Bug 502748

Summary:	Some effects cause changes in window opacity to be delayed until the next window surface update
Product:	[Plasma] kwin	Reporter:	Tech-Tac <im.tech.tac>
Component:	effects-various	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	CONFIRMED ---
Severity:	normal	CC:	nate, xaver.hugl
Priority:	NOR
Version First Reported In:	6.3.4
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Tech-Tac 2025-04-13 14:50:00 UTC

SUMMARY
Changing window opacity (through setting a mouse wheel window action for example) while the invert effect (and some other third party effects like kwin-effect-rounded-corners) doesn't actually update the window's opacity until the content inside changes. This doesn't occur on windows the effect doesn't affect or when it is off.

STEPS TO REPRODUCE
1. Turn on invert effect
2. Invert a window
3. Change its opacity
4. Move the mouse around or resize it

OBSERVED RESULT
Window opacity doesn't visually change until the window updates its content.

EXPECTED RESULT
Window opacity should update instantly.

SOFTWARE/OS VERSIONS

Windowing: Wayland
Linux: Arch, latest packages
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.9.0

Comment 1 Tech-Tac 2025-06-16 12:10:57 UTC

This also occurs with all effects that directly deform window surfaces, including wobbly windows and the magic lamp effect