Bug 502529

Summary:	Shading is almost working, but creates artefacts in shaded state, where usually the window shadow is placed, but window shadow is disabled
Product:	[Plasma] kwin	Reporter:	Hans-Peter Jansen <hpj>
Component:	Window shading	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate
Priority:	NOR	Keywords:	X11-only
Version First Reported In:	6.3.4
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Hans-Peter Jansen 2025-04-07 16:58:40 UTC

SUMMARY

Window shading is almost working correctly, but creates artefacts in shaded state, where usually the window shadow is placed, but window shadow is disabled altogether, compositing is enabled, but apps may override. 

The artefacts expose some formerly displayed screen content, therefore it seems to be a redraw issue. Some may flicker, other not.

STEPS TO REPRODUCE

I configured my systems to shade the window with a double click on the window bar. 
Enable compositor
Note: NVIDIA graphics driver 570.133.07 (probably reproducible with other hardware as well)
disable window shadow (but the glitch is even stronger with window shadow enabled)
Shade a window, hopefully observe the glitch

OBSERVED RESULT

Will attach a short video, glitch appears since some time

EXPECTED RESULT

No such artifacts

SOFTWARE/OS VERSIONS

Operating System: openSUSE Tumbleweed 20250403
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.2
Kernel Version: 6.14.0-6-preempt (64-bit)
Graphics Platform: X11
Processors: 24 × AMD Ryzen 9 3900X 12-Core Processor
Memory: 62.3 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 3060
Manufacturer: ASUS