From aaf03b94861cbf5a602863e4542dd1c2e54ba365 Mon Sep 17 00:00:00 2001
From: Brian <brian.paul@tungstengraphics.com>
Date: Thu, 30 Aug 2007 14:31:42 -0600
Subject: [PATCH] Fix lost edge flags problem when clipping.

In emit_poly() we need to compute header.edgeflags from the vertex
edge flags.  Also need to set header.det so later stages can determine
front/back orientation.
---
 src/mesa/pipe/draw/draw_clip.c     | 12 ++++++++++--
 src/mesa/pipe/draw/draw_unfilled.c |  6 ++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/mesa/pipe/draw/draw_clip.c b/src/mesa/pipe/draw/draw_clip.c
index a23b7a28109..1396b60f45e 100644
--- a/src/mesa/pipe/draw/draw_clip.c
+++ b/src/mesa/pipe/draw/draw_clip.c
@@ -177,11 +177,15 @@ static INLINE void do_tri( struct draw_stage *next,
 
 static void emit_poly( struct draw_stage *stage,
 		       struct vertex_header **inlist,
-		       unsigned n )
+		       unsigned n,
+                       const struct prim_header *origPrim)
 {
    struct prim_header header;
    unsigned i;
 
+   /* later stages may need the determinant, but only the sign matters */
+   header.det = origPrim->det;
+
    for (i = 2; i < n; i++) {
       header.v[0] = inlist[0];
       header.v[1] = inlist[i-1];
@@ -194,6 +198,10 @@ static void emit_poly( struct draw_stage *stage,
 	 if (i != 2)   header.v[0]->edgeflag = 0;
 	 if (i != n-1) header.v[2]->edgeflag = 0;
 
+         header.edgeflags = ((header.v[0]->edgeflag << 0) | 
+                             (header.v[1]->edgeflag << 1) | 
+                             (header.v[2]->edgeflag << 2));
+
 	 stage->next->tri( stage->next, &header );
 
 	 header.v[0]->edgeflag = tmp0;
@@ -302,7 +310,7 @@ do_clip_tri( struct draw_stage *stage,
    /* Emit the polygon as triangles to the setup stage:
     */
    if (n >= 3)
-      emit_poly( stage, inlist, n );
+      emit_poly( stage, inlist, n, header );
 }
 
 
diff --git a/src/mesa/pipe/draw/draw_unfilled.c b/src/mesa/pipe/draw/draw_unfilled.c
index 4215b8b2280..b0d6f3d0655 100644
--- a/src/mesa/pipe/draw/draw_unfilled.c
+++ b/src/mesa/pipe/draw/draw_unfilled.c
@@ -104,6 +104,12 @@ static void lines( struct draw_stage *stage,
    struct vertex_header *v1 = header->v[1];
    struct vertex_header *v2 = header->v[2];
 
+#if 0
+   assert(((header->edgeflags & 0x1) >> 0) == header->v[0]->edgeflag);
+   assert(((header->edgeflags & 0x2) >> 1) == header->v[1]->edgeflag);
+   assert(((header->edgeflags & 0x4) >> 2) == header->v[2]->edgeflag);
+#endif
+
    if (header->edgeflags & 0x1) line( stage, v0, v1 );
    if (header->edgeflags & 0x2) line( stage, v1, v2 );
    if (header->edgeflags & 0x4) line( stage, v2, v0 );
-- 
2.11.0