Bug 450669

Summary:	KWin's Window Open/Close Animation (brief flashing light when fading in/out with blur)
Product:	[Plasma] kwin	Reporter:	ratijas <me>
Component:	compositing	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate
Priority:	NOR
Version First Reported In:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description ratijas 2022-02-21 19:17:53 UTC

SUMMARY

Some KWin effects badly interact with each other, I'd say incompatible for some scenarios. Especially Window Open/Close Animation don't play nicely with blurry background, and semi-transparency while Alt (or Meta) + dragging windows around with a mouse.

Video showcases some of these glitches: https://youtu.be/pGp53kkyXrY

STEPS TO REPRODUCE
1. Enable effects like in my video.
2. Open System Tray popup (full representation dialog).
3. Hold Alt (or Meta?) and press on it, then release

OBSERVED RESULT
Popup turns semi-transparent, rapidly loosing its blurriness. On release it flashes with lighter-than-it-should-be background while regaining blurry background with an animation. Same glitch can be observed on tooltips.

EXPECTED RESULT
Popups should animate smoothly between transparency levels and blurriness, no matter target values are or which effects are enabled.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.24.80
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.2
Kernel Version: 5.16.10-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 970M/PCIe/SSE2