svga: implement an index buffer translation cache

Some OpenGL apps, like Cinebench R15, have many glDrawElements(GL_QUADS)
calls.  Since we don't directly support quads we have to convert these
calls into GL_TRIANGLES which involves generating a new index buffer.

This patch saves the new/translated index buffer in the hope that it
can be reused for a later draw call.

Cinebench R15 increases by about 20% with this change.
The NobelClinician Viewer app also hits this code.
Tested with full piglit run.

Reviewed-by: Charmaine Lee <[email protected]>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/gallium/drivers/svga/svga_resource_buffer.h b/src/gallium/drivers/svga/svga_resource_buffer.h
index daf9c18a95a..69075888892 100644
--- a/src/gallium/drivers/svga/svga_resource_buffer.h
+++ b/src/gallium/drivers/svga/svga_resource_buffer.h
@@ -192,6 +192,17 @@ struct svga_buffer
    unsigned size;  /**< Approximate size in bytes */
 
    boolean dirty;  /**< Need to do a readback before mapping? */
+
+   /** In some cases we try to keep the results of the translate_indices()
+    * function from svga_draw_elements.c
+    */
+   struct {
+      enum pipe_prim_type orig_prim, new_prim;
+      struct pipe_resource *buffer;
+      unsigned index_size;
+      unsigned offset;  /**< first index */
+      unsigned count;   /**< num indices */
+   } translated_indices;
 };