gallium: add start_slot parameter to set_vertex_buffers

This allows updating only a subrange of buffer bindings.

set_vertex_buffers(pipe, start_slot, count, NULL) unbinds buffers in that
range. Binding NULL resources unbinds buffers too (both buffer and user_buffer
must be NULL).

The meta ops are adapted to only save, change, and restore the single slot
they use. The cso_context can save and restore only one vertex buffer slot.
The clients can query which one it is using cso_get_aux_vertex_buffer_slot.
It's currently set to 0. (the Draw module breaks if it's set to non-zero)

It should decrease the CPU overhead when using a lot of meta ops, but
the drivers must be able to treat each vertex buffer slot as a separate
state (only r600g does so at the moment).

I can imagine this also being useful for optimizing some OpenGL use cases.

Reviewed-by: Brian Paul <[email protected]>

4 files changed, 7 insertions, 28 deletions

diff --git a/src/gallium/drivers/svga/svga_context.h b/src/gallium/drivers/svga/svga_context.h
index f2f26da1cd5..32671ecafa7 100644
--- a/src/gallium/drivers/svga/svga_context.h
+++ b/src/gallium/drivers/svga/svga_context.h
@@ -234,8 +234,6 @@ struct svga_state
       unsigned flag_1d;
       unsigned flag_srgb;
    } tex_flags;
-
-   boolean any_user_vertex_buffers;
 };
 
 struct svga_prescale {
diff --git a/src/gallium/drivers/svga/svga_pipe_blit.c b/src/gallium/drivers/svga/svga_pipe_blit.c
index 34ac995ef60..a44ed12adf7 100644
--- a/src/gallium/drivers/svga/svga_pipe_blit.c
+++ b/src/gallium/drivers/svga/svga_pipe_blit.c
@@ -183,9 +183,7 @@ static void svga_blit(struct pipe_context *pipe,
 
    /* XXX turn off occlusion and streamout queries */
 
-   util_blitter_save_vertex_buffers(svga->blitter,
-                                    svga->curr.num_vertex_buffers,
-                                    svga->curr.vb);
+   util_blitter_save_vertex_buffer_slot(svga->blitter, svga->curr.vb);
    util_blitter_save_vertex_elements(svga->blitter, (void*)svga->curr.velems);
    util_blitter_save_vertex_shader(svga->blitter, svga->curr.vs);
    /*util_blitter_save_geometry_shader(svga->blitter, svga->curr.gs);*/
diff --git a/src/gallium/drivers/svga/svga_pipe_vertex.c b/src/gallium/drivers/svga/svga_pipe_vertex.c
index 58469910732..82bd1b33efe 100644
--- a/src/gallium/drivers/svga/svga_pipe_vertex.c
+++ b/src/gallium/drivers/svga/svga_pipe_vertex.c
@@ -23,6 +23,7 @@
  *
  **********************************************************/
 
+#include "util/u_helpers.h"
 #include "util/u_inlines.h"
 #include "pipe/p_defines.h"
 #include "util/u_math.h"
@@ -36,32 +37,14 @@
 
 
 static void svga_set_vertex_buffers(struct pipe_context *pipe,
-                                    unsigned count,
+                                    unsigned start_slot, unsigned count,
                                     const struct pipe_vertex_buffer *buffers)
 {
    struct svga_context *svga = svga_context(pipe);
-   unsigned i;
-   boolean any_user_buffer = FALSE;
-
-   /* Check for no change */
-   if (count == svga->curr.num_vertex_buffers &&
-       memcmp(svga->curr.vb, buffers, count * sizeof buffers[0]) == 0)
-      return;
-
-   /* Adjust refcounts */
-   for (i = 0; i < count; i++) {
-      pipe_resource_reference(&svga->curr.vb[i].buffer, buffers[i].buffer);
-      if (svga_buffer_is_user_buffer(buffers[i].buffer))
-         any_user_buffer = TRUE;
-   }
-
-   for ( ; i < svga->curr.num_vertex_buffers; i++)
-      pipe_resource_reference(&svga->curr.vb[i].buffer, NULL);
 
-   /* Copy remaining data */
-   memcpy(svga->curr.vb, buffers, count * sizeof buffers[0]);
-   svga->curr.num_vertex_buffers = count;
-   svga->curr.any_user_vertex_buffers = any_user_buffer;
+   util_set_vertex_buffers_count(svga->curr.vb,
+                                 &svga->curr.num_vertex_buffers,
+                                 buffers, start_slot, count);
 
    svga->dirty |= SVGA_NEW_VBUFFER;
 }
diff --git a/src/gallium/drivers/svga/svga_swtnl_state.c b/src/gallium/drivers/svga/svga_swtnl_state.c
index e9239bafef9..dea3a26b6f2 100644
--- a/src/gallium/drivers/svga/svga_swtnl_state.c
+++ b/src/gallium/drivers/svga/svga_swtnl_state.c
@@ -98,7 +98,7 @@ update_swtnl_draw( struct svga_context *svga,
                                 svga->curr.fs->draw_shader);
 
    if (dirty & SVGA_NEW_VBUFFER)
-      draw_set_vertex_buffers(svga->swtnl.draw, 
+      draw_set_vertex_buffers(svga->swtnl.draw, 0,
                               svga->curr.num_vertex_buffers, 
                               svga->curr.vb);