Bug 454213

Summary:	An animation duration >0s for window buttons causes stuttering
Product:	[Plasma] kwin	Reporter:	doncbugs
Component:	aurorae	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal
Priority:	NOR
Version First Reported In:	5.24.5
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description doncbugs 2022-05-22 13:43:13 UTC

SUMMARY
I noticed that there are not many themes that use an animation for Aurorae window buttons. Everyone appears to use Animation=0 in their theme's rc file. I have observed that when a button whose hovered state is similar to its normal state animates, the animation briefly shows transparency, causing the icon to look as though it flickered instead of smoothly transitioned. 

STEPS TO REPRODUCE
1. Select an Aurorae theme (I used Willow Dark for best visibility)
2. Change the rc file so animation can occur (I set it to 200) and reapply the theme
3. On the focused window, hover over the buttons (e.g. maximize/restore)

OBSERVED RESULT
Animating the icon from the icon to the icon with a light background causes a brief stutter

EXPECTED RESULT
Animation smoothly transitions without "blinking"

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.24.5
KDE Frameworks Version: 5.94.0
Qt Version: 5.15.4
Kernel Version: 5.17.9-arch1-1 (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION
I believe it is less noticeable with the inactive window because of the great different between the normal lightness and hovered lightness, making the blink less noticeable. Fixing this may require changing the algorithm for the fade or giving the option to change the animation style.