Difference between revisions of "MetaFun - MetaPost in ConTeXt"

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(Less <cmd>, more {{cmd|...}})
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< [[Graphics]]|[[Metafun]]|[[Metapost]]>
 
< [[Graphics]]|[[Metafun]]|[[Metapost]]>
  
ConTeXT provides a tight integration of TeX and [[MetaPost]]. MetaPost can used behind the scenes for some graphic trickery. This integration is also helpful for drawing figures in MetaPost and use them in the document. Some of the commonly used commands for this are
+
ConTeXT provides a tight integration of TeX and [[MetaPost]]. MetaPost can used behind the scenes for some graphic trickery. This integration is also helpful for drawing figures in MetaPost and use them in the document. This page is a brief overviw of some of the commonly used commands.
  
 
== \defineMPinstance and \setupMPinstance ==
 
== \defineMPinstance and \setupMPinstance ==
  
 
{{cmd|defineMPinstance}} and {{cmd|setupMPinstance}} can be used to set up MetaPost invocations with particular features. One use case could be to select a sans serif font for all MetaPost
 
{{cmd|defineMPinstance}} and {{cmd|setupMPinstance}} can be used to set up MetaPost invocations with particular features. One use case could be to select a sans serif font for all MetaPost
labels. Example:
+
labels.  
 
 
<texcode>
 
\setupMPinstance [metafun] [textstyle=sans]
 
\starttext
 
 
 
\startMPcode
 
  draw textext("some text") ;
 
\stopMPcode
 
 
 
\stoptext
 
</texcode>
 
 
 
Another use case could be to create a custom setup with important text in bold and red for
 
selected MetaPost graphics. Example:
 
 
 
<texcode>
 
\defineMPinstance
 
  [important]
 
  [metafun] % needs to be inherited from the global metafun instance
 
  [textcolor=red]
 
 
 
\defineMPinstance
 
  [veryimportant]
 
  [important]
 
  [textstyle=bold]
 
 
 
\starttext
 
 
 
% normal black text
 
\startMPcode
 
  draw textext("some text") ;
 
\stopMPcode
 
 
 
% red text
 
\startMPcode{important}
 
  draw textext("some text") ;
 
\stopMPcode
 
 
 
% red bold text
 
\startMPcode{veryimportant}
 
  draw textext("some text") ;
 
\stopMPcode
 
 
 
\stoptext
 
</texcode>
 
 
 
  
 
=== \startMPenvironment ===
 
=== \startMPenvironment ===
  
 
{{cmd|startMPenvironment}} is a '''deprecated''' evironment in which one could place settings that one only wanted to apply in the MetaPost environment, but not in the document itself. One should use {{cmd|defineMPinstance}} and {{cmd|setupMPinstance}}, instead.
 
{{cmd|startMPenvironment}} is a '''deprecated''' evironment in which one could place settings that one only wanted to apply in the MetaPost environment, but not in the document itself. One should use {{cmd|defineMPinstance}} and {{cmd|setupMPinstance}}, instead.
 
An example of its usage:
 
 
<texcode>
 
\startMPenvironment
 
\usetypescript[times][texnansi]
 
\switchtobodyfont[times,10pt]
 
\stopMPenvironment
 
</texcode>
 
 
An MPenvironment is sort of like <b>verbatimtex..etex</b> in regular (standalone) MetaPost figures.  Here is an example of using verbatimtex in a regular MetaPost figure:
 
<texcode>
 
verbatimtex
 
% center-align and stack the two arguments
 
\def\2#1#2{\vbox{\halign{\hfil##\hfil\cr #1\cr #2\cr}}}
 
etex
 
 
beginfig(1)
 
  z0 = (2in,0);
 
  draw fullcircle scaled 3cm;
 
  label(btex \2{sun}{mass $M$} etex, origin);
 
  draw fullcircle scaled 1.5cm shifted z0;
 
  label(btex \2{earth}{mass $m$} etex, z0);
 
endfig;
 
end
 
</texcode>
 
 
To integrate such a graphic into a ConTeXt source file, there are several choices. 
 
