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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 This page is a brief overviw of some of the commonly used commands for this are.

labels. Example: <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 forselected 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> 

{{cmd|startMPpage}} produces a page a containing MetaPost graphic. Thepage is just large enough to contain the graphic. The resulting pdf isself-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.

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. 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|usestaticMPfigurestartstaticMPgraphic}} 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 causedby conflicting -progname= arguments when using the web2c versionof MetaPost. Make sure you do not have conflicting memory settings for both main_memory.mpostas well as main_memory.metafun The best is to remove all trace of '.mpost' and '.metafun' memorysettings 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 bewell 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&mpmain_memory.context = 1500000main_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 workedchanged.