1 files changed, 80 insertions, 1 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_primitive_restart.c b/src/mesa/drivers/dri/i965/brw_primitive_restart.c
index d7136ed6fb9..962ff18fede 100644
--- a/src/mesa/drivers/dri/i965/brw_primitive_restart.c
+++ b/src/mesa/drivers/dri/i965/brw_primitive_restart.c
@@ -32,6 +32,74 @@
 #include "brw_draw.h"
 
 /**
+ * Check if the hardware's cut index support can handle the primitive
+ * restart index value.
+ */
+static bool
+can_cut_index_handle_restart_index(struct gl_context *ctx,
+                                   const struct _mesa_index_buffer *ib)
+{
+   bool cut_index_will_work;
+
+   switch (ib->type) {
+   case GL_UNSIGNED_BYTE:
+      cut_index_will_work = (ctx->Array.RestartIndex & 0xff) == 0xff;
+      break;
+   case GL_UNSIGNED_SHORT:
+      cut_index_will_work = (ctx->Array.RestartIndex & 0xffff) == 0xffff;
+      break;
+   case GL_UNSIGNED_INT:
+      cut_index_will_work = ctx->Array.RestartIndex == 0xffffffff;
+      break;
+   default:
+      cut_index_will_work = false;
+      assert(0);
+   }
+
+   return cut_index_will_work;
+}
+
+/**
+ * Check if the hardware's cut index support can handle the primitive
+ * restart case.
+ */
+static bool
+can_cut_index_handle_prims(struct gl_context *ctx,
+                           const struct _mesa_prim *prim,
+                           GLuint nr_prims,
+                           const struct _mesa_index_buffer *ib)
+{
+   if (!can_cut_index_handle_restart_index(ctx, ib)) {
+      /* The primitive restart index can't be handled, so take
+       * the software path
+       */
+      return false;
+   }
+
+   for ( ; nr_prims > 0; nr_prims--) {
+      switch(prim->mode) {
+      case GL_POINTS:
+      case GL_LINES:
+      case GL_LINE_STRIP:
+      case GL_TRIANGLES:
+      case GL_TRIANGLE_STRIP:
+         /* Cut index supports these primitive types */
+         break;
+      default:
+         /* Cut index does not support these primitive types */
+      //case GL_LINE_LOOP:
+      //case GL_TRIANGLE_FAN:
+      //case GL_QUADS:
+      //case GL_QUAD_STRIP:
+      //case GL_POLYGON:
+         return false;
+      }
+   }
+
+   return true;
+}
+
+/**
  * Check if primitive restart is enabled, and if so, handle it properly.
  *
  * In some cases the support will be handled in software. When available
@@ -77,7 +145,18 @@ brw_handle_primitive_restart(struct gl_context *ctx,
     */
    brw->prim_restart.in_progress = true;
 
-   vbo_sw_primitive_restart(ctx, prim, nr_prims, ib);
+   if (can_cut_index_handle_prims(ctx, prim, nr_prims, ib)) {
+      /* Cut index should work for primitive restart, so use it
+       */
+      brw->prim_restart.enable_cut_index = true;
+      brw_draw_prims(ctx, prim, nr_prims, ib, GL_FALSE, -1, -1, NULL);
+      brw->prim_restart.enable_cut_index = false;
+   } else {
+      /* Not all the primitive draw modes are supported by the cut index,
+       * so take the software path
+       */
+      vbo_sw_primitive_restart(ctx, prim, nr_prims, ib);
+   }
 
    brw->prim_restart.in_progress = false;