unicode-math Use different font for latin alphabet

Question

I am trying to use STIX Two Math for math. font as a non math font (symbol-wise, letters will be the only thing for math mode), but only for the letters involved in math, i. e. abcdefghijklmnopqrstuvwxyz and ABCDEFGHIJKLMNOPQRSTUVWXYZ.

\documentclass{article}

\usepackage{fontspec}
\usepackage[math-style = upright]{unicode-math}

% ======================================================

\renewcommand{\normalsize}{\fontsize{10}{11}\selectfont}

\newcommand{\currentFont}{
    ItalicFont = font Italic,
    BoldFont = font Bold,
    BoldItalicFont = font Bold Italic,
}

\newcommand{\normalFontFeatures}{
    Kerning = On,
    Style = Historic,
    Ligatures = {Historic, Rare},
}

% ======================================================

\setmainfont[
    Language = English,
    \currentFont
    \normalFontFeatures
]{font}

\setmathfont[range = {"0028-"1D7CB}, StylisticSet = 008]{STIX Two Math}
\setmathfont[range = {"41-"7B,}]{font} % range = unicode range for alphabet

% ------------------------------------------------------

\setmathfont[range = {"41-"7B}]{font} % Ignore, check NOTE
\setmathfont[range = bfup -> up]{font Bold} % Ignore, check NOTE
\setmathfont[range = it -> up]{font Italic} % Ignore, check NOTE
\setmathfont[range = bfit -> up]{font Bold Italic} % Ignore, check NOTE

% ======================================================

\begin{document}

    \textit{F=ma}

    $$ \mathbfit{F=ma} \quad \mathbf{F=ma} \quad F=ma \quad \mathit{F=ma}$$

\end{document}

NOTE: unicode-math not deciding what font to use for Bold Italic is a problem with my particular font files. Because of this I am currently using a work-around for getting it to display the way the image shows. But this feels so unnatural and inconvenient to be the correct way though.

Will Robertson solved it But I still have a problem with bfit. It refuses to show \mathbfit{F=ma} with the proper font, this could be fixed though, just by adding

\setmathfont[range = bfit -> up]{Bold Italic}

in the preamble.

Thanks.

Answer 1

For a start, this seems to work for me:

\documentclass{article}
\usepackage{unicode-math}
\setmathfontface\mathrm{texgyreheros-regular.otf}
\begin{document}
$\mathrm{abc}$
\end{document}

Please provide a complete minimal example to demonstrate the rest and I might be able to answer in more detail.

---

Here's another example that will hopefully work for you:

\documentclass{article}
\usepackage[math-style=upright]{unicode-math}
\setmathfont{xits-math.otf}
\setmathfont{texgyreheros-regular.otf}[range=up/{Latin,latin}]
\begin{document}
    \[
       \symbfit{F=ma} \quad \symbf{F=ma} \quad F=ma \quad \symit{F=ma}
    \]
\end{document}

Is that what you're trying to achieve?