%% fontfam.tex
%%%%%%%%%%%%%%%%%%%%
% Petr Olsak, 2016

% This is module for OPmac macros, see http://petr.olsak.net/opmac.html 
% The file is read automatically when \fontfam macro is used.
% The command:
%    \fontfam [Font Family Name]
% loads the approriate fontfile or lists the available 
% Font Family Names if unknown. Example:
%    \fontfam [Times]  or \fontfam [Times Roman] ... does \input ctimes

% See end of this file this for more details.

\ifx\OPmacversion\udefined \input opmac \fi

\def\fontfamL{}
\def\setfontfam [#1]{\def\fsname{}\setfsname #1 {} \setfontfamB{#1}}
\def\setfsname #1 {\ifx\relax#1\relax 
   \lowercase\expandafter{\expandafter\def\expandafter\fsname\expandafter{\fsname}}% 
   \else \addto\fsname{#1}\expandafter\setfsname\fi
}
\def\setfontfamB#1#2#3#4#5#6(#7)#8{\sdef{fs:\fsname}{\fontfamexec{#1}{#2}{#3}{#4}{#5}{#7}{#8}}%
   \expandafter\addto\expandafter\fontfamL\csname fs:\fsname\endcsname
}
\def\fontfam[#1]{\def\fontfamname{#1}%
   \ifx\fotenc\undefined
      \ifx\chyph\undefined \def\fotenc{8t}\else \def\fotenc{8z}\fi
      \ifx\font\corkencoded \def\fotenc{8t}\fi
      \ifx\font\unicoded   \def\fotenc{U}\fi
      \def\tmp##1##2\relax{\def\tmp{##2}}\tmp ^^^^abcd\relax
      \ifx\tmp\empty \def\fotenc{U}\fi
   \fi
   \let\fontfamexec=\fontfamexecA 
   \def\fsname{}\setfsname #1 {} 
   \expandafter \ifx \csname fs:\fsname\endcsname \relax
      \immediate\write16{\string\fontfam: unknown font family [#1] (\fotenc). Choose:}
      {\let\fontfamexec=\fontfamexecB \fontfamL}%
   \else \csname fs:\fsname\expandafter\expandafter\expandafter\endcsname
   \fi
}
\def\fontfamexecA#1#2#3#4#5#6#7{\testfotenc{#6}\iftrue#7 \else
   \opwarning{[#1] (#6) family unavailable in \fotenc\space enc}\fi
}
\def\fontfamexecB#1#2#3#4#5#6#7{\testfotenc{#6}%
   \iftrue
      {\toks2={#2}\toks3={#3}\toks4={#4}%
       \immediate\write16{ [#1] \space {\the\toks2} {\the\toks3}%
           \ifx\relax#4\relax \else \space\the\toks4 \fi
           \ifx\relax#5\relax \else \space +#5\fi \space(#6)}}%
   \else
       \immediate\write16{ -- [#1] (#6) -- unavailable in \fotenc\space enc.}%
   \fi
}
\def\testfotenc#1{\def\tmpa{ #1 }\edef\tmpb{\space\fotenc\space}%
   \ifx\relax#1\relax \def\tmpa{x}\def\tmpb{x}\fi
   \expandafter\isinlist\expandafter\tmpa\expandafter{\tmpb}%
}

\def\famalias#1#2{\slet{fs:#1}{fs:#2}}
\def\fontfamnote#1{\addto\fontfamL{\fontfamnoteA{#1}}}
\def\fontfamnoteA#1{\immediate\write16{=== #1 ===}}

\input fontfam-global

\openin10=fontfam-local
\ifeof10 \else \closein10 \input fontfam-local \fi

\setfontfam [Catalog] {} {} {print catalogue} {} () {\input fontfam-catalog}
\famalias{catalogue}{catalog}

\endinput

------------------------------------------------------------

After

  \input opmac

you can use 

  \fontfam [Font Family Name].

The [Font Family Names] are declared in fontfam-global.tex file and a user
can set his/her own data to fontfam-local.tex file with analogical syntax.

The parameter [Font Family Name] is case insensitive and the spaces are
irrelevat in it. So [Times Roman] is the same as [TimesRoman] or [timesroman].

If a required [Font Family Name] is not known, then all available Font Family
Names are printed on terminal and into log file. Typical usage: \fontfam [?].

If a required [Font Family Name] is known then appropriate \input fontfile
is done. Nothing more. This means that \fontfam gives you only possibility to
keep a good overview about fontfiles.

You can use special parameter \fontfam [Catalog]. Then all available font
families are printed to the document with font samples. The pre-defined font
sample can be rewritten by \def\fontfamsample{...}. 

If you want to print only selected families in the catalog, give these
families in comma separated list in the macro \catalogfams before
\fontfam[Catalog] is executed. Example:

\def\catalogfams{Times Roman, Helvetica, KP fonts} \fontfam[Catalog]

Each fontfile supports a limited set of encodings of the fonts. This is
listed in round brackets: 8t means T1 encoding, 8z means IL2 encoding and 
U means Unicode. The default encoding is 8t in pdftex, 8z in pdfcsplain.
XeTeX or LuaTeX uses U as default. The csplain provides one change of default 
encoding at begining of the document using \input t1code or \input ucode.

If a fontfile (required by [Font Family name]) does not provide chosen encoding 
then warning occurs and nothig is done. The list of [Font Family Names]
printed by \fontfam [?] or \fontfam [Catalog] includes only those Names
which provides the encoding currently chosen.

The fontfam-global.tex or fontfam-local.tex files uses \setfontfam with
following format:

\setfontfam [Name] {modifiers} {variants} {comment} {math} (encodings) {\input fontfile}

Note, that \setfontfam changed its syntax in Jun. 2016. New version use
first {modifiers} then {variants}.

The \famalias macro can be used:

\famalias{aliasname}{origname}

The aliasname and origname must be lowecase and without spaces. See
fontfam-global.tex for examples.

\fontfamnote{text} prints text to the listing of font families.

Note that the macro file fontfam.tex and the data fontfam-global.tex and
fontfam-local.tex are read on demand only when \fontfam macro is used in
OPmac. It is not loaded by OPmac directly because user may not need to use
\fontfam, so the data are irrelevant in such case. And you can generate
a TeX format with opmac macros.