Re: [possible patch] Basic fontspec code for LuaLaTeX and XelaTeX (was "LaTeX export: when is it more useful...")

[Juan Manuel Macías]

Stefan Nobis writes:

> Juan Manuel Macías <maciaschain@posteo.net> writes:
>
>> 1. There could be a defcustom, something like 'org-latex-use-fontspec'
>> (I would vote for nil by default).
>
> I would vote to activate this by default.

I voted nil because of the available fonts issue. But I think what you
say below is a good idea, so it could be activated by default

>> (format
>>  \\usepackage{iftex}
>>  \\ifpdftex
>>  \\relax
>>  \\else
>>  \\usepackage{fontspec}
>>  \\usepackage{unicode-math}
>>  \\defaultfontfeatures{Scale=MatchLowercase}
>>  \\defaultfontfeatures[\\rmfamily]{Ligatures=TeX}
>>  \\setmainfont{%s}
>>  \\setsansfont{%s}
>>  \\setmonofont{%s}
>>  \\fi
>>  org-latex-fontspec-mainfont
>>  org-latex-fontspec-sansfont
>>  org-latex-fontspec-monofont)
>
> I would prefer to make it easier to stick with the default fonts. So
> only add the font selection commands (including defaultfontfeatures)
> when the font variables are non-nil. If no font has been explicitly
> chosen, just use the default (in case of lualatex Latin Modern).
>
> For me, it does not matter whether the 'org-latex-fontspec-*'
> variables have a default of nil or set to the Free* fonts or something
> else. For my configuration, I would set these variable to nil in order
> to get the LaTeX default fonts and would like to go with the default
> preamble of Org and then add to this on a per document basis.
>
> This way, the whole configuration would be a little more composable, I
> think.

Sounds like a good idea and I agree. If I understand correctly, if the
sans, roman, and mono font variables (or any of them) are non-nil,
enable font selection. Otherwise, leave the default Latin Modern font.

By the way, although I've already commented on it in some post in the
parent thread, i think this package I wrote might be useful for doing a
quick visual test of a font (including opentype features test), using
org-latex-preview (compiling with LuaTeX). It can be done on any font
marked in dired. There are three options: insert arbitrary characters,
insert the Unicode code of the characters, or display a specimen of the
font. The default specimen is in the file specimen.tex, which can be
edited to add examples and languages.

Some screenshots:

https://i.imgur.com/3faKSjA.png

https://i.imgur.com/OJfUcO9.png

To create font tables I often use the LaTeX package unicodefonttable. An
example of usage within Org:

#+header: :headers '("\\usepackage{unicodefonttable}")
#+begin_src latex :imagemagick yes :iminoptions -density 600 :results raw 
:results file :file -2256080143431736233.png
\displayfonttable*[range-start=1F00,range-end=1FFE]{Old Standard}
\displayfonttable*[range-start=0600,range-end=06FF]{FreeSerif}
#+end_src

A screenshot:

https://i.imgur.com/Fwsg7bb.png

Maybe it could also be added as an emergency fallback font GNU Unifont:

https://unifoundry.com/

Best regards,

Juan Manuel