first attempt at color inversion

[pgmmpk]

added invertColor option to \cuKrukPara.

Idea is to allow this:

\cuKrukPara[invertColor]{ aaa \\ bbb}

[pgmmpk]

Addresses issue #55

[typiconman]

Hmm. I get an error:
! Package xkeyval Error: no value specified for key `invertColor'.

Here's my M(n)WE:

\documentclass{article}
\usepackage{polyglossia}
\usepackage{fontspec}
\usepackage{churchslavonic}
\setdefaultlanguage{churchslavonic}
\newfontfamily\churchslavonicfont[Script=Cyrillic,Ligatures=TeX]{PonomarUnicode.otf}
\newfontfamily\musicFont[Scale=1.5]{MezenetsUnicode}
\let\cuKrukFont=\musicFont
\begin{document}
\cuKruk[invertColor]{𜽰𜼅}{Тво}
\end{document}

[pgmmpk]

Oops. this option exists only for \cuKrukPara, not (yet) for \cuKruk. Please try with \cuKrukPara - seem to work here

[typiconman]

Still no luck. If I try to compile this code:

\documentclass{article}
\usepackage{polyglossia}
\usepackage{fontspec}
\usepackage{churchslavonic}
\setdefaultlanguage{churchslavonic}
\newfontfamily\churchslavonicfont[Script=Cyrillic,Ligatures=TeX]{PonomarUnicode.otf}
\newfontfamily\musicFont[Scale=1.5]{MezenetsUnicode}
\let\cuKrukFont=\musicFont

\begin{document}

\cuKrukPara[invertColor]{
𜽟 𜾆𜼱𜼇
\\
Хри-сто́съ
}

\end{document}

I get the message: ! Package xkeyval Error: no value specified for key `invertColor'..

If I specify a vaue for invertColor, as the message suggests (e.g., invertColor=1), I get a different error:
! Use of \cu@kinovar@color doesn't match its definition.

[pgmmpk]

I see many problems there. Will need some time to review.

[typiconman]

Yes, now it works!