%D \module
%D   [       file=meta-ini,
%D        version=2008.03.25,
%D          title=\METAPOST\ Graphics,
%D       subtitle=Initialization,
%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.

\writestatus{loading}{MetaPost Graphics / Initializations}

\unprotect

\startmessages  dutch  library: metapost
  title: metapost
      1: metapost bibliotheek -- wordt geladen
\stopmessages

\startmessages  english  library: metapost
  title: metapost
      1: loading metapost library --
\stopmessages

\startmessages  german  library: metapost
  title: metapost
      1: loading metapost library --
\stopmessages

\startmessages  czech  library: metapost
  title: metapost
      1: loading metapost library --
\stopmessages

\startmessages  italian  library: metapost
  title: metapost
      1: caricamento della libreria metapost --
\stopmessages

\startmessages  norwegian  library: metapost
  title: metapost
      1: metapost bibliotek -- blir lest inn
\stopmessages

\startmessages  romanian  library: metapost
  title: metapost
      1: se incarca biblioteca metapost --
\stopmessages

\startmessages  french  library: metapost
  title: metapost
      1: chargement de la bibliothèque metapost --
\stopmessages

%D Instead of sharing code with \MKII, I decided to copy
%D the code. Otherwise maintainance becomes a pain and after all,
%D the \MKII\ code will not change.

\let\useMETAFUNformattrue \relax \let\useMETAFUNformatfalse\relax
\let     \longMPlinestrue \relax \let     \longMPlinesfalse\relax
\let   \runMPgraphicstrue \relax \let   \runMPgraphicsfalse\relax
\let\runMPTEXgraphicstrue \relax \let\runMPTEXgraphicsfalse\relax
\let \MPstaticgraphictrue \relax \let \MPstaticgraphicfalse\relax

\let\maxnofMPgraphics\scratchcounter

\newtoks \MPextensions       % mp, once
\newtoks \MPinitializations  % tex, each
\newtoks \MPuserinclusions   % mp, user
\newtoks \MPfinalizations    % mp, user
\newtoks \everyMPgraphic     % mp
\newtoks \everyMPTEXgraphic  % tex

\long\def\startMPextensions#1\stopMPextensions
  {\global\MPextensions\expandafter{\the\MPextensions#1}}

\long\def\startMPinitializations#1\stopMPinitializations
  {\global\MPinitializations\expandafter{\the\MPinitializations#1}}

\long\def\startMPinclusions
  {\dosingleempty\dostartMPinclusions}

\long\def\dostartMPinclusions[#1]#2\stopMPinclusions
  {\doifnot{#1}{+}{\global\MPuserinclusions\emptytoks}%
   \global\MPuserinclusions\expandafter{\the\MPuserinclusions#2}}

\def\MPinclusions
  {\dosingleempty\doMPinclusions}

\long\def\doMPinclusions[#1]#2%
  {\doifnot{#1}{+}{\global\MPuserinclusions\emptytoks}%
   \global\MPuserinclusions\expandafter{\the\MPuserinclusions#2}}

\ifx \overlaywidth     \undefined \def \overlaywidth     {4cm} \fi
\ifx \overlayheight    \undefined \def \overlayheight    {3cm} \fi
\ifx \overlaylinewidth \undefined \def \overlaylinewidth {0pt} \fi

\def\presetMPdefinitions
  {\edef\overlaywidth    {\overlaywidth    \space}%
   \edef\overlayheight   {\overlayheight   \space}%
   \edef\overlaylinewidth{\overlaylinewidth\space}%
   \edef\currentwidth    {\the\hsize       \space}%
   \edef\currentheight   {\the\vsize       \space}}

\def\currentMPformat{metafun}

\long\def\processMPgraphic#1% todo: extensions and inclusions outside beginfig
  {\blabelgroup
   \enableincludeMPgraphics
   \the\everyMPgraphic
   \presetMPdefinitions
   \setMPrandomseed % this has to change
   % we need to preexpand the token lists
    \setbox\MPgraphicbox\hbox\bgroup
      \ctxlua {
        metapost.graphic(
            "\currentMPformat",
            \@EA\!!bs\the\MPinitializations;\theMPrandomseed;#1;\!!es,                 % code
            \@EA\@EA\@EA\!!bs\@EA\the\@EA\MPextensions\@EA;\the\MPuserinclusions;\!!es % optional preamble
        )
     }%
   \egroup
   \placeMPgraphic
   \global\MPextensions\emptytoks
   \global\MPuserinclusions\emptytoks
   \elabelgroup}

\newif\ifsetMPrandomseed \setMPrandomseedtrue % false by default

\def\setMPrandomseed
  {\let\theMPrandomseed\empty
   \ifsetMPrandomseed \ifx\getrandomnumber\undefined \else
     \getrandomnumber\localMPseed\zerocount{4095}%
     \def\theMPrandomseed{randomseed:=\localMPseed}%
   \fi\fi}

%D To be integrated

\def\@@MPG{@MPG@}

\def\doifMPgraphicelse#1%
  {\blabelgroup
   \doifdefinedelse{\@@MPG#1}%
     {\elabelgroup\firstoftwoarguments}
     {\elabelgroup\secondoftwoarguments}}

