[Mesa-dev] Mesa (master): mesa/st: ask GLSL to not emit noise since we have a dummy implementation

Luca Barbieri luca at luca-barbieri.com
Tue Sep 14 01:01:40 PDT 2010

> Yes.  Returning 0.5 is wrong.  I don't think HLSL has noise, so there
> shouldn't be a compatibility issue there.

Yes, in fact, nothing seems to use the NOISE opcodes at all.
Also, I can't find evidence of any hardware ever having implemented it.
AMD IL has Perlin noise opcodes, but it looks like they are lowered to
normal instructions since the ISA docs don't say anything about it.

Is there any reason to not just remove them from both Mesa IR and TGSI
and make EmitNoNoise implicit?

And it seems both ATI (according to ShaderAnalyzer) and nVidia
(according to the web) just return 0 at least on some hardware.

More information about the mesa-dev mailing list