gallium: Implement draw_vbo and set_index_buffer for all drivers.

Some drivers define a generic function that is called by all drawing
functions.  To implement draw_vbo for such drivers, either draw_vbo
calls the generic function or the prototype of the generic function is
changed to match draw_vbo.

Other drivers have no such generic function.  draw_vbo is implemented by
calling either draw_arrays and draw_elements.

For most drivers, set_index_buffer does not mark the state dirty for
tracking.  Instead, the index buffer state is emitted whenever draw_vbo
is called, just like the case with draw_elements.  It surely can be
improved.

3 files changed, 44 insertions, 0 deletions

diff --git a/src/gallium/drivers/svga/svga_context.h b/src/gallium/drivers/svga/svga_context.h
index 9a46de643f..67a7614c8a 100644
--- a/src/gallium/drivers/svga/svga_context.h
+++ b/src/gallium/drivers/svga/svga_context.h
@@ -190,6 +190,7 @@ struct svga_state
    struct svga_vertex_shader *vs;
 
    struct pipe_vertex_buffer vb[PIPE_MAX_ATTRIBS];
+   struct pipe_index_buffer ib;
    struct pipe_resource *cb[PIPE_SHADER_TYPES];
 
    struct pipe_framebuffer_state framebuffer;
diff --git a/src/gallium/drivers/svga/svga_pipe_draw.c b/src/gallium/drivers/svga/svga_pipe_draw.c
index 58e930d983..fceaa83d70 100644
--- a/src/gallium/drivers/svga/svga_pipe_draw.c
+++ b/src/gallium/drivers/svga/svga_pipe_draw.c
@@ -248,10 +248,34 @@ svga_draw_arrays( struct pipe_context *pipe,
                             start, count);
 }
 
+static void
+svga_draw_vbo(struct pipe_context *pipe, const struct pipe_draw_info *info)
+{
+   struct svga_context *svga = svga_context(pipe);
+
+   if (info->indexed && svga->curr.ib.buffer) {
+      unsigned offset;
+
+      assert(svga->curr.ib.offset % svga->curr.ib.index_size == 0);
+      offset = svga->curr.ib.offset / svga->curr.ib.index_size;
+
+      svga_draw_range_elements(pipe, svga->curr.ib.buffer,
+                               svga->curr.ib.index_size, info->index_bias,
+                               info->min_index, info->max_index,
+                               info->mode, info->start + offset, info->count);
+   }
+   else {
+      svga_draw_range_elements(pipe, NULL, 0, 0,
+                               info->min_index, info->max_index,
+                               info->mode, info->start, info->count);
+   }
+}
+
 
 void svga_init_draw_functions( struct svga_context *svga )
 {
    svga->pipe.draw_arrays = svga_draw_arrays;
    svga->pipe.draw_elements = svga_draw_elements;
    svga->pipe.draw_range_elements = svga_draw_range_elements;
+   svga->pipe.draw_vbo = svga_draw_vbo;
 }
diff --git a/src/gallium/drivers/svga/svga_pipe_vertex.c b/src/gallium/drivers/svga/svga_pipe_vertex.c
index 23808ad08e..86c79459f3 100644
--- a/src/gallium/drivers/svga/svga_pipe_vertex.c
+++ b/src/gallium/drivers/svga/svga_pipe_vertex.c
@@ -66,6 +66,24 @@ static void svga_set_vertex_buffers(struct pipe_context *pipe,
 }
 
 
+static void svga_set_index_buffer(struct pipe_context *pipe,
+                                  const struct pipe_index_buffer *ib)
+{
+   struct svga_context *svga = svga_context(pipe);
+
+   if (ib) {
+      pipe_resource_reference(&svga->curr.ib.buffer, ib->buffer);
+      memcpy(&svga->curr.ib, ib, sizeof(svga->curr.ib));
+   }
+   else {
+      pipe_resource_reference(&svga->curr.ib.buffer, NULL);
+      memset(&svga->curr.ib, 0, sizeof(svga->curr.ib));
+   }
+
+   /* TODO make this more like a state */
+}
+
+
 static void *
 svga_create_vertex_elements_state(struct pipe_context *pipe,
                                   unsigned count,
@@ -109,6 +127,7 @@ void svga_cleanup_vertex_state( struct svga_context *svga )
 void svga_init_vertex_functions( struct svga_context *svga )
 {
    svga->pipe.set_vertex_buffers = svga_set_vertex_buffers;
+   svga->pipe.set_index_buffer = svga_set_index_buffer;
    svga->pipe.create_vertex_elements_state = svga_create_vertex_elements_state;
    svga->pipe.bind_vertex_elements_state = svga_bind_vertex_elements_state;
    svga->pipe.delete_vertex_elements_state = svga_delete_vertex_elements_state;