Cannot type anything on Russian

[sindzicat]

Hello all!

\fontfam[Termes]
\typosize[11/13]
\margins/1 a4 (1,1,1,1)cm
\rulang
Привет
\bye

output in console:

$ optex document.tex
This is LuaTeX, Version 1.18.1 (MiKTeX 24.4 Portable)
 restricted system commands enabled.
(./document.tex This is OpTeX (Olsak's Plain TeX), version <1.15 Jun 2024>
(C:/Apps/miktex-portable/texmfs/install/tex/luatex/optex/base/f-termes.opm
FONT: [Termes] -- \Termes (TeX Gyre Termes fonts based on Times)
 mods:{\caps } vars:{\rm \bf \it \bi } math:{Termes}
MATH-FONT: "[texgyretermes-math]" -- unicode math prepared.

(C:/Apps/miktex-portable/texmfs/install/tex/luatex/optex/base/unimath-codes.opm
(C:/Apps/miktex-portable/texmfs/install/tex/luatex/optex/base/mathclass.opm)
(C:/Apps/miktex-portable/texmfs/install/tex/luatex/optex/base/unimath-table.opm
)))
(C:/Apps/miktex-portable/texmfs/install/tex/generic/hyph-utf8/patterns/tex/hyph-ru.tex)
(C:/Apps/miktex-portable/texmfs/install/tex/luatex/optex/base/lang-data.opm)
[1
Missing character: There is no П (U+041F) in font [texgyretermes-regular]:+tlig;!
{C:/Apps/miktex-portable/texmfs/data/fonts/map/pdftex/pdftex.map}
Missing character: There is no р (U+0440) in font [texgyretermes-regular]:+tlig;!
Missing character: There is no и (U+0438) in font [texgyretermes-regular]:+tlig;!
Missing character: There is no в (U+0432) in font [texgyretermes-regular]:+tlig;!
Missing character: There is no е (U+0435) in font [texgyretermes-regular]:+tlig;!
Missing character: There is no т (U+0442) in font [texgyretermes-regular]:+tlig;!
])<c:/apps/miktex-portable/texmfs/install/fonts/opentype/public/tex-gyre/texgyretermes-regular.otf>
Output written on document.pdf (1 page, 2468 bytes).
Transcript written on document.log.

But this font has cyrillic letters:

What I do wrong?

Also I'd like to have short code examples in OpTeX user documentation.

[vlasakm]

At first, I thought this may require setting the OpenType script correctly to Cyrillic, i.e.

\_setff{script=cyrl}
\fontfam[Termes]
\typosize[11/13]
\margins/1 a4 (1,1,1,1)cm
\rulang
Привет
\bye

But that doesn't seem to help:

This is LuaTeX, Version 1.18.0 (mmtex 20240512)
(./test.tex This is OpTeX (Olsak's Plain TeX), version <1.14 Feb 2024>
(/usr/share/mmtex/tex/optex/base/f-termes.opm
FONT: [Termes] -- \Termes (TeX Gyre Termes fonts based on Times)
 mods:{\caps } vars:{\rm \bf \it \bi } math:{Termes}
MATH-FONT: "[texgyretermes-math]" -- unicode math prepared.
(/usr/share/mmtex/tex/optex/base/unimath-codes.opm (/usr/share/mmtex/tex/optex/base/mathclass.opm) (/usr/share/mmtex/tex/optex/base/unimath-table.opm))) (/usr/share/mmtex/tex/hyph-utf8/hyph-ru.tex) (/usr/share/mmtex/tex/optex/base/lang-data.opm) [1
Missing character: There is no П (U+041F) in font [texgyretermes-regular]:+tlig;script=cyrl;!
Missing character: There is no р (U+0440) in font [texgyretermes-regular]:+tlig;script=cyrl;!
Missing character: There is no и (U+0438) in font [texgyretermes-regular]:+tlig;script=cyrl;!
Missing character: There is no в (U+0432) in font [texgyretermes-regular]:+tlig;script=cyrl;!
Missing character: There is no е (U+0435) in font [texgyretermes-regular]:+tlig;script=cyrl;!
Missing character: There is no т (U+0442) in font [texgyretermes-regular]:+tlig;script=cyrl;!
])</usr/share/fonts/tex-gyre/texgyretermes-regular.otf>
Output written on test.pdf (1 page, 2460 bytes).
Transcript written on test.log.

I tried to confirm that the font has the characters (e.g. и, U+0438, but I came out emty handed:

$ otfinfo -u /usr/share/fonts/tex-gyre/texgyretermes-regular.otf | grep 438
uni2260 438 notequal

Running ttx and checking the output also doesn't seem to show the character. Does the font really have those characters, or am I searching in a wrong way?

If script=cyrl font feature is the right path, then search for \_preplangmore ru or \_setff{script=cyrl} in the documentation for an idea of how to integrate opentype script switching (or even font switching) into OpTeX language switching.

[sindzicat]

Sorry, I don't know TeX so deeply. The only I know this font definitely contains Cyrillic letters.

[Udi-Fogiel]

I don't think this font contains Cyrillic letters. Word processors don't always use the specified font. If it does not contain certain glyphs they may use a fall back.
For example

But when I export the file to pdf and inquire the fonts embedded in the file I see

[vlasakm]

I'll just add that to what @Udi-Fogiel said, that in "TeX" world we usually don't do font fallbacks, so fonts have to explicitly be chosen. If you want to mix latin with Termes and cyrillic with other font, you can do something based on what I had above.

If you have a font in mind it would be possible to try to come up with such a setup for you.

[Udi-Fogiel]

@vlasakm see the fallback and multiscript features described in section 6.1 and font combination described in section 7 of luaotfload's manual.

[vlasakm]

@Udi-Fogiel Oh yes, I forgot about that, as I have to admit I have never used it.

[sindzicat]

Let's say, this font don't have Cyrillic chars. Is it possible to use Times New Roman in Optex?