[Mesa-dev] [PATCH 1/2] draw: cleanup the distance culling code a bit

[Zack Rusin]

We don't need the clamped variable, because we can just
return early. We should also do the regular culling after
the distance culling passes.
All spotted by Brian.

Signed-off-by: Zack Rusin <zackr at vmware.com>
---
 src/gallium/auxiliary/draw/draw_pipe_cull.c |   79 ++++++++++++---------------
 1 file changed, 36 insertions(+), 43 deletions(-)

diff --git a/src/gallium/auxiliary/draw/draw_pipe_cull.c b/src/gallium/auxiliary/draw/draw_pipe_cull.c
index 50a25e3..dd9965f 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_cull.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_cull.c
@@ -51,10 +51,10 @@ static INLINE struct cull_stage *cull_stage( struct draw_stage *stage )
    return (struct cull_stage *)stage;
 }
 
-static INLINE
-boolean cull_distance_is_out(float dist)
+static INLINE boolean
+cull_distance_is_out(float dist)
 {
-   return (dist < 0) || util_is_inf_or_nan(dist);
+   return (dist < 0.0f) || util_is_inf_or_nan(dist);
 }
 
 /*
@@ -68,23 +68,21 @@ static void cull_point( struct draw_stage *stage,
 {
    const unsigned num_written_culldistances =
       draw_current_shader_num_written_culldistances(stage->draw);
-
-   if (num_written_culldistances) {
-      unsigned i;
-      boolean culled = FALSE;
-      for (i = 0; i < num_written_culldistances; ++i) {
-         unsigned cull_idx = i / 4;
-         unsigned out_idx =
-            draw_current_shader_culldistance_output(stage->draw, cull_idx);
-         unsigned idx = i % 4;
-         float cull1 = header->v[0]->data[out_idx][idx];
-         boolean vert1_out = cull_distance_is_out(cull1);
-         if (vert1_out)
-            culled = TRUE;
-      }
-      if (!culled)
-         stage->next->point( stage->next, header );
+   unsigned i;
+      
+   debug_assert(num_written_culldistances);
+
+   for (i = 0; i < num_written_culldistances; ++i) {
+      unsigned cull_idx = i / 4;
+      unsigned out_idx =
+         draw_current_shader_culldistance_output(stage->draw, cull_idx);
+      unsigned idx = i % 4;
+      float cull1 = header->v[0]->data[out_idx][idx];
+      boolean vert1_out = cull_distance_is_out(cull1);
+      if (vert1_out)
+         return;
    }
+   stage->next->point( stage->next, header );
 }
 
 /*
@@ -94,29 +92,27 @@ static void cull_point( struct draw_stage *stage,
  * on primitives without faces (e.g. points and lines)
  */
 static void cull_line( struct draw_stage *stage,
-		      struct prim_header *header )
+                       struct prim_header *header )
 {
    const unsigned num_written_culldistances =
-      draw_current_shader_num_written_culldistances(stage->draw);
-
-   if (num_written_culldistances) {
-      unsigned i;
-      boolean culled = FALSE;
-      for (i = 0; i < num_written_culldistances; ++i) {
-         unsigned cull_idx = i / 4;
-         unsigned out_idx =
-            draw_current_shader_culldistance_output(stage->draw, cull_idx);
-         unsigned idx = i % 4;
-         float cull1 = header->v[0]->data[out_idx][idx];
-         float cull2 = header->v[1]->data[out_idx][idx];
-         boolean vert1_out = cull_distance_is_out(cull1);
-         boolean vert2_out = cull_distance_is_out(cull2);
-         if (vert1_out && vert2_out)
-            culled = TRUE;
-      }
-      if (!culled)
-         stage->next->line( stage->next, header );
+      draw_current_shader_num_written_culldistances(stage->draw);   
+   unsigned i;
+
+   debug_assert(num_written_culldistances);
+
+   for (i = 0; i < num_written_culldistances; ++i) {
+      unsigned cull_idx = i / 4;
+      unsigned out_idx =
+         draw_current_shader_culldistance_output(stage->draw, cull_idx);
+      unsigned idx = i % 4;
+      float cull1 = header->v[0]->data[out_idx][idx];
+      float cull2 = header->v[1]->data[out_idx][idx];
+      boolean vert1_out = cull_distance_is_out(cull1);
+      boolean vert2_out = cull_distance_is_out(cull2);
+      if (vert1_out && vert2_out)
+         return;
    }
+   stage->next->line( stage->next, header );
 }
 
 /*
@@ -133,7 +129,6 @@ static void cull_tri( struct draw_stage *stage,
    /* Do the distance culling */
    if (num_written_culldistances) {
       unsigned i;
-      boolean culled = FALSE;
       for (i = 0; i < num_written_culldistances; ++i) {
          unsigned cull_idx = i / 4;
          unsigned out_idx =
@@ -146,10 +141,8 @@ static void cull_tri( struct draw_stage *stage,
          boolean vert2_out = cull_distance_is_out(cull2);
          boolean vert3_out = cull_distance_is_out(cull3);
          if (vert1_out && vert2_out && vert3_out)
-            culled = TRUE;
+            return;
       }
-      if (!culled)
-         stage->next->tri( stage->next, header );
    }
 
    /* Do the regular face culling */
-- 
1.7.10.4