gallium: add a cull distance semantic

cull distance is analogous to clip distance. If a register is
given this semantic, then the values in it are assumed to be a
float32 distance to a plane. Primitives will be completely
discarded if the plane distance for all of the vertices in
the primitive are < 0.

Signed-off-by: Zack Rusin <[email protected]>
Reviewed-by: Jose Fonseca <[email protected]>
Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

0 files changed, 0 insertions, 0 deletions