Re: [Devel] Problems with font naming and Xft

[David Turner]

Hello Owen,

Owen Taylor a écrit :
> 
> It's been reported to me (http://bugzilla.gnome.org/show_bug.cgi?id=68113)
> that GTK+-2.0, when using Xft has problems with some Japanese fonts of
> not displaying any name at all.
> 
> The problem seems to be that Xft is simply using the family_name field
> of FT_Face and this field is initialized in a rather haphazard way.
> 
> From reading the code in FreeType, it looks like what it does is it
> picks a (more or less) random Unicode name from the font, which could
> be for any language, and then converts that from Unicode to "ASCII"
> by assigning each character of the result to one byte of the Unicode
> character. (If there is only an Apple Roman name, and no unicode names,
> it similarly assumes that Apple Roman is ASCII.)
> 
> Now, I can probably figure out some way of using FT_Get_Sfnt_Name()
> directly, bypassing Xft, but it seems to me that that freetype could
> do better on a couple of counts when setting the family_name field:
> 
>  - If there is a name for the English language ID, it should use
>    that. Yes, this is English-centric, but, it can't be less useful
>    to pick the English name than a completely random name, and it's
>    much more likely that the English name is going to be in the
>    ASCII subset of Unicode.
>
>  - When converting from a different encoding into ASCII, if there
>    characters with values greater than 127, replace them with
>    ? or some other substitute character rather than the low byte.
>
Agreed.. Actually, the font name selection code was pretty buggy
before 2.0.9, though it worked for most fonts. It got better in
2.0.9 to deal with broken fonts that include invalid name table
entries.

I've just commited a more general fix to the STABLE branch of the
code on the CVS. Could you please download it and report problems with
it.. ?


Thanks for spotting this !!

- David Turner

 
> Regards,
>                                         Owen
> 
> [
>  I think fontconfig should have some way of getting the name for a
>  font localized into a particular language... my best idea as to an API
>  would be to have a call like:
> 
>   char *FcConfigGetLocalizedName (FcConfig *config, FcPattern *p, const char 
> *langid);
> 
>  the FC_LANG_* constants are not appropriate for the langid here, so you'd
>  need something different.
> ]
>