Diagrams.TwoD.Path.Metafont

Define Diagrams Paths by specifying points and optionally directions and tension. Calculate control points to maintain smooth curvature at each point, following rules implemented in Donald Knuth's Metafont.

This module is intended to be imported qualified.

Documentation

module Diagrams.TwoD.Path.Metafont.Combinators

fromString :: (TrailLike t, V t ~ V2, N t ~ n, Read n, RealFloat n) => Text -> Either ParseError t

MF.fromString parses a Text value in MetaFont syntax, and attempts to return a TrailLike. Only a subset of Metafont is supported; see the tutorial for details.

fromPath :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => MFP n -> t

Should you wish to construct the MFPath in some other fashion, fromPath makes a TrailLike directly from the MFPath

fromStrings :: (TrailLike t, V t ~ V2, N t ~ n, Read n, RealFloat n) => [Text] -> Either [ParseError] [t]

fromStrings takes a list of MetaFont strings, and returns either all errors, or, if there are no parsing errors, a TrailLike for each string. fromStrings is provided as a convenience because the MetaFont &-join is not supported. mconcat (<>) on the TrailLike is equivalent, with clearer semantics.

flex :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => [P2 n] -> t

flex ps draws a Trail through the points ps, such that at every point p ∊ ps except the endpoints, the Trail is parallel to the line from the first to the last point. This is the same as the flex command defined in plain MetaFont.

metafont :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => MFPathData P n -> t

metafont converts a path defined in the Metafont combinator synax into a native Diagrams TrailLike.

metafontParser :: (Num n, Read n) => Parser (MFPath (Maybe (PathDir n)) (BasicJoin n) n)

Parse a Text value in Metafont syntax, as destribed in /The METAFONTbook/.