On 12/13/2011 09:11 PM, Jose Fonseca wrote:
>
>
> ----- Original Message -----
>> This is an updated version of the patch set I sent to the list a few
>> hours
>> ago.
>
>
>> There is now a TGSI property called
>> TGSI_PROPERTY_NUM_CLIP_DISTANCES
>> that drivers can use to determine how many of the 8 available clip
>> distances
>> are actually used by a shader.
>
> Can't the info in TGSI_PROPERTY_NUM_CLIP_DISTANCES be easily derived from the
> shader, and queried through src/gallium/auxiliary/tgsi/tgsi_scan.h ?
>
>
> Could you also elaborate on why TGSI_SEMANTIC_CLIPDIST is useful for the
> drivers? I personally don't have nothing against it, but just like to
> understand why it makes a difference.
>
Why does TGSI_SEMANTIC_*POSITION* make a difference ?
Right, because the position values are consumed by the fixed function
rasterizer. So are the clip distances.
This is not about pipe_clip_state.ucp but about what this legacy cruft
has to be turned into if GL_CLIP_PLANEi is used instead of GLSL 1.3's
gl_ClipDistance[i].
The same mentality ("What's information useful for ?") cost me
TGSI_SEMANTIC_TEXCOORD and now I have to rely on a hack to make point
coordinate replacement work on nvc0
(http://cgit.freedesktop.org/mesa/mesa/tree/src/gallium/drivers/nvc0/nvc0_program.c#n29).
I'm sorry I'm a bit sensitive on the issue of dropping information at
the gallium threshold.
> Jose
> _______________________________________________
> mesa-dev mailing list
> mesa-dev@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
