i965: don't intepolate clip distances on pre-GEN6.

On pre-GEN6 chips, the VUE slots set aside for clip distance aren't
actually used, so there is no reason for the clipper to waste time
interpolating them.

When commit 62bad54727 changed the enum
value used to represent these VUE slots, that caused the clipper to
start interpolating them as an accidental side effect.  This patch
reverts to the old clipper behavior.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This commit is contained in:
Paul Berry 2011-09-23 21:55:20 -07:00
parent 64ce64a3f8
commit f02ed012c9

View file

@ -160,8 +160,14 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1)); brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1));
else else
brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta)); brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta));
} else if (vert_result == VERT_RESULT_PSIZ) { } else if (vert_result == VERT_RESULT_PSIZ ||
/* PSIZ doesn't need interpolation */ vert_result == VERT_RESULT_CLIP_DIST0 ||
vert_result == VERT_RESULT_CLIP_DIST1) {
/* PSIZ doesn't need interpolation because it isn't used by the
* fragment shader. CLIP_DIST0 and CLIP_DIST1 don't need
* intepolation because on pre-GEN6, these are just placeholder VUE
* slots that don't perform any action.
*/
} else if (vert_result < VERT_RESULT_MAX) { } else if (vert_result < VERT_RESULT_MAX) {
/* This is a true vertex result (and not a special value for the VUE /* This is a true vertex result (and not a special value for the VUE
* header), so interpolate: * header), so interpolate: