stable 1998.03.27

1 files changed, 864 insertions, 484 deletions

diff --git a/tex/context/base/supp-mps.tex b/tex/context/base/supp-mps.tex
index 8fe6c292f..95a51991f 100644
--- a/tex/context/base/supp-mps.tex
+++ b/tex/context/base/supp-mps.tex
@@ -1,484 +1,864 @@
-%D \module

-%D   [       file=supp-mps,

-%D        version=1997.07.05,

-%D          title=\CONTEXT\ Support Macros,

-%D       subtitle=\METAPOST\ Inclusion,

-%D         author=Hans Hagen,

-%D           date=\currentdate,

-%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]

-%C

-%C This module is part of the \CONTEXT\ macro||package and is

-%C therefore copyrighted by \PRAGMA. Non||commercial use is

-%C granted.

-

-% E-tex   : a primitive that tells us that \write18 works

-% E-tex   : \executeMetaPost filename

-% ConTeXt : automatic flush at end of job

- 

-%D \METAPOST\ is John Hobbys alternative for \METAFONT\ and

-%D produces superior \POSTSCRIPT\ code. In this module we

-%D integrate \METAPOST\ support int \CONTEXT.  We offer two

-%D tracks:

-%D

-%D \startopsomming

-%D \som generating \METAPOST\ code, running this program from

-%D      within \TEX\ using \type{\write18}, and importing the

-%D      result

-%D \som generating \METAPOST\ code, processing the code

-%D      afterward, and importing the result in a second pass

-%D \stopopsomming

-%D

-%D The first approach uses a non standard \TEX\ feature,

-%D implemented in Web2c. I'm not going to discuss the pros and

-%D cons of running programs from within others, but all

-%D arguments against this can be overcome by implementing a

-%D \TEX\ worthy primitive:

-%D

-%D \starttypen

-%D \excuteMetaPost filename

-%D \stoptypen

-%D

-%D Ok then, let's start:

-

-\writestatus{loading}{Context Support Macros / MetaPost Inclusion}

-

-\unprotect

-

-%D \macros

-%D   {startMPgraphic}

-%D

-%D From within \TEX\ one can execute \METAPOST\ code by putting

-%D it between the two commands

-%D

-%D \starttypen

-%D \startMPgraphic

-%D \stopMPgraphic

-%D \stoptypen

-%D

-%D This is implemented as:

-

-\def\startMPgraphic#1\stopMPgraphic%

-  {\startwritingMPgraphic

-   \writeMPgraphic{#1}%

-   \stopwritingMPgraphic}

-

-%D \macros

-%D   {startwritingMPgraphic,

-%D    writeMPgraphic,

-%D    stopwritingMPgraphic}

-%D

-%D If the writing process is divided into more steps, one can

-%D use the components of this macro directly.

-%D

-%D \starttypen

-%D \startwritingMPgraphic

-%D ...

-%D \writeMPgraphic{...}

-%D ...

-%D \writeMPgraphic{...}

-%D ...

-%D \stopwritingMPgraphic

-%D \stoptypen

-

-%D \macros

-%D   {ifrunMPgraphics}

-%D

-%D These macros look a bit more complicated that one would

-%D expect at first sight. This is due to the two ways of

-%D processing these graphics, mentioned in a previous

-%D paragraph. Which method is used, the direct or indirect

-%D one, depends on a boolean.

-

-\newif\ifrunMPgraphics

-

-%D If set to true, one can do with a single pass, else one must

-%D process the \METAPOST\ file \type{mpgraph} between two

-%D succesive \TEX\ runs.

-

-\def\MPgraphicfile{mpgraph}

-

-%D When we run \METAPOST\ from within \TEX, each graphic is 

-%D processed at once, which means that we reuse this file many 

-%D times. When however the execution is delayed, all graphics 

-%D are saved in a separate figure. The current graphic is 

-%D characterized bij a number:

-

-\newcounter\currentMPgraphic

-

-%D \macros

-%D   {ifreuseMPgraphics}

-%D

-%D If one want to reuse grapics, one can save much redundant

-%D run time by setting the next switch to true. 

-

-\newif\ifreuseMPgraphics

-

-%D The three macros responsible for writing the graphic 

-%D implement both schemes. 

-

-%D \macro

-%D   {MPinclusions}

-%D

-%D One can include for instance common input commands by 

-%D assigning those to the token register:

-

-\newtoks\MPinclusions

-

-\def\writeMPgraphic%

-  {\immediate\write\scratchwrite}

-

-\def\startwritingMPgraphic%

-  {\ifrunMPgraphics

-     \ifreuseMPgraphics \else

-       \doglobal\newcounter\currentMPgraphic 

-     \fi

-     \doglobal\increment\currentMPgraphic 

-     \immediate\openout\scratchwrite=\MPgraphicfile.mp

-     \immediate\write\scratchwrite{\the\MPinclusions}%

-   \else

-     \doglobal\increment\currentMPgraphic 

-     \ifnum\currentMPgraphic=1

-       \immediate\openout\scratchwrite=\MPgraphicfile.mp

-       \immediate\write\scratchwrite{\the\MPinclusions}%

-     \fi

-   \fi

-   \immediate\write\scratchwrite{beginfig(\currentMPgraphic);}%

-   \global\let\flushMPgraphics\dodostopwritingMPgraphic

-   \global\let\stopwritingMPgraphic=\dostopwritingMPgraphic}

-

-\def\dostopwritingMPgraphic%

-  {\immediate\write\scratchwrite{endfig;}%

-   \ifrunMPgraphics

-     \dodostopwritingMPgraphic

-   \fi}

-

-\def\dodostopwritingMPgraphic%

-  {\ifnum\currentMPgraphic>0

-     \immediate\write\scratchwrite{end.}%

-     \immediate\closeout\scratchwrite

-     \runMPgraphic{\MPgraphicfile}%

-   \fi

-   \global\let\flushMPgraphics=\relax}

-

-\let\stopwritingMPgraphic=\relax

-\let\flushMPgraphics     =\relax

-

-%D \macros

-%D   {flushMPgraphics}

-%D

-%D When we use the indirect method, all graphics are saved in

-%D one file. This means that we cannot close this file after 

-%D every \type{\stopMPgraphic}. Therefore we need to say:

-%D

-%D \starttypen

-%D \flushMPgraphic

-%D \stoptypen

-%D 

-%D else the file is closed without writing the \METAPOST\ end

-%D command. One will notice this fast enough when in indirect 

-%D mode. When using the direct mode this command is not 

-%D implicitly needed, but ommiting it makes files less 

-%D portable.

