Mesa (master): i965: Add a comment explaining one of the brw_draw_upload. c loops.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 7f9e1a7720f5e7b464c39e3640e8ed64687e9645
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7f9e1a7720f5e7b464c39e3640e8ed64687e9645

Author: Eric Anholt <eric at anholt.net>
Date:   Fri Sep 21 07:26:33 2012 +0200

i965: Add a comment explaining one of the brw_draw_upload.c loops.

Reviewed-and-tested-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/brw_draw_upload.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c
index 31e092e..f5f65ca 100644
--- a/src/mesa/drivers/dri/i965/brw_draw_upload.c
+++ b/src/mesa/drivers/dri/i965/brw_draw_upload.c
@@ -411,6 +411,10 @@ static void brw_prepare_vertices(struct brw_context *brw)
 	    intel_buffer_object(glarray->BufferObj);
 	 int k;
 
+	 /* If we have a VB set to be uploaded for this buffer object
+	  * already, reuse that VB state so that we emit fewer
+	  * relocations.
+	  */
 	 for (k = 0; k < i; k++) {
 	    const struct gl_client_array *other = brw->vb.enabled[k]->glarray;
 	    if (glarray->BufferObj == other->BufferObj &&