After opening and closing again the Application launcher leaves traces behind on the desktop background as well as other windows, which were behind it. When moving the mousepointer over this area, the half transparent echo of the launcher flickers. It goes away, when clicking on a second window, the effect stops Reproducible: Always
KWin supportInformation: https://paste.kde.org/pvp6qt5ru
As a try: disable the sliding popus effect
Good call! Setting "Animation speed" in Compositor KCM to "Instant" crashed my user session, but after logging in again it used the new setting and no traces are there anymore.
Ok, that seems to be something I had seen in the past already. The sliding popups effect destroys the buffer age.
Still happening. I tried to disable Buffer age mechanism with environment variable KWIN_USE_BUFFER_AGE=0, but this made the whole thing even worse. Then all kind of windows leave traces behind. Forcing to QPainter backend solves the issue. So it's an OpenGl problem. I'm wondering if it's because of the old Intel APU in my laptop. It only supports OpenGl v2.1. I don't have the problem for example on my more modern PC.
Here you can see it in action: https://streamable.com/t7ypw Although I have to say this seems again more like a buffer age problem, which is reshowing the saved buffer with the cursor whenever the cursor is painted in Kate.
Also decreasing the animation speed from 2 to 3 (with "Instant" being 0), solves the issue.
Correction: Happens also on my PC.
From the video that's clearly an issue with buffer age. We are presenting an old buffer.
Yea, the question is only, why it's going completely nuts when deactivating the buffer age functionality. But this might be another problem unrelated.
is this still an issue with current drm platform?
>is this still an issue with current drm platform? Super old, and not reported by anyone else. Please reopen if there's still an issue