-

-%D \macros

-%D   {loadcurrentMPgraphic,

-%D    placeMPgraphic}

-%D

-%D Once defined, we can call for this graphic by saying:

-%D

-%D \starttypen

-%D \loadcurrentMPgraphic{setups}

-%D \placeMPgraphic

-%D \stoptypen

-%D

-%D This two stage insert permits some intermediate manipulations

-%D of the graphic, which temporary saved in:

-

-\newbox\MPgraphic

-

-\def\loadcurrentMPgraphic#1%

-  {\loadMPgraphic{\MPgraphicfile.\currentMPgraphic}{#1}}

-

-\def\loadMPgraphic#1#2%

-  {\setbox\MPgraphic=\hbox{\insertMPfile{#1}{#2}}}

-

-\def\placeMPgraphic%

-  {\box\MPgraphic}

-

-%D \macros

-%D   {startreusableMPgraphic, reuseMPgraphic, useMPbox}

-%D 

-%D One can use the next macro for defining graphics that are

-%D to be reused. When the next switch is set, graphics are 

-%D cached. 

- 

-\newif\ifuseMPbox % nog eens cyclische buffer

-

-\long\def\startreusableMPgraphic#1#2\stopreusableMPgraphic%

-  {\reuseMPgraphicstrue

-   \doifundefined{MP:#1}

-     {\startMPgraphic#2\stopMPgraphic

-      \ifuseMPbox

-        \ifx\setobject\undefined

-          \newbox\somebox

-          \global\setbox\somebox=\vbox

-            {\loadMPgraphic{\MPgraphicfile.\currentMPgraphic}{}%

-             \placeMPgraphic}%

-          \global\setevalue{MP:#1}%

-            {\copy\the\somebox\relax}%

-        \else

-          \setobject{MP:#1}

-            \vbox

-              {\loadMPgraphic{\MPgraphicfile.\currentMPgraphic}{}%

-               \placeMPgraphic}%

-          \global\setvalue{MP:#1}%

-            {\getobject{MP:#1}}%

-        \fi

-      \else

-        \global\setevalue{MP:#1}%

-          {\noexpand\loadMPgraphic{\MPgraphicfile.\currentMPgraphic}{}%

-           \noexpand\placeMPgraphic}%

-      \fi}}

-

-\def\reuseMPgraphic#1%

-  {\getvalue{MP:#1}}

-

-%D \macro

-%D   {startuseMPgraphic,useMPgraphic}

-%D

-%D The every||time||it's||used original one is defined below.

-%D This one makes sense when the graphic uses random numbers.

-

-\def\startuseMPgraphic#1#2\stopuseMPgraphic%

-  {\reuseMPgraphicstrue 

-   \long\setvalue{MP:#1}%

-     {\startMPgraphic#2\stopMPgraphic 

-      \loadcurrentMPgraphic{}%

-      \placeMPgraphic}}

-

-\let\useMPgraphic=\reuseMPgraphic

-

-%D We didn't yet define the macro responsible for processing 

-%D the graphic from within \TEX. 

-

-\def\runMPgraphic#1%

-  {\ifrunMPgraphics

-     \executeMETAPOST{#1}%

-   \else 

-     \message{[flush and process \MPgraphicfile.mp afterwards]}%

-   \fi}

-

-%D \macros

-%D   {executeMetaPost, executeMETAPOST, executesystemcommand}

-%D

-%D With \type{\executeMETAPOST} being defined as:

- 

-\ifx\undefined\executeMetaPost

-  \def\executeMETAPOST#1{\executesystemcommand{\executeMetaPost{#1}}}

-\fi

-

-%D There are two system dependant definitions: 

-

-\ifx\undefined\executesystemcommand 

-  \def\executesystemcommand#1{\immediate\write18{#1}}

-\fi

-

-\ifx\undefined\executeMetaPost

-  \def\executeMetaPost#1{mpost #1}

-\fi

-

-%D \macros

-%D   {insertMPfile}

-%D

-%D One can define this command in advance or redefine it after

-%D loading this module. The same goes for the forward 

-%D reference to the figure loading macro:

-

-\ifx\undefined\insertMPfile 

-

-  \def\insertMPfile#1#2%

-      {\ifx\undefined\externalfigure 

-         \message{[insert file #1 here]}%

-       \else

-         \externalfigure[#1][\c!type=eps,\c!methode=mps,#2]%

-       \fi}

-

-\fi

-

-%D This macro takes {\em two} arguments, the second one can be

-%D used to pass info to the inclusion macro. Some examples 

-%D of its use can be found in the modules \type{supp-tpi} and 

-%D \type{prag-log}. 

-

-%D For some reason, \METAPOST\ needs the public domain \DVI\ to

-%D \POSTSCRIPT\ converter \DVIPS. This symbiosis originates in

-%D the need to include the fonts (glyphs) that \METAPOST\ uses

-%D in the \POSTSCRIPT\ file. Driver independancy was one of my

-%D prerequisites for using \METAPOST, so I decided to build

-%D this kind of support myself. Personally I consider driver

-%D dependancy a drawback for the dissemination of such a

-%D package. The second part of this module more or less 

-%D decouples \METAPOST\ and \DVIPS. 

-%D 

-%D The macros hereafter are copied from the module

-%D \type{m-metapost}. After writing module \type{supp-pdf} I

-%D added this method to the module named and after a while

-%D decided to hook it into module \type{spec-yy}. Therefore 

-%D they made it into a support module, but in a slightly 

-%D different way. 

