Re: Fallback fonts in LaTeX export for non latin scripts

[Ihor Radchenko <yantar92@posteo.net>]

Juan Manuel Macías <maciaschain@posteo.net> writes:

>> Do I understand correctly that onchar=id will not break anything if text
>> is correctly marked with \selectlanguage{<lang>}?
>
> To load language features (hyphen rules, captions, etc.) there is no
> problem. But to load a font associated with a language, the font of the
> last declared language will always be loaded.

May we explicitly set the needed font around language environments?

Something like

\setfontforrussian
\selectlanguage{russian}
....

\setfontforbulgarian
\selectlanguage{bulgarian}
....


> In any case (to organize myself mentally) I thought that it could be
> done on two levels:
>
> - Level 0: The fonts associated with each script are loaded (from a
>   defcustom list) if luatex is the current engine. And low-level code is
>   generated in Lua with the luaotfload.add_fallback function. That code
>   can be in a Lua file or directly within the preamble, enclosed in the
>   \directlua primitive (mode=harf means that HarfBuzz is used as otf
>   rendering):
> ...

Sounds reasonable.

> - Level 1: The user can load language properties and associate fonts
>   with each language using Babel's high-level code (via keywords in Org,
>   as we have commented in previous messages). Here you can also modify
>   the default fonts (also, as we mentioned before): main, mono, sans and
>   math. If the language is declared with an asterisk (for example:
>   russian*) the onchar=etc property will be included in the preamble,
>   and it would not be necessary to switch to russian explicitly. It is
>   assumed that in this scenario the only language with Cyrillic script
>   would be Russian. For language swithcing, in the rest of the cases,
>   some babel command would have to be used using @@latex:@@, special
>   blocks, etc. When Org already has its own language switching
>   mechanism, this would be used instead. Wdyt?

I am not sure if I like "russian*" idea. May you explain a bit more
about how onchar works? What if language characters are intersecting,
and not using exactly the same char sets?

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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