Bug 475886 - Blurry window titles for some apps with fractional scaling
Summary: Blurry window titles for some apps with fractional scaling
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: decorations (other bugs)
Version First Reported In: master
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: qt6, wayland-only
: 466426 467179 472332 (view as bug list)
Depends on:
Blocks:
 
Reported: 2023-10-20 18:06 UTC by Michel Le Bihan
Modified: 2024-10-01 19:43 UTC (History)
9 users (show)

See Also:
Latest Commit: https://invent.kde.org/plasma/kwin/-/commit/4283ba00c60297353eed5d447e11ef9c43117417
Version Fixed In:
Sentry Crash Report:

Attachments
System Settings -- affected (1.05 MB, image/png)
2023-10-20 18:06 UTC, Michel Le Bihan 		Details
Info Center -- affected (1.07 MB, image/png)
2023-10-20 18:07 UTC, Michel Le Bihan 		Details
Kate -- affected (1.02 MB, image/png)
2023-10-20 18:07 UTC, Michel Le Bihan 		Details
Dolphin -- not affected (1.16 MB, image/png)
2023-10-20 18:07 UTC, Michel Le Bihan 		Details
Help Center -- not affected (1.10 MB, image/png)
2023-10-20 18:08 UTC, Michel Le Bihan 		Details
Settings - Plastik (1.05 MB, image/png)
2023-10-24 15:05 UTC, Michel Le Bihan 		Details
Info Center - Plastik (1.04 MB, image/png)
2023-10-24 15:05 UTC, Michel Le Bihan 		Details
View All Add an attachment

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Description Michel Le Bihan 2023-10-20 18:06:16 UTC 
SUMMARY
Some window titles are blurry. Found in: System Settings, Info Center and Kate


STEPS TO REPRODUCE
1. Download the `neon-unstable-20231015-1119.iso` iso
2. Enable the Wayland session in SDDM, logout and log in selecting the Wayland session
3. Set scaling to 125%
4. Open System Settings, Info Center or Kate. Only those 3 apps seem affected.
5. Notice that the window title is blurry
6. Open any other app like Dolphin or Help Center
7. Notice that window titles appear very sharp

OBSERVED RESULT
Some window titles are blurry

EXPECTED RESULT
Window titles shouldn't be blurry 

ADDITIONAL INFORMATION
Please see attached screenshots
Comment 1 Michel Le Bihan 2023-10-20 18:06:46 UTC 
Created attachment 162457 [details]
System Settings -- affected
Comment 2 Michel Le Bihan 2023-10-20 18:07:16 UTC 
Created attachment 162458 [details]
Info Center -- affected
Comment 3 Michel Le Bihan 2023-10-20 18:07:38 UTC 
Created attachment 162459 [details]
Kate -- affected
Comment 4 Michel Le Bihan 2023-10-20 18:07:56 UTC 
Created attachment 162460 [details]
Dolphin -- not affected
Comment 5 Michel Le Bihan 2023-10-20 18:08:29 UTC 
Created attachment 162461 [details]
Help Center -- not affected
Comment 6 Nate Graham 2023-10-23 22:19:25 UTC 
Seems to only affect the titlebars of QML apps, not QtWidgets apps. Possibly related to Bug 464069?

Either way, can't reproduce with today's git master and 125% scale. However I'm testing with Qt 6.5.2, not 6.6 like Neon has.

Can you reproduce the issue with other window decoration themes, Michel?
Comment 7 Michel Le Bihan 2023-10-24 15:04:36 UTC 
Hello,
I tested other themes and they are also affected. I noticed something interesting with Plastik. Window titles are very sharp at the beginning and then are getting blurry.
Comment 8 Michel Le Bihan 2023-10-24 15:05:04 UTC 
Created attachment 162544 [details]
Settings - Plastik
Comment 9 Michel Le Bihan 2023-10-24 15:05:22 UTC 
Created attachment 162545 [details]
Info Center - Plastik
Comment 10 Nate Graham 2023-10-24 18:28:07 UTC 
Thanks for the info.
Comment 11 David Edmundson 2023-11-11 22:30:04 UTC 
*** Bug 466426 has been marked as a duplicate of this bug. ***
Comment 12 David Edmundson 2023-11-11 22:30:45 UTC 
*** Bug 472332 has been marked as a duplicate of this bug. ***
Comment 13 Michel Le Bihan 2024-01-15 20:53:22 UTC 
*** Bug 467179 has been marked as a duplicate of this bug. ***
Comment 14 Michel Le Bihan 2024-01-15 20:55:13 UTC 
Hello,
I can't reproduce this issue anymore with KWin 5.92.0, so I consider it fixed.
Comment 15 Brandon Liles 2024-09-16 15:36:41 UTC 
I don't think this is fixed. My setup is a laptop screen that is scaled 150% with an external monitor that is scaled 100%. I have also tried having the external monitor scaled 125% and 175%. I still see blurry window titles and borders with non-breeze themes. The bug can be particularly noticed when dragging the window from the screen it was opened on to the opposite screen. Adjusting the laptop screen to 200% scaling reduces the ugliness of the window title, but you can still see that the border has been scaled instead of it being redrawn for the scaling factor of the current monitor.
Comment 16 Brandon Liles 2024-09-16 15:38:32 UTC 
I'm sorry in my previous comment I neglected to include version information:

KDE Plasma 6 on Kubuntu 24.10 (development branch).
Plasma version: 6.1.5
KDE Frameworks: 6.5.0
Qt Version: 6.6.2
Wayland
Intel graphics
Comment 17 Alex B 2024-10-01 19:43:35 UTC 
I can also confirm this issue still exists (at least while running on compiled plasma on Ubuntu 24.04 [I'm aware it's not officially supported]).
I have the following:
Plasma 6.1.5
kded6 6.6.0
QT 6.7.2
On Wayland with AMD graphics.