\def\includeMPgraphic#1%
  {\executeifdefined{\@@MPG#1};}

\def\enableincludeMPgraphics
  {\let\handleuseMPgraphic     \secondoftwoarguments
   \let\handlereusableMPgraphic\secondoftwoarguments}

\let\MPdrawingdata\empty

\newif\ifMPdrawingdone  \MPdrawingdonefalse
\newif\ifMPshiftdrawing \MPshiftdrawingfalse

\def\resetMPdrawing
  {\globallet\MPdrawingdata\empty
   \global\MPdrawingdonefalse}

\def\pushMPdrawing
  {\globalpushmacro\MPdrawingdata
   \globallet\MPdrawingdata\empty}

\def\popMPdrawing
  {\globalpopmacro\MPdrawingdata}

\def\getMPdrawing
  {\ifMPdrawingdone
     \expandafter\processMPgraphic\expandafter{\MPdrawingdata}%
   \fi}

\def\startMPdrawing
  {\dosingleempty\dostartMPdrawing}

\long\def\dostartMPdrawing[#1]#2\stopMPdrawing
  {\relax
   \bgroup
   \enableincludeMPgraphics
   \presetMPdefinitions % in case #2 has measures
   \doifelse{#1}{-}{\convertargument#2\to\asciia}{\long\def\asciia{#2}}%
   \long\xdef\MPdrawingdata{\MPdrawingdata\asciia}%
   \egroup}

\let\stopMPdrawing\relax

\let\MPdrawingdata\empty

\newif\ifMPdrawingdone  \MPdrawingdonefalse
\newif\ifMPshiftdrawing \MPshiftdrawingfalse

\def\resetMPdrawing
  {\globallet\MPdrawingdata\empty
   \global\MPdrawingdonefalse}

\def\pushMPdrawing
  {\globalpushmacro\MPdrawingdata
   \globallet\MPdrawingdata\empty}

\def\popMPdrawing
  {\globalpopmacro\MPdrawingdata}

\def\getMPdrawing
  {\ifMPdrawingdone
     \expandafter\processMPgraphic\expandafter{\MPdrawingdata}%
   \fi}

\def\startMPdrawing
  {\dosingleempty\dostartMPdrawing}

\long\def\dostartMPdrawing[#1]#2\stopMPdrawing
  {\relax
   \bgroup
   \enableincludeMPgraphics
   \presetMPdefinitions % in case #2 has measures
   \doifelse{#1}{-}{\convertargument#2\to\asciia}{\long\def\asciia{#2}}%
   \long\xdef\MPdrawingdata{\MPdrawingdata\asciia}%
   \egroup}

\let\stopMPdrawing\relax

\long\def\startMPclip#1#2\stopMPclip
  {\blabelgroup
   \long\setgvalue{MPC:#1}{\ctxlua{metapost.getclippath(\!!bs#2\!!es)}}%
   \elabelgroup}

\let\stopMPclip\relax

\def\grabMPclippath#1#2#3#4#5%
  {\blabelgroup
   \edef\width {#3\space}\let\overlaywidth \width
   \edef\height{#4\space}\let\overlayheight\height
   \doifundefined{MPC::#1}
     {\doifdefinedelse{MPC:#1}
        {\xdef\MPclippath{\getvalue{MPC:#1}}%
         \ifx\MPclippath\empty\xdef\MPclippath{#5}\fi
         \setxvalue{MPC::#1}{\MPclippath}}
        {\setxvalue{MPC::#1}{#5}}}%
   \xdef\MPclippath{\getvalue{MPC::#1}}%
   % #2 : method is obsolete, only pdf now, we can always
   % gsub the result to ps
   \elabelgroup}

%D Next we will use these support macros.

\startMPextensions
    if unknown context_tool: input mp-tool; fi;
    if unknown context_spec: input mp-spec; fi;
    if unknown context_grph: input mp-grph; fi;
\stopMPextensions

%D Since we want lables to follow the document settings, we
%D also set the font related variables.

\startMPinitializations % scale is not yet ok
    defaultfont:="\truefontname{Regular}";
    defaultscale:=\the\bodyfontsize/10pt;
\stopMPinitializations

\startMPinitializations % scale is not yet ok
    defaultfont:="rm-lmtt10";
\stopMPinitializations

%D In order to support fancy text features (like outline
%D fonts), we set:

\startMPextensions
    graphictextformat:="context";
    graphictextdirective "\the\everyMPTEXgraphic";
\stopMPextensions

%D A signal that we're in combines \CONTEXT||\METAFUN mode:

\startMPextensions
    string contextversion;
    contextversion:="\contextversion";
\stopMPextensions

%D Some safeguards:
%D
%D \starttyping
%D \appendtoks \cleanupfeatures \to \everyMPgraphic
%D \stoptyping
%D
%D No, we don't want that (else we loose UTF etc).

%D Another one:

\prependtoks \MPstaticgraphictrue \to \everyoverlay
\prependtoks \MPstaticgraphictrue \to \everypagebody

% %D We save the number of graphics for the sake of \TEXEXEC.
%
% \newcounter\totalnofMPgraphics
%
% \def\thenofMPgraphics{\the\nofMPgraphics} % from supp-mps
%
% \appendtoks
%   \savecurrentvalue\totalnofMPgraphics\thenofMPgraphics
% \to \everybye

%D \macros
%D   {setupMPvariables}
%D
%D When we build collections of \METAPOST\ graphics, like
%D background and buttons, the need for passing settings
%D arises. By (mis|)|using the local prefix that belongs to
%D \type {\framed}, we get a rather natural interface to
%D backgrounds. To prevent conflicts, we will use the \type
%D {-} in \METAPOST\ specific variables, like:
%D
%D \starttyping
%D \setupMPvariables[meta:button][size=20pt]
%D \stoptyping

\def\@@meta{meta:}

\def\setupMPvariables
  {\dodoubleempty\dosetupMPvariables}

\def\dosetupMPvariables[#1][#2]%
  {\ifsecondargument
     \getrawparameters[#1:][#2]% brr, todo: [\@@meta#1:]
   \else
     \getrawparameters[\@@meta][#1]%
   \fi}

\let\@@framed\s!unknown

\def\MPvariable#1%
  {\csname
     \ifcsname\@@framed\@@meta#1\endcsname\@@framed\fi\@@meta#1%
   \endcsname}

\let\MPvar\MPvariable

\let\setMPvariables\setupMPvariables

\def\MPrawvar#1#2{\csname#1:#2\endcsname}

%D \macros
%D   {startuniqueMPgraphic, uniqueMPgraphic}
%D
%D This macros is probably of most use to myself, since I like
%D to use graphics that adapt themselves. The next \METAPOST\
%D kind of graphic is both unique and reused when possible.
%D
%D \starttyping
%D \defineoverlay[example][\uniqueMPgraphic{test}]
%D
%D \startuniqueMPgraphic {test}
%D   draw unitsquare xscaled \overlaywidth yscaled \overlayheight ;
%D \stopuniqueMPgraphic
%D \stoptyping

\def\overlaystamp % watch the \MPcolor, since colors can be redefined
  {\overlaywidth:\overlayheight:\overlaydepth:\MPcolor\overlaycolor:\MPcolor\overlaylinecolor}

%D A better approach is to let additional variables play a role
%D in determining the uniqueness. In the next macro, the
%D second, optional, argument is used to guarantee the
%D uniqueness, as well as prepare variables for passing them to
%D \METAPOST.
%D
%D \starttyping
%D \startuniqueMPgraphic{meta:hash}{gap,angle,...}
%D \stoptyping
%D
%D The calling macro also accepts a second argument. For
%D convenient use in overlay definitions, we use \type {{}}
%D instead of \type {[]}.
%D
%D \starttyping
%D \uniqueMPgraphic{meta:hash}{gap=10pt,angle=30}
%D \stoptyping

\newcount\MPobjectcounter
\newif   \ifMPshiftdrawing \MPshiftdrawingfalse
\newbox  \MPgraphicbox

\def\placeMPgraphic
  {\ifMPshiftdrawing
     \edef\next
       {\wd\MPgraphicbox\the\wd\MPgraphicbox
        \ht\MPgraphicbox\the\ht\MPgraphicbox
        \dp\MPgraphicbox\the\dp\MPgraphicbox}%
     \setbox\MPgraphicbox\hbox
       {\hskip\MPllx\onebasepoint\raise\MPlly\onebasepoint\box\MPgraphicbox}%
     \next
   \fi
   \box\MPgraphicbox}

\def\reuseMPbox#1#2#3#4#5% space delimiting would save some tokens
  {\xdef\MPllx{#2}%        but it's not worth the effort and looks
   \xdef\MPlly{#3}%        ugly as well
   \xdef\MPurx{#4}%
   \xdef\MPury{#5}%
   \getobject{MP}{#1}}

\long\def\handleuniqueMPgraphic#1#2#3%
  {\blabelgroup
   \def\@@meta{#1:}%
   \extendMPoverlaystamp{#2}% incl prepare
   \ifundefined{\@@MPG\overlaystamp:#1}%
     \enableincludeMPgraphics
     \forgetall
     \global\advance\MPobjectcounter\plusone
     \setobject{MP}{\number\MPobjectcounter}\vbox{\processMPgraphic{#3}}%
     \setxvalue{\@@MPG\overlaystamp:#1}{\noexpand\reuseMPbox{\number\MPobjectcounter}{\MPllx}{\MPlly}{\MPurx}{\MPury}}%
   \fi
   \getvalue{\@@MPG\overlaystamp:#1}%
   \elabelgroup}

\long\def\startuniqueMPgraphic
  {\blabelgroup
   \dodoublegroupempty\dostartuniqueMPgraphic}

\long\def\dostartuniqueMPgraphic#1#2#3\stopuniqueMPgraphic%
  {\long\setgvalue{\@@MPG#1}{\handleuniqueMPgraphic{#1}{#2}{#3}}%
   \elabelgroup}

\unexpanded\def\uniqueMPgraphic
  {\dodoublegroupempty\douniqueMPgraphic}

\def\douniqueMPgraphic#1#2%
  {\blabelgroup
   \setupMPvariables[#1][#2]%
   \getvalue{\@@MPG#1}\empty
   \elabelgroup}

\let\stopuniqueMPcode \relax % so that we can use it in \expanded

\long\def\handleuseMPgraphic#1#2#3%
  {\blabelgroup
   \forgetall % check this
   \def\@@meta{#1:}%
   \prepareMPvariables{#2}%
   \enableincludeMPgraphics
   \processMPgraphic{#3}%
   \elabelgroup}

\long\def\startuseMPgraphic
  {\blabelgroup
   \dodoublegroupempty\dostartuseMPgraphic}

\long\def\dostartuseMPgraphic#1#2#3\stopuseMPgraphic
  {\long\setgvalue{\@@MPG#1}{\handleuseMPgraphic{#1}{#2}{#3}}%
   \elabelgroup}

\long\def\startusableMPgraphic % redundant but handy
  {\blabelgroup
   \dodoublegroupempty\dostartusableMPgraphic}

\long\def\dostartusableMPgraphic#1#2#3\stopusableMPgraphic
  {\long\setgvalue{\@@MPG#1}{\handleuseMPgraphic{#1}{#2}{#3}}%
   \elabelgroup}

\let\stopuseMPgraphic    \relax % so that we can use it in \expanded
\let\stopusableMPgraphic \relax % so that we can use it in \expanded

\long\def\handlereusableMPgraphic#1#2#3%
  {\blabelgroup
   \def\@@meta{#1:}%
   \prepareMPvariables{#2}%
   \enableincludeMPgraphics
   \global\advance\MPobjectcounter\plusone
   \setobject{MP}{\number\MPobjectcounter}\vbox{\processMPgraphic{#3}}%
   \setxvalue{\@@MPG#1}{\noexpand\reuseMPbox{\number\MPobjectcounter}{\MPllx}{\MPlly}{\MPurx}{\MPury}}%
   \getvalue{\@@MPG#1}%
   \elabelgroup}

\long\def\startreusableMPgraphic
  {\blabelgroup
   \dodoublegroupempty\dostartreusableMPgraphic}

\long\def\dostartreusableMPgraphic#1#2#3\stopreusableMPgraphic
  {\long\setgvalue{\@@MPG#1}{\handlereusableMPgraphic{#1}{#2}{#3}}%
   \elabelgroup}

\let\stopreusableMPgraphic \relax % so that we can use it in \expanded

\unexpanded\def\useMPgraphic
  {\dodoublegroupempty\douseMPgraphic}

\def\douseMPgraphic#1#2%
  {\blabelgroup
   \doifsomething{#2}{\setupMPvariables[#1][#2]}%
   \getvalue{\@@MPG#1}\empty
   \elabelgroup}

\let\reuseMPgraphic   \useMPgraphic   % we can save a setup here if needed
\let\reusableMPgraphic\reuseMPgraphic % we can save a setup here if needed

\let\stopuseMPcode      \relax % so that we can use it in \expanded
\let\stopusableMPcode   \relax % so that we can use it in \expanded
\let\stopreusableMPcode \relax % so that we can use it in \expanded
\let\stopuniqueMPcode   \relax % so that we can use it in \expanded

\def\enableincludeMPgraphics
  {\let\handleuseMPgraphic     \thirdofthreearguments
   \let\handlereusableMPgraphic\thirdofthreearguments}

%D \macros
%D   {startuniqueMPpagegraphic,uniqueMPpagegraphic}
%D
%D Experimental.

\def\MPpageprefix{\doifoddpageelse oe:}

\def\overlaypagestamp
  {\MPpageprefix\overlaywidth:\overlayheight:\overlaydepth:\MPcolor\overlaycolor:\MPcolor\overlaylinecolor}

\long\def\startuniqueMPpagegraphic
  {\blabelgroup
   \dodoublegroupempty\dostartuniqueMPpagegraphic}

\long\def\dostartuniqueMPpagegraphic#1#2#3\stopuniqueMPpagegraphic
  {\long\setgvalue{\@@MPG o:#1}{\handleuniqueMPgraphic{o:#1}{#2}{#3}}%
   \long\setgvalue{\@@MPG e:#1}{\handleuniqueMPgraphic{e:#1}{#2}{#3}}%
   \elabelgroup}

\unexpanded\def\uniqueMPpagegraphic
  {\dodoublegroupempty\douniqueMPpagegraphic}

\def\douniqueMPpagegraphic#1#2%
  {\blabelgroup
   \let\overlaystamp\overlaypagestamp
   \setupMPvariables[\MPpageprefix#1][#2]% prefix is new here
   \getvalue{\@@MPG\MPpageprefix#1}{}%
   \elabelgroup}

%D One way of defining a stamp is:
%D
%D \starttyping
%D \def\extendMPoverlaystamp#1%
%D   {\def\docommand##1%
%D      {\edef\overlaystamp{\overlaystamp:\MPvariable{##1}}}%
%D    \processcommalist[#1]\docommand}
%D \stoptyping

%D Since we need to feed \METAPOST\ with expanded dimensions,
%D we introduce a dedicated expansion engine.

