Red damage region
This is useful to visualize which parts of the screen are being damaged. Add a new 'damage-region' value for CLUTTER_PAINT and paint the damaged regions accordingly.
To use it, switch to another TTY and run:
$ env CLUTTER_PAINT=damage-region dbus-run-session -- gnome-shell --display-server --wayland
I'm not entirely sure whether it makes sense to paint both the clip AND the damage region. The native renderer for instance does not support redrawing regions.
Edited by Georges Basile Stavracas Neto