WebGL2 device
CPU width, default 256
CPU height, default 128
number of readback slots, default 4
minimum frameUpdate ticks before polling a slot, default 2
Submit a packed capture every N pack attempts (update /
updateGPUDepthBuffer). Harvest still polls every frameUpdate.
The downsample chain is skipped on ticks that will not capture.
Default 1. Raise on devices where getBufferSubData hitches.
WebGL2 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 transform feedback (float view-space Z). GPU->CPU download lives in CoverageTFStateQueue (TFStateQueue + PBO/FIFO shared with WebGL HZB).