%D \module
%D   [       file=font-tra,
%D        version=2009.01.02, % or so
%D          title=\CONTEXT\ Font Macros,
%D       subtitle=Tracing,
%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.

\unprotect

%D \macros
%D   {showbodyfont}
%D
%D One can call for a rather simple overview of a bodyfont and the
%D relations between its alternative fonts.
%D
%D \showsetup{showbodyfont}
%D
%D The current bodyfont (here we omitted the argument) looks like:
%D
%D \showbodyfont
%D
%D The implementation is rather straightforward in using
%D \type{\halign}.

\fetchruntimecommand \showbodyfont  {\f!fontprefix\s!run}

%D \macros
%D   {showfontstrip, testminimalbaseline, showminimalbaseline}
%D
%D The next command can come in handy when combining
%D different fonts into a collection (typeface) and
%D determining optimal baseline distances.
%D
%D \showfontstrip \blank \showminimalbaseline

\fetchruntimecommand \showfontstrip       {\f!fontprefix\s!run}
\fetchruntimecommand \testminimalbaseline {\f!fontprefix\s!run}
\fetchruntimecommand \showminimalbaseline {\f!fontprefix\s!run}

%D \macros
%D   {showkerning}
%D
%D A goody is:
%D
%D \showkerning{Can you guess what kerning is?}

\fetchruntimecommand \showkerning {\f!fontprefix\s!run}

%D \macros
%D   {showbodyfontenvironment,showfont,showfontstyle,showligatures}
%D
%D The current bodyfontenvironment is:
%D
%D \showbodyfontenvironment
%D
%D This overview is generated using:
%D
%D \showsetup{showbodyfontenvironment}

\fetchruntimecommand \showbodyfontenvironment {\f!fontprefix\s!run}

%D
%D The following command generates a fontmap:
%D
%D \startbuffer
%D \showfont[SansBold at 12pt]
%D \stopbuffer
%D
%D \typebuffer
%D \getbuffer

\fetchruntimecommand \showfont           {\f!fontprefix\s!run}
\fetchruntimecommand \showfontstyle      {\f!fontprefix\s!run}
\fetchruntimecommand \showligature       {\f!fontprefix\s!run}
\fetchruntimecommand \showligatures      {\f!fontprefix\s!run}
\fetchruntimecommand \showcharratio      {\f!fontprefix\s!run}
\fetchruntimecommand \showfontparameters {\f!fontprefix\s!run}

\unexpanded\def\checkcharactersinfont  {\ctxcommand{checkcharactersinfont()}}
\unexpanded\def\removemissingcharacters{\ctxcommand{removemissingcharacters()}}
\unexpanded\def\showchardata         #1{\ctxcommand{showchardata("#1")}}
\unexpanded\def\showfontdata           {\ctxcommand{showfontparameters()}}

%D \macros
%D   {doiffontpresentelse}
%D
%D \starttyping
%D \doiffontpresentelse{texnansi-lmr10}{YES}{NO}
%D \doiffontpresentelse{adam-lindsay-modern-serif}{YES}{NO}
%D \stoptyping

\def\doiffontpresentelse#1{\ctxcommand{doifelse(fonts.names.exists("#1"))}}

% experimental, maybe this becomes a module

\newbox\otfcollector

\unexpanded\def\startotfcollecting{\ctxlua{nodes.tracers.steppers.start()}}
\unexpanded\def\stopotfcollecting {\ctxlua{nodes.tracers.steppers.stop()}}
\def\resetotfcollecting{\ctxlua{nodes.tracers.steppers.reset()}}

% Rather experimental:
%
% \page \showotfcomposition{arabtype*arab-default at 48pt}{-1}{الضَّرَّ} \page
% \page \showotfcomposition{arabtype*arab-default at 48pt}{-1}{لِلّٰهِ}   \page

\def\showotfstepglyphs#1%
  {\ctxlua{nodes.tracers.steppers.glyphs(\number\otfcollector,#1)}%
   \unhbox\otfcollector}

\def\otfstepcharcommand#1#2#3% font char class
  {\removeunwantedspaces
   \hskip.5em plus .125em\relax
   \doif{#3}{mark}{\underbar}{U+\hexnumber{#2}}:\ruledhbox{\ctxlua{nodes.tracers.fontchar(#1,#2)}}%
   \hskip.5em plus .125em\relax}

\def\otfstepmessagecommand#1#2%
  {\begingroup
   \tttf\language\minusone
   \veryraggedright
   \forgetparindent
   \forgeteverypar
   \hangindent1em
   \hangafter\plusone
   \dontleavehmode\hbox{\detokenize{#1}}\removeunwantedspaces
   \doifsomething{#2}{\break\detokenize{#2}}\endgraf
   \endgroup
   \blank}

\def\showotfstepchars#1%
  {\ctxlua{nodes.tracers.steppers.codes(#1,"otfstepcharcommand")}}

\def\showotfstepmessages#1%
  {\ctxlua{nodes.tracers.steppers.messages(#1,"otfstepmessagecommand",true)}}

\def\showotfstepfeatures
  {\ctxlua{nodes.tracers.steppers.features()}}

\def\showotfsteps
  {\begingroup
   \veryraggedright
   \forgetparindent
   \forgeteverypar
   \dontleavehmode\bgroup\tttf \language\minusone features: \showotfstepfeatures\egroup
   \blank
   \dontleavehmode\bgroup\tttf result:\egroup
   \blank
   \startlinecorrection
   \ruledhbox\bgroup\box\otfcompositionbox\egroup
   \stoplinecorrection
   \dorecurse{\ctxlua{nodes.tracers.steppers.nofsteps()}}
     {\blank
      \showotfstepmessages\recurselevel
      \blank
      \startlinecorrection
      \dontleavehmode\bgroup\resetallattributes\pardir TLT\textdir TLT\relax\tttf\recurselevel: \showotfstepchars\recurselevel\egroup
      \stoplinecorrection
      \blank
      \startlinecorrection
      \ruledhbox % can be mode
        \bgroup\resetallattributes\showotfstepglyphs\recurselevel\egroup % reset is new, we don't want additional processing
      \stoplinecorrection
      \blank}%
   \endgroup}

\unexpanded\def\startotfsample
  {\enabletrackers[*otf.sample]% beware, kind of global
   \startotfcollecting
   \begingroup
   \veryraggedright
   \forgetparindent
   \forgeteverypar}

\unexpanded\def\stopotfsample
  {\endgroup
   \stopotfcollecting
   \disabletrackers[*otf.sample]% beware, kind of global: otf.sample
   \showotfsteps
   \resetotfcollecting}

\newbox\otfcompositionbox

\def\showotfcomposition#1#2#3% {font*features at size}, rl=-1, text
  {\begingroup
   \veryraggedright
   \forgetparindent
   \forgeteverypar
   \setupcolors[\c!state=\v!start]% can be option
   \startotfsample
   \global\setbox\otfcompositionbox\hbox{\definedfont[#1]\ifnum#2<0 \textdir TRT\else\ifnum#2>0 \textdir TLT\fi\fi\relax#3}%
   \stopotfsample
   \endgroup}

\protect \endinput