[Mesa-dev] [PATCH 1/3] r600: Change default behaviour for undefined COLOR0

[Axel Davy]

On 03/04/2016 20:41, Roland Scheidegger wrote :
> Am 03.04.2016 um 10:11 schrieb Axel Davy:
>> d3d 9 needs COLOR0 to be 1.0 on all channels when
>> undefined. 0.0 for the others is fine.
>> GL behaviour is undefined.
>>
> Not that I care what drivers use by default for undefined values, but it
> probably would be better to fix that properly in the state tracker since
> certainly gallium doesn't impose that default...
>
> Roland
>
Implementing it properly in the state tracker is a bit annoying,
because of possible combinations of usage ff pipeline vs non ff pipeline.
It would be made easier if (0,0,0,0) was defined as the default in gallium,
so only COLOR0 would have to be checked, else all outputs/inputs have to 
be checked.

As it seems rather easy to fix in the driver, I chose that way.

There seems to be very few games relying on the behaviour.

Axel