From f58ab8e75c082a0aea36ed63fe7e21fb5fac14b6 Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Mon, 14 Apr 2008 10:56:56 -0600
Subject: [PATCH] gallium: take reduced prim, fill modes into account when
 culling

---
 src/gallium/drivers/softpipe/sp_context.h     |  2 ++
 src/gallium/drivers/softpipe/sp_draw_arrays.c | 15 +++++++++++++++
 src/gallium/drivers/softpipe/sp_setup.c       | 11 ++++++++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/softpipe/sp_context.h b/src/gallium/drivers/softpipe/sp_context.h
index 2442bd1eb00..0e1d5e561d9 100644
--- a/src/gallium/drivers/softpipe/sp_context.h
+++ b/src/gallium/drivers/softpipe/sp_context.h
@@ -105,6 +105,8 @@ struct softpipe_context {
 
    int psize_slot;
 
+   unsigned reduced_api_prim;  /**< PIPE_PRIM_POINTS, _LINES or _TRIANGLES */
+
 #if 0
    /* Stipple derived state:
     */
diff --git a/src/gallium/drivers/softpipe/sp_draw_arrays.c b/src/gallium/drivers/softpipe/sp_draw_arrays.c
index 61bcf518993..421509495a0 100644
--- a/src/gallium/drivers/softpipe/sp_draw_arrays.c
+++ b/src/gallium/drivers/softpipe/sp_draw_arrays.c
@@ -78,6 +78,20 @@ softpipe_unmap_constant_buffers(struct softpipe_context *sp)
 }
 
 
+static unsigned reduced_prim[PIPE_PRIM_POLYGON + 1] = {
+   PIPE_PRIM_POINTS,
+   PIPE_PRIM_LINES,
+   PIPE_PRIM_LINES,
+   PIPE_PRIM_LINES,
+   PIPE_PRIM_TRIANGLES,
+   PIPE_PRIM_TRIANGLES,
+   PIPE_PRIM_TRIANGLES,
+   PIPE_PRIM_TRIANGLES,
+   PIPE_PRIM_TRIANGLES,
+   PIPE_PRIM_TRIANGLES
+};
+
+
 boolean
 softpipe_draw_arrays(struct pipe_context *pipe, unsigned mode,
                      unsigned start, unsigned count)
@@ -115,6 +129,7 @@ softpipe_draw_elements(struct pipe_context *pipe,
       assert(0);
 #endif
 
+   sp->reduced_api_prim = reduced_prim[mode];
 
    if (sp->dirty)
       softpipe_update_derived( sp );
diff --git a/src/gallium/drivers/softpipe/sp_setup.c b/src/gallium/drivers/softpipe/sp_setup.c
index 0164d0588d6..813d7031083 100644
--- a/src/gallium/drivers/softpipe/sp_setup.c
+++ b/src/gallium/drivers/softpipe/sp_setup.c
@@ -1254,7 +1254,16 @@ void setup_prepare( struct setup_context *setup )
       sp->quad.first->begin(sp->quad.first);
    }
 
-   setup->winding = sp->rasterizer->cull_mode;
+   if (sp->reduced_api_prim == PIPE_PRIM_TRIANGLES &&
+       sp->rasterizer->fill_cw == PIPE_POLYGON_MODE_FILL &&
+       sp->rasterizer->fill_ccw == PIPE_POLYGON_MODE_FILL) {
+      /* we'll do culling */
+      setup->winding = sp->rasterizer->cull_mode;
+   }
+   else {
+      /* 'draw' will do culling */
+      setup->winding = PIPE_WINDING_NONE;
+   }
 }
 
 
-- 
2.30.2