Who can write a package to call for upright Greek lowercase letters compatible with the computer modern italic ones?

Question

Update

Now some volunteer contacts me and the project begins. Thanks go to all the readers.

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Sometimes we need to call for upright Greek lowercase letters compatible with the computer modern italic ones in shapes. Here is a solution for which XeLaTeX couldn't be used. And as follows @David Carlisle also gives a solution involving the unicode-math package which may be clashed with some other packages, for example, the mathspec package. So it's necessary to create a single and smart package to invoke computer modern upright greek lowercase letters as mathematical symbols.

Now I've created the regular and bold OTF font files for them, then who can write a package maybe called cmupgreek (there is already a upgreek package for upright Greek letters from the Euler or Adobe Symbol fonts)?

The following is the screen shots for shapes of them.

The commands for them are as follows, and we could get the bold ones if we use \mathbf{}, \boldmath and so on.

Command Unicode
\upalpha 03B1
\upbeta 03B2
\upgamma 03B3
\updelta 03B4
\upepsilon 03B5
\upzeta 03B6
\upeta 03B7
\uptheta 03B8
\upiota 03B9
\upkappa 03BA
\uplambda 03BB
\upmu 03BC
\upnu 03BD
\upxi 03BE
\upomicron 03BF
\uppi 03C0
\uprho 03C1
\upsigma 03C3
\uptao 03C4
\upupsilon 03C5
\upphi 03C6
\upchi 03C7
\uppsi 03C8
\upomega 03C9
\upvartheta 03D1
\upvarphi 03D5
\upvarpi 03D6
\upvarsigma 03D8
\upvarkappa 03F0
\upvarrho 03F1
\upvarepsilon 03F5

Answer 1

Any Unicode Math font includes Greek in upright, italic, bold upright, bold italic, bold sans serif and slanted bold sans serif. unicode-math makes these available using \sym... commands, or you can simply type the characters directly: αβγ (which also works in other contexts such as web pages).

\documentclass{article}
\usepackage{unicode-math}
\begin{document}
$
\symup{\alpha}\symup{\beta}\symup{\gamma}
\symbfup{\alpha}\symbfup{\beta}\symbfup{\gamma}
\symit{\alpha}\symit{\beta}\symit{\gamma}
\symbfit{\alpha}\symbfit{\beta}\symbfit{\gamma}
\symbfsf{\alpha}\symbfsf{\beta}\symbfsf{\gamma}
\symbfsfit{\alpha}\symbfsfit{\beta}\symbfsfit{\gamma}
$
$αβγ$
\end{document}

this shows the Latin Modern font, so in the style of Computer Modern, but the same input works with any font. Adding \setmathfont{Stix Two Math} produces

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As requested, an example not using unicode-math and showing how you can use any font with Unicode Mathematical Greek with no special package support needed. (I loaded the fonts by font name, you may need to use the file name if you have not configured fontconfig).

The example loads (but does not use) mathspec so you need xelatex here (otherwise the example would also work in lualatex)

\documentclass{article}
\usepackage{mathspec}% not needed here but just to show it is compatible
\usepackage{fontspec}
% Any Font with Mathmatical Greek in Unicode positions will work here
% I am using some standard ones but you could use your new font
\newfontfamily\lmfont{Latin Modern Math}[NFSSFamily=lmmath]
\DeclareMathAlphabet\mathlm{TU}{lmmath}{m}{n}
\newfontfamily\ncmfont{NewComputerModernMath}[NFSSFamily=ncmmath]
\DeclareMathAlphabet\mathncm{TU}{ncmmath}{m}{n}
\newfontfamily\stxfont{STIX Two Math}[NFSSFamily=stix2math]
\DeclareMathAlphabet\mathstix{TU}{stix2math}{m}{n}
\begin{document}
LM
$\mathlm{αβγ}$
NCM
$\mathncm{αβγ}$
Stix2
$\mathstix{αβγ}$
\end{document}