[Mesa-dev] [PATCH 1/2] vbo: Make vbo_sw_primitive_restart optionally count primitives.

[Paul Berry]

This will be necessary in order to get the i965 back-end to produce
the correct value of gl_PrimitiveIDIn when using software primitive
restart.
---
 src/mesa/drivers/dri/i965/brw_primitive_restart.c |  2 +-
 src/mesa/vbo/vbo.h                                |  3 ++-
 src/mesa/vbo/vbo_exec_array.c                     |  2 +-
 src/mesa/vbo/vbo_primitive_restart.c              | 16 +++++++++++++++-
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_primitive_restart.c b/src/mesa/drivers/dri/i965/brw_primitive_restart.c
index 2ee6055..2572c12 100644
--- a/src/mesa/drivers/dri/i965/brw_primitive_restart.c
+++ b/src/mesa/drivers/dri/i965/brw_primitive_restart.c
@@ -175,7 +175,7 @@ brw_handle_primitive_restart(struct gl_context *ctx,
       /* Not all the primitive draw modes are supported by the cut index,
        * so take the software path
        */
-      vbo_sw_primitive_restart(ctx, prims, nr_prims, ib);
+      vbo_sw_primitive_restart(ctx, prims, nr_prims, ib, NULL);
    }
 
    brw->prim_restart.in_progress = false;
diff --git a/src/mesa/vbo/vbo.h b/src/mesa/vbo/vbo.h
index c4472e9..ec3b6f5 100644
--- a/src/mesa/vbo/vbo.h
+++ b/src/mesa/vbo/vbo.h
@@ -182,7 +182,8 @@ void
 vbo_sw_primitive_restart(struct gl_context *ctx,
                          const struct _mesa_prim *prim,
                          GLuint nr_prims,
-                         const struct _mesa_index_buffer *ib);
+                         const struct _mesa_index_buffer *ib,
+                         GLuint *prim_count);
 
 void GLAPIENTRY
 _es_Color4f(GLfloat r, GLfloat g, GLfloat b, GLfloat a);
diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index 1670409..afe2a15 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -579,7 +579,7 @@ vbo_handle_primitive_restart(struct gl_context *ctx,
        ctx->Const.PrimitiveRestartInSoftware &&
        ctx->Array._PrimitiveRestart) {
       /* Handle primitive restart in software */
-      vbo_sw_primitive_restart(ctx, prim, nr_prims, ib);
+      vbo_sw_primitive_restart(ctx, prim, nr_prims, ib, NULL);
    } else {
       /* Call driver directly for draw_prims */
       vbo->draw_prims(ctx, prim, nr_prims, ib,
diff --git a/src/mesa/vbo/vbo_primitive_restart.c b/src/mesa/vbo/vbo_primitive_restart.c
index 418f882..13a8c43 100644
--- a/src/mesa/vbo/vbo_primitive_restart.c
+++ b/src/mesa/vbo/vbo_primitive_restart.c
@@ -158,12 +158,17 @@ find_sub_primitives(const void *elements, unsigned element_size,
  *
  * This function breaks up calls into the driver so primitive restart
  * support is not required in the driver.
+ *
+ * If a non-NULL value is passed in prim_count, then prior to each draw call,
+ * that value is updated to contain the number of primitives previously
+ * processed.
  */
 void
 vbo_sw_primitive_restart(struct gl_context *ctx,
                          const struct _mesa_prim *prims,
                          GLuint nr_prims,
-                         const struct _mesa_index_buffer *ib)
+                         const struct _mesa_index_buffer *ib,
+                         GLuint *prim_count)
 {
    GLuint prim_num;
    struct sub_primitive *sub_prims;
@@ -197,6 +202,9 @@ vbo_sw_primitive_restart(struct gl_context *ctx,
       ctx->Driver.UnmapBuffer(ctx, ib->obj);
    }
 
+   if (prim_count != NULL)
+      *prim_count = 0;
+
    /* Loop over the primitives, and use the located sub-primitives to draw
     * each primitive with a break to implement each primitive restart.
     */
@@ -220,6 +228,12 @@ vbo_sw_primitive_restart(struct gl_context *ctx,
                                GL_FALSE, -1, -1,
                                NULL);
             }
+            if (prim_count != NULL) {
+               *prim_count +=
+                  vbo_count_tessellated_primitives(temp_prim.mode,
+                                                   temp_prim.count,
+                                                   temp_prim.num_instances);
+            }
          }
          if (sub_end_index >= end_index) {
             break;
-- 
1.8.4