Bug 412089

Summary: Windows decorations (and their context menu) become blurry when fractional display scaling is used on Wayland
Product: [Plasma] kwin Reporter: Patrick Silva <bugseforuns>
Component: wayland-genericAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: claudius.ellsel, humufr, major-mayer, notmart, null, postix, yamiyukisenpai
Priority: NOR Keywords: wayland-only
Version First Reported In: 5.20.90   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: example of blurry window and not blurry
Screenshot showing blurry decoration

Description Patrick Silva 2019-09-19 22:21:26 UTC
STEPS TO REPRODUCE
1. start Wayland session
2. enable fractional display scaling in "Display configuration" KCM (I use 1.2 scale factor)
3. 

OBSERVED RESULT
buttons, icons and text of the windows decorations look blurry.
The icons and the text also look blurry in the context menu of the windows decorations.

EXPECTED RESULT
windows decorations and their context menus look crisp

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.16.90
KDE Frameworks Version: 5.62.0
Qt Version: 5.13.1
Comment 1 humufr 2019-09-20 07:08:14 UTC
Created attachment 122750 [details]
example of blurry window and not blurry
Comment 2 humufr 2019-09-20 07:09:35 UTC
The problem is not only for fractional display. The strange thins is that it happens for some applications but not all e.g. it is blurry for firefox, gimp, inkscape, chrome, chromium  but not for digikam, dolphin, Kate, nautilus or Libreoffice.
Comment 3 Patrick Silva 2019-09-20 11:07:39 UTC
Dolphin and Kate are affected on my system.
Firefox, GIMP, inkscape are also affected because they are Xwayland apps (see bug 412088).
Comment 4 humufr 2019-10-15 18:38:10 UTC
It will be great that a non fractional scaling working again in 5.17.1

If scaling is 2 it is considered as a real instead of an integer and so Xwayland application are blurry. This is a clear regression from 5.16 and plasma wayland cannot be used if any Xwayland apps is needed and there are still plenty of them around!
Comment 5 Patrick Silva 2020-05-15 14:18:58 UTC
Operating System: Arch Linux 
KDE Plasma Version: 5.18.90
KDE Frameworks Version: 5.70.0
Qt Version: 5.15.0 rc2
Comment 6 Claudius Ellsel 2020-08-10 11:03:49 UTC
(In reply to humufr from comment #1)
> Created attachment 122750 [details]
> example of blurry window and not blurry

I don't see the window decorations (title, close button for example) to be blurry here (at least not more than for Kate). Are you sure you don't mean the content of the window like the tabs?
Comment 8 Nate Graham 2022-02-18 18:56:53 UTC
*** Bug 444395 has been marked as a duplicate of this bug. ***
Comment 9 major-mayer 2022-04-12 14:37:00 UTC
I can confirm that on my system this issue appears as well.
I have a primary UHD display that uses 125% scaling and a secondary FHD display that uses 100% scaling.
You can clearly see a difference between the sharpness of the content of the window and the window decorations.
Comment 10 Marco Martin 2022-04-19 14:27:32 UTC
is firefox there running in XWayland?
Comment 11 postix 2022-05-24 19:51:10 UTC
C.f. https://invent.kde.org/plasma/kwin/-/issues/86 (Fractional Scaling)
Comment 12 Patrick Silva 2022-09-18 17:33:23 UTC
Cannot reproduce with Breeze decoration and display scale 125%.


Operating System: Arch Linux
KDE Plasma Version: 5.25.90
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Graphics Platform: X11
Comment 13 major-mayer 2022-09-18 17:50:37 UTC
Created attachment 152192 [details]
Screenshot showing blurry decoration
Comment 14 major-mayer 2022-09-18 17:51:09 UTC
I can still reproduce this on Plasma 5.25, especially when using custom themes like Materia (see Screenshot).
Comment 15 Patrick Silva 2022-09-18 17:53:23 UTC
(In reply to lrdarknesss from comment #14)
> I can still reproduce this on Plasma 5.25, especially when using custom
> themes like Materia (see Screenshot).

you are facing bug 438401
Comment 16 major-mayer 2022-09-18 18:00:15 UTC
(In reply to Patrick Silva from comment #15)
> (In reply to lrdarknesss from comment #14)
> > I can still reproduce this on Plasma 5.25, especially when using custom
> > themes like Materia (see Screenshot).
> 
> you are facing bug 438401

Ah okay, thanks for the hint.
When using just the default Breeze theme, the font isn't too sharp either (might be a general fractional scaling problem), but it's much better than with custom themes.
Comment 17 Patrick Silva 2022-09-25 01:26:36 UTC
(In reply to lrdarknesss from comment #16)
> When using just the default Breeze theme, the font isn't too sharp either
> (might be a general fractional scaling problem)

You are right. See bug 446674