diff options
author | Brian <brian.paul@tungstengraphics.com> | 2007-07-13 14:22:46 -0600 |
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committer | Brian <brian.paul@tungstengraphics.com> | 2007-07-13 14:22:46 -0600 |
commit | dc313b578386dc07f4916fba98da061af3ab18e5 (patch) | |
tree | 28dc7a6218e61a152136555e3f32d017c1762b2d /src/mesa/pipe/draw/draw_cull.c | |
parent | 2bf4a500de24347476ce96cdd48d68ddeecbb019 (diff) |
Fix more polygon winding, culling confusion.
If the determinant of the triangle is positive, its winding is CCW (right-handed coord system).
Diffstat (limited to 'src/mesa/pipe/draw/draw_cull.c')
-rw-r--r-- | src/mesa/pipe/draw/draw_cull.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/src/mesa/pipe/draw/draw_cull.c b/src/mesa/pipe/draw/draw_cull.c index 863686f150..e563f9f45f 100644 --- a/src/mesa/pipe/draw/draw_cull.c +++ b/src/mesa/pipe/draw/draw_cull.c @@ -40,7 +40,7 @@ struct cull_stage { struct draw_stage stage; - GLuint mode; /**< one of PIPE_WINDING_x */ + GLuint winding; /**< which winding(s) to cull (one of PIPE_WINDING_x) */ }; @@ -54,7 +54,7 @@ static void cull_begin( struct draw_stage *stage ) { struct cull_stage *cull = cull_stage(stage); - cull->mode = stage->draw->setup.cull_mode; + cull->winding = stage->draw->setup.cull_mode; stage->next->begin( stage->next ); } @@ -78,10 +78,12 @@ static void cull_tri( struct draw_stage *stage, header->det = ex * fy - ey * fx; if (header->det != 0) { - /* non-zero area */ - GLuint mode = (header->det > 0) ? PIPE_WINDING_CW : PIPE_WINDING_CCW; + /* if (det > 0 then Z points toward camera and triangle is + * counter-clockwise winding. + */ + GLuint winding = (header->det > 0) ? PIPE_WINDING_CCW : PIPE_WINDING_CW; - if ((mode & cull_stage(stage)->mode) == 0) { + if ((winding & cull_stage(stage)->winding) == 0) { /* triangle is not culled, pass to next stage */ stage->next->tri( stage->next, header ); } |