WebWorker backend support

[fuzzie360]

Use the WebWorker API to run the kernel on CPU cores.

Challenges:

• WebWorkers are purely asynchronous. Blocked by Truly asynchronous kernel API support #4 for API parity among all backends which might break graceful fallback.

[robertleeplummerjr]

Couldn't one just load gpu in the webworker? Done!

[fuzzie360]

As a general update to this enhancement, I think API-wise, maybe we should just return a Promise just like how we just return a Texture object anyway. To support graceful fallback, we could implement an async unrwraper to turn our different output types (Arrays, Promises, Textures) into Arrays.

@robertleeplummerjr what you are describing requires this tho https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas It would actually improve the user experience for our normal GPU kernels by allowing JavaScript to execute something while awaiting for a response from GPU, But, WebWorkers also improve CPU performance which is something we could try and achieve too.

[robertleeplummerjr]

I was more thinking just cpu fallback in webworker, but your recommendation is a touché to my angarde.

[ubernaut]

Just chiming in to say I would love to be able to run GPU.js in a webworker on a GPU. Too bad only Firefox supports webgl in a webworker at this point https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas#Browser_compatibility

[robertleeplummerjr]

agreed. I have a feeling that will be the case for only a short time. It is just too good of a feature.

[robertleeplummerjr]

wait a tick... basic support?

[feljx]

Is gpu.js usable in a web worker?

[robertleeplummerjr]

Unit tests:

gpu.js/test/features/offscreen-canvas.js

Line 19 in 5397186

function testOffscreenCanvas(mode, done) {

[robertleeplummerjr]

I believe this to be working.