Hi Juan Manuel, Thank you for writing this, which is the clearest explanation I have seen of the advantages of LuaLaTeX/XeLaTeX. I have been using LaTeX for nearly 30 years, but stopped using it intensively every day when pdfLaTeX was still the bleeding edge. When I started again in the last couple of years, it has been a bit confusing to understand why and what all these different versions are. These days I use LuaLaTeX as well, but most of the documents I process are exported from Org-mode.
Best, --Diego On Mon, Apr 5, 2021 at 10:49 PM Juan Manuel Macías <maciasch...@posteo.net> wrote: > Hi all, > > There have been some threads recently about exporting to LaTeX, but I > think something that I consider interesting for novice Org/LaTeX users > has not been commented: the choice of the TeX engine. I think this is > important because although people often say they "use LaTeX", what they > actually use is TeX via the La-TeX format. What TeX engine to choose? I > would dare to say the following: unless you want to maintain some > backward compatibility with old documents, I highly recommend using > LuaTeX or XeTeX, especially LuaTeX. Although pdfTeX is very popular > among average or veterans LaTeX users, I think using it nowadays doesn't > make much sense (IMHO). LuaTeX is the natural evolution of pdfTeX and > adds the great advantage of accesing the TeX internals through Lua > scripting. > > (What follows is specially intended for those Org users who haven't used > XeTeX or LuaTeX yet). > > LuaTeX and XeTeX are *100% Unicode-based* and you can use your system > fonts (open type, true type, etc.) in your documents in a simple way > through the fontspec (https://www.ctan.org/pkg/fontspec) package, which > provides a very neat interface and manages all OpenType features (LuaTeX > and XeTeX use HarfBuzz as otf rendering engine). In LuaTeX also you can > use any font that is not installed in your system: just indicate the > path to the fonts files. This is very useful to test new fonts without > installing them... In all modern word processing systems the user has > always been able to pick a font easily, and that has been historically > quite complex, hard and complicated in the (La)TeX ecosystem. > > For example, if we want to use globally the Palatino Linotype family in > our LuaLaTeX document: > > \setmainfont{Palatino Linotype} > > We can add some OpenType features, like old style numbering: > > \setmainfont{Linux Libertine O}[Numbers=LowerCase] > > And if we want to use another font for italics, with certain properties > (color[1] and scaling): > > \setmainfont{Crimson} > [Numbers=Lowercase, > ItalicFont=MinionPro-It.otf, > ItalicFeatures={Color=red, > Scale=MatchLowercase}] > > ([1] Requires the xcolor package) > > We can also define our own family with its properties (for example, with > upper case numbers and letters tracking): > > \newfontfamily\myfamily{crimson} > [Numbers=Lining,LetterSpace=3.0] > > Furthermore (for more advanced users), in LuaTeX we can define new > opentype features on the fly, both positional and of substitution (as > long as the typeface includes the glyphs needed to replace). For > example, if I use the Crimson typeface, a contextual substitution for > character Q + u can be defined, by including some Lua code through the > LuaTeX primitive `directlua': > > \directlua{ > fonts.handlers.otf.addfeature{ > name = "mycontextual", > type = "chainsubstitution", > lookups = { > { > type = "substitution", > data = { > ["Q"] = "Q.alt01", > }, > }, > }, > data = { > rules = { > { > after = { { "u" } }, > current = { { "Q" } }, > lookups = { 1 }, > }, > }, > }, > } > } > > ... And add anywhere in the text: > > \addfontfeature{RawFeature=+mycontextual} > > If I had to choose, finally, between XeTeX and LuaTeX, I would choose > LuaTeX, for things like these and many other reasons. In addition, there > are emerging cool new packages that only work with LuaTeX. > > Anyway, XeTeX is another very good option too, especially for users who > prefer something that works more "out of the box" and is less esotheric > than LuaTeX. > > To export to PDF always with LuaTeX we can put in our ~ /.emacs: > > (setq org-latex-pdf-process > '("lualatex -shell-escape -interaction nonstopmode -output-directory > %o %f" > "lualatex -shell-escape -interaction nonstopmode -output-directory > %o %f" > "lualatex -shell-escape -interaction nonstopmode -output-directory > %o %f")) > > Or with latexmk, which will take care of compiling as many times as > necessary for indexes, bibliographies, etc .: > > (setq org-latex-pdf-process > '("latexmk -lualatex -e '$lualatex=q/lualatex %%O -shell-escape > %%S/' %f")) > > Best regards, > > Juan Manuel > >
