[luatex] using fea files in plain TeX

[Dohyun Kim]

2009/7/11 Khaled Hosny <khaledhosny at eglug.org>:
>
> I'd like to know about other issue (probably with fixes), and we can fix
> them for luaotfload until Hans releases another beta.
>

1.
This simple tex code fails to compile:

\input luatex-fonts
\font\tenrm=ec-lmr10
\tenrm
\bye

so I have added following code, which of course
was copied from context's lua code.

fonts.enc.known = fonts.enc.known or
{
    texnansi = true,
    ec       = true,
    qx       = true,
    t5       = true,
    t2a      = true,
    t2b      = true,
    t2c      = true,
    unicode  = true
}

2.
This tex file fails as well:

\documentclass{article}
\input luatex-fonts
\DeclareFontEncoding{EU1}{}{}
\DeclareErrorFont{EU1}{lmr}{m}{n}{10}
\DeclareFontSubstitution{EU1}{lmr}{m}{n}
\def\encodingdefault{EU1}
\def\rmdefault{lmr}
\def\sfdefault{lmss}
\def\ttdefault{lmtt}
\begin{document}
\ttfamily\bfseries
\end{document}

3.
I could not get visible spaces (U+2423) in verbatim environment.

\documentclass{article}
\input luatex-fonts
\DeclareFontEncoding{EU1}{}{}
\DeclareErrorFont{EU1}{lmr}{m}{n}{10}
\DeclareFontSubstitution{EU1}{lmr}{m}{n}
\def\encodingdefault{EU1}
\def\rmdefault{lmr}
\def\sfdefault{lmss}
\def\ttdefault{lmtt}
\begin{document}
\verb*|a b|
\end{document}


To deal with second and third issues,
I modified "define_font" callback.register function
similarly to the following:

callback.register('define_font',function(name,size,id)
    local fontdata = fonts.define.read(name,size,id) -- by hans
    if type(fontdata) == "table" then
        fontdata.name = name -- ttfamily/bfseries
        if fontdata.shared -- visible space
            and fontdata.shared.otfdata
            and fontdata.shared.otfdata.metadata
            and fontdata.shared.otfdata.metadata.isfixedpitch then
            if fontdata.characters[0x2423] then
                fontdata.characters[0x20] = fontdata.characters[0x2423]
            end
        end
    end
    return fontdata
end)


The additions and modifications shown in this thread
are just temporary measures.
Certainly, true and correct patches to these issues
should come from Hans, as he alone fully understands
the codes of luatex-plain.

Regards,
Dohyun Kim