draw: fix/improve dirty state validation

This patch does two things:

1. Constant buffer state changes were broken (but happened to work by
   dumb luck).  The problem is we weren't calling draw_do_flush() in
   draw_set_mapped_constant_buffer() when we changed that state.  All the
   other draw_set_foo() functions were calling draw_do_flush() already.

2. Use a simpler state validation step when we're changing light-weight
   parameter state such as constant buffers, viewport dims or clip planes.
   There's no need to revalidate the whole pipeline when changing state
   like that.  The new validation method is called bind_parameters()
   and is called instead of the prepare() method.  A new
   DRAW_FLUSH_PARAMETER_CHANGE flag is used to signal these light-weight
   state changes.  This results in a modest but measurable increase in
   FPS for many Mesa demos.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/gallium/auxiliary/draw/draw_private.h b/src/gallium/auxiliary/draw/draw_private.h
index e52b3fd..2223fcb 100644
--- a/src/gallium/auxiliary/draw/draw_private.h
+++ b/src/gallium/auxiliary/draw/draw_private.h
@@ -144,6 +144,8 @@ struct draw_context
       unsigned opt;     /**< bitmask of PT_x flags */
       unsigned eltSize; /* saved eltSize for flushing */
 
+      boolean rebind_parameters;
+
       struct {
          struct draw_pt_middle_end *fetch_emit;
          struct draw_pt_middle_end *fetch_shade_emit;
@@ -434,8 +436,9 @@ void draw_pipeline_flush( struct draw_context *draw,
  * Flushing 
  */
 
-#define DRAW_FLUSH_STATE_CHANGE              0x8
-#define DRAW_FLUSH_BACKEND                   0x10
+#define DRAW_FLUSH_PARAMETER_CHANGE 0x1  /**< Constants, viewport, etc */
+#define DRAW_FLUSH_STATE_CHANGE     0x2  /**< Other/heavy state changes */
+#define DRAW_FLUSH_BACKEND          0x4  /**< Flush the output buffer */
 
 
 void draw_do_flush( struct draw_context *draw, unsigned flags );