gallium: convert rasterizer state to use gl-style front/back concepts

[mesa.git] / src / gallium / auxiliary / draw / draw_pipe_cull.c

diff --git a/src/gallium/auxiliary/draw/draw_pipe_cull.c b/src/gallium/auxiliary/draw/draw_pipe_cull.c
index 053be5f050dec7d7d168ab634e77ac993af169a7..bf84ce30ed1cf3aabeaf45b497a8909cea7525e5 100644 (file)
--- a/src/gallium/auxiliary/draw/draw_pipe_cull.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_cull.c
@@ -40,7 +40,8 @@
 
 struct cull_stage {
    struct draw_stage stage;
-   unsigned winding;  /**< which winding(s) to cull (one of PIPE_WINDING_x) */
+   unsigned cull_face;  /**< which face(s) to cull (one of PIPE_FACE_x) */
+   unsigned front_ccw;
 };
 
 
@@ -50,19 +51,17 @@ static INLINE struct cull_stage *cull_stage( struct draw_stage *stage )
 }
 
 
-
-
 static void cull_tri( struct draw_stage *stage,
                      struct prim_header *header )
 {
-   const unsigned pos = stage->draw->vs.position_output;
+   const unsigned pos = draw_current_shader_position_output(stage->draw);
 
    /* Window coords: */
    const float *v0 = header->v[0]->data[pos];
    const float *v1 = header->v[1]->data[pos];
    const float *v2 = header->v[2]->data[pos];
 
-   /* edge vectors e = v0 - v2, f = v1 - v2 */
+   /* edge vectors: e = v0 - v2, f = v1 - v2 */
    const float ex = v0[0] - v2[0];
    const float ey = v0[1] - v2[1];
    const float fx = v1[0] - v2[0];
@@ -72,37 +71,42 @@ static void cull_tri( struct draw_stage *stage,
    header->det = ex * fy - ey * fx;
 
    if (header->det != 0) {
-      /* if (det < 0 then Z points toward camera and triangle is 
+      /* if det < 0 then Z points toward the camera and the triangle is 
        * counter-clockwise winding.
        */
-      unsigned winding = (header->det < 0) ? PIPE_WINDING_CCW : PIPE_WINDING_CW;
+      unsigned ccw = (header->det < 0);
+      unsigned face = ((ccw == cull_stage(stage)->front_ccw) ?
+                       PIPE_FACE_FRONT :
+                       PIPE_FACE_BACK);
 
-      if ((winding & cull_stage(stage)->winding) == 0) {
+      if ((face & cull_stage(stage)->cull_face) == 0) {
          /* triangle is not culled, pass to next stage */
         stage->next->tri( stage->next, header );
       }
    }
 }
 
+
 static void cull_first_tri( struct draw_stage *stage, 
                            struct prim_header *header )
 {
    struct cull_stage *cull = cull_stage(stage);
 
-   cull->winding = stage->draw->rasterizer->cull_mode;
+   cull->cull_face = stage->draw->rasterizer->cull_face;
+   cull->front_ccw = stage->draw->rasterizer->front_ccw;
 
    stage->tri = cull_tri;
    stage->tri( stage, header );
 }
 
 
-
 static void cull_flush( struct draw_stage *stage, unsigned flags )
 {
    stage->tri = cull_first_tri;
    stage->next->flush( stage->next, flags );
 }
 
+
 static void cull_reset_stipple_counter( struct draw_stage *stage )
 {
    stage->next->reset_stipple_counter( stage->next );
@@ -129,6 +133,7 @@ struct draw_stage *draw_cull_stage( struct draw_context *draw )
       goto fail;
 
    cull->stage.draw = draw;
+   cull->stage.name = "cull";
    cull->stage.next = NULL;
    cull->stage.point = draw_pipe_passthrough_point;
    cull->stage.line = draw_pipe_passthrough_line;
@@ -139,7 +144,7 @@ struct draw_stage *draw_cull_stage( struct draw_context *draw )
 
    return &cull->stage;
 
- fail:
+fail:
    if (cull)
       cull->stage.destroy( &cull->stage );