[Mesa-dev] About merging pipe-video to master

[Henri Verbeet]

2011/7/12 Christian König <deathsimple at vodafone.de>:
> Am Dienstag, den 12.07.2011, 15:44 +0200 schrieb Henri Verbeet:
>> 2011/7/12 Christian König <deathsimple at vodafone.de>:
>> > +           // TODO get BLEND_CLAMP state from rasterizer state
>> Is this comment still accurate?
> Yes it is, the very first generation of R600 chipsets need to know if
> blend clamping is enabled, to enable an additionally optimisation for
> the color export (EXPORT_NORM).
>
> The problem is that I'm unsure how to get that state from the rasterizer
> structure into r600_cb, reprogramming color_info in r600_draw_vbo just
> like Vadim Girlin did for his patches, seems to be a bit to much
> overhead to me.
>
I don't think you can in the current setup. You'd pretty much have to
do something along the lines of r600_spi_update() or
r600_update_alpha_ref().

> It took me a week to figure out what's going wrong here and why the
> pipeline doesn't did what I wanted. The downside with my patches is that
> it disables the export optimisation on the early R600 generation
> chipsets, but my overall feeling is that it's better to render right and
> slow instead of fast and wrong.
>
I guess my point was mostly that there's not much of a point in doing
the clamping both through BLEND_CLAMP and the fragment shader. Also, I
guess we need this for EG+ as well.

Thanks for clearing this up.