Support for stylistic variant

[Xintong-Li]

Some math fonts provide alternative stylistic set for users. For instance, by enabling stylistic set 2, users of New Computer Modern Math will get upright integrals. Similarly, by enabling stylistic set 8, STIX2 Math will enable upright integrals.

In unicode-math, this can be declared when setting up the font via \setmathfont{NewCMMath-Regular.otf}[StylisticSet=2] .

Is there any way to activate stylistic variant in OpTeX, or is there any further plan of supporting this?

Thank you.

[olsak]

You can use otfinfo -f to list all font features provided by given font. For example

otfinfo -f NewCMMath-Regular.otf
ss01	Stylistic Set 1
ss02	Stylistic Set 2

This means that this font supports two font features listed here. You can add directly the font features to the math font loaded by the \lodmath command (note that \fontfam uses it) by adding features to the internal \_mfontfeatures macro. So:

\addto\_mfontfeatures{ss02;}
\fontfam[newcm]

test: $\int f$
\bye

prints the math symbols from stylistic set 02.

Note, that you need not any conversion of font features of the font (ss02 in our examaple) to a different LaTeX terminology (StylisticSet=2 in your example from LaTeX unicode-math). Use directly font features listed by otfinfo.

[Xintong-Li]

Thank you for the explanation.