Bug 410082 - Artifacts when settings scale effect on closing
Summary: Artifacts when settings scale effect on closing
Alias: None
Product: kwin
Classification: Plasma
Component: effects-various (show other bugs)
Version: unspecified
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
Depends on:
Reported: 2019-07-21 20:03 UTC by Marcus
Modified: 2021-11-02 10:41 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In:

Scale settings (87.14 KB, image/png)
2019-07-21 20:03 UTC, Marcus
Video showing the artifacts (1.70 MB, video/x-matroska)
2019-07-21 20:09 UTC, Marcus
Video configuration (72.21 KB, image/png)
2019-08-27 14:52 UTC, Marcus
Window animation duration 150ms (29.98 KB, image/png)
2019-08-27 14:53 UTC, Marcus
Scale Up Effect Visual Bug Demonstration (1.07 MB, video/mp4)
2021-11-02 10:41 UTC, Khiu

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Description Marcus 2019-07-21 20:03:17 UTC
Created attachment 121666 [details]
Scale settings

When settings scale effects on closing windows, it generates visual artifacts on the area that is not being actively refreshed, until those areas gets the focus.

1. Open system settings
2. Go to Desktop Behavior
3. Select Desktop Effects
4. Activate Scale animation setting the close scale more than 1x
5. Open multiple windows (not fullscreen) so that once you close one, there is at least one inactive window in background.

A flickering visual artifact appears (It may last for long time)

Clean closing animation

Linux/KDE Plasma: Kubuntu 19.04
(available in About System)
KDE Plasma Version: 5.16.3
KDE Frameworks Version: 5.59.0
Qt Version: 5.12.2

This bug is pretty easy to verify. It happens with both the desktop with an AMD card and a notebook that uses Nvidia proprietary driver.
Comment 1 Marcus 2019-07-21 20:09:58 UTC
Created attachment 121667 [details]
Video showing the artifacts
Comment 2 Vlad Zahorodnii 2019-08-27 05:46:16 UTC
> It happens with both the desktop with an AMD card
Hmm, I'm not able to reproduce this bug. What's your animation speed?
Comment 3 Marcus 2019-08-27 14:52:42 UTC
Created attachment 122383 [details]
Video configuration

The speed is just sightly faster than standard
Comment 4 Marcus 2019-08-27 14:53:18 UTC
Created attachment 122384 [details]
Window animation duration 150ms
Comment 5 Marcus 2019-08-27 14:57:59 UTC
As to how to reproduce it, it is important that when the window scales on close, it scales to more than 1x (I have 1.2), then it happens basically every time. There are almost always artifacts. Sometimes they flicker in reaction to mouse movement, sometimes they stand still.
About the composition, sometimes a whole portion of window remains there (like the upper bar, with the buttons to minimize, maximize, ... sometimes ii's just the shadow of the window that remains there.
Comment 6 Marcus 2019-08-27 14:59:06 UTC
If you haven't seen the video yet, please look at it.
Comment 7 Vlad Zahorodnii 2019-08-28 08:15:35 UTC
Alright, after tweaking animation speed I reproduced the bug but only once. It's very difficult bug to reproduce.
Comment 8 Khiu 2021-11-02 10:41:17 UTC
Created attachment 143124 [details]
Scale Up Effect Visual Bug Demonstration

Happened upon this bug recently when changing the settings of the Scale effect.
Can't get the bug to show when closing, but when opening windows it's quite noticeable.
This happens when the "scale" setting is over 1,00.