[Mesa-dev] [PATCH V3 0/5] Interpolation fixes for Gen4/5

[Chris Forbes]

This series adds support for GLSL 1.30 / EXT_gpu_shader4's 'flat' and
'noperspective' varying interpolation qualifiers on Gen4/5.

Based on Olivier Galibert's series from July 2012, with some simplifications
(that series contained a number of fixes for other bugs which have been
addressed in master already -- two-sided lighting, vue map inconsistencies)

The interpolation qualifiers are still passed through brw->, which Eric
doesn't like in the original version -- which I have some alternatives for:

1) Leave it as-is, but if anything other than the program key builders
go looking in brw->interpolation_mode, it's *wrong*.

2) Tack it onto the VUE map, and have the VS code produce it at the same time
as the VUE map itself. (When we have a GS, the GS will have to do this too).

3) Make the clip program key the primary source, and have the SF program key
builder go snooping in it.

4) Have the clip and SF program key builders redundantly compute it.

The other review point from V2 no longer exists -- fixes to the two-sided
lighting behavior are already done.

I've dropped all the Reviewed-by: lines from V2, since this has changed a fair
bit and could do with a fresh look.

With this series, all of the GLSL 1.30 interpolation tests pass on Gen5 except
those which use gl_ClipDistance, since it's not supported yet.

-- Chris