WebGPURenderer: Introduce syncWithGPU

[RenaudRohlinger]

Description

This pull request introduces a new syncWithGPU helper to our codebase, providing a unified method for synchronizing CPU operations with GPU processing in both WebGPU and WebGL contexts.

Example usage:

async loop() {

    await renderer.computeAsync(veryHeavyComputeProgram)
    await renderer.syncWithGPU() // wait for the GPU to resolve its operations
}

Note: syncWithGPU is not included in computeAsync and renderAsync because it may have performance implications and is applicable only in specific edge cases. Therefore, providing an API for users to handle synchronization themselves is more appropriate.

This contribution is funded by Utsubo

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	690.8 171.12	690.8 171.12	+0 B +0 B
WebGPU	816.46 220.09	816.63 220.15	+175 B +60 B
WebGPU Nodes	815.97 219.96	816.14 220.02	+175 B +60 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	463.45 111.9	463.45 111.9	+0 B +0 B
WebGPU	538.64 145.42	538.81 145.47	+175 B +59 B
WebGPU Nodes	494.75 135.28	494.93 135.35	+175 B +62 B

[Makio64]

Oh I though :
await renderer.computeAsync(veryHeavyComputeProgram) // is waiting gpu task to finish
renderer.computeAsync(veryHeavyComputeProgram) // is not waiting gpu task to finish

I suggest a more direct name : waitGPUCompleted

[RenaudRohlinger]

Oh I though :
await renderer.computeAsync(veryHeavyComputeProgram) // is waiting gpu task to finish
renderer.computeAsync(veryHeavyComputeProgram) // is not waiting gpu task to finish

I think in the end developers will always go for the async option, and calling the backend methods such as await this.device.queue.onSubmittedWorkDone(); in WebGPU and gl.fenceSync, gl.flush() in WebGL2 will impact the performances even if we don't specify that it's an await operation.

If we consider that computeAsync and renderAsync are more expensive operation that are really async and will potentially freeze the render/CPU I'm fine with this solution.

Also I agree with the name. Or maybe waitForGPUCompletion.