Editing MetaPost (section)

{{short description|Programming language}}
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{{Infobox programming language
| name = MetaPost
| logo = MPlogo.svg
| paradigm = [[Imperative programming|imperative]], [[typesetting]]
| released = {{Start date|1994}}
| designer = John D. Hobby
| developer = Taco Hoekwater, Luigi Scarso
| latest_release_version = 1.8
| latest_release_date = {{start date and age|2013|06|17|df=yes}}
| latest_preview_version = 2.0rc2
| latest_preview_date = {{start date and age|2018|02|19|df=yes}}
| typing = [[duck typing|duck]], [[dynamic typing|dynamic]], [[strong typing|strong]]
| implementations = 
| dialects = 
| influenced by = [[Metafont]]
| influenced = 
| operating_system = [[Cross-platform]]
| license = [[LGPL]]
| website = {{URL|http://tug.org/metapost}}
| file_ext = 
}}

'''MetaPost''' refers to both a [[programming language]] and the [[interpreter (computer software)|interpreter]] of the MetaPost programming language. Both are derived from [[Donald Knuth]]'s [[Metafont]] language and interpreter. MetaPost produces vector graphic diagrams from a geometric/algebraic description. The language shares Metafont's declarative syntax for manipulating lines, curves, points and geometric transformations. However,

* Metafont is set up to produce fonts, in the form of image files (in .gf format) with associated font metric files (in .tfm format), whereas MetaPost produces [[encapsulated PostScript|EPS]], [[Scalable Vector Graphics|SVG]], or [[Portable Network Graphics|PNG]] files
* The output of Metafont consists of the fonts at a fixed resolution in a raster-based format, whereas MetaPost's output is vector-based graphics (lines, [[Bézier curve]]s)
* Metafont output is monochrome, whereas MetaPost uses [[RGB]] or [[CMYK]] colors.
* The MetaPost language can include text labels on the diagrams, either strings from a specified font, or anything else that can be typeset with [[TeX]].
* Starting with version 1.8, Metapost allows floating-point arithmetic with 64 bits (default: 32 bit fixed-point arithmetic)

Many of the limitations of MetaPost derive from features of Metafont. For instance, 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]].