Main window doesn't have an opaque region (performance)
STR:
- open looking glass (
alt
+f2
->lg
) - enable
OPAQUE_REGION
underFLAGS
Observe that the main window has a purple tint instead of green. This has a performance impact in compositors, as it means they need to draw the background of the window on every repaint - instead of only drawing the window content (or even using direct scanout).
I suppose this is another case where window { background: none; }
was set to work around rendering issues, see also GNOME/gtk#5612
If possible, it would be good to reinstate the background and thus the opaque region.