-

-%D \macros

-%D   {UseMetaPostGraphic, DontUseMetaPostGraphics}

-%D   {}

-%D 

-%D The method we use is both robust and simple: one can do 

-%D with calling the next macro with the filename as argument:

-%D

-%D \starttypen

-%D \UseMetaPostGraphic{filename}

-%D \stoptypen

-%D

-%D We can turn of this mechanism with: 

-%D

-%D \starttypen

-%D \DontUseMetaPostGraphics

-%D \stoptypen

-

-\def\UseMetaPostGraphic#1%

-  {\bgroup

-   \message{[MP fonts #1]}%

-   %\uncatcodespecials

-   \endlinechar=-1

-   \setMPspecials

-   \obeyMPspecials

-   \setbox0=\hbox

-     {\hskip-\maxdimen

-      \doprocessfile\scratchread{#1}\handleMPSline}%

-   \smashbox0 

-   \box0

-   \egroup}

-

-\def\DontUseMetaPostGraphics%

-  {\let\UseMetaPostGraphic=\gobbleoneargument}

-

-%D The characters are collected in a box and moved as far as

-%D possible into the left margin. The resulting box has no

-%D dimensions and can be prepended (appended) to the special

-%D that handles the inclusion. The characters are in the file

-%D but made invisible. 

-

-%D We scan the graphics file for the \type{fshow} operator,

-%D that is, lines that start with \type{(}. If found it

-%D interprets the line, which looks like: 

-%D

-%D \starttypen

-%D (string ... string) font size fshow

-%D \stoptypen

-%D 

-%D Font definitions specified in the preamble are simply 

-%D ignored. Only lines starting with \type{(} are interpreted.  

-

-\def\dohandleMPSline#1#2\relax%

-  {\if#1(%

-     \expandafter\includeMPcharacters\fileline\relax

-   \fi}

-

-\def\handleMPSline%

-  {\expandafter\dohandleMPSline\fileline\relax}

-

-%D Before we start scanning for data, we first change some 

-%D \CATCODES. The first set of macro's is copied from module 

-%D \type{supp-pdf}. This scheme is a bit overdone for this 

-%D module, but using the same macros saves us some memory.

-

-\def\octalMPcharacter#1#2#3%

-  {\char'#1#2#3\relax}

-

-\bgroup

-\catcode`\|=\@@comment

-\catcode`\%=\@@active

-\catcode`\[=\@@active

-\catcode`\]=\@@active

-\catcode`\{=\@@active

-\catcode`\}=\@@active

-\catcode`B=\@@begingroup

-\catcode`E=\@@endgroup

-\gdef\ignoreMPspecials|

-  B\def%BE|

-   \def[BE|

-   \def]BE|

-   \def{BE|

-   \def}BEE     

-\gdef\obeyMPspecials|

-  B\def%B\char 37\relax E|

-   \def[B\char 91\relax E|

-   \def]B\char 93\relax E|

-   \def{B\char123\relax E|

-   \def}B\char125\relax EE   

-\gdef\setMPspecials|

-  B\catcode`\%=\@@active

-   \catcode`\[=\@@active

-   \catcode`\]=\@@active

-   \catcode`\{=\@@active

-   \catcode`\}=\@@active

-   \catcode`\$=\@@letter

-   \catcode`\_=\@@letter

-   \catcode`\#=\@@letter

-   \catcode`\^=\@@letter

-   \catcode`\&=\@@letter

-   \catcode`\|=\@@letter

-   \catcode`\~=\@@letter

-   \def\(B\char40\relax     E|

-   \def\)B\char41\relax     E|

-   \def\\B\char92\relax     E|

-   \def\0B\octalMPcharacter0E|

-   \def\1B\octalMPcharacter1E|

-   \def\2B\octalMPcharacter2E|

-   \def\3B\octalMPcharacter3E|

-   \def\4B\octalMPcharacter4E|

-   \def\5B\octalMPcharacter5E|

-   \def\6B\octalMPcharacter6E|

-   \def\7B\octalMPcharacter7E|

-   \def\8B\octalMPcharacter8E|

-   \def\9B\octalMPcharacter9EE

-\egroup

-

-%D The lines starting with \type{(} are interpreted and 

-%D handled by 

-

-\def\includeMPcharacters(#1) #2 #3 #4\relax%

-  {\font\temp=#2 at #3bp\temp#1}

-

-%D This method is both robust and reasonable fast. The only 

-%D disadvantage is that when not embedded properly in the 

-%D graphics inclusion macros, one has to load all graphics by

-%D hand.  

-

-%D Now let's see if things work all right and show the example 

-%D files that are part of the \METAPOST\ distribution:

-%D

-%D \startregelcorrectie

-%D \steluitlijnenin[midden]

-%D \leavevmode

-%D \startcombinatie[3*3]

-%D   {\externfiguur[mp-exa-1][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-2][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-3][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-4][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-5][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-6][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-7][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-8][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D   {\externfiguur[mp-exa-9][methode=mps,kader=aan,breedte=.2\hsize]} {}

-%D \stopcombinatie

-%D \stopregelcorrectie

-%D

-%D Here we used calls like: 

-%D

-%D \starttypen

-%D \externfiguur[mp-exa-1][methode-mps,kader=aan,breedte=.2\hsize]

