[SOLVED] Font rendering issues (kerning, etc.) with Firefox 52.7.0 and XFCE 4.12

arcctgx · 03-14-2018, 04:03 PM

Hi,

I'm on Slackware64-14.2, using XFCE 4.12 desktop with Firefox 52.7.0. I have some problems with the way the fonts are displayed on some websites. As I move the mouse cursor the rendering of fonts slightly changes: letter spacing becomes different, kerning seems to change, and certain letters (b, d and such) are becoming thinner. This problem was also visible in previous Firefox versions.

I have created an animated gif illustrating that issue (see attachment below). This one is from the Mattermost web app, and I was simply moving the mouse cursor up and down along that menu (the cursor itself is not visible in the gif). I have noticed similar effects in several different websites, most notably on last.fm and Facebook.

I suspect this is a configuration error on my side, but unfortunately I have no clue what I should correct. I don't even know what search terms should I use to learn more about this subject (googling "firefox bad kerning" didn't return any results relevant to my case). I tried to use a fresh Firefox profile and the issue was still visible, so I guess that rules out Firefox configuration. Maybe something about fontconfig settings is wrong, or I didn't switch on something that is necessary?

For the record, these are the fontconfig settings enabled in /etc/fonts/conf.d/:

Code:

10-autohint.conf -> ../conf.avail/10-autohint.conf
10-scale-bitmap-fonts.conf -> /etc/fonts/conf.avail/10-scale-bitmap-fonts.conf
10-sub-pixel-rgb.conf -> ../conf.avail/10-sub-pixel-rgb.conf
20-unhint-small-dejavu-sans.conf -> ../conf.avail/20-unhint-small-dejavu-sans.conf
20-unhint-small-dejavu-sans-mono.conf -> ../conf.avail/20-unhint-small-dejavu-sans-mono.conf
20-unhint-small-dejavu-serif.conf -> ../conf.avail/20-unhint-small-dejavu-serif.conf
20-unhint-small-vera.conf -> ../conf.avail/20-unhint-small-vera.conf
30-metric-aliases.conf -> ../conf.avail/30-metric-aliases.conf
30-urw-aliases.conf -> ../conf.avail/30-urw-aliases.conf
40-nonlatin.conf -> ../conf.avail/40-nonlatin.conf
44-wqy-zenhei.conf -> ../conf.avail/44-wqy-zenhei.conf
45-latin.conf -> ../conf.avail/45-latin.conf
49-sansserif.conf -> ../conf.avail/49-sansserif.conf
50-user.conf -> ../conf.avail/50-user.conf
51-local.conf -> ../conf.avail/51-local.conf
57-dejavu-sans.conf -> ../conf.avail/57-dejavu-sans.conf
57-dejavu-sans-mono.conf -> ../conf.avail/57-dejavu-sans-mono.conf
57-dejavu-serif.conf -> ../conf.avail/57-dejavu-serif.conf
60-latin.conf -> ../conf.avail/60-latin.conf
65-fonts-persian.conf -> ../conf.avail/65-fonts-persian.conf
65-nonlatin.conf -> ../conf.avail/65-nonlatin.conf
66-wqy-zenhei-sharp.conf -> ../conf.avail/66-wqy-zenhei-sharp.conf
69-unifont.conf -> ../conf.avail/69-unifont.conf
80-delicious.conf -> ../conf.avail/80-delicious.conf
90-synthetic.conf -> ../conf.avail/90-synthetic.conf
90-ttf-bengali-fonts.conf -> ../conf.avail/90-ttf-bengali-fonts.conf
90-ttf-devanagari-fonts.conf -> ../conf.avail/90-ttf-devanagari-fonts.conf
90-ttf-gujarati-fonts.conf -> ../conf.avail/90-ttf-gujarati-fonts.conf
90-ttf-kannada-fonts.conf -> ../conf.avail/90-ttf-kannada-fonts.conf
90-ttf-malayalam-fonts.conf -> ../conf.avail/90-ttf-malayalam-fonts.conf
90-ttf-oriya-fonts.conf -> ../conf.avail/90-ttf-oriya-fonts.conf
90-ttf-punjabi-fonts.conf -> ../conf.avail/90-ttf-punjabi-fonts.conf
90-ttf-tamil-fonts.conf -> ../conf.avail/90-ttf-tamil-fonts.conf
90-ttf-telugu-fonts.conf -> ../conf.avail/90-ttf-telugu-fonts.conf

I would be grateful for any pointers. What should I be looking for?

AwesomeMachine · 03-25-2018, 08:13 PM

And, is this condition simply intolerable? It could be the font antialiasing setting. I don't know how to adjust that on your system. But it might be a path to investigate.

ondoho · 03-26-2018, 12:57 AM

well op clearly says:

Quote:

Originally Posted by arcctgx

I have some problems with the way the fonts are displayed on some websites.

I have created an animated gif illustrating that issue (see attachment below). This one is from the Mattermost web app

...which leads me to assume that otherwise everything's OK.

i would try to narrow it down:
try different browsers & versions, different sites.
maybe it is browser specific? maybe it is site (oops, sorry, "webapp") specific or javascript specific?

arcctgx · 03-26-2018, 05:25 PM

Thank you for your answers.

I investigated further. The issue is visible in Firefox 52.7.2 (ESR) and in 59.0.2. I can't reproduce it using latest version of Google Chrome. On the other hand, I don't see the issue in Firefox running in Windows 7 and Windows 10. So it looks like it's Firefox and Linux specific. This is not good.

I tested various antialiasing settings, without any visible effect on the issue. As for the websites, I'm actually noticing this in more websites now that I started paying more attention. I have no idea if it's related to Javascript. Maybe it is, I wouldn't be surprised.

