WebGPU coverage depth buffer.
Downsamples camera depth with a 4-tap max chain that keeps the 256∶128 aspect at every level. The last level is packed with a compute shader (float view-space Z). GPU→CPU download lives in CoverageGpuReadbackQueue.
WebGPU device
CPU width, default 256
CPU height, default 128
Last GPU downsample target. The packed 256×128 download is cpuDepth, not a texture.
WebGPU coverage depth buffer.
Downsamples camera depth with a 4-tap max chain that keeps the 256∶128 aspect at every level. The last level is packed with a compute shader (float view-space Z). GPU→CPU download lives in CoverageGpuReadbackQueue.