WebGPUAttributeUtils: fix updateAttribute() when using range (#29966)

[holtsetio]

Related issue: #29966

Description

When using updateAttribute() with a range, the range start and count were wrongfully multiplied by array.BYTES_PER_ELEMENT before calling writeBuffer(), even though the writeBuffer() function expects the range start and count as number of typed array elements, not as bytes.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	339.14 78.99	339.14 78.99	+0 B +0 B
WebGPU	483.41 134.17	483.51 134.22	+100 B +51 B
WebGPU Nodes	482.88 134.07	482.98 134.13	+100 B +54 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	464.62 111.98	464.62 111.98	+0 B +0 B
WebGPU	552.54 149.53	552.64 149.58	+100 B +48 B
WebGPU Nodes	508.42 139.24	508.52 139.29	+100 B +47 B

[RenaudRohlinger]

Good catch! Thanks!

Related PR:
#27103

[RenaudRohlinger]

Some additional context:

https://www.w3.org/TR/webgpu/#dom-gpuqueue-writebuffer

If data is an ArrayBuffer or DataView, let the element type be "byte". Otherwise, data is a TypedArray; let the element type be the type of the TypedArray.

Which means that ArrayBuffer or DataView still require * array.BYTES_PER_ELEMENT.

I suggest we add a condition const isTypedArray = ArrayBuffer.isView( attribute.array ) && attribute.array instanceof DataView !== true to handle both case.

[RenaudRohlinger]

Updated the PR consequently.