Re: LaTeX export: when is it more useful to use LuaTeX instead of pdfTeX?

[Juan Manuel Macías]

Hi, Tim, thank you for your comments,

Tim Cross writes:

> Juan, I think it would be great to add your post to worg. I'm happy to
> do this, but I think it wold also be good if we could include a basic
> 'setup' i.e. what changes people might need to (or should do to maximise
> benefit) in order to try out luatex. For example, what settings to put
> in org-latex-pdf-process (I'm guessing something like "lualatex
> -interaction nonstopmode -output-directory %o %f") and what (if any)
> packages to add/remove from the org-latex-packages-alist etc (I'm
> guessing that perhaps some font related packages may need tweaking?).
>
> Ideally, what would be good is a very simple recipe for what someone
> should do in order to try out luatex and get the most out of it (or at
> least see potential).

I have no problem with my post being added to worg, but I don't have
much experience in working with worg... Of course, I can prepare
everything you need, if you think it might be useful.

The *only* difference between a minimal document for lualatex and a
minimal document for pdfLaTeX is that for LuaLaTeX it is not necessary
to load the fontenc and inputenc packages. The following mwe
compiles perfectly in LuaLaTeX:

\documentclass{article}
\begin{document}
Hello world!
á é í ó ú ñ à è ì ò ù
\end{document}

LuaTeX defaults to an otf version of the Computer Modern font, so any
user who isn't interested in fonts and writing in non-Latin languages,
but wants to work in a real Unicode environment, won't need to fine-tune
fonts, nor load any special package. The rest is exactly the same as any
document for pdfLaTeX.

If in the Org document is added:

#+LATEX_COMPILER: lualatex 

the fontenc and inputenc packages are not loaded in the output, which is
correct and it is the minimum requirement for LuaLaTeX. I think Org is
already doing a good job here.

If the user wants to use other fonts, the fontspec package must be
loaded. Depending on the user's needs, you can go from the simplest to
the most complex configurations (the different options and possibilities
are explained in detail in the fontspec manual). The simplest: if a user
just wants to use the Times New Roman font as the main font in his
document, this lines would suffice:

\usepackage{fontspec}
\setmainfont{Times New Roman}

That is, by indicating the name of the family (Times New Roman), luatex
would use this family for normal text, italics, bold, etc. Of course,
it's a good idea to load a family that has italic, bold, bold italic,
and other subtypes. Fontspec has tons more options, but this would be
the basics. But I think this aspect is more on the LaTeX side than in
the Org side.

LuaTeX can use the fonts installed on the system, without the need to
add more (that is, simply by putting the name of the family, LuaTeX
accesses them); and you can also use any font in any directory, just by
giving the path. I wrote BTW this little package to preview any font in
Emacs, and test the opentype features. it uses org-latex-preview in the
background and compiles with LuaTeX:

https://gitlab.com/maciaschain/org-font-spec-preview

Best regards,

Juan Manuel