-%D \stoptypen

-

-\protect 

-

-\endinput

+%D \module
+%D   [       file=supp-mps,
+%D        version=1997.07.05,
+%D          title=\CONTEXT\ Support Macros,
+%D       subtitle=\METAPOST\ Inclusion,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. Non||commercial use is
+%C granted.
+
+% E-tex   : a primitive that tells us that \write18 works
+% E-tex   : \executeMetaPost filename
+% ConTeXt : automatic flush at end of job
+
+% The MP generation support is still experimental.
+
+%D \METAPOST\ is John Hobbys alternative for \METAFONT\ and
+%D produces superior \POSTSCRIPT\ code. In this module we
+%D integrate \METAPOST\ support int \CONTEXT.  We offer two
+%D tracks:
+%D
+%D \startopsomming
+%D \som generating \METAPOST\ code, running this program from
+%D      within \TEX\ using \type{\write18}, and importing the
+%D      result
+%D \som generating \METAPOST\ code, processing the code
+%D      afterward, and importing the result in a second pass
+%D \stopopsomming
+%D
+%D The first approach uses a non standard \TEX\ feature,
+%D implemented in Web2c. I'm not going to discuss the pros and
+%D cons of running programs from within others, but all
+%D arguments against this can be overcome by implementing a
+%D \TEX\ worthy primitive:
+%D
+%D \starttypen
+%D \excuteMetaPost filename
+%D \stoptypen
+%D
+%D Ok then, let's start:
+
+\ifx \undefined \writestatus \input supp-mis.tex \relax \fi
+
+\writestatus{loading}{Context Support Macros / MetaPost Inclusion}
+
+\unprotect
+
+%D \macros
+%D   {startMPgraphic}
+%D
+%D From within \TEX\ one can execute \METAPOST\ code by putting
+%D it between the two commands
+%D
+%D \starttypen
+%D \startMPgraphic
+%D \stopMPgraphic
+%D \stoptypen
+%D
+%D This is implemented as:
+
+\long\def\startMPgraphic#1\stopMPgraphic%
+  {\startwritingMPgraphic
+   \writeMPgraphic{#1}%
+   \stopwritingMPgraphic}
+
+%D \macros
+%D   {startMPrun}
+%D
+%D If we just wat to run \METAPOST\ code, that is, not to
+%D explictly generate a figure in terms of \type{beginfig} and
+%D \type{endfig}, we can use: 
+%D
+%D \starttypen
+%D \startMPgraphic
+%D \stopMPgraphic
+%D \stoptypen
+%D
+%D \starttypen
+%D \startMPrun
+%D \stopMPrun
+%D \stoptypen
+%D
+%D The next boolean is for internal purposes only.
+
+\newif\ifMPrun \MPrunfalse
+
+\long\def\startMPrun#1\stopMPrun% geeft nog conflicten met nummer!
+  {\MPruntrue
+   \startwritingMPgraphic
+   \writeMPgraphic{#1}%
+   \stopwritingMPgraphic
+   \MPrunfalse}
+  
+%D \macros
+%D   {startwritingMPgraphic,
+%D    writeMPgraphic,
+%D    stopwritingMPgraphic}
+%D
+%D If the writing process is divided into more steps, one can
+%D use the components of this macro directly.
+%D
+%D \starttypen
+%D \startwritingMPgraphic
+%D ...
+%D \writeMPgraphic{...}
+%D ...
+%D \writeMPgraphic{...}
+%D ...
+%D \stopwritingMPgraphic
+%D \stoptypen
+
+%D \macros
+%D   {ifrunMPgraphics}
+%D
+%D These macros look a bit more complicated that one would
+%D expect at first sight. This is due to the two ways of
+%D processing these graphics, mentioned in a previous
+%D paragraph. Which method is used, the direct or indirect
+%D one, depends on a boolean.
+
+\newif\ifrunMPgraphics
+
+%D If set to true, one can do with a single pass, else one must
+%D process the \METAPOST\ file \type{mpgraph} between two
+%D succesive \TEX\ runs.
+
+\def\MPgraphicfile{mpgraph}
+
+%D \macros
+%D   {MPgraphic}
+%D
+%D When we run \METAPOST\ from within \TEX, each graphic is
+%D processed at once, which means that we reuse this file many
+%D times. When however the execution is delayed, all graphics
+%D are saved in a separate figure. The current graphic is
+%D characterized bij a \COUNTER. This counter is available 
+%D in \type{\MPgraphic}.
+
+\newcount\currentMPgraphic
+
+\def\MPgraphic{0}
+
+%D \macros
+%D   {ifreuseMPgraphics}
+%D
+%D If one want to reuse grapics, one can save much redundant
+%D run time by setting the next switch to true.
+
+\newif\ifreuseMPgraphics
+
+%D The three macros responsible for writing the graphic
+%D implement both schemes.
+
+%D \macros
+%D   {MPinclusions, startMPinclusions}
+%D
+%D One can include for instance common input commands by
+%D passing them to \type{\MPinclusions}: 
+%D
+%D \starttypen
+%D \MPinclusions{input tools}
+%D \stoptypen
+
+\let\theMPinclusions=\empty
+
+\long\def\startMPinclusions#1\stopMPinclusions%
+  {\long\def\theMPinclusions{\writeMPgraphic{#1}}}
+
+\long\def\MPinclusions#1%
+  {\startMPinclusions#1\stopMPinclusions}
+
+%D \macros
+%D   {iflongMPlines}
+%D
+%D When grabbing a graphic deifnition, newlines are turned
+%D into spaces. By default we split the graphic definition
+%D at the colon, but long lines are still possible by
+%D setting the next boolean to true.
+
+\newif\iflongMPlines
+
+\long\def\writeMPgraphic#1%
+  {\bgroup
+   \iflongMPlines
+     \let\par=\empty
+     \long\def\flush##1##2\par%
+       {\ifx##1\relax \else
+          \immediate\write\scratchwrite{##1##2}%
+          \expandafter\flush
+        \fi}%
+     \flush#1\empty\par\relax\par
+   \else
+     \long\def\flush##1##2;%
+       {\ifx##1\relax \else
+          \dowriteMPgraphicline##1##2btex\relax etex\end
+          \expandafter\flush
+        \fi}%
+     \flush#1\empty;\relax;%
+   \fi
+   \egroup}
+
+%D The \type{;} aware method (the \type{\else} branch) also 
+%D takes care of \type{btex}||\type{etex} bound data. 
+
+\def\dowriteMPgraphicline%
+  {\futurelet\next\dodowriteMPgraphicline}
+
+\long\def\dodowriteMPgraphicline#1btex#2#3etex#4\end%
+  {\ifx\next\empty\else\ifx\next\relax\else
+     \bgroup
+     \let\par=\empty
+     \ifx#2\relax
+       \immediate\write\scratchwrite{#1;}%
+       \egroup
+     \else
+       \convertargument#2#3\to\ascii
+       \immediate\write\scratchwrite{#1btex \ascii etex;}%
+       \egroup
+       \dowriteMPgraphicline#4btex\relax etex\end
+     \fi
+   \fi\fi}
+
+%D This stripper is suboptimal in the sense that more
+%D \type{;}'s are output than feasible. Anyhow, \METAPOST\ 
+%D can handle this and users may consider it being a sort 
+%D of error prevention bonus. 
+
+\def\writeMPgraph%
+  {\immediate\write\scratchwrite{mpgraph:=\the\currentMPgraphic;}}
+
+\def\startwritingMPgraphic%
+  {\ifrunMPgraphics
+     \ifMPrun \else \ifreuseMPgraphics \else
+       \global\currentMPgraphic=0
+     \fi \fi 
+     \global\advance\currentMPgraphic by 1
+     \xdef\MPgraphic{\the\currentMPgraphic}%
+     \immediate\openout\scratchwrite=\MPgraphicfile.mp
+     \writeMPgraph
+     \theMPinclusions
+   \else
+     \global\advance\currentMPgraphic by 1
+     \xdef\MPgraphic{\the\currentMPgraphic}%
+     \ifnum\currentMPgraphic=1
+       \immediate\openout\scratchwrite=\MPgraphicfile.mp
+       \writeMPgraph
+       \theMPinclusions
+     \fi
+   \fi
+   \ifMPrun \else
+     \immediate\write\scratchwrite{beginfig(\the\currentMPgraphic);}%
+   \fi
+   \global\let\flushMPgraphics\dodostopwritingMPgraphic
+   \global\let\stopwritingMPgraphic=\dostopwritingMPgraphic}
+
+\def\dostopwritingMPgraphic%
+  {\ifMPrun \else 
+     \immediate\write\scratchwrite{endfig;}%
+   \fi
+   \ifrunMPgraphics
+     \dodostopwritingMPgraphic
+   \fi}
+
+\def\dodostopwritingMPgraphic%
+  {\ifnum\currentMPgraphic>0
+     \immediate\write\scratchwrite{end.}%
+     \immediate\closeout\scratchwrite
+     \runMPgraphic{\MPgraphicfile}%
+   \fi
+   \global\let\flushMPgraphics=\relax}
+
+\let\stopwritingMPgraphic=\relax
+\let\flushMPgraphics     =\relax
+
+%D \macros
+%D   {flushMPgraphics}
+%D
+%D When we use the indirect method, all graphics are saved in
+%D one file. This means that we cannot close this file after
+%D every \type{\stopMPgraphic}. Therefore we need to say:
+%D
+%D \starttypen
+%D \flushMPgraphic
+%D \stoptypen
+%D
+%D else the file is closed without writing the \METAPOST\ end
+%D command. One will notice this fast enough when in indirect
+%D mode. When using the direct mode this command is not
+%D implicitly needed, but ommiting it makes files less
+%D portable.
+
+%D \macros
+%D   {loadcurrentMPgraphic,
+%D    placeMPgraphic}
+%D
+%D Once defined, we can call for this graphic by saying:
+%D
+%D \starttypen
+%D \loadcurrentMPgraphic{setups}
+%D \placeMPgraphic
+%D \stoptypen
+%D
+%D This two stage insert permits some intermediate manipulations
+%D of the graphic, which temporary saved in:
+
+\newbox\MPgraphicbox
+
+\def\loadcurrentMPgraphic#1%
+  {\loadMPgraphic{\MPgraphicfile.\the\currentMPgraphic}{#1}}
+
+\def\loadMPgraphic#1#2%
+  {\setbox\MPgraphicbox=\hbox{\insertMPfile{#1}{#2}}}
+
+\def\placeMPgraphic%
+  {\box\MPgraphicbox}
+
+%D \macros
+%D   {startreusableMPgraphic, reuseMPgraphic, useMPbox}
+%D
+%D One can use the next macro for defining graphics that are
+%D to be reused. When the next switch is set, graphics are
+%D cached.
+
+\newif\ifuseMPbox % nog eens cyclische buffer
+
+\def\douseMPbox#1%
+  {\setobject{#1}
+     \vbox
+       {\loadMPgraphic{\MPgraphicfile.\the\currentMPgraphic}{}%
+        \placeMPgraphic}%
+     \setgvalue{#1}%
+       {\getobject{#1}}}
+
+\def\nouseMPbox#1%
+  {\setxvalue{#1}%
+     {\noexpand\loadMPgraphic{\MPgraphicfile.\the\currentMPgraphic}{}%
+      \noexpand\placeMPgraphic}}
+
+\ifCONTEXT \else \let\douseMPbox=\nouseMPbox \fi
+ 
+\long\def\startreusableMPgraphic#1#2\stopreusableMPgraphic%
+  {\reuseMPgraphicstrue
+   \doifundefined{MP:#1}
+     {\startMPgraphic#2\stopMPgraphic
+      \ifuseMPbox
+        \douseMPbox{MP:#1}%
+      \else
+        \nouseMPbox{MP:#1}%
+      \fi}}
+
+\def\reuseMPgraphic#1%
+  {\getvalue{MP:#1}}
+
+%D \macros
+%D   {startuseMPgraphic,useMPgraphic}
+%D
+%D The every||time||it's||used original one is defined below.
+%D This one makes sense when the graphic uses random numbers.
+
+\long\def\startuseMPgraphic#1#2\stopuseMPgraphic%
+  {\reuseMPgraphicstrue
+   \long\setgvalue{MP:#1}%
+     {\startMPgraphic#2\stopMPgraphic
+      \loadcurrentMPgraphic{}%