\def\prepareMPvariable#1%
  {\ifundefined{\@@framed\@@meta#1}%
     \doprepareMPvariable{\@@meta#1}%
   \else
     \doprepareMPvariable{\@@framed\@@meta#1}%
   \fi}

% \startlines
% \def\xxx{\lineheight}     \doprepareMPvariable{xxx} \xxx
% \def\xxx{2pt}             \doprepareMPvariable{xxx} \xxx
% \def\xxx{2}               \doprepareMPvariable{xxx} \xxx
% \def\xxx{\scratchcounter} \doprepareMPvariable{xxx} \xxx
% \def\xxx{red}             \doprepareMPvariable{xxx} \xxx
% \def\xxx{0.4}             \doprepareMPvariable{xxx} \xxx
% \stoplines

\def\doprepareMPvariable#1%
  {\edef\theMPvariable{\getvalue{#1}}%
   \doifelsenothing\theMPvariable
     {\setevalue{#1}{\MPcolor{black}}}
     {\defconvertedcommand\ascii\theMPvariable % otherwise problems
      \doifcolorelse \ascii                    % with 2\bodyfontsize
        {\setevalue{#1}{\MPcolor\theMPvariable}}
        {% can be aux macro
         \setbox\scratchbox\hbox{\scratchdimen\theMPvariable sp}%
         \ifdim\wd\scratchbox=\zeropoint
         % \scratchcounter\theMPvariable
         % \setevalue{#1}{\the\scratchcounter}%
         % also accepts 0.number :
           \setevalue{#1}{\number\theMPvariable}%
         \else
           \scratchdimen\theMPvariable
           \setevalue{#1}{\the\scratchdimen}%
         \fi}}}

%D We redefine \type {\extendMPoverlaystamp} to preprocess
%D variables using \type {\prepareMPvariable}.

\def\doextendMPoverlaystamp#1%
  {\prepareMPvariable{#1}%
   \edef\overlaystamp{\overlaystamp:\MPvariable{#1}}}

\def\extendMPoverlaystamp#1%
  {\processcommalist[#1]\doextendMPoverlaystamp}

\def\prepareMPvariables#1%
  {\processcommalist[#1]\prepareMPvariable}

%D \macros
%D   {MPdatafile}
%D
%D We redefine a macro from \type {supp-mps.tex}:

\def\MPdataMPDfile{\jobname-mp.mpd}
\def\MPdataMPOfile{\jobname-mp.mpo}
\def\MPdataMPYfile{\jobname-mp.mpy}

\startMPextensions
    boolean collapse_data; collapse_data:=true;
    def data_mpd_file = "\MPdataMPDfile" enddef ;
    def data_mpo_file = "\MPdataMPOfile" enddef ;
    def data_mpy_file = "\MPdataMPYfile" enddef ;
\stopMPextensions

\newcount\currentMPgraphic \currentMPgraphic\zerocount

\def\getMPdata
  {%\let\MPdata\secondoftwoarguments
   \long\def\MPdata##1##2{\ifnum##1=\currentMPgraphic\relax##2\fi}%
   \startreadingfile
   \startnointerference
   \readlocfile\MPdataMPDfile\donothing\donothing
   \stopnointerference
   \stopreadingfile}

%D \macros
%D   {MPrunfile}
%D
%D This one is more abstract and does not assume knowledge
%D of buffer prefixes.

\def\MPrunfile#1%
  {\bufferprefix mprun.#1}

%D For the moment, the next one is a private macro:

% TODO ! ! ! ! ! !

\def\processMPbuffer
  {\dosingleempty\doprocessMPbuffer}

\def\doprocessMPbuffer[#1]%
  {\doifelsenothing{#1}
     {\doprocessMPbuffer[\jobname]}
     {\processMPgraphic{\ctxlua{tex.sprint(tex.ctxcatcodes,buffers.collect(string.split("#1",",")))}}}}

\def\runMPbuffer
  {\dosingleempty\dorunMPbuffer}

\def\dorunMPbuffer[#1]% processing only
  {\startnointerference\doprocessMPbuffer[#1]\stopnointerference}

%D \macros
%D   {startMPenvironment, resetMPenvironment}
%D
%D In order to synchronize the main \TEX\ run and the runs
%D local to \METAPOST, environments can be passed.

