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

Use front/back instead of cw/ccw throughout.
Also, use offset_point/line/fill instead of offset_cw/ccw.

Brings gallium representation of this state into line with its main
user, and also what turns out to be the most common hardware
representation.

This fixes a long-standing bias in the interface towards the
architecture of the software rasterizer.

5 files changed, 25 insertions, 16 deletions

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 02abddf1491..61980c3e4f5 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -566,7 +566,7 @@ draw_get_rasterizer_no_cull( struct draw_context *draw,
       memset(&rast, 0, sizeof(rast));
       rast.scissor = scissor;
       rast.flatshade = flatshade;
-      rast.front_winding = PIPE_WINDING_CCW;
+      rast.front_ccw = 1;
       rast.gl_rasterization_rules = draw->rasterizer->gl_rasterization_rules;
 
       draw->rasterizer_no_cull[scissor][flatshade] =
diff --git a/src/gallium/auxiliary/draw/draw_pipe_cull.c b/src/gallium/auxiliary/draw/draw_pipe_cull.c
index dc66c65a56c..bf84ce30ed1 100644
--- 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;
 };
 
 
@@ -73,9 +74,12 @@ static void cull_tri( struct draw_stage *stage,
       /* 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 );
       }
@@ -88,7 +92,8 @@ static void cull_first_tri( struct draw_stage *stage,
 {
    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 );
diff --git a/src/gallium/auxiliary/draw/draw_pipe_twoside.c b/src/gallium/auxiliary/draw/draw_pipe_twoside.c
index eef0238b157..808b2fb0b58 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_twoside.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_twoside.c
@@ -141,7 +141,7 @@ static void twoside_first_tri( struct draw_stage *stage,
     * if the triangle is back-facing (negative).
     * sign = -1 for CCW, +1 for CW
     */
-   twoside->sign = (stage->draw->rasterizer->front_winding == PIPE_WINDING_CCW) ? -1.0f : 1.0f;
+   twoside->sign = stage->draw->rasterizer->front_ccw ? -1.0f : 1.0f;
 
    stage->tri = twoside_tri;
    stage->tri( stage, header );
diff --git a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
index a30fada86a0..d1f05129b93 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
@@ -159,9 +159,10 @@ static void unfilled_first_tri( struct draw_stage *stage,
 				struct prim_header *header )
 {
    struct unfilled_stage *unfilled = unfilled_stage(stage);
+   const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;
 
-   unfilled->mode[0] = stage->draw->rasterizer->fill_ccw; /* front */
-   unfilled->mode[1] = stage->draw->rasterizer->fill_cw;  /* back */
+   unfilled->mode[rast->front_ccw ? 0 : 1] = rast->fill_front;
+   unfilled->mode[rast->front_ccw ? 1 : 0] = rast->fill_back;
 
    stage->tri = unfilled_tri;
    stage->tri( stage, header );
diff --git a/src/gallium/auxiliary/draw/draw_pipe_validate.c b/src/gallium/auxiliary/draw/draw_pipe_validate.c
index 2a50af7a414..72dfbc4d4ab 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_validate.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_validate.c
@@ -122,12 +122,14 @@ draw_need_pipeline(const struct draw_context *draw,
          return TRUE;
 
       /* unfilled polygons */
-      if (rasterizer->fill_cw != PIPE_POLYGON_MODE_FILL ||
-          rasterizer->fill_ccw != PIPE_POLYGON_MODE_FILL)
+      if (rasterizer->fill_front != PIPE_POLYGON_MODE_FILL ||
+          rasterizer->fill_front != PIPE_POLYGON_MODE_FILL)
          return TRUE;
       
       /* polygon offset */
-      if (rasterizer->offset_cw || rasterizer->offset_ccw)
+      if (rasterizer->offset_point ||
+          rasterizer->offset_line ||
+          rasterizer->offset_tri)
          return TRUE;
 
       /* two-side lighting */
@@ -222,8 +224,8 @@ static struct draw_stage *validate_pipeline( struct draw_stage *stage )
       next = draw->pipeline.pstipple;
    }
 
-   if (rast->fill_cw != PIPE_POLYGON_MODE_FILL ||
-       rast->fill_ccw != PIPE_POLYGON_MODE_FILL) {
+   if (rast->fill_front != PIPE_POLYGON_MODE_FILL ||
+       rast->fill_back != PIPE_POLYGON_MODE_FILL) {
       draw->pipeline.unfilled->next = next;
       next = draw->pipeline.unfilled;
       precalc_flat = TRUE;		/* only needed for triangles really */
@@ -235,8 +237,9 @@ static struct draw_stage *validate_pipeline( struct draw_stage *stage )
       next = draw->pipeline.flatshade;
    }
 	 
-   if (rast->offset_cw ||
-       rast->offset_ccw) {
+   if (rast->offset_point ||
+       rast->offset_line ||
+       rast->offset_tri) {
       draw->pipeline.offset->next = next;
       next = draw->pipeline.offset;
       need_det = TRUE;
@@ -255,7 +258,7 @@ static struct draw_stage *validate_pipeline( struct draw_stage *stage )
     * to less work emitting vertices, smaller vertex buffers, etc.
     * It's difficult to say whether this will be true in general.
     */
-   if (need_det || rast->cull_mode) {
+   if (need_det || rast->cull_face != PIPE_FACE_NONE) {
       draw->pipeline.cull->next = next;
       next = draw->pipeline.cull;
    }