Fully passes only on desktop and ES3 (Mesa), expecting minor differences
onother GPUs. ES2 is slightly broken and needs fixing; doesn't even
compile on WebGL 1 and causes a serious GPU stall on WebGL 2 -- in both
causes caused by the unbounded nested loops. Rendering doesn't work on
WebGL 1 at the moment, since luminance formats are not renderable. And
for a RGBA output format I would need some utility to get rid of the
extra channels in order to pass the comparison.
Lots of work to do here.
Vladimír Vondruš