SUMMARY I have RGB sub-pixel rendering enabled. It works as expected everywhere inside KDE / QT applications, but window titles are rendered with only grayscale anti-aliasing. From what I can tell looking at some old screenshots, the issue first appeared sometime in 2018 or 2019. I think this probably affects anywhere that KWin draws text, but I'm not sure where that is besides the window title, so I can't verify. Text drawn as part in Plasma (e.g. in the task bar) respects the rendering settings. STEPS TO REPRODUCE 1. Enable RGB sub-pixel rendering for fonts in your system settings. (I also have anti-aliasing enabled and hinting disabled, although this shouldn't matter.) 2. Restart KWin and see if window titles are subpixel rendered. (If you take a screenshot and zoom in close, you should see color fringing around the glyphs.) OBSERVED RESULT Window titles are not subpixel rendered. EXPECTED RESULT They should be. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.26.0 KDE Frameworks Version: 5.99.0 Qt Version: 5.15.6 Kernel Version: 6.0.1-arch1-1 (64-bit) Graphics Platform: X11
Can reproduce.
Reproduced on 6.0.0. Operating System: Arch Linux KDE Plasma Version: 6.0.0 KDE Frameworks Version: 6.0.0 Qt Version: 6.6.2 Kernel Version: 6.7.6-arch1-1 (64-bit) Graphics Platform: Wayland
*** Bug 502136 has been marked as a duplicate of this bug. ***