Copyright	(c) 2011 diagrams-lib team (see LICENSE)
License	BSD-style (see LICENSE)
Maintainer	diagrams-discuss@googlegroups.com
Safe Haskell	None
Language	Haskell2010

Diagrams.Path

Contents

Paths
Constructing paths
Eliminating paths
Modifying paths
Miscellaneous

Description

This module defines paths, which are collections of concretely located Trails. Many drawing systems (cairo, svg, ...) have a similar notion of "path". Note that paths with multiple trails are necessary for being able to draw e.g. filled objects with holes in them.

Synopsis

Paths

newtype Path v Source

A path is a (possibly empty) list of Located Trails. Hence, unlike trails, paths are not translationally invariant, and they form a monoid under superposition (placing one path on top of another) rather than concatenation.

Constructors

Path [Located (Trail v)]

Instances

Eq v => Eq (Path v)
Ord v => Ord (Path v)
Show v => Show (Path v)
Semigroup (Path v)
Monoid (Path v)
(HasLinearMap v, InnerSpace v, OrderedField (Scalar v)) => IsPrim (Path v)
(InnerSpace v, OrderedField (Scalar v)) => Juxtaposable (Path v)
(InnerSpace v, OrderedField (Scalar v)) => Enveloped (Path v)
Traced (Path R2)
(HasLinearMap v, InnerSpace v, OrderedField (Scalar v)) => Transformable (Path v)
VectorSpace v => HasOrigin (Path v)
Wrapped (Path v)
(InnerSpace v, OrderedField (Scalar v)) => TrailLike (Path v)	Paths are trail-like; a trail can be used to construct a singleton path.
(InnerSpace v, OrderedField (Scalar v)) => Alignable (Path v)
(VectorSpace v, InnerSpace v, (~) * s (Scalar v), Ord s, Fractional s, Floating s, Show s, Show v) => Deformable (Path v)
(HasLinearMap v, InnerSpace v, OrderedField (Scalar v)) => Renderable (Path v) NullBackend
(Show v, OrderedField (Scalar v), InnerSpace v, HasLinearMap v) => Renderable (Path v) ShowBackend
Rewrapped (Path v) (Path v')
Typeable (* -> *) Path
type V (Path v) = v
type Unwrapped (Path v) = [Located (Trail v)]

pathTrails :: Path v -> [Located (Trail v)] Source

Extract the located trails making up a Path.

Constructing paths

Since paths are TrailLike, any function producing a TrailLike can be used to construct a (singleton) path. The functions in this section are provided for convenience.

pathFromTrail :: (InnerSpace v, OrderedField (Scalar v)) => Trail v -> Path v Source

Convert a trail to a path beginning at the origin.

pathFromTrailAt :: (InnerSpace v, OrderedField (Scalar v)) => Trail v -> Point v -> Path v Source

Convert a trail to a path with a particular starting point.

pathFromLocTrail :: (InnerSpace v, OrderedField (Scalar v)) => Located (Trail v) -> Path v Source

Convert a located trail to a singleton path. This is equivalent to trailLike, but provided with a more specific name and type for convenience.

Eliminating paths

pathVertices :: (InnerSpace v, OrderedField (Scalar v)) => Path v -> [[Point v]] Source

Extract the vertices of a path, resulting in a separate list of vertices for each component trail (see trailVertices).

pathOffsets :: (InnerSpace v, OrderedField (Scalar v)) => Path v -> [v] Source

Compute the total offset of each trail comprising a path (see trailOffset).

pathCentroid :: (InnerSpace v, OrderedField (Scalar v)) => Path v -> Point v Source

Compute the centroid of a path (i.e. the average location of its vertices).

fixPath :: (InnerSpace v, OrderedField (Scalar v)) => Path v -> [[FixedSegment v]] Source

Convert a path into a list of lists of FixedSegments.

Modifying paths

scalePath :: (HasLinearMap v, InnerSpace v, OrderedField (Scalar v)) => Scalar v -> Path v -> Path v Source

Scale a path using its centroid (see pathCentroid) as the base point for the scale.

reversePath :: (InnerSpace v, OrderedField (Scalar v)) => Path v -> Path v Source

Reverse all the component trails of a path.

Miscellaneous

explodePath :: (VectorSpace (V t), TrailLike t) => Path (V t) -> [[t]] Source

"Explode" a path by exploding every component trail (see explodeTrail).

partitionPath :: (Located (Trail v) -> Bool) -> Path v -> (Path v, Path v) Source

Partition a path into two paths based on a predicate on trails: the first containing all the trails for which the predicate returns True, and the second containing the remaining trails.