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 <[email protected]>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index c231aba1963..bc2f0e1d03f 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -289,7 +289,7 @@ void draw_set_rasterize_stage( struct draw_context *draw,
 void draw_set_clip_state( struct draw_context *draw,
                           const struct pipe_clip_state *clip )
 {
-   draw_do_flush( draw, DRAW_FLUSH_STATE_CHANGE );
+   draw_do_flush(draw, DRAW_FLUSH_PARAMETER_CHANGE);
 
    memcpy(&draw->plane[6], clip->ucp, sizeof(clip->ucp));
 }
@@ -301,7 +301,7 @@ void draw_set_clip_state( struct draw_context *draw,
 void draw_set_viewport_state( struct draw_context *draw,
                               const struct pipe_viewport_state *viewport )
 {
-   draw_do_flush( draw, DRAW_FLUSH_STATE_CHANGE );
+   draw_do_flush(draw, DRAW_FLUSH_PARAMETER_CHANGE);
    draw->viewport = *viewport; /* struct copy */
    draw->identity_viewport = (viewport->scale[0] == 1.0f &&
                               viewport->scale[1] == 1.0f &&
@@ -368,6 +368,8 @@ draw_set_mapped_constant_buffer(struct draw_context *draw,
                 shader_type == PIPE_SHADER_GEOMETRY);
    debug_assert(slot < PIPE_MAX_CONSTANT_BUFFERS);
 
+   draw_do_flush(draw, DRAW_FLUSH_PARAMETER_CHANGE);
+
    switch (shader_type) {
    case PIPE_SHADER_VERTEX:
       draw->pt.user.vs_constants[slot] = buffer;