feat: Port point-cloud-layer to WebGPU

[Kaapp]

Ports point-cloud-layer to WebGPU. Requires fixes in visgl/luma.gl#2353.

Limitations:

• LASLoader will not work yet as loading data asynchronously requires buffers to be recreated which luma will not currently handle correctly.

A few scary edge cases to note:

• Unusued uniforms will be trimmed from the shader at compilation - however we will still try to provide them as they are in the source code. This results in an error like the following:

luma.gl: bindGroup creation: Number of entries (x) did not match the expected number of entries (y) for [BindGroupLayout (unlabeled)]

• The order of the supplied attributes is quite important, luma will correctly calculate the sizes for each buffer, but re-ordering the bindings (e.g. swapping @binding(2) with @binding(4)) can result in the byteStride changing, I believe due to byte alignment but I'm not certain. If this happens, an error like the following will be displayed as the buffers are no longer big enough:

Vertex range (x) requires a larger buffer (y) than the bound buffer size (z) of the vertex buffer at slot a with stride b.

Change List

• Port point-cloud-layer shaders to WGSL.
• Add normal to project shader
• Add point-cloud example temporarily using Airports data to avoid async loading complications.

Screen.Recording.2025-03-17.at.22.09.29.mov

[felixpalmer]

@ibgreen any reason why WGSL cannot be added to layer-uniforms.ts?

[ibgreen]

I suppose they could. I noticed that the only layer uniform we have is opacity, and given that we need to add support for premultiplied colors, so we likely need a color module that would be a natural home for an opacity uniforms, so I felt that might replace layer uniforms.

[coveralls]

coverage: 91.63% (+0.003%) from 91.627%
when pulling 690563b on Kaapp:cpk/point-cloud-webgpu
into cb17e82 on visgl:master.

[ibgreen]

Your luma changes are available in 9.1.6

[ibgreen]

Did you test under webgl? I had issues with these changes in the layer. Didn't get to the bottom of it, but maybe supplying an undefined parameters option is triggering something?