Indexing fonts

[Michal Vlasák]

On Tue Dec 20, 2022 at 3:15 PM CET, Marcel Fabian Krüger wrote:
> But it's almost certain that in no case fontconfig matters under LuaTeX
> since LuaTeX doesn't link against fontconfig, so this would either
> require to call the fontconfig shell utilities or to load a fontconfig
> library dynamically, but of which don't work except when running with
> shell-escape.

Sorry, I am not really familiar with Windows on this matter, but I would
still like to clarify for Linux (and maybe other systems):

While fontconfig the program (fc-cache, ...) shouldn't matter,
luaotfload parses fontconfig configuration files (like
/etc/fonts/fonts.conf and others included by it):

    https://github.com/latex3/luaotfload/blob/79fb28b633691fc7349e1d833317049ba9954e80/src/luaotfload-database.lua#L2411-L2416

That's how luaotfload accesses "system fonts". Though there is another
thing to keep in mind: luaotfload excludes any "system fonts" whose
location contains "texmf" (so for example without other setup Latin
Modern fonts from the Debian fonts-lmodern package can't be used).

    https://github.com/latex3/luaotfload/blob/79fb28b633691fc7349e1d833317049ba9954e80/src/luaotfload-parsers.lua#L286-L299

Also I didn't see The XeTeX reference guide [1] linked in this thread,
"The \font command" section might be interesting on some level.

[1]: https://mirrors.ctan.org/info/xetexref/xetex-reference.pdf

Michal