MetaPost

< Math, MetaFun, Graphics

MetaPost is a graphical programming language, based on Donald Knuth's MetaFont. Normally MP graphics are converted to PostScript and used with dvips, but ConTeXt can use it directly with PDF (see the MP to PDF manual).

MetaPost is ConTeXt's native graphics language. MetaFun is a MetaPost module by Hans Hagen that adds a lot of extra features; it is enabled by default, so one could say that MetaFun is ConTeXt's default dialect of MetaPost.

Documentation & Tutorials

• A User's Manual for MetaPost
• Learning METAPOST by doing (this and this link are not working)
• A Beginner's Guide to METAPOST for Creating High-Quality Graphics by Troy Henderson
• MetaFun
• Lots of examples
• Color in MetaPost describes how to get color mixtures, TeX colors, and transparent effects in MetaPost graphics.
• MetaPost in ConTeXt

Using MetaPost in ConTeXt

With \startuseMPgraphic, you define a piece of graphics code that is processed anew every time the graphic is placed with \useMPgraphic. Further commands are described at MetaPost in ConTeXt.

\def\mycolor{.625red}

\startuseMPgraphic{name}
  fill fullcircle scaled 20pt withcolor \mycolor;
\stopuseMPgraphic

red: \useMPgraphic{name}

\def\mycolor{.625blue}
blue: \useMPgraphic{name}

Different Packages, Extensions & Applications of Metapost

• MetaPlot - graph drawing
• MetaObj - object-oriented drawing, see also the page about MetaObj and Labels

• finomaton - drawing finite state automata
• statsmac - metapost macros for statistics graphs
• MetaUML - MetaPost library for typesetting UML diagrams
• METAGRAPH - drawing (un)directed graphs

3D support

• FeatPost
• 3DLDF
• m3D

TODO: needs major review (See: To-Do List)

MetaPost relatives

Font Creation

• MetaType1, see CTAN

3D drawing

• Asymptote - inspired by MetaPost & fully generalizes MetaPost path construction algorithms to three-dimensions

Testing plain MetaPost

To test whether MetaPost is installed on your system, create a file called test.mp:

beginfig(1)
  draw fullcircle scaled 3cm ;
endfig ;
end ;

• apply MetaPost on the testfile

mp test.mp
or
mpost test.mp

• that should create a postscript file test.1
• open test.1 with a postscript viewer like Ghostview, Okular, … You should see a circle.

Testing MetaPost embedded in ConTeXt

If MetaPost is installed on your system and working correctly, you can

\starttext
\startMPcode
  draw fullcircle scaled 3cm;
\stopMPcode
\stoptext

• for mkii you need to have write18 support enabled and run

texexec --pdf test.tex

• for mkiv run

context test.tex

• that should create a pdf file test.pdf
• open test.pdf with a pdf viewer like Adobe Acrobat, Okular... You should see a circle.

Text in MetaPost

Text that is typeset using textext or btex … etex adapts to the body font. However, when label("Foo", pair) or "Foo" infont defaultfont is used, which is not the recommended way, the text is typeset using the font MetafunDefault, which can be changed if desired. Example:

\starttext
  \startMPcode
     label("Foo", origin);
     draw textext("Bar") yshifted -LineHeight;
  \stopMPcode

  \definefontsynonym
    [MetafunDefault]
    [Bold*default]

  \switchtobodyfont [pagella, 18pt]

  \startMPcode
     label("Foo", origin);
     draw textext("Foo") yshifted -LineHeight;
  \stopMPcode
\stoptext

Gives:

The recommended way to typeset text is to use the textext macro and change the font using \setupMPinstance.

Other Links

• Metapost home page: http://tug.org/metapost
• John Hobby's page: http://cm.bell-labs.com/who/hobby/MetaPost.html
• Current development: http://foundry.supelec.fr/projects/metapost/
• http://melusine.eu.org/syracuse/metapost/