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View Full Version : [kubuntu] (10.10)Differences in font rendering between Qt and gtk.



RobbieThe1st
March 7th, 2011, 09:41 AM
I've got a slight problem here, and have had it for a while: When I use the "Sharp'N'Clear" .fonts.conf from Here (https://wiki.ubuntu.com/Fonts#Manual%20Font%20Smoothing), and set an optimized font like Arial, gtk-based applications render correctly, while Qt-based ones don't:
http://img26.imageshack.us/img26/3117/oddfonts.png
As you can see, the top window(Firefox) has it's fonts clean and nice. The bottom one(Dolphin) does not. Both are set to Arial 9.
I've tried it with a number of different applications, including some custom PyQt4 stuff, and it's clear that it's -all- Qt-based applications and not just one or two.

For further information, I've had this problem ever since I upgraded from Kubuntu 9.10 a while back - That version worked correctly on both Qt and gtk, but nothing since has.

Any ideas?

Thanks,

-Rob

RobbieThe1st
March 9th, 2011, 01:07 PM
Let me just bump my post - I don't -think- it's against the rules.

Copper Bezel
March 9th, 2011, 02:45 PM
I'd like a response on this, as well, if anyone has any thoughts. After installing System Settings from Kubuntu to tweak the appearance of KDE applications to fit my GTK ones (under Gnome,) my font smoothing in QT applications went all to hell, making it difficult to read text in Chrome and OpenOffice.

ratcat
March 9th, 2011, 05:51 PM
Try this, Free Sands 9pt, 126 dpi, smoothing enabled on Kde. This settings the best rez on large screens, 1920 and up.

Copper Bezel
March 9th, 2011, 08:12 PM
I'm on a netbook. = ) 10", 1024 x 600, which means it's actually a fairly low resolution per inch. GTK apps have no trouble displaying 7 or even 6 point font legibly. There has to be a better solution than just making the fonts larger.

RobbieThe1st
March 10th, 2011, 05:17 AM
I'm on a netbook. = ) 10", 1024 x 600, which means it's actually a fairly low resolution per inch. GTK apps have no trouble displaying 7 or even 6 point font legibly. There has to be a better solution than just making the fonts larger.
Yes, exactly.

Personally, I've got a ~100DPI 1920x1080 screen and I can't stand anti-aliased rendering of fonts in small sizes(<14-16px or so). On the other hand, my phone and it's 230-dpi screen... there it looks OK. But I can barely -see- each pixel there, whereas on my desktop screen it's easily noticeable.

That all being said, I think the problem -has- to lie in the rendering library - Does the Qt one have bytecode hinting enabled? I recall how it -used- to be disabled by default on most things because of patent issues, but IIRC they expired a year or so ago.

edit:
Out of curiosity, I checked. Looks like Qt uses libfreetype6 along with GTK. I tried downgrading it to the Karmic-updates version(2.3.9-5ubuntu0.4), and while it downgraded without errors, there's seemingly no change in font-rendering even after a reboot.

Copper Bezel
April 10th, 2011, 04:40 PM
I hate bumping this after all of this time, but I installed the rest of kde-standard and made the appropriate tweaks in System Settings (RGB sub-pixel rendering and full hinting, on by default in Gnome Ubuntu but not in standard KDE) and I'm no longer experiencing any difficulty with font rendering - text in Qt apps and GTK ones are comparably smoothed.