%D \module
%D   [       file=syst-fnt,
%D        version=2006.08.11,
%D          title=\CONTEXT\ System Macros,
%D       subtitle=Font Things,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

% formal names cf the tb \& tbt

\unprotect

%D It makes no longer sense to use font dimensions. For a while we had \typ
%D {\scaledfontdimen [1-7] <font>} but in the end went for the real deal. For
%D previous (and intermediate) definitions one can look in the archives. In the
%D end it also saves a little bit of overhead but more important, it gives less
%D tracing, and for practical reasons we keep the next indirectness because we
%D syntax highlight these (formerly) pseudo constants different than primitives.

% \permanent\protected\def\fontslantperpoint   {\scaledfontdimen\plusone  }
% \permanent\protected\def\fontinterwordspace  {\scaledfontdimen\plustwo  }
% \permanent\protected\def\fontinterwordstretch{\scaledfontdimen\plusthree}
% \permanent\protected\def\fontinterwordshrink {\scaledfontdimen\plusfour }
% \permanent\protected\def\fontexheight        {\scaledfontdimen\plusfive }
% \permanent\protected\def\fontemwidth         {\scaledfontdimen\plussix  }
% \permanent\protected\def\fontextraspace      {\scaledfontdimen\plusseven}

\aliased\let\mathaxisheight      \Umathaxis                  % takes style

\aliased\let\fontslantperpoint   \scaledfontslantperpoint    % takes font
\aliased\let\fontinterwordspace  \scaledfontinterwordspace
\aliased\let\fontinterwordstretch\scaledfontinterwordstretch
\aliased\let\fontinterwordshrink \scaledfontinterwordshrink
\aliased\let\fontexheight        \scaledfontexheight
\aliased\let\fontemwidth         \scaledfontemwidth
\aliased\let\fontextraspace      \scaledfontextraspace

\aliased\let\slantperpoint       \scaledslantperpoint        % current font
\aliased\let\interwordspace      \scaledinterwordspace
\aliased\let\interwordstretch    \scaledinterwordstretch
\aliased\let\interwordshrink     \scaledinterwordshrink
\aliased\let\exheight            \scaledexheight
\aliased\let\emwidth             \scaledemwidth
\aliased\let\extraspace          \scaledextraspace

\permanent\def\currentspaceskip{\interwordspace\s!plus\interwordstretch\s!minus\interwordshrink\relax}

\permanent\def\currentspacevalue{\the\interwordspace
  \ifzeropt\interwordstretch\else{ plus  }\the\interwordstretch\fi
  \ifzeropt\interwordshrink \else{ minus }\the\interwordshrink \fi}

\permanent\def\usedspacevalue{\ifzeropt\spaceskip\the\spaceskip\else\currentspacevalue\fi}

\permanent\def\mathstacktotal{\dimexpr\Umathstacknumup\scriptstyle+\Umathstackdenomdown\scriptstyle\relax}
\permanent\def\mathstackvgap {\Umathstackvgap\scriptstyle}

\protect \endinput