\ifx\everyMPTEXgraphic\undefined
  \newtoks\everyMPTEXgraphic
\fi

%D A more general way of passing environments is:

\def\startMPenvironment % second arg gobbles spaces, so that reset gives \emptytoks
  {\bgroup
   \catcode`\^^M=\@@space
   \dodoubleempty\dostartMPenvironment}

\long\def\dostartMPenvironment[#1][#2]#3\stopMPenvironment
  {\egroup
   \doif{#1}\s!reset\resetMPenvironment % reset mp toks
   \doif{#1}\v!global{#3}%              % use in main doc too
   \doif{#1}+{#3}%                      % use in main doc too
   \defconvertedargument\ascii{#3}%
   \expandafter\appendtoks\ascii\to\everyMPTEXgraphic}

\def\resetMPenvironment
  {\everyMPTEXgraphic\emptytoks % = is really needed !
   \startMPenvironment
     \global\loadfontfileoncetrue
   \stopMPenvironment}

\resetMPenvironment

\def\useMPenvironmentbuffer[#1]%
  {\expanded{\startMPenvironment\noexpand\readfile{\TEXbufferfile{\jobname}}{}{}}\stopMPenvironment}

\useMPenvironmentbuffer[mp]

%D This command takes \type {[reset]} as optional
%D argument.
%D
%D \starttyping
%D \startMPenvironment
%D   \setupbodyfont[pos,14.4pt]
%D \stopMPenvironment
%D
%D \startMPcode
%D   draw btex \sl Hans Hagen etex scaled 5 ;
%D \stopMPcode
%D \stoptyping
%D
%D The most simple case:

\long\def\startMPcode#1\stopMPcode
  {\processMPgraphic{#1}}

\let\stopMPcode\relax

%D The \type {\resetMPenvironment} is a quick way to erase
%D the token list.
%D
%D You should be aware of independencies. For instance, if you use a font
%D in a graphic that is not used in the main document, you need to load the
%D typescript at the outer level (either directly or by using the global
%D option).
%D
%D \starttyping
%D \usetypescript[palatino][texnansi]
%D
%D \startMPenvironment
%D     \usetypescript[palatino][texnansi]
%D     \enableregime[utf]
%D     \setupbodyfont[palatino]
%D \stopMPenvironment
%D
%D \startMPpage
%D     draw btex aap‒noot coördinatie – één etex ;
%D \stopMPpage
%D \stoptyping

%D Loading specific \METAPOST\ related definitions is
%D accomplished by:

\def\douseMPlibrary#1%
  {\ifundefined{\c!file\f!metapostprefix#1}%
     \letvalueempty{\c!file\f!metapostprefix#1}%
     \makeshortfilename[\truefilename{\f!metapostprefix#1}]%
     \startreadingfile
       \readsysfile\shortfilename{\showmessage\m!metapost1{#1}}\donothing
     \stopreadingfile
   \fi}

\def\useMPlibrary[#1]%
  {\processcommalist[#1]\douseMPlibrary}

%D \macros
%D   {setMPtext, MPtext, MPstring, MPbetex}
%D
%D To be documented:
%D
%D \starttyping
%D \setMPtext{identifier}{text}
%D
%D \MPtext  {identifier}
%D \MPstring{identifier}
%D \MPbetex {identifier}
%D \stoptyping

\def\@@MPT{@MPT@}

\def\forceMPTEXgraphic
  {\long\def\checkMPTEXgraphic##1{\global\MPTEXgraphictrue}}

\def\setMPtext#1#2% todo : #1 must be made : safe
  {%\forceMPTEXgraphic
   \defconvertedargument\ascii{#2}%
   \dodoglobal\letvalue{\@@MPT#1}\ascii}

\def\MPtext       #1{\executeifdefined{\@@MPT#1}\empty}
\def\MPstring    #1{"\executeifdefined{\@@MPT#1}\empty"}
\def\MPbetex #1{btex \executeifdefined{\@@MPT#1}\empty\space etex}

%D Unfortunately \METAPOST\ does not have \CMYK\ support
%D built in, but by means of specials we can supply the
%D information needed to handle them naturaly.

\newif\ifMPcmykcolors \MPcmykcolorstrue
\newif\ifMPspotcolors \MPspotcolorstrue

\startMPinitializations
    cmykcolors:=\ifMPcmykcolors true\else false\fi;
    spotcolors:=\ifMPspotcolors true\else false\fi;
\stopMPinitializations

%D In order to communicate conveniently with the \TEX\
%D engine, we introduce some typesetting variables.

\startMPextensions
    color OverlayColor,OverlayLineColor;
\stopMPextensions

\startMPinitializations
    OverlayWidth:=\overlaywidth;
    OverlayHeight:=\overlayheight;
    OverlayDepth:=\overlayheight;
    OverlayColor:=\MPcolor{\overlaycolor};
    OverlayLineWidth:=\overlaylinewidth;
    OverlayLineColor:=\MPcolor{\overlaylinecolor};
    %
    BaseLineSkip:=\the\baselineskip;
    LineHeight:=\the\baselineskip;
    BodyFontSize:=\the\bodyfontsize;
    %
    TopSkip:=\the\topskip;
    StrutHeight:=\strutheight;
    StrutDepth:=\strutdepth;
    %
    CurrentWidth:=\the\hsize;
    CurrentHeight:=\the\vsize;
    %
    EmWidth:=\the\emwidth;
    ExHeight:=\the\exheight;
    %
    PageNumber:=\the\pageno;
    RealPageNumber:=\the\realpageno;
    LastPageNumber:= \lastpage;
\stopMPinitializations

\appendtoks
    \disablediscretionaries
    \disablecompoundcharacters
\to \everyMPgraphic

\appendtoks
    \expanded{\definecolor[currentcolor][\currentcolorname]}%
\to \everyMPgraphic

\appendtoks
    \baselineskip1\baselineskip
    \lineheight  1\lineheight
    \topskip     1\topskip
\to \everyMPgraphic

\appendtoks
    \let \# \letterhash
    \let \_ \letterunderscore
    \let \& \letterampersand
    \let \{ \letteropenbrace
    \let \} \letterclosebrace
\to \everyMPgraphic

%D Alas, the prologue settings differ per driver.