+      \placeMPgraphic}}
+
+\let\useMPgraphic=\reuseMPgraphic
+
+%D We didn't yet define the macro responsible for processing
+%D the graphic from within \TEX.
+
+\def\runMPgraphic#1%
+  {\ifrunMPgraphics
+     \executeMETAPOST{#1}%
+   \else
+     \message{[flush and process \MPgraphicfile.mp afterwards]}%
+   \fi}
+
+%D \macros
+%D   {executeMetaPost, executeMETAPOST, executesystemcommand}
+%D
+%D With \type{\executeMETAPOST} being defined as:
+
+\ifx\undefined\executeMetaPost
+  \def\executeMETAPOST#1{\executesystemcommand{\executeMetaPost{#1}}}
+\fi
+
+%D There are two system dependant definitions:
+
+\ifx\undefined\executesystemcommand
+  \def\executesystemcommand#1{\immediate\write18{#1}}
+\fi
+
+\ifx\undefined\executeMetaPost
+  \def\executeMetaPost#1{mpost #1}
+\fi
+
+%D \macros
+%D   {insertMPfile}
+%D
+%D One can define this command in advance or redefine it after
+%D loading this module. The same goes for the forward
+%D reference to the figure loading macro:
+
+\ifx\undefined\insertMPfile
+
+  \def\insertMPfile#1#2%
+    {\ifx\undefined\externalfigure
+       \message{[insert file #1 here]}%
+     \else
+       \externalfigure[#1][\c!type=eps,\c!methode=mps,#2]%
+     \fi}
+
+\fi
+
+%D This macro takes {\em two} arguments, the second one can be
+%D used to pass info to the inclusion macro. Some examples
+%D of its use can be found in the modules \type{supp-tpi} and
+%D \type{prag-log}.
+
+%D This module can be used in \PLAIN\ \TEX too. When using 
+%D \DVIPS, just try to process:
+%D 
+%D \starttypen
+%D \input supp-mps
+%D
+%D \runMPgraphicstrue
+%D 
+%D \def\insertMPfile#1#2%
+%D   {\special{psfile=#1}}
+%D 
+%D \startuseMPgraphic{1}
+%D   prologues := 1;
+%D   draw (0,0) withpen pencircle scaled 100;
+%D \stopuseMPgraphic
+%D 
+%D \useMPgraphic{1}
+%D \stoptypen
+%D 
+%D Don't forget to enable \type{\write18}. When does not say
+%D \type{\runMPgraphicstrue}, the \METAPOST\ scratch file 
+%D must be closed by saying
+%D 
+%D \starttypen
+%D \flushMPgraphics
+%D \stoptypen
+%D
+%D When using the indirect method, one has to process the file
+%D \type{mpgraph.mp} between two successive \TEX\ runs. 
+
+%D For some reason, \METAPOST\ needs the public domain \DVI\ to
+%D \POSTSCRIPT\ converter \DVIPS. This symbiosis originates in
+%D the need to include the fonts (glyphs) that \METAPOST\ uses
+%D in the \POSTSCRIPT\ file. Driver independancy was one of my
+%D prerequisites for using \METAPOST, so I decided to build
+%D this kind of support myself. Personally I consider driver
+%D dependancy a drawback for the dissemination of such a
+%D package. The second part of this module more or less
+%D decouples \METAPOST\ and \DVIPS.
+%D
+%D The macros hereafter are copied from the module
+%D \type{m-metapost}. After writing module \type{supp-pdf} I
+%D added this method to the module named and after a while
+%D decided to hook it into module \type{spec-yy}. Therefore
+%D they made it into a support module, but in a slightly
+%D different way.
+
+%D \macros
+%D   {includeMPfonts, ifincludeMPfonts}
+%D   {}
+%D
+%D The method we use is both robust and simple: one can do
+%D with calling the next macro with the filename as argument:
+%D
+%D \starttypen
+%D \includeMPfonts{filename}
+%D \stoptypen
+%D
+%D We can turn of this mechanism with:
+%D
+%D \starttypen
+%D \includeMPfontsfalse
+%D \stoptypen
+
+\newif\ifincludeMPfonts \includeMPfontstrue
+
+\def\includeMPfonts#1%
+  {\ifincludeMPfonts
+     \bgroup
+     \message{[MP fonts #1]}%
+     %\uncatcodespecials
+     \endlinechar=-1
+     \setMPspecials
+     \obeyMPspecials
+     \setbox0=\hbox
+       {\hskip-\maxdimen
+        \doprocessfile\scratchread{#1}\handleMPfont}%
+     \smashbox0
+     \box0
+     \egroup
+   \fi}
+
+\def\UseMetaPostGraphic      {\includeMPfonts}      % upward compatible
+\def\DontUseMetaPostGraphics {\includeMPfontsfalse} % upward compatible
+
+%D The characters are collected in a box and moved as far as
+%D possible into the left margin. The resulting box has no
+%D dimensions and can be prepended (appended) to the special
+%D that handles the inclusion. The characters are in the file
+%D but made invisible.
+
+%D We scan the graphics file for the \type{fshow} operator,
+%D that is, lines that start with \type{(}. If found it
+%D interprets the line, which looks like:
+%D
+%D \starttypen
+%D (string ... string) font size fshow
+%D \stoptypen
+%D
+%D Font definitions specified in the preamble are simply
+%D ignored. Only lines starting with \type{(} are interpreted.
+
+\def\dohandleMPfont#1#2\relax%
+  {\if#1(%
+     \expandafter\includeMPcharacters\fileline\relax
+   \fi}
+
+\def\handleMPfont%
+  {\expandafter\dohandleMPfont\fileline\relax}
+
+%D Before we start scanning for data, we first change some
+%D \CATCODES. The first set of macro's is copied from module
+%D \type{supp-pdf}. This scheme is a bit overdone for this
+%D module, but using the same macros saves us some memory.
