Mesa (master): i965/gen7: Make primitives_written counting work.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 43e0d775973446e84621fdb56af85f0027ed579c
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=43e0d775973446e84621fdb56af85f0027ed579c

Author: Eric Anholt <eric at anholt.net>
Date:   Thu Dec 22 10:50:21 2011 -0800

i965/gen7: Make primitives_written counting work.

The code was relying on gs.prog_data's copy of the
number-of-verts-per-prim, which segfaulted on gen7 since it doesn't
make a GS program.  We can easily calculate that value right here.

v2: Fix svbi_0_starting_index regression.

Reviewed-by: Paul Berry <stereotype441 at gmail.com>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/brw_draw.c |   33 +++++++++++++++++++++++++++------
 1 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_draw.c b/src/mesa/drivers/dri/i965/brw_draw.c
index 93f27d7..621195d 100644
--- a/src/mesa/drivers/dri/i965/brw_draw.c
+++ b/src/mesa/drivers/dri/i965/brw_draw.c
@@ -379,6 +379,30 @@ static void brw_postdraw_set_buffers_need_resolve(struct brw_context *brw)
    }
 }
 
+static int
+verts_per_prim(GLenum mode)
+{
+   switch (mode) {
+   case GL_POINTS:
+      return 1;
+   case GL_LINE_STRIP:
+   case GL_LINE_LOOP:
+   case GL_LINES:
+      return 2;
+   case GL_TRIANGLE_STRIP:
+   case GL_TRIANGLE_FAN:
+   case GL_POLYGON:
+   case GL_TRIANGLES:
+   case GL_QUADS:
+   case GL_QUAD_STRIP:
+      return 3;
+   default:
+      _mesa_problem(NULL,
+		    "unknown prim type in transform feedback primitive count");
+      return 0;
+   }
+}
+
 /**
  * Update internal counters based on the the drawing operation described in
  * prim.
@@ -398,14 +422,11 @@ brw_update_primitive_count(struct brw_context *brw,
        * able to reload SVBI 0 with the correct value in case we have to start
        * a new batch buffer.
        */
-      unsigned svbi_postincrement_value =
-         brw->gs.prog_data->svbi_postincrement_value;
+      unsigned verts = verts_per_prim(prim->mode);
       uint32_t space_avail =
-         (brw->sol.svbi_0_max_index - brw->sol.svbi_0_starting_index)
-         / svbi_postincrement_value;
+         (brw->sol.svbi_0_max_index - brw->sol.svbi_0_starting_index) / verts;
       uint32_t primitives_written = MIN2 (space_avail, count);
-      brw->sol.svbi_0_starting_index +=
-         svbi_postincrement_value * primitives_written;
+      brw->sol.svbi_0_starting_index += verts * primitives_written;
 
       /* And update the TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN query. */
       brw->sol.primitives_written += primitives_written;