Bug 504835

Summary: Opentype bitmap (.otb) fonts, like Terminus, are invisible in gtk applications when font hinting is set to "None"
Product: [Applications] systemsettings Reporter: Russell Haley <yumpusamongus+kde>
Component: kcm_fontsAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: nate
Priority: NOR    
Version First Reported In: 6.3.5   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Russell Haley 2025-05-26 19:22:36 UTC 
STEPS TO REPRODUCE
1. (on Fedora) install terminus-fonts package
2. Configure a GTK app (gvim, mousepad, gedit, gnome-terminal, etc.) to use Terminus font.
3. Open System Settings / Text & Fonts / Fonts, and set "Hinting" to "None" 
4. Restart the GTK app.

OBSERVED RESULT

Text is invisible.

EXPECTED RESULT

Text is visible (and rendered in Terminus).

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 42
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0
Kernel Version: 6.14.6-300.fc42.x86_64 (64-bit)
Graphics Platform: Wayland


ADDITIONAL INFORMATION

Apologies for reporting as general/unspecified, but I don't know what components are implicated here. Maybe systemsettings?

I have a *hunch* that maybe whatever passes fontconfig parameters should be doing something like "hinting=true + hinstyle=hintnone" instead of "hinting=false", or vice-versa.
Comment 1 Nate Graham 2025-05-27 23:03:00 UTC 
Unfortunately this is all happening in the Qt font chooser dialog; we don't have any control over what it's doing under the hood. I think for now your best bet is to not use that feature. Please also feel free to report this at https://bugreports.qt.io.

Thanks!