+
+\def\octalMPcharacter#1#2#3%
+  {\char'#1#2#3\relax}
+
+\bgroup
+\catcode`\|=\@@comment
+\catcode`\%=\@@active
+\catcode`\[=\@@active
+\catcode`\]=\@@active
+\catcode`\{=\@@active
+\catcode`\}=\@@active
+\catcode`B=\@@begingroup
+\catcode`E=\@@endgroup
+\gdef\ignoreMPspecials|
+  B\def%BE|
+   \def[BE|
+   \def]BE|
+   \def{BE|
+   \def}BEE
+\gdef\obeyMPspecials|
+  B\def%B\char 37\relax E|
+   \def[B\char 91\relax E|
+   \def]B\char 93\relax E|
+   \def{B\char123\relax E|
+   \def}B\char125\relax EE
+\gdef\setMPspecials|
+  B\catcode`\%=\@@active
+   \catcode`\[=\@@active
+   \catcode`\]=\@@active
+   \catcode`\{=\@@active
+   \catcode`\}=\@@active
+   \catcode`\$=\@@letter
+   \catcode`\_=\@@letter
+   \catcode`\#=\@@letter
+   \catcode`\^=\@@letter
+   \catcode`\&=\@@letter
+   \catcode`\|=\@@letter
+   \catcode`\~=\@@letter
+   \def\(B\char40\relax     E|
+   \def\)B\char41\relax     E|
+   \def\\B\char92\relax     E|
+   \def\0B\octalMPcharacter0E|
+   \def\1B\octalMPcharacter1E|
+   \def\2B\octalMPcharacter2E|
+   \def\3B\octalMPcharacter3E|
+   \def\4B\octalMPcharacter4E|
+   \def\5B\octalMPcharacter5E|
+   \def\6B\octalMPcharacter6E|
+   \def\7B\octalMPcharacter7E|
+   \def\8B\octalMPcharacter8E|
+   \def\9B\octalMPcharacter9EE
+\egroup
+
+%D The lines starting with \type{(} are interpreted and
+%D handled by
+
+\def\includeMPcharacters(#1) #2 #3 #4\relax%
+  {\font\temp=#2 at #3bp\temp#1}
+
+%D This method is both robust and reasonable fast. The only
+%D disadvantage is that when not embedded properly in the
+%D graphics inclusion macros, one has to load all graphics by
+%D hand.
+
+%D Now let's see if things work all right and show the example
+%D files that are part of the \METAPOST\ distribution:
+%D
+%D \startregelcorrectie
+%D \steluitlijnenin[midden]
+%D \leavevmode
+%D \startcombinatie[3*3]
+%D   {\externfiguur[mp-exa-1][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-2][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-3][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-4][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-5][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-6][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-7][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-8][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D   {\externfiguur[mp-exa-9][methode=mps,kader=aan,breedte=.2\hsize]} {}
+%D \stopcombinatie
+%D \stopregelcorrectie
+%D
+%D Here we used calls like:
+%D
+%D \starttypen
+%D \externfiguur[mp-exa-1][methode-mps,kader=aan,breedte=.2\hsize]
+%D \stoptypen
+
+%D \macros
+%D   {convertMPcolors,
+%D    ifconvertMPcolors,ifreduceMPcolors,ifforceMPcolors}
+%D
+%D When I told the editors that I wanted to use colored
+%D \METAPOST\ graphics in the color issue of the \MAPS, I was
+%D asked to use the \kap{CMYK} colorspace instead of \kap{RGB}
+%D one. However, \METAPOST\ only supports \kap{RGB} colors. I
+%D decided to write a utility to convert the \type
+%D {setrgbcolor} operators into \type {setcmykcolor} ones, and
+%D some experiments showed me that I could best let \TEX\ do it
+%D itself. Here it is:
+%D
+%D There are two booleans that control the conversion process.
+%D These are false by default.
+
+\newif\ifconvertMPcolors
+\newif\ifreduceMPcolors
+\newif\ifforcegrayMPcolors
+
+%D The main macro is calles as:
+%D
+%D \starttypen
+%D \convertMPcolors{filename}
+%D \stoptypen
+%D
+%D When active, this macro returns a message saying if indeed
+%D conversion took place. The old file is overwritten! This
+%D saves time in a succesive passes and can't harm, simply
+%D because MP can generate them anew.
+
+\def\convertMPcolorpath{} % {./}
+\def\convertMPcolorfile{metacmyk.eps}
+
+\def\convertMPcolors#1%
+  {\bgroup
+   \ifforcegrayMPcolors
+     \donetrue
+   \else\ifconvertMPcolors
+     \donetrue
+   \else
+     \donefalse
+   \fi\fi
+   \ifdone
+     \message{[MP color conversion #1}%
+     \endlinechar=-1
+     \uncatcodespecials
+     \donefalse
+     \immediate\openout\scratchwrite=\convertMPcolorpath\convertMPcolorfile
+     \doprocessfile\scratchread{#1}\handleMPcolor
+     \immediate\closeout\scratchwrite
+     \ifdone
+       \immediate\openout\scratchwrite=\convertMPcolorpath#1
+       \doprocessfile\scratchread{\convertMPcolorpath \convertMPcolorfile}\handleMPcopy
+       \immediate\closeout\scratchwrite
+       \message{done]}%
+     \else
+       \message{not needed]}%
+     \fi
+     \immediate\openout\scratchwrite=\convertMPcolorpath\convertMPcolorfile
+     \immediate\closeout\scratchwrite
+   \fi
+   \egroup}
+
+%D The process is rather simple: read a line, look for the
+%D \type {setrgbcolor} operator, recalculate the components and
+%D check for gray reduction or black removal, write the result
+%D to a temporary file, and go on. Afterwards, the file is
+%D copied back. We don't have to reduce to gray scales;
+%D \METAPOST\ already takes care of that.
