[Mesa-dev] Samping GL_R32UI?

[Roland Scheidegger]

Am 01.02.2017 um 05:32 schrieb Andrew A.:
> Are there any known issues with using usampler2D on a GL_R32UI texture
> in llvmpipe from within a VS/FS? I'm getting expected results on
> Nvidia drivers (proprietary), but not with mesa llvmpipe (always get
> zero).

Not that I know of. There should be plenty of tests testing this.
My best guess is your texture is incomplete - nvidia is known to ignore
this for some cases but mesa would not.
This would affect all mesa drivers presumably, not just llvmpipe.
(This silent "non-error condition" is quite nasty and non-obvious in
some cases - for instance if you use texelFetch which ignores all
ordinary texture parameters such as wrap modes or filtering, however
according to OpenGL rules the texture would still be incomplete
depending on min/mag filter - and I know nvidia would ignore this
particular case.)

Roland