\ifx\undefined\MPprologues \def\MPprologues{0} \fi

\startMPinitializations
    prologues:=\MPprologues;
    mpprocset:=1;
\stopMPinitializations

\appendtoks
    \def\MPprologues{0}%
    \def\MPOSTdriver{dvips}%
\to \everyresetspecials

%D \macros
%D   {PDFMPformoffset}
%D
%D In \PDF, forms are clipped and therefore we have to take
%D precautions to get this right. Since this is related to
%D objects, we use the same offset as used there.

\def\PDFMPformoffset{\objectoffset}

%D \macros
%D   {insertMPfile}
%D
%D Bypassing the special driver and figure mechanism is not
%D that nice but saves upto 5\% time in embedding \METAPOST\
%D graphics by using the low level \PDF\ converter directly,
%D given of course that we use \PDFTEX. As a result we need to
%D fool around with the object trigger.

\newtoks\everyinsertMPfile

\let\insertMPfileARG\insertMPfile

\def\insertMPfile#1#2% in context #2 is empty
  {\doifelsenothing{#2}{\doinsertMPfile{#1}}{\insertMPfileARG{#1}{#2}}}

\def\includeMPasEPS#1% untested !!
  {\bgroup
   \message{[MP as EPS #1]}%
   \the\everyinsertMPfile
   \dogetEPSboundingbox{#1}\!!widtha\!!heighta\!!widthb\!!heightb
   \setbox\scratchbox\vbox to \!!heightb
     {\vfill
      \let \@@DriverImageType  \c!mps
      \def \@@DriverImageFile  {#1}%
      \edef\@@DriverImageWidth {\the\!!widthb }%
      \edef\@@DriverImageHeight{\the\!!heightb}%
      \doinsertfile}%
   \wd\scratchbox\!!widthb
   \dp\scratchbox\zeropoint
   \box\scratchbox
   \egroup}

\def\includeMPasPDF#1%
  {\bgroup
   \the\everyinsertMPfile
   \ifinobject \else \chardef\makeMPintoPDFobject\plustwo \fi % when needed
   \convertMPtoPDF{#1}{1}{1}% no \plusone !
   \egroup}

%D So, using a low level approach (thereby avoiding the slower
%D figure analysis macros) pays off. This kind of
%D optimizations are a bit tricky since we must make sure that
%D special resources end up in the (PDF) files. Because the
%D \METAPOST\ to \PDF\ can handle objects itself, it is not
%D that complicated.

%D We hook a couple of initializations into the graphic
%D macros.

\appendtoks
    \let\figuretypes\c!mps
    \runutilityfilefalse
    \consultutilityfilefalse
\to \everyinsertMPfile

%D One more: (still needed?)

\startMPextensions
    def initialize_form_numbers =
        do_initialize_numbers;
    enddef;
\stopMPextensions

\startMPinitializations
    HSize:=\the\hsize ;
    VSize:=\the\vsize ;
\stopMPinitializations

\startMPextensions
    vardef ForegroundBox =
        unitsquare xysized(HSize,VSize)
    enddef ;
    vardef PageFraction =
        if \lastpage>1: (\realfolio-1)/(\lastpage-1) else: 1 fi
    enddef ;
\stopMPextensions

%D And some more. These are not really needed since we
%D don't use the normal figure inclusion macros any longer.

\appendtoks
    \externalfigurepostprocessors\emptytoks % safeguard
\to \everyinsertMPfile

%D We also take care of disabling fancy figure features, that
%D can terribly interfere when dealing with symbols,
%D background graphics and running (postponed) graphics.
%D You won't believe me if I tell you what funny side effects
%D can occur. One took me over a day to uncover when
%D processing the screen version of the \METAFUN\ manual.

%D For my eyes only:

\def\doifelseMPgraphic#1{\doifdefinedelse{\@@MPG#1}}

%D \macros
%D   {startMPcolor}
%D
%D The following time consuming method uses \METAPOST\ to
%D calculate a color. This enables a match between colors
%D resulting from a complex calculation (e.g. for a title
%D page) and those in the text.