+
+\def\handleMPcolor
+  {\expandafter\dohandleMPcolor\fileline setrgbcolor*\\}
+
+\def\dohandleMPcolor#1setrgbcolor#2#3\\%
+  {\if#2*%
+     \immediate\write\scratchwrite{#1}%
+   \else
+     \dodohandleMPcolor#1setrgbcolor#2#3\\%
+   \fi}
+
+\def\dodohandleMPcolor#1 #2 #3setrgbcolor#4setrgbcolor*\\%
+  {\bgroup
+   \ifforcegrayMPcolors
+     \convertRGBtoGRAY{#1}{#2}{#3}%
+     \immediate\write\scratchwrite
+       {\@@cl@@s \space setgray #4}%
+   \else
+     \dimen0=1pt \advance\dimen0 by -#1pt
+     \dimen2=1pt \advance\dimen2 by -#2pt
+     \dimen4=1pt \advance\dimen4 by -#3pt
+     \ifreduceMPcolors
+       \dimen6=\dimen0
+       \ifdim\dimen2<\dimen6 \dimen6=\dimen2 \fi
+       \ifdim\dimen4<\dimen6 \dimen6=\dimen4 \fi
+       \advance\dimen0 by -\dimen6
+       \advance\dimen2 by -\dimen6
+       \advance\dimen4 by -\dimen6
+     \else
+       \dimen6=\!!zeropoint
+     \fi
+     \immediate\write\scratchwrite
+       {\withoutpt{\the\dimen0} \space
+        \withoutpt{\the\dimen2} \space
+        \withoutpt{\the\dimen4} \space
+        \withoutpt{\the\dimen6} \space setcmykcolor #4}%
+    \fi
+    \egroup
+    \donetrue} % needed for message
+
+\def\handleMPcopy%
+  {\immediate\write\scratchwrite{\fileline}}
+
+%D The next macro is needed for forced conversion. This macro
+%D is copied from \type{colo-ini}, just in case one uses this
+%D module outside \CONTEXT.
+
+\ifx\convertRGBtoGRAY\undefined
+
+  \def\convertRGBtoGRAY#1#2#3%
+    {\scratchdimen=#1\s!pt
+     \scratchdimen=300\scratchdimen
+     \scratchcounter=\scratchdimen
+     \scratchdimen=#2\s!pt
+     \scratchdimen=590\scratchdimen
+     \advance\scratchcounter by \scratchdimen
+     \scratchdimen=#3\s!pt
+     \scratchdimen=110\scratchdimen
+     \advance\scratchcounter by \scratchdimen
+     \advance\scratchcounter by \!!medcard
+     \divide\scratchcounter by \!!maxcard
+     \edef\@@cl@@s{\realcolorvalue\scratchcounter}}
+
+\fi
+
+%D The next examples show the color conversion macros in
+%D action. These examples also demonstrate in||text \METAPOST\
+%D handling. As we will see, the conversion is hooked into the
+%D \CONTEXT\ color mechanism.
+%D
+%D By setting both \type{rgb} and \type{cmyk} to off, we force
+%D conversion to gray scales using:
+%D
+%D \plaatsformule[-]
+%D   \startformule
+%D   G = .30r + .59g + .11b
+%D   \stopformule
+%D
+%D By using buffers, we keep the \ASCII\ layout clean:
+%D
+%D \startbuffer
+%D \startbuffer[rgb]
+%D   \stelkleurenin[rgb=ja,cmyk=nee,reductie=nee,conversie=nee]
+%D   \useMPgraphic{hans}
+%D \stopbuffer
+%D
+%D \startbuffer[cmyk]
+%D   \stelkleurenin[rgb=nee,cmyk=ja,reductie=nee,conversie=nee]
+%D   \useMPgraphic{hans}
+%D \stopbuffer
+%D
+%D \startbuffer[cmy]
+%D   \stelkleurenin[rgb=nee,cmyk=ja,reductie=ja,conversie=nee]
+%D   \useMPgraphic{hans}
+%D \stopbuffer
+%D
+%D \startbuffer[gray]
+%D   \stelkleurenin[rgb=nee,cmyk=nee,reductie=nee,conversie=nee]
+%D   \useMPgraphic{hans}
+%D \stopbuffer
+%D \stopbuffer
+%D
+%D \typebuffer
+%D \haalbuffer
+%D
+%D The graphic is rather simple and is generated each time
+%D it's called:
+%D
+%D \global\runMPgraphicstrue
+%D
+%D \startbuffer
+%D \startbuffer[graphic]
+%D   \startuseMPgraphic{hans}
+%D     width  :=\the\tekstbreedte/5;
+%D     height := width/4;
+%D     fill fullcircle
+%D       xscaled width
+%D       yscaled height
+%D       withcolor (\RedGreenBlue);
+%D   \stopuseMPgraphic
+%D \stopbuffer
+%D \stopbuffer
+%D
+%D \typebuffer
+%D \haalbuffer
+%D
+%D Next we combine the four alternative interpretations in a
+%D combination:
+%D
+%D \startbuffer
+%D \startbuffer[result]
+%D   \startcombinatie[4]
+%D     {\haalbuffer[rgb]}  {\tfxx original}
+%D     {\haalbuffer[cmyk]} {\ttxx\string\convertMPcolorstrue}
+%D     {\haalbuffer[cmy]}  {\ttxx\string\reduceMPcolorstrue}
+%D     {\haalbuffer[gray]} {\ttxx\string\forcegrayMPcolorstrue}
+%D   \stopcombinatie
+%D \stopbuffer
+%D \stopbuffer
+%D
+%D \typebuffer
+%D \haalbuffer
+%D
+%D Finally we call the buffers, using different setting:
+%D
+%D \startbuffer
+%D \plaatsfiguur
+%D   {\METAPOST\ color conversions}
+%D   {\def\RedGreenBlue{.1,.4,.6}\haalbuffer[graphic]\haalbuffer[result]\vskip6pt
+%D    \def\RedGreenBlue{.1,.6,.4}\haalbuffer[graphic]\haalbuffer[result]\vskip6pt
+%D    \def\RedGreenBlue{.4,.1,.6}\haalbuffer[graphic]\haalbuffer[result]\vskip6pt
+%D    \def\RedGreenBlue{.4,.6,.1}\haalbuffer[graphic]\haalbuffer[result]\vskip6pt
+%D    \def\RedGreenBlue{.6,.1,.4}\haalbuffer[graphic]\haalbuffer[result]\vskip6pt
+%D    \def\RedGreenBlue{.6,.4,.1}\haalbuffer[graphic]\haalbuffer[result]}
+%D \stopbuffer
+%D
+%D \typebuffer
+%D \haalbuffer
+%D
+%D By the way, when the \POSTSCRIPT\ file resulting from
+%D this input is converted into \PDF\ and viewed in Acrobat
+%D Reader, one can quite different colors from those
+%D displayed in \GHOSTSCRIPT, which view equals the
+%D \POSTSCRIPT\ originals.
+
+\protect
+
+\endinput