And I wouldn't call this font issue "intolerable". It's just that somehing is clearly wrong, and I'd like to find a solution.

Daedra · 03-26-2018, 10:35 PM

Have you tried removing 10-autohint.conf from /etc/fonts/conf.d? The patent for the bytecode interpreter has expired and has been automatically enabled in version of freetype 2.4 and beyond, there really is no use for the autohinter anymore. Not sure if it will fix your problem, but might be worth a try.

Myk267 · 03-27-2018, 12:48 AM

I keep looking at this topic and thinking, "Wow, I remember exactly this, but that was during Slackware 14-ish times".

Was this a clean install of 14.2 or an upgrade? Your conf.d directory looks a little different than mine. Here's my conf.d from a pretty recent install and updated 14.2:

Code:

10-scale-bitmap-fonts.conf -> /etc/fonts/conf.avail/10-scale-bitmap-fonts.conf
20-unhint-small-dejavu-sans-mono.conf -> ../conf.avail/20-unhint-small-dejavu-sans-mono.conf
20-unhint-small-dejavu-sans.conf -> ../conf.avail/20-unhint-small-dejavu-sans.conf
20-unhint-small-dejavu-serif.conf -> ../conf.avail/20-unhint-small-dejavu-serif.conf
20-unhint-small-vera.conf -> ../conf.avail/20-unhint-small-vera.conf
30-metric-aliases.conf -> ../conf.avail/30-metric-aliases.conf
30-urw-aliases.conf -> ../conf.avail/30-urw-aliases.conf
40-nonlatin.conf -> ../conf.avail/40-nonlatin.conf
42-luxi-mono.conf -> ../conf.avail/42-luxi-mono.conf
44-wqy-zenhei.conf -> ../conf.avail/44-wqy-zenhei.conf
45-latin.conf -> ../conf.avail/45-latin.conf
49-sansserif.conf -> ../conf.avail/49-sansserif.conf
50-user.conf -> ../conf.avail/50-user.conf
51-local.conf -> ../conf.avail/51-local.conf
57-dejavu-sans-mono.conf -> ../conf.avail/57-dejavu-sans-mono.conf
57-dejavu-sans.conf -> ../conf.avail/57-dejavu-sans.conf
57-dejavu-serif.conf -> ../conf.avail/57-dejavu-serif.conf
60-latin.conf -> ../conf.avail/60-latin.conf
60-liberation.conf -> ../conf.avail/60-liberation.conf
65-fonts-persian.conf -> ../conf.avail/65-fonts-persian.conf
65-nonlatin.conf -> ../conf.avail/65-nonlatin.conf
69-unifont.conf -> ../conf.avail/69-unifont.conf
80-delicious.conf -> ../conf.avail/80-delicious.conf
90-synthetic.conf -> ../conf.avail/90-synthetic.conf
90-ttf-bengali-fonts.conf -> ../conf.avail/90-ttf-bengali-fonts.conf
90-ttf-devanagari-fonts.conf -> ../conf.avail/90-ttf-devanagari-fonts.conf
90-ttf-gujarati-fonts.conf -> ../conf.avail/90-ttf-gujarati-fonts.conf
90-ttf-kannada-fonts.conf -> ../conf.avail/90-ttf-kannada-fonts.conf
90-ttf-malayalam-fonts.conf -> ../conf.avail/90-ttf-malayalam-fonts.conf
90-ttf-oriya-fonts.conf -> ../conf.avail/90-ttf-oriya-fonts.conf
90-ttf-punjabi-fonts.conf -> ../conf.avail/90-ttf-punjabi-fonts.conf
90-ttf-tamil-fonts.conf -> ../conf.avail/90-ttf-tamil-fonts.conf
90-ttf-telugu-fonts.conf -> ../conf.avail/90-ttf-telugu-fonts.conf
99pdftoopvp.conf

At a glance, I confirm what Daedra wrote about 10-autohint. It also looks like you're missing 42-luxi-mono.conf and 60-liberation.conf. I would be more concerned with the missing liberation font settings than luxi mono, given your example gif.

arcctgx · 03-27-2018, 03:17 PM

Quote:

Originally Posted by Daedra

there really is no use for the autohinter anymore. Not sure if it will fix your problem, but might be worth a try.

That was it! I disabled 10-autohint.conf, and this issue I described is gone now. Thanks!

Quote:

Originally Posted by Myk267

I keep looking at this topic and thinking, "Wow, I remember exactly this, but that was during Slackware 14-ish times". Was this a clean install of 14.2 or an upgrade? Your conf.d directory looks a little different than mine.

That was a fresh install of Slackware-14.2, but I wasn't happy with the way fonts appeared, so I must've changed something. I've had this (very dated...) site bookmarked for I don't remember how long: http://kev009.com/wp/2009/12/getting...n-gentoo-linux, and it looks like I was following this.

Now that 10-autohint.conf is gone, I had to change some options in XFCE Appearance menu to get my fonts to look better. Previously I had the autohinting set to "Full", but now I had to set it to "Slight". I was using this old setting for such a long time that now everything looks different and strange... Not in a bad way, just totally not what I was used to.

So it looks like I need to find some modern guide on how to configure font rendering in Linux... Does anyone know a good one?

Daedra · 03-27-2018, 10:02 PM

Have you tried infinality? You can find slackware builds for it here https://github.com/archfan/bob-infinality-bundle

ilovepenquins · 04-20-2018, 11:30 AM

Quote:

Originally Posted by Daedra

Have you tried infinality? You can find slackware builds for it here https://github.com/archfan/bob-infinality-bundle

bohoomil's fontconfigs seem to work ok with recent freetype