Libertinus: Support for calligraphic characters in Libertine Math

[capnrefsmmat]

Calligraphic characters (the \mathcal range) don't appear to be supported in Libertine Math:

\documentclass[11pt]{article}
\usepackage{fontspec}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amssymb}

\usepackage{unicode-math}

\setmainfont[Numbers=OldStyle,Ligatures=TeX]{Libertine Serif}
\newfontfamily{\Lpnum}[Numbers=Lining,Ligatures=TeX]{Libertine Serif}
\setsansfont[Ligatures=TeX]{Libertine Sans}

\setmathfont{Libertine Math}

\begin{document}
${\cal A B C D E F G H I J K L M N O P Q R S T U V W X Y Z}$ ${\cal H}_i$
\end{document}

produces, with both LuaTeX and XeTeX,

XITS Math has a full range I can use with \setmathfont[range={\mathcal,\mathbfcal}]{xits-math.otf}, but it'd be nice if Libertine Math had its own set (perhaps borrowed from XITS or elsewhere).

Thanks for the otherwise lovely fonts.

[capnrefsmmat]

(Moving discussion here from #39.)

I've dug around for OpenType fonts with calligraphic alphabets under the Open Font License or similar; the only three I've found are XITS/STIX, Asana Math, and the brand-spanking-new TeX Gyre DejaVu Math, based on the DejaVu sans-serif font. (Not quite OFL, but the license seems very liberal.)

I put together some vaguely mathematical gibberish to test a few of the characters in actual use, plus the whole range of the alphabet, using Libertinus Math as the base.

Screenshots of each:

The DejaVu characters don't seem to fit at all, but XITS seems like a fairly good match, and I may use its calligraphic characters until they can be added to Libertinus.

Source: mathcal.tex.txt

I hope this proves helpful.

[khaledhosny]

I’m fine with XITS if others agree it is a good match (it seems fine from these screenshots).

[godbyk]

Of those presented, XITS has my vote.

[khaledhosny]

Please test and report any issues with the script alphabet.

[capnrefsmmat]

Just swapped in the updated font to my thesis proposal. Looks very good. Thanks for the very quick update!

My only comment is that I am not sure about the placement of subscripts:

I'm not sure whether the subscript _t_ should be pulled in closer; maybe it needs italic correction?

[khaledhosny]

Yes, the spacing of scripts alphabet in STIX leaves a a lot to be desired. I thought I fixed it to some degree in XITS, but I’ll look again.

[adityam]

Is it also possible to include the stylistic set for calligraphic. With xits, I can use the following:

\setupbodyfont[xits]
\starttext
$\cal ABCDE$
\setupmathematics[stylealternative={calligraphic}]
$\cal ABCDE$
\stoptext

but the same code does not work with Libertinus. Not sure if this is due to the missing stylistic set or the missing .lfg file

[khaledhosny]

Libertinus does not have alternate calligraphic alphabet, and since Unicode seem to have promised to encode one in the future, I’m going to wait for that.

[madsmh]

Any news on the calligraphic alphabet?