 
1. Place the definition of <b>\2</b> in the MPenvironment.  However, that fails (as of the 2006.09.28 beta but it's likely to work soon, knowing Hans) because the definition is stored as a macro itself, and then the parameters #1 and #2 become ##1 and ##2, alas.  There is a <b>\startbuffer</b> trick that Hans posted on the mailing list.  But perhaps the easiest is:
 
 
2. Place the definition of <b>\2</b> in the ConTeXt environment, and change <b>btex..etex</b> to <b>\sometxt</b>.  Here's an example:
 
 
<texcode>
 
% in a large document, put this def in an environment
 
\def\2#1#2{\vbox{\halign{\hfil##\hfil\cr #1\cr #2\cr}}}
 
 
\starttext
 
 
% earth and sun
 
\startreusableMPgraphic{fig}
 
  z0 = (2in,0);
 
  draw fullcircle scaled 3cm;
 
  label(\sometxt{\2{sun}{mass $M$}}, origin);
 
  draw fullcircle scaled 1.5cm shifted z0;
 
  label(\sometxt{\2{earth}{mass $m$}}, z0);
 
\stopreusableMPgraphic
 
 
\reuseMPgraphic{fig}
 
 
\stoptext
 
</texcode>
 
 
Warning: <b>\sometxt</b> cannot be used in loops.  Instead use <b>\textext</b>.  [Someone who understands why should expand this statement!]
 
  
 
== \startMPinclusions ==
 
== \startMPinclusions ==
  
 
Inside {{cmd|startMPinclusions}} one can specify MetaPost files to ''input'', and also define MetaPost functions.
 
Inside {{cmd|startMPinclusions}} one can specify MetaPost files to ''input'', and also define MetaPost functions.
For example
 
<texcode>
 
\startMPinclusions
 
input boxes ;
 
 
vardef my_metapost_fun(expr var)=
 
...
 
enddef ;
 
\stopMPinclusions
 
</texcode>
 
 
  
 
== \startMPpage ==
 
== \startMPpage ==
  
{{cmd|startMPpage}} produces a page a containing MetaPost graphic. The
+
{{cmd|startMPpage}} produces a page a containing MetaPost graphic. The page is just large enough to contain the graphic. The resulting pdf is self-contained (it has all the fonts embedded) This is useful if you want to send the figure to a coauthor or a journal.  
page is just large enough to contain the graphic. The resulting pdf is
 
self-contained (it has all the fonts embedded) This is useful if you want to send the figure to a coauthor or a journal. For example, one can have
 
 
 
<texcode>
 
\starttext
 
\startMPpage
 
draw fullcircle scaled 2cm ;
 
dotlabel.bot(textext("(0,0)"),origin) ;
 
\stopMPpage
 
 
 
\startMPpage
 
draw fullcircle scaled 2cm ;
 
drawarrow (0,0)--(1cm,0) ;
 
label.bot(textext("$r$"),(5mm,0)) ;
 
\stopMPpage
 
 
 
\stoptext
 
</texcode>
 
 
 
Processing this file using
 
<texcode>
 
texmfstart texexec --pdf filename
 
</texcode>
 
gives a pdf with two pages of graphics.
 
  
 
== \startstaticMPfigure ==
 
== \startstaticMPfigure ==
  
The {{cmd|startuseMPgraphic}} series of commands were designed for using MetaPost for drawing fancy frames and backgrounds and not for using <i>stand-alone</i> graphics for a document. {{cmd|startstaticMPfigure}} creates a separate pdf file containing the graphic. This pdf can be included in the document using {{cmd|usestaticMPfigure}}. ConTeXt is clever enough to recompile the resulting MetaPost file, only if something inside the start stop staticMPgraphic has changed.
+
The {{cmd|startuseMPgraphic}} series of commands were designed for using MetaPost for drawing fancy frames and backgrounds and not for using <i>stand-alone</i> graphics for a document. {{cmd|startstaticMPfigure}} creates a separate pdf file containing the graphic. This pdf can be included in the document using {{cmd|usestaticMPfigure}}. ConTeXt is clever enough to recompile the resulting MetaPost file only if something inside the {{cmd|startstaticMPgraphic}} has changed.
 
 
For example,
 
<texcode>
 
\startstaticMPfigure{center}
 
draw fullcircle scaled 2cm ;
 
dotlabel.bot(textext("(0,0)"),origin) ;
 
\stopstaticMPfigure
 
 
 
\startstaticMPfigure{radius}
 
draw fullcircle scaled 2cm ;
 
drawarrow (0,0)--(1cm,0) ;
 
label.bot(textext("$r$"),(5mm,0)) ;
 
\stopstaticMPfigure
 
 
 
\starttext
 
 
 
Circle centered \usestaticMPfigure[center][width=1cm] at origin with radius
 
\usestaticMPfigure[radius][width=1cm] $r=1\,\text{cm}$.
 
