Fonts in global menubar and elsewhere become jagged when antialiasing is set to "grayscale"

[Jay S]

When I upgraded to Oneiric, the fonts in Unity -- in the global menubar, the clock, my name in the user menu, and in the hover text for apps on the dock -- became very jagged and seemingly fully hinted. After some playing around I discovered that changing the antialiasing setting in gnome-tweak-tool from "Grayscale" to "Rgba" fixed this problem.

[Paul Sladen (sladen)]

Please can you post a screenshot of what you're seeing. There is a bug whereby unity-panel-service picks up the wrong font, but that doesn't quite fit with the textual description here.

A screenshot (or ideally one before, and after) would be very useful.

[Jay S (topdownjimmy)]

Here's the strange font-hinting in the clock and user menu, above a gedit instance with normal font rendering. This is what happens when antialiasing is set to Grayscale in gnome-tweak-tool ("Advanced Settings").

I guess there aren't many people who use grayscale antialiasing. ;)

[Omer Akram (om26er)]

I confirm, its been like that for quite a few months it seems.

[Павло Вахнівський (paulnivsci)]

Same here. Fonts in menus an applications are smoothed, but not in Unity panel and launcher

[Павло Вахнівський (paulnivsci)]

You can see this bug only when 'Antialiasing' set to 'Grayscale' and 'Hinting' is 'Full' or 'Medium'. With no hinting or even when it is set to 'Slight' fonts are smoothed

[Andrey Logvinov (andrey-logvinov-81)]

I have hinting set to "None" and antialiasing to "Grayscale", the bug is present (fonts in unity panel and launcher are not antialiased). I use a 42'' LCD TV as display and I have to set display resolution to lower than native because otherwise text and other UI items will be too small. Rgba smoothig makes no sense in this configuration since logical display subpixels do not correspond to physical subpixels and color artifacts become visible.

[Andrey Logvinov (andrey-logvinov-81)]

Well it turns out I was wrong in my previous comment. I tried to set hinting to "full" and then back "none" again and text in unity panel and launcher is now properly antialiased.

[Andrey Logvinov (andrey-logvinov-81)]

But after reboot the font is agan not antialiased. It only becomes antialiased after setting hinting to some other value and back to "none" in gnome-tweak-tool.

[Andrey Logvinov (andrey-logvinov-81)]

Apparently this is a bug in unity-4.24.0/plugins/unityshell/src/FontSettings.cpp
It checks for gtk-xft-rgba value and if it's "none", sets antialiasing to CAIRO_ANTIALIAS_NONE.
I added gtk-xft-antialias value check and if it's nonzero, set antialiasing to CAIRO_ANTIALIAS_GRAY instead. This fixed the problem for me.
See attached diff for FontSettings.cpp.

[Ubuntu Foundations Team Bug Bot (crichton)]

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[Omer Akram (om26er)]

Andrey, thanks for the patch, could you please check if it applies to unity trunk and propose a bzr branch to lp:unity with your fix?

[Andrey Logvinov (andrey-logvinov-81)]

Done.
https://code.launchpad.net/~andrey-logvinov-81/unity/fix-grayscale-smoothing/+merge/84836