[Mesa-dev] [PATCH 2/7] i965/gen7: Make primitives_written counting work.

[Eric Anholt]

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.
---
 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 082bb9a..c116d39 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.
@@ -397,14 +421,11 @@ 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;
 
       /* And update the TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN query. */
       brw->sol.primitives_written += primitives_written;
-- 
1.7.7.3