compositor: add an assign_planes hook to the output
This allows each output back end to optimize drawing using overlay planes
and cursors (yet to be integrated). If a surface is assigned to a
plane, the back end should clear its damage field so that the later
repaint code won't look at it.
diff --git a/src/compositor-wayland.c b/src/compositor-wayland.c
index 386f9b6..00ad189 100644
--- a/src/compositor-wayland.c
+++ b/src/compositor-wayland.c
@@ -442,6 +442,7 @@
output->base.repaint = wayland_output_repaint;
output->base.set_hardware_cursor = wayland_output_set_cursor;
output->base.destroy = wayland_output_destroy;
+ output->base.assign_planes = NULL;
wl_list_insert(c->base.output_list.prev, &output->base.link);