I remember that I could use the "Show Paint" effect to verify that my applications only update regions that actually changed. Trying the "Show Paint" effect today, I see that the complete screen is flashing, even on small changes. Steps to reproduce: - enable Show Paint effect, set a shortcut to activate it, and activate it - type into Konsole Actual result: - complete screen flashes Expected result: - only the cursor line in Konsole flashes System: KWin from 5.27 stable branch on X11
I investigated things I could see on my laptop and whilst it looked valid, closer inspection showed something else. We're double buffered on wayland, if we flip between the new and old buffers without repainting those areas you will see the old buffer buffer with the old overlays. It doesn't mean it's actually repainted. i.e flipping between all 8 colours shows we're repainting, going between 2 colours is not necessarily a sign of anything. Please reopen if we have something more concrete to show we're fully repainting, otherwise I think this is just the effect giving (very!) confusing results.
I'm not using Wayland.