

PS: Tested the line to stop extra iterations

  if(global_id.x >= arrayLength(&output)) {
    return;
  }

And currently the result is correct even without that line. I wonder whether they also changed that behaviour or I'm mistyping something.

@surma

[iampi31415]

Also would like to suggest re-writing:

for (let i = 0; i < NUM_BALLS; i++) {
  inputBalls[i * 6 + 0] = randomBetween(2, 10); // radius
  inputBalls[i * 6 + 1] = 0; // padding
  inputBalls[i * 6 + 2] = randomBetween(0, ctx.canvas.width); // position.x
  inputBalls[i * 6 + 3] = randomBetween(0, ctx.canvas.height); // position.y
  inputBalls[i * 6 + 4] = randomBetween(-100, 100); // velocity.x
  inputBalls[i * 6 + 5] = randomBetween(-100, 100); // velocity.y
}

to

for (let i = 0; i < NUM_BALLS * 6; i+=6) {
  inputBalls[i + 0] = randomBetween(2, 10); // radius
  inputBalls[i + 1] = 0; // padding
  inputBalls[i + 2] = randomBetween(0, ctx.canvas.width); // position.x
  inputBalls[i + 3] = randomBetween(0, ctx.canvas.height); // position.y
  inputBalls[i + 4] = randomBetween(-100, 100); // velocity.x
  inputBalls[i + 5] = randomBetween(-100, 100); // velocity.y
}

But it is a matter of preference. I'm just kind of practising :-)

[surma]

Wanna whip up a PR?