i965 Gen4/5: clip: correctly handle flat varyings

Previously we only gave special treatment to the builtin color varyings.
This patch adds support for arbitrary flat-shaded varyings, which is
required for GLSL 1.30.

Based on Olivier Galibert's patch from last year:
http://lists.freedesktop.org/archives/mesa-dev/2012-July/024340.html

V5: Move key.do_flat_shading to brw_clip_compile.has_flat_shading
V6: Real bools.

[V1-2]: Signed-off-by: Olivier Galibert <galibert at pobox.com>
Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 9 insertions, 37 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_clip_util.c b/src/mesa/drivers/dri/i965/brw_clip_util.c
index 37b7734..9d77d1e 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_util.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_util.c
@@ -290,49 +290,21 @@ struct brw_reg brw_clip_plane_stride( struct brw_clip_compile *c )
 }
 
 
-/* If flatshading, distribute color from provoking vertex prior to
+/* Distribute flatshaded attributes from provoking vertex prior to
  * clipping.
  */
-void brw_clip_copy_colors( struct brw_clip_compile *c,
+void brw_clip_copy_flatshaded_attributes( struct brw_clip_compile *c,
 			   GLuint to, GLuint from )
 {
    struct brw_compile *p = &c->func;
 
-   if (brw_clip_have_varying(c, VARYING_SLOT_COL0))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL0)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL0)));
-
-   if (brw_clip_have_varying(c, VARYING_SLOT_COL1))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL1)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL1)));
-
-   if (brw_clip_have_varying(c, VARYING_SLOT_BFC0))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC0)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC0)));
-
-   if (brw_clip_have_varying(c, VARYING_SLOT_BFC1))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC1)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC1)));
+   for (int i = 0; i < c->vue_map.num_slots; i++) {
+      if (c->key.interpolation_mode.mode[i] == INTERP_QUALIFIER_FLAT) {
+         brw_MOV(p,
+                 byte_offset(c->reg.vertex[to], brw_vue_slot_to_offset(i)),
+                 byte_offset(c->reg.vertex[from], brw_vue_slot_to_offset(i)));
+      }
+   }
 }