Designed by John D. Hobby First appeared 1994 (1994) | Developer Taco Hoekwater | |
Paradigm imperative, typesetting Stable release 1.212 / 19 October 2010; 6 years ago (2010-10-19) Preview release 1.750 / 27 April 2011; 5 years ago (2011-04-27) | ||
MetaPost refers to both a programming language and the interpreter of the MetaPost programming language. Both are derived from Donald Knuth's Metafont language and interpreter. MetaPost produces diagrams in the PostScript programming language from a geometric/algebraic description. The language shares Metafont's declarative syntax for manipulating lines, curves, points and geometric transformations. However,
Contents
Many of the limitations of MetaPost derive from features of Metafont. For instance, numbers have a low-precision fixed-point representation, sufficient for representing the coordinates of points in a glyph, but this can be restrictive when working with figures in a larger coordinate space. Moreover, MetaPost does not support all features of PostScript. Most notably, paths can have only one segment (so that regions are simply connected), and regions can be filled only with uniform colours. PostScript level 1 supports tiled patterns and PostScript 3 supports Gouraud shading. To this end, the Asymptote graphics language has been developed to address these shortcomings.
Availability and usage
MetaPost is distributed with many distributions of the TeX and Metafont framework. In particular, it is included in the teTeX and the TeX Live distribution, common on Linux and Unix (including Mac OS X) platforms.
The encapsulated postscript produced by Metapost can be included in TeX, ConTeXt, and LaTeX documents via standard eps-inclusion commands. This output can also be included in the PDFTeX dialect of TeX, thus directly giving PDF output from TeX. This ability is implemented in ConTeXt and in the LaTeX graphics package, and can be used from plain TeX via the supp-pdf.tex macro file. ConTeXt even supports the creation of MetaPost files from within the TeX file.
Examples
This is a single file example.mp which when processed by the MetaPost interpreter (via the command mpost on Linux) produces three eps files example.1, example.2, example.3. These are pictured on the right.
The resulting three eps files can be used in TeX via LaTeX's includegraphics command, ConTeXt's externalfigure, Plain TeX's epsfbox command, or (in Plain pdftex) the convertMPtoPDF command from supp-pdf.tex. To view or print the third diagram, this inclusion is necessary, as the TeX fonts (Computer Modern) are not included in the eps files produced by MetaPost.