Moving Post-Processing to Compute about filament

[romainguy]

WebGL 2 does not support compute shaders. There was a draft for a WebGL 2 Compute extension but it's been superseded by the WebGPU effort.

Moving some of the post processing to compute, even async compute, will not cut frame times in half on mobile. The bulk of the work remains on the ALUs and texture units.

[Nolram12345]

It's true that WebGL2 does not support compute shaders - for that the current frag/vert option would certainly be a good fallback.
My statement that it would cut frame times in half were not specifically about mobile. These types of best-case gains would mainly be visible on Desktop at resolutions of 4K. But the performance advantage is still significant, even at lower resolutions and on mobile. Particularly on the latest devices, which have displays that are in fact at 1440p, fragment throughput and synchronous evaluation becomes a higher bottleneck, especially when rendering more complex scenes.
Frag performance currently seems like the biggest bottleneck Filament has in most configurations I've tested.

[pixelflinger]

this is currently not a priority