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]>

1 files changed, 11 insertions, 8 deletions

diff --git a/src/gallium/auxiliary/util/u_blit.c b/src/gallium/auxiliary/util/u_blit.c
index bf1c392cd41..ab1549e2de6 100644
--- a/src/gallium/auxiliary/util/u_blit.c
+++ b/src/gallium/auxiliary/util/u_blit.c
@@ -133,7 +133,7 @@ util_create_blit(struct pipe_context *pipe, struct cso_context *cso)
    for (i = 0; i < 2; i++) {
       ctx->velem[i].src_offset = i * 4 * sizeof(float);
       ctx->velem[i].instance_divisor = 0;
-      ctx->velem[i].vertex_buffer_index = 0;
+      ctx->velem[i].vertex_buffer_index = cso_get_aux_vertex_buffer_slot(cso);
       ctx->velem[i].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
    }
 
@@ -665,7 +665,7 @@ util_blit_pixels(struct blit_state *ctx,
    cso_save_vertex_shader(ctx->cso);
    cso_save_geometry_shader(ctx->cso);
    cso_save_vertex_elements(ctx->cso);
-   cso_save_vertex_buffers(ctx->cso);
+   cso_save_aux_vertex_buffer_slot(ctx->cso);
 
    /* set misc state we care about */
    if (writemask)
@@ -776,7 +776,9 @@ util_blit_pixels(struct blit_state *ctx,
                                   z);
 
    if (ctx->vbuf) {
-      util_draw_vertex_buffer(ctx->pipe, ctx->cso, ctx->vbuf, offset,
+      util_draw_vertex_buffer(ctx->pipe, ctx->cso, ctx->vbuf,
+                              cso_get_aux_vertex_buffer_slot(ctx->cso),
+                              offset,
                               PIPE_PRIM_TRIANGLE_FAN,
                               4,  /* verts */
                               2); /* attribs/vert */
@@ -795,7 +797,7 @@ util_blit_pixels(struct blit_state *ctx,
    cso_restore_vertex_shader(ctx->cso);
    cso_restore_geometry_shader(ctx->cso);
    cso_restore_vertex_elements(ctx->cso);
-   cso_restore_vertex_buffers(ctx->cso);
+   cso_restore_aux_vertex_buffer_slot(ctx->cso);
    cso_restore_stream_outputs(ctx->cso);
 
    pipe_sampler_view_reference(&sampler_view, NULL);
@@ -869,7 +871,7 @@ util_blit_pixels_tex(struct blit_state *ctx,
    cso_save_vertex_shader(ctx->cso);
    cso_save_geometry_shader(ctx->cso);
    cso_save_vertex_elements(ctx->cso);
-   cso_save_vertex_buffers(ctx->cso);
+   cso_save_aux_vertex_buffer_slot(ctx->cso);
 
    /* set misc state we care about */
    cso_set_blend(ctx->cso, &ctx->blend_write_color);
@@ -923,8 +925,9 @@ util_blit_pixels_tex(struct blit_state *ctx,
                                   s0, t0, s1, t1,
                                   z);
 
-   util_draw_vertex_buffer(ctx->pipe, ctx->cso,
-                           ctx->vbuf, offset,
+   util_draw_vertex_buffer(ctx->pipe, ctx->cso, ctx->vbuf,
+                           cso_get_aux_vertex_buffer_slot(ctx->cso),
+                           offset,
                            PIPE_PRIM_TRIANGLE_FAN,
                            4,  /* verts */
                            2); /* attribs/vert */
@@ -942,6 +945,6 @@ util_blit_pixels_tex(struct blit_state *ctx,
    cso_restore_vertex_shader(ctx->cso);
    cso_restore_geometry_shader(ctx->cso);
    cso_restore_vertex_elements(ctx->cso);
-   cso_restore_vertex_buffers(ctx->cso);
+   cso_restore_aux_vertex_buffer_slot(ctx->cso);
    cso_restore_stream_outputs(ctx->cso);
 }