Re: [Gimp-user] Characters became tofu after deleting fonts on Ubuntu

[Ken Moffat <zarniwhoop ntlworld com>]

On Fri, Oct 05, 2018 at 08:50:06PM +0800, dqwyy wrote:
> Hi all.
>
> I'm sorry that English is not my native language so I'm not good at it. Here is my problem.
>
> I'm a new user on Ubuntu and I'm so excited that I can control my computer completely. Ubuntu, as a 
> GNU/Linux OS is so free that I can customize it. I only use English, Chinese and Japanese so that I deleted 
> all the fonts that I don't need. I think three fonts for English/western scripts are enough so I deleted 
> all the fonts except Freesans, Freeserif and Freemono. I think one sans serif font, one serif font and one 
> monospace font are enough. This looks really concise. I don't need to find a font on the long drop-down 
> menu at Office software anymore.

Font problems are often hard to solve, I hope the words I use will
be understandable.

Your logic for limiting the available fonts sounds sensible,
but there are certain complications :

1. An application selects a font by using 'fontconfig'. The process
can have sometimes unexpected results, because fontconfig may reject
a font on the assumption that it lacks required characters for the
specified language.

2. Fontconfig looks at files in /etc/fonts/conf.d/ for the rules.
I have known some CJK fonts to add their own files there, causing a
CJK Sans font to be used for Serif.

3. But in a default western layout, the fallback fonts are the
DejaVu variants.

In gnome applications, I needed to add DejaVu fonts several years
ago because of odd tofu - the reason was whitespace varieties
(non-breaking spaces and similar) and DejaVu provided these.

The missing text uses a Sans font, at a small size.

So, I suggest that you try adding the DejaVu Sans font.

> Things go well until I installed Gimp. I launched gimp after installing it and found nearly all the 
> characters became "tofu" (some boxes). General speaking, this only happens when lacking of fonts. However, 
> I already have fonts for Latin scripts. I also have CJK (Chinese, Japanese and Korean) fonts with basic 
> Latin scripts included of course. So I think Gimp use the fonts which are deleted by me, and there are 
> something wrong with the fallback, too. I don't know which fonts do it use and I tried reinstall the fonts 
> named "Ubuntu" to my computer (I think that "Ubuntu" font is the default font of Ubuntu, isn't it?) but 
> nothing changed and I still got tofu.
>
> So could you please help me to solve this problem? Maybe I should reinstall all the fonts which are deleted 
> by me? But I can't get those fonts unless I reinstall my OS. Well, this may be a weird problem because I 
> think there is nobody but me to delete so many fonts on Ubuntu. XD
>
> My OS version is Ubuntu 18.04.1 LTS, the gimp version is 2.10.
>
> Here are some screenshots. Thank you very much.
> Screenshots:
> [1. The tofu on gimp] https://i.imgur.com/PmMYVuv.png

A Sans font is being used for the titles, but all the smaller items,
even the numbers, are tofu.

> [2. My fonts setting] https://i.imgur.com/6u8SnXV.png

I see you are using Source Han Sans for titles, and a larger size of
FreeMono for monospace (sensible, FreeMono is rather small).

I think that Source Han was incorporated into google's Noto fonts.
It is a long time since I last looked at font details, but certainly
for Noto the non-western fonts (e.g. their various CJK versions,
also other writing systems) do not include the western characters.

Perhaps, try using a different font for 'Interface' (I am not
familiar with this tool, but that looks a likely setting) - DejaVu
Sans ought to work.

Possibly, your locale is affecting this.  Which locale are you
using ?

Other tools to use to try to work out what is happening:

fc-list | less

That should confirm which fonts are installed.

fc-match 'Font name'  e.g. fc-match 'FreeMono'

fc-match -a 'Sans' | less
 That just lists all the Sans fonts

fc-match 'Sans'
 - for me, this reports "WenQuanYi Zen Hei" "Regular"
 but if I use LC_ALL=kr_KR fc-match 'Sans' I get DejaVu Sans

(I have a local configuration in /etc/fonts/local.conf which is
probably doing that).

Maybe your Scaling Factor (1.25) is making the font too big to fit
in the available space ?

> [3. My font manager] https://i.imgur.com/undefined.png

Bad link!
> Regards,
> dqwyy <me dqwyy moe>
> http://a.dqwyy.moe
> October 5, 2018

All I can add is "Good Luck".

ĸen
-- 
                      Well grubbed , old mole!