Hi,
I have noticed that luatex now supports variable fonts and I've started
experimenting. I am asking a question here but I am unsure if it is
actually tied to luatex or luaotfload or maybe fontspec. In case, please
be so kind to address me to the correct forum.
I have noticed that luatex may get very unhappy unless you explicitly
set values for the axes. For instance see the comments on
https://tex.stackexchange.com/questions/355104/tex-luatex-xetex-fontspec-support-for-opentype-variable-fonts.
If you do
\documentclass[a4paper,12pt]{article}
\usepackage{fontspec}
\setmainfont{Source Serif 4 Variable}
\begin{document}
The quick brown fox jumps over the lazy dog.
\end{document}
then this fails with
error: (file .fonts/source-serif-4.004/VAR/SourceSerif4Variab
le-Roman.otf) (cff): Type2 Charstring Parser: subroutine called but no
subrouti
ne found
! ==> Fatal error occurred, no output PDF file produced!
To make the code work you need to add a
\defaultfontfeatures{RawFeature={+axis={wght=100}}}
Is this expected?
Shouldn't the font selection mechanism be able to determine a suitable
weight for the font if it is not specified? If I am correct the font
fvar table should be able to provide a defaultValue for each axis.
Why does this happen with the wght axis, but not for the opsz axis?
Thanks for considering this matter,
Best,
Sergio
