| Summary: | Font Management KCM preview exhibits jagged rendering with Wayland and fractional scaling | ||
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| Product: | [Applications] systemsettings | Reporter: | Gilles Gagniard <gilles> |
| Component: | kcm_fonts | Assignee: | Plasma Bugs List <plasma-bugs-null> |
| Status: | CONFIRMED --- | ||
| Severity: | normal | CC: | greenulito, john.kizer, kdedev, madness742, nate, strong.drum0546, u0sd2qpny |
| Priority: | NOR | ||
| Version First Reported In: | 6.2.5 | ||
| Target Milestone: | --- | ||
| Platform: | Arch Linux | ||
| OS: | Linux | ||
| See Also: |
https://bugs.kde.org/show_bug.cgi?id=502322 https://bugs.kde.org/show_bug.cgi?id=502103 https://bugs.kde.org/show_bug.cgi?id=501715 |
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| Latest Commit: | Version Fixed/Implemented In: | ||
| Sentry Crash Report: | |||
| Attachments: |
Font Management with bad font rendering in preview panel
Chromium vs Firefox, 125% fractional scaling, 1080p |
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Description
Gilles Gagniard
2025-01-29 19:42:11 UTC
Can reproduce. *** Bug 501975 has been marked as a duplicate of this bug. *** This issue is not limited to the Font Management KCM — it also affects other software, applications, and browsers. Assuming it's only related to the Font KCM creates a false impression that the problem is minor and can be postponed. In reality, it's a broader and more important issue that deserves timely attention. (In reply to Alex J Green from comment #3) > This issue is not limited to the Font Management KCM — it also affects other > software, applications, and browsers. Assuming it's only related to the Font > KCM creates a false impression that the problem is minor and can be > postponed. In reality, it's a broader and more important issue that deserves > timely attention. Indeed, there are several "old" KDE applications (examples: KolourPaint, KPatience) whose rendering seem to be broken as well with similar symptoms. Maybe the issue is not related to font rendering itself, but a more general bitmap scaling issue when fractional scaling is enabled. > Indeed, there are several "old" KDE applications (examples: KolourPaint, > KPatience) whose rendering seem to be broken as well with similar symptoms. > Maybe the issue is not related to font rendering itself, but a more general > bitmap scaling issue when fractional scaling is enabled. The problem has wider surface, than just "old" KDE applications. If for example I open in Firefox https://fonts.google.com/noto/specimen/Noto+Sans and set background to black (there is a theme button on the page) and change font (there is a dropdown on that page) from 48px to 20px, then fonts become colored like a rainbow. This is only observed under Wayland session with non integer scale. Slowly scroll page up and down -- and characters change their shape. (In reply to Alex J Green from comment #5) > If for example I open in Firefox > https://fonts.google.com/noto/specimen/Noto+Sans and set background to black > (there is a theme button on the page) and change font (there is a dropdown > on that page) from 48px to 20px, then fonts become colored like a rainbow. > This is only observed under Wayland session with non integer scale. Slowly > scroll page up and down -- and characters change their shape. This may be a different bug, since browsers can set extra parameters for font rendering outside of KDE's control. I'll let those more experienced with font rendering make that determination. I found a similar problem in bug 511126, which was fixed for that user by settin this in Firefox in about:config: widget.wayland.fractional-scale.enabled = true However, I am still able to reproduce the font rendering problem on that page with that setting enabled. Can reproduce the scaling issue in "Font Management" but not the Firefox issue that Alex J Green reported in comment #5. Operating System: Arch Linux KDE Plasma Version: 6.5.0 KDE Frameworks Version: 6.19.0 Qt Version: 6.10.0 Graphics Platform: Wayland Created attachment 186241 [details]
Chromium vs Firefox, 125% fractional scaling, 1080p
(In reply to Lenzoid from comment #8) > Created attachment 186241 [details] > Chromium vs Firefox, 125% fractional scaling, 1080p Correction, I do see aliasing problems in Firefox with fractional scaling enabled. May not be the same bug but I'm posting a Chromium vs Firefox screenshot anyway. Sorry for the noise. |