 
 
\stoptext
 
</texcode>
 
 
 
* '''center''' and '''radius''' above are ''labels'' that are used to access the figure.
 
* {{cmd|usestaticMPfigure}} takes the first argument as the ''label'' of the figure to be inserted. The second argument has the same options as the second argument of {{cmd|externalfigure}}
 
* To force the figure files to be regenerated, remove all the <code>*.mp.md5</code> files from the current directory.
 
==Transparent colors in figures==
 
 
 
You can use transparent colors!  For example:
 
 
 
<texcode>
 
\runMPgraphicstrue
 
\setupcolors[state=start]
 
\starttext
 
\startreusableMPgraphic{a}
 
fill unitsquare scaled 1cm withcolor yellow;
 
fill unitsquare shifted (0.5,0.5)
 
  scaled 1cm withcolor transparent(1,0.5,red);
 
\stopreusableMPgraphic
 
 
 
\placefigure[force,none]{}{\reuseMPgraphic{a}}
 
\stoptext
 
</texcode>
 
 
 
If you see black squares rather than a yellow one underneath a partially transparent red one, then you probably hit the 'missing specials' problem diagnosed by Taco (ntg-context list, 23 Sep 2006 22:00:42 +0200):
 
 
 
<pre>
 
This all sounds like the 'missing specials' problem that is caused
 
by conflicting -progname= arguments when using the web2c version
 
of MetaPost.
 
 
 
Make sure you do not have conflicting memory settings for both
 
  main_memory.mpost
 
as well as
 
  main_memory.metafun
 
 
 
The best is to remove all trace of '.mpost' and '.metafun' memory
 
settings from your texmf.cnf, but at least make sure all the
 
'.mpost' and 'metafun' values are the same .
 
 
 
Then regenerate metafun using texexec --make, and all should be
 
well again.
 
</pre>
 
 
 
And indeed it fixed it for me (Sanjoy).  These were the memory setting in the ''/etc/texmf/texmf.d/95NonPath.cnf''
 
configlet that is part of Debian and Ubuntu distributions of TeX:
 
 
 
<pre>
 
main_memory = 1000000 % words of inimemory available; also applies to inimf&mp
 
main_memory.context = 1500000
 
main_memory.mpost = 1500000
 
</pre>
 
 
 
I commented out the .mpost line (there was no separate metafun line,
 
which I guess instead used the main_memory value of 1000000),
 
regenerated ''/etc/texmf/texmf.cnf'' with ''update-texmf'' (as root), then regenerated metafun with ''texexec --make metafun'' (as me) and transparency worked.
 
  
 
[[Category:Graphics]]
 
[[Category:Graphics]]
 
[[Category:Metapost]]
 
[[Category:Metapost]]

Revision as of 12:58, 26 November 2012

< Graphics|Metafun|Metapost>

ConTeXT provides a tight integration of TeX and MetaPost. MetaPost can used behind the scenes for some graphic trickery. This integration is also helpful for drawing figures in MetaPost and use them in the document. This page is a brief overviw of some of the commonly used commands.

\defineMPinstance and \setupMPinstance

\defineMPinstance and \setupMPinstance can be used to set up MetaPost invocations with particular features. One use case could be to select a sans serif font for all MetaPost labels.

\startMPenvironment

\startMPenvironment is a deprecated evironment in which one could place settings that one only wanted to apply in the MetaPost environment, but not in the document itself. One should use \defineMPinstance and \setupMPinstance, instead.

\startMPinclusions

Inside \startMPinclusions one can specify MetaPost files to input, and also define MetaPost functions.

\startMPpage

\startMPpage produces a page a containing MetaPost graphic. The page is just large enough to contain the graphic. The resulting pdf is self-contained (it has all the fonts embedded) This is useful if you want to send the figure to a coauthor or a journal.

\startstaticMPfigure

The \startuseMPgraphic series of commands were designed for using MetaPost for drawing fancy frames and backgrounds and not for using stand-alone graphics for a document. \startstaticMPfigure creates a separate pdf file containing the graphic. This pdf can be included in the document using \usestaticMPfigure. ConTeXt is clever enough to recompile the resulting MetaPost file only if something inside the \startstaticMPgraphic has changed.