X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fgallium%2Fauxiliary%2Fdraw%2Fdraw_pipe_unfilled.c;h=7a88ce0f6d70f0b4a71120f26cd2248f663601e1;hb=76feef0823df75a36f264f48ec843dd863fd5b89;hp=a30fada86a0913b64fa7ec608cfc110e9249a301;hpb=eaad99d230c2c265b2cc20df0bf1f6f4a7837a67;p=mesa.git

diff --git a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
index a30fada86a0..7a88ce0f6d7 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
@@ -37,6 +37,7 @@
 #include "pipe/p_defines.h"
 #include "draw_private.h"
 #include "draw_pipe.h"
+#include "draw_fs.h"
 
 
 struct unfilled_stage {
@@ -47,6 +48,8 @@ struct unfilled_stage {
     * and PIPE_POLYGON_MODE_POINT,
     */
    unsigned mode[2];
+
+   int face_slot;
 };
 
 
@@ -55,8 +58,33 @@ static INLINE struct unfilled_stage *unfilled_stage( struct draw_stage *stage )
    return (struct unfilled_stage *)stage;
 }
 
+static void
+inject_front_face_info(struct draw_stage *stage,
+                       struct prim_header *header)
+{
+   struct unfilled_stage *unfilled = unfilled_stage(stage);
+   unsigned ccw = header->det < 0.0;
+   boolean is_front_face = (
+      (stage->draw->rasterizer->front_ccw && ccw) ||
+      (!stage->draw->rasterizer->front_ccw && !ccw));
+   int slot = unfilled->face_slot;
+   unsigned i;
+
+   /* In case the backend doesn't care about it */
+   if (slot < 0) {
+      return;
+   }
+
+   for (i = 0; i < 3; ++i) {
+      struct vertex_header *v = header->v[i];
+      v->data[slot][0] = is_front_face;
+      v->data[slot][1] = is_front_face;
+      v->data[slot][2] = is_front_face;
+      v->data[slot][3] = is_front_face;
+   }
+}
 
-
+   
 static void point( struct draw_stage *stage,
 		   struct vertex_header *v0 )
 {
@@ -83,6 +111,8 @@ static void points( struct draw_stage *stage,
    struct vertex_header *v1 = header->v[1];
    struct vertex_header *v2 = header->v[2];
 
+   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 );
@@ -99,6 +129,8 @@ static void lines( struct draw_stage *stage,
    if (header->flags & DRAW_PIPE_RESET_STIPPLE)
       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 );
@@ -134,7 +166,8 @@ static void unfilled_tri( struct draw_stage *stage,
 			  struct prim_header *header )
 {
    struct unfilled_stage *unfilled = unfilled_stage(stage);
-   unsigned mode = unfilled->mode[header->det >= 0.0];
+   unsigned cw = header->det >= 0.0;
+   unsigned mode = unfilled->mode[cw];
   
    if (0)
       print_header_flags(header->flags);
@@ -159,9 +192,10 @@ 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[0] = rast->front_ccw ? rast->fill_front : rast->fill_back;
+   unfilled->mode[1] = rast->front_ccw ? rast->fill_back : rast->fill_front;
 
    stage->tri = unfilled_tri;
    stage->tri( stage, header );
@@ -190,6 +224,29 @@ static void unfilled_destroy( struct draw_stage *stage )
    FREE( stage );
 }
 
+/*
+ * Try to allocate an output slot which we can use
+ * to preserve the front face information.
+ */
+void
+draw_unfilled_prepare_outputs( struct draw_context *draw,
+                               struct draw_stage *stage )
+{
+   struct unfilled_stage *unfilled = unfilled_stage(stage);
+   const struct pipe_rasterizer_state *rast = draw ? draw->rasterizer : 0;
+   boolean is_unfilled = (rast &&
+                          (rast->fill_front != PIPE_POLYGON_MODE_FILL ||
+                           rast->fill_back != PIPE_POLYGON_MODE_FILL));
+   const struct draw_fragment_shader *fs = draw->fs.fragment_shader;
+
+   if (is_unfilled && fs && fs->info.uses_frontface)  {
+      unfilled->face_slot = draw_alloc_extra_vertex_attrib(
+         stage->draw, TGSI_SEMANTIC_FACE, 0);
+   } else {
+      unfilled->face_slot = -1;
+   }
+}
+
 
 /**
  * Create unfilled triangle stage.
@@ -200,9 +257,6 @@ struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
    if (unfilled == NULL)
       goto fail;
 
-   if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))
-      goto fail;
-
    unfilled->stage.draw = draw;
    unfilled->stage.name = "unfilled";
    unfilled->stage.next = NULL;
@@ -214,6 +268,11 @@ struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
    unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
    unfilled->stage.destroy = unfilled_destroy;
 
+   unfilled->face_slot = -1;
+
+   if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))
+      goto fail;
+
    return &unfilled->stage;
 
  fail: