+static xcb_screen_t *
+get_screen_for_root(xcb_connection_t *conn, xcb_window_t root)
+{
+ xcb_screen_iterator_t screen_iter =
+ xcb_setup_roots_iterator(xcb_get_setup(conn));
+
+ for (; screen_iter.rem; xcb_screen_next (&screen_iter)) {
+ if (screen_iter.data->root == root)
+ return screen_iter.data;
+ }
+
+ return NULL;
+}
+
+static xcb_visualtype_t *
+get_xcb_visualtype_for_depth(struct loader_dri3_drawable *draw, int depth)
+{
+ xcb_visualtype_iterator_t visual_iter;
+ xcb_screen_t *screen = draw->screen;
+ xcb_depth_iterator_t depth_iter;
+
+ if (!screen)
+ return NULL;
+
+ depth_iter = xcb_screen_allowed_depths_iterator(screen);
+ for (; depth_iter.rem; xcb_depth_next(&depth_iter)) {
+ if (depth_iter.data->depth != depth)
+ continue;
+
+ visual_iter = xcb_depth_visuals_iterator(depth_iter.data);
+ if (visual_iter.rem)
+ return visual_iter.data;
+ }
+
+ return NULL;
+}
+
+/* Get red channel mask for given drawable at given depth. */
+static unsigned int
+dri3_get_red_mask_for_depth(struct loader_dri3_drawable *draw, int depth)
+{
+ xcb_visualtype_t *visual = get_xcb_visualtype_for_depth(draw, depth);
+
+ if (visual)
+ return visual->red_mask;
+
+ return 0;
+}
+