%D \module
%D   [       file=m-gnuplot,
%D        version=2006.01.04,
%D          title=\CONTEXT\ Extra Modules,
%D       subtitle=\GNUPLOT\ Inclusion,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright=\PRAGMA]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

% todo: reuse (only if really needed)

% \enablemode[demo]

%D example:
%D
%D \starttyping
%D texexec --pdf --mode=demo m-gnuplot
%D \stoptyping

\unprotect

\ifx\operatingsystem\undefined \def\operatingsystem{unix} \fi % texexec will set that

\newcounter\GNUPLOTnumber

\def\startGNUPLOTinclusions
  {\bgroup
   \obeylines
   \dostartGNUPLOTinclusions}

\def\dostartGNUPLOTinclusions#1\stopGNUPLOTinclusions
  {\gdef\GNUPLOTinclusions{#1}%
   \egroup}

\def\startGNUPLOTgraphic#1%
  {\bgroup
   \obeylines
   \dostartGNUPLOTgraphic{#1}}

\def\dostartGNUPLOTgraphic#1#2\stopGNUPLOTgraphic
  {\doglobal\increment\GNUPLOTnumber
   \letgvalue{gpg:n:#1}\GNUPLOTnumber
   \setgvalue{gpg:d:\GNUPLOTnumber}{#2}%
   \egroup}

\def\useGNUPLOTgraphic
  {\dodoubleempty\douseGNUPLOTgraphic}

\def\douseGNUPLOTgraphic[#1][#2]%
  {\iffirstargument
     \@EA\dodouseGNUPLOTgraphic % like \externalfigure[name][optional args]
   \else
     \@EA\redouseGNUPLOTgraphic % like \useMPgraphic{name}
   \fi[#1][#2]}

\def\redouseGNUPLOTgraphic[#1][#2]#3%
  {\dodouseGNUPLOTgraphic[#3][]}

\def\dodouseGNUPLOTgraphic[#1][#2]%
  {\bgroup
   \doifdefined{gpg:n:#1}
     {\edef\GNUPLOTnumber{\getvalue{gpg:n:#1}}%
      \edef\GNUPLOTfile  {\bufferprefix gnuplot-\GNUPLOTnumber}%
      \bgroup
      % hm, gnuplot only seems to handle lf so we cannot use \mappartolineend
      % also, in order to prevent fuzzy runs (or no runs) we add a ; to each line
      \def\par{;\rawcharacter{10}}%
      \immediate\openout\scratchwrite=\GNUPLOTfile.gpd
      \immediate\write\scratchwrite{set terminal "\@@GNUPLOTmethod"}%
      \immediate\write\scratchwrite{\GNUPLOTinclusions}%
      \immediate\write\scratchwrite{set output "\GNUPLOTfile.\@@GNUPLOTsuffix"}%
      \immediate\write\scratchwrite{\getvalue{gpg:d:\GNUPLOTnumber}}%
      \immediate\write\scratchwrite{quit}%
      \immediate\closeout\scratchwrite
      \egroup
      \processGNUPLOTgraphic
      \convertGNUPLOTgraphic
      \externalfigure[\@@GNUPLOTresult][#2]}%
   \egroup}

% we assume pdf inclusion, eps wil be implemented when applicable

\def\setupGNUPLOT
  {\dodoubleempty\getparameters[@@GNUPLOT]}

\def\processGNUPLOTgraphic
  {\doifelse\operatingsystem{mswin}
     {\executesystemcommand{start pgnuplot \GNUPLOTfile.gpd}} % start is needed else gp fails
     {\executesystemcommand{gnuplot \GNUPLOTfile.gpd}}}

\def\convertGNUPLOTgraphic
  {\doifsomething\@@GNUPLOThandle{\executesystemcommand{\@@GNUPLOThandle}}}

\def\defineGNUPLOThandle#1#2#3#4#5% name output suffix conversion-method result
  {\setvalue{@@GNUPLOT-#1}{{#2}{#3}{#4}{#5}}}

\def\@@GNUPLOToutput{\filterfromvalue{@@GNUPLOT-\@@GNUPLOTmethod}41}
\def\@@GNUPLOTsuffix{\filterfromvalue{@@GNUPLOT-\@@GNUPLOTmethod}42}
\def\@@GNUPLOThandle{\filterfromvalue{@@GNUPLOT-\@@GNUPLOTmethod}43}
\def\@@GNUPLOTresult{\filterfromvalue{@@GNUPLOT-\@@GNUPLOTmethod}44}

\defineGNUPLOThandle{postscript}{postscript}{ps} {texmfstart newpstopdf \GNUPLOTfile.ps}{\GNUPLOTfile.pdf}
\defineGNUPLOThandle{ps}        {postscript}{ps} {texmfstart newpstopdf \GNUPLOTfile.ps}{\GNUPLOTfile.pdf}
\defineGNUPLOThandle{pdf}       {pdf}       {pdf}{}                                     {\GNUPLOTfile.pdf}
\defineGNUPLOThandle{metapost}  {mp}        {mp} {texmfstart mptopdf    \GNUPLOTfile.mp}{\GNUPLOTfile-0.pdf}
\defineGNUPLOThandle{mp}        {mp}        {mp} {texmfstart mptopdf    \GNUPLOTfile.mp}{\GNUPLOTfile-0.pdf}
\defineGNUPLOThandle{png}       {png}       {png}{}                                     {\GNUPLOTfile.png}

\setupGNUPLOT[\c!method=ps]

\protect \doifnotmode{demo}{\endinput}

\starttext

\startGNUPLOTinclusions
    set title "trigonometry"
\stopGNUPLOTinclusions

\startGNUPLOTgraphic{sin}
    plot sin(x)
\stopGNUPLOTgraphic

\startGNUPLOTgraphic{cos}
    plot cos(x)
\stopGNUPLOTgraphic

\useGNUPLOTgraphic{sin} \endgraf
\useGNUPLOTgraphic{cos} \endgraf
\useGNUPLOTgraphic[cos] \endgraf

\setupGNUPLOT[method=ps]  \useGNUPLOTgraphic[sin][object=no,height=2cm] \blank
%setupGNUPLOT[method=pdf] \useGNUPLOTgraphic[sin][object=no,height=2cm] \blank
\setupGNUPLOT[method=png] \useGNUPLOTgraphic[sin][object=no,height=2cm] \blank
\setupGNUPLOT[method=mp]  \useGNUPLOTgraphic[sin][object=no,height=2cm] \blank

\stoptext