[Mesa-dev] [PATCH] draw: fix line stippling with unfilled prims

[sroland at vmware.com]

From: Roland Scheidegger <sroland at vmware.com>

The unfilled stage was not filling in the prim header, and the line stage
then decided to reset the stipple counter or not based on the uninitialized
data. This causes some failures in conform linestipple test (albeit quite
randomly happening depending on environment).
So fill in the prim header in the unfilled stage - I am not entirely sure
if anybody really needs determinant after that stage, but there's at least
later stages (wide line for instance) which copy over the determinant as well.
---
 src/gallium/auxiliary/draw/draw_pipe_unfilled.c | 56 +++++++++++++++++--------
 1 file changed, 38 insertions(+), 18 deletions(-)

diff --git a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
index 8e6435c..b9ded14 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
@@ -86,27 +86,33 @@ inject_front_face_info(struct draw_stage *stage,
 }
 
    
-static void point( struct draw_stage *stage,
-		   struct vertex_header *v0 )
+static void point(struct draw_stage *stage,
+                  struct prim_header *header,
+                  struct vertex_header *v0)
 {
    struct prim_header tmp;
+   tmp.det = header->det;
+   tmp.flags = 0;
    tmp.v[0] = v0;
-   stage->next->point( stage->next, &tmp );
+   stage->next->point(stage->next, &tmp);
 }
 
-static void line( struct draw_stage *stage,
-		  struct vertex_header *v0,
-		  struct vertex_header *v1 )
+static void line(struct draw_stage *stage,
+                 struct prim_header *header,
+                 struct vertex_header *v0,
+                 struct vertex_header *v1)
 {
    struct prim_header tmp;
+   tmp.det = header->det;
+   tmp.flags = 0;
    tmp.v[0] = v0;
    tmp.v[1] = v1;
-   stage->next->line( stage->next, &tmp );
+   stage->next->line(stage->next, &tmp);
 }
 
 
-static void points( struct draw_stage *stage,
-		    struct prim_header *header )
+static void points(struct draw_stage *stage,
+                   struct prim_header *header)
 {
    struct vertex_header *v0 = header->v[0];
    struct vertex_header *v1 = header->v[1];
@@ -114,27 +120,41 @@ static void points( struct draw_stage *stage,
 
    inject_front_face_info(stage, header);
 
-   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) point( stage, v0 );
-   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) point( stage, v1 );
-   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) point( stage, v2 );
+   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag)
+      point(stage, header, v0);
+   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag)
+      point(stage, header, v1);
+   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag)
+      point(stage, header, v2);
 }
 
 
-static void lines( struct draw_stage *stage,
-		   struct prim_header *header )
+static void lines(struct draw_stage *stage,
+                  struct prim_header *header)
 {
    struct vertex_header *v0 = header->v[0];
    struct vertex_header *v1 = header->v[1];
    struct vertex_header *v2 = header->v[2];
 
    if (header->flags & DRAW_PIPE_RESET_STIPPLE)
-      stage->next->reset_stipple_counter( stage->next );
+      /*
+       * XXX could revisit this. The only stage which cares is the line
+       * stipple stage. Could just emit correct reset flags here and not
+       * bother about all the calling through reset_stipple_counter
+       * stages. Though technically it is necessary if line stipple is
+       * handled by the driver, but this is not actually hooked up when
+       * using vbuf (vbuf stage reset_stipple_counter does nothing).
+       */
+      stage->next->reset_stipple_counter(stage->next);
 
    inject_front_face_info(stage, header);
 
-   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) line( stage, v2, v0 );
-   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) line( stage, v0, v1 );
-   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) line( stage, v1, v2 );
+   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag)
+      line(stage, header, v2, v0);
+   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag)
+      line(stage, header, v0, v1);
+   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag)
+      line(stage, header, v1, v2);
 }
 
 
-- 
2.1.4