+static void
+setup_index_buffer(GLcontext *ctx,
+ const struct _mesa_index_buffer *ib,
+ struct pipe_index_buffer *ibuffer)
+{
+ struct st_context *st = st_context(ctx);
+ struct pipe_context *pipe = st->pipe;
+
+ memset(ibuffer, 0, sizeof(*ibuffer));
+ if (ib) {
+ struct gl_buffer_object *bufobj = ib->obj;
+
+ switch (ib->type) {
+ case GL_UNSIGNED_INT:
+ ibuffer->index_size = 4;
+ break;
+ case GL_UNSIGNED_SHORT:
+ ibuffer->index_size = 2;
+ break;
+ case GL_UNSIGNED_BYTE:
+ ibuffer->index_size = 1;
+ break;
+ default:
+ assert(0);
+ return;
+ }
+
+ /* get/create the index buffer object */
+ if (bufobj && bufobj->Name) {
+ /* elements/indexes are in a real VBO */
+ struct st_buffer_object *stobj = st_buffer_object(bufobj);
+ pipe_resource_reference(&ibuffer->buffer, stobj->buffer);
+ ibuffer->offset = pointer_to_offset(ib->ptr);
+ }
+ else {
+ /* element/indicies are in user space memory */
+ ibuffer->buffer =
+ pipe_user_buffer_create(pipe->screen, (void *) ib->ptr,
+ ib->count * ibuffer->index_size,
+ PIPE_BIND_INDEX_BUFFER);
+ }
+ }
+}