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

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

diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c
index 31e092e2cc62d03bc279985b96ebedb7b3591d6b..f5f65caf058d19577e79f824188b9ba138520f32 100644 (file)
--- 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 &&