mesa: add/update comments in _mesa_copy_buffer_subdata()

[mesa.git] / src / mesa / drivers / dri / i965 / brw_clip_util.c

diff --git a/src/mesa/drivers/dri/i965/brw_clip_util.c b/src/mesa/drivers/dri/i965/brw_clip_util.c
index 8c9f0e49575dbda4a781d16d94da6856ab9d9818..bf8cc3ac81545eed29f26b26603c59c3c7220ccf 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_clip_util.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_util.c
@@ -135,7 +135,7 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
                             struct brw_indirect v0_ptr, /* from */
                             struct brw_indirect v1_ptr, /* to */
                             struct brw_reg t0,
-                            GLboolean force_edgeflag)
+                            bool force_edgeflag)
 {
    struct brw_compile *p = &c->func;
    struct brw_reg tmp = get_tmp(c);
@@ -151,17 +151,26 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
       
    /* Iterate over each attribute (could be done in pairs?)
     */
-   for (slot = 2*c->header_regs; slot < c->vue_map.num_slots; slot++) {
+   for (slot = 0; slot < c->vue_map.num_slots; slot++) {
+      int vert_result = c->vue_map.slot_to_vert_result[slot];
       GLuint delta = brw_vue_slot_to_offset(slot);
 
-      if (c->vue_map.slot_to_vert_result[slot] == VERT_RESULT_EDGE) {
+      if (vert_result == VERT_RESULT_EDGE) {
         if (force_edgeflag) 
            brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1));
         else
            brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta));
-      }
-      else {
-        /* Interpolate: 
+      } else if (vert_result == VERT_RESULT_PSIZ ||
+                 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) {
+        /* This is a true vertex result (and not a special value for the VUE
+         * header), so interpolate:
          *
          *        New = attr0 + t*attr1 - t*attr0
          */
@@ -198,8 +207,8 @@ void brw_clip_interp_vertex( struct brw_clip_compile *c,
 
 void brw_clip_emit_vue(struct brw_clip_compile *c, 
                       struct brw_indirect vert,
-                      GLboolean allocate,
-                      GLboolean eot,
+                      bool allocate,
+                      bool eot,
                       GLuint header)
 {
    struct brw_compile *p = &c->func;