wayland surface shadows with XRGB pixel format
I've noticed that when using buffer format WL_SHM_FORMAT_XRGB8888
, a shadow will be drawn around the respective surface:
This has been tested with https://github.com/emersion/hello-wayland by replacing WL_SHM_FORMAT_ARGB8888
by WL_SHM_FORMAT_XRGB8888
on mutter 3.28.4.
This behaviour is (1) inconsistent between formats and (2) inconsistent between compositors.
Furthermore, the "XRGB" image has different colours than the original version:
How can this behaviour be controlled (disable for XRGB / enable for ARGB)?