% \startuseMPgraphic{somecolors}
%   color c[] ; c[1] := .7[red,green] ; c[2] := .7[blue,yellow] ;
% \stopuseMPgraphic

% \startMPcolor[shade-1][t=.2,a=1]
%   \includeMPgraphic{somecolors} ; fill fullcircle withcolor c[1] ;
% \stopMPcolor

% \startMPcolor[shade-2][t=.2,a=1]
%   \includeMPgraphic{somecolors} ; fill fullcircle withcolor c[2] ;
% \stopMPcolor

% \blackrule[width=\hsize,height=4cm,color=shade-1]
% \blackrule[width=\hsize,height=4cm,color=shade-2]

\def\startMPcolor
  {\dodoubleempty\dostartMPcolor}

\long\def\dostartMPcolor[#1][#2]#3\stopMPcolor % slow but sometimes handy
  {\startnointerference
     \def\handleMPgraycolor{\expanded{\defineglobalcolor[#1][s=\!MPgMPa1,#2]}}%
     \def\handleMPrgbcolor {\expanded{\defineglobalcolor[#1][r=\!MPgMPa1,g=\!MPgMPa2,b=\!MPgMPa3,#2]}}%
     \def\handleMPcmykcolor{\expanded{\defineglobalcolor[#1][c=\!MPgMPa1,m=\!MPgMPa2,y=\!MPgMPa3,k=\!MPgMPa4,#2]}}%
     \processMPgraphic{#3}%
   \stopnointerference}

%D New:

\definelayerpreset % no dx,dy - else nasty non-mp placement
  [mp]
  [\c!y=-\MPury bp,
   \c!x=\MPllx bp,
   \c!method=\v!fit]

\definelayer
  [mp]
  [\c!preset=mp]

%D Usage:
%D
%D \starttyping
%D \defineproperty[one][layer][state=start]
%D \defineproperty[two][layer][state=stop]
%D
%D \startuseMPgraphic{step-1}
%D   fill fullcircle scaled 10cm withcolor red ;
%D \stopuseMPgraphic
%D
%D \startuseMPgraphic{step-2}
%D   fill fullcircle scaled 5cm withcolor green ;
%D \stopuseMPgraphic
%D
%D \setlayer[mp]{\property[one]{\useMPgraphic{step-1}}}
%D \setlayer[mp]{\property[two]{\useMPgraphic{step-2}}}
%D
%D \ruledhbox{\flushlayer[mp]}
%D \stoptyping
%D
%D Reusing graphics is also possible (now):
%D
%D \starttyping
%D \startreusableMPgraphic{axis}
%D   tickstep := 1cm ; ticklength := 2mm ;
%D   drawticks unitsquare xscaled 4cm yscaled 3cm shifted (-1cm,-1cm) ;
%D   tickstep := tickstep/2 ; ticklength := ticklength/2 ;
%D   drawticks unitsquare xscaled 4cm yscaled 3cm shifted (-1cm,-1cm) ;
%D \stopreusableMPgraphic
%D
%D \startuseMPgraphic{demo}
%D   drawpoint "1cm,1.5cm" ;
%D \stopuseMPgraphic
%D
%D \definelayer[mp][preset=mp]
%D \setlayer[mp]{\reuseMPgraphic{axis}}
%D \setlayer[mp]{\useMPgraphic{demo}}
%D \ruledhbox{\flushlayer[mp]}
%D \stoptyping

%D \macros
%D   {startstaticMPfigure,useMPstaticfigure}
%D
%D Static figures are processed only when there has been
%D something changed. Here is Aditya Mahajan's testcase:
%D
%D \startbuffer
%D \startstaticMPfigure{circle}
%D   fill fullcircle scaled 1cm withcolor blue;
%D \stopstaticMPfigure
%D
%D \startstaticMPfigure{axis}
%D   drawarrow (0,0)--(2cm,0) ;
%D   drawarrow (0,0)--(0,2cm) ;
%D   label.llft(textext("(0,0)") ,origin) ;
%D \stopstaticMPfigure
%D \stopbuffer
%D
%D \typebuffer \getbuffer

\def\usestaticMPfigure
  {\dodoubleempty\dousestaticMPfigure}

\def\dousestaticMPfigure[#1][#2]%
  {\ifsecondargument
     \scale[#2]{\reuseMPgraphic{#1@S@}}%
   \else
     \reuseMPgraphic{#1@S@}%
   \fi}

\def\startstaticMPfigure#1#2\stopstaticMPfigure
  {\startreusableMPgraphic{static:#1}#2\stopreusableMPgraphic}

\long\def\startstaticMPgraphic
  {\blabelgroup
   \dodoublegroupempty\dostartstaticMPgraphic}

\long\def\dostartstaticMPgraphic#1#2#3\stopstaticMPgraphic
  {\long\setgvalue{\@@MPG#1@S@}{\handlereusableMPgraphic{#1}{#2}{#3}}%
   \elabelgroup}

%D New:

\newconditional\manyMPspecials % when set to true, > 1000 specials can be used

\settrue \manyMPspecials % per 1/4/2006

\prependtoks
  _special_div_ := 1000\ifconditional\manyMPspecials0\fi ;
\to \MPextensions

%D Needed (will become default):

\prependtoks
  \resetlanguagespecifics
\to \everyMPgraphic

%D Needed too.

\let\initializeMPgraphics\relax

% Done.

\protect \endinput