Bug 443501 - Blurred image on Wayland
Summary: Blurred image on Wayland
Status: CLOSED UPSTREAM
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (other bugs)
Version First Reported In: 5.22.90
Platform: openSUSE Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-10-08 23:33 UTC by Andreas
Modified: 2021-11-01 00:23 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:

Attachments
Wayland with blur (513.94 KB, image/jpeg)
2021-10-08 23:33 UTC, Andreas 		Details
X11 without blur (584.53 KB, image/jpeg)
2021-10-08 23:34 UTC, Andreas 		Details
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Description Andreas 2021-10-08 23:33:26 UTC 
Created attachment 142267 [details]
Wayland with blur

SUMMARY
I have uhd display with 225% scale. Image on wayland looks blurry. It's hard to see on a 15" UHD display, but there is blur at 100% scaling too.
Blurred image on Intel and NVIDIA GPU

STEPS TO REPRODUCE
1. OpenSUSE Leap 15.3 + Plasma 5.22.90

OBSERVED RESULT
Blurred image

EXPECTED RESULT
No blurred image

SOFTWARE/OS VERSIONS
Linux: OpenSUSE Leap 15.3
KDE Plasma Version: 5.22.90
KDE Frameworks Version: 5.86
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Dell Precision 7530, Intel UHD P630, NVIDIA Quadro P3200
Comment 1 Andreas 2021-10-08 23:34:07 UTC 
Created attachment 142268 [details]
X11 without blur
Comment 2 Andreas 2021-10-08 23:53:47 UTC 
The virtualbox in the screenshot is an example of blur, the plasma looks the same blurry.
Comment 3 Nate Graham 2021-10-18 01:57:00 UTC 
This happens because You are using a high DPI scale factor but the app in question is not Wayland-native and instead uses XWayland. XWayland is not able to use the app's X11-specific scaling support, so the result is blurriness. This needs to be fixed in one of the following ways:

1. XWayland gains support for X11 scaling
2. The app becomes Wayland-native

All of these things are outside of KDE's control, I'm afraid.
Comment 4 Andreas 2021-10-29 11:37:21 UTC 
No, Plasma is blurry too.
Comment 5 Nate Graham 2021-10-29 14:48:37 UTC 
Right, in addition to XWayland apps being blurry at all scale factors above 100%, even native wayland apps like Plasma are blurry at scale factors other than 100%, 200%, 300%, etc. It's also a Wayland protocol limitation at the moment.
Comment 6 Andreas 2021-10-29 14:51:03 UTC 
The bug is also present at a scale of 100 and 200%.
Comment 7 Nate Graham 2021-10-29 14:56:19 UTC 
Please attach a screenshot showing blur at 100%.
Comment 8 Andreas 2021-11-01 00:23:21 UTC 
Hi,

you're right. I took 2 screenshots in X11 and Wayland but couldn't see the difference.
The bug can be closed.