Copyright	(c) 2014 diagrams-lib team (see LICENSE)
License	BSD-style (see LICENSE)
Maintainer	diagrams-discuss@googlegroups.com
Safe Haskell	None
Language	Haskell2010

Diagrams.Direction

Description

Type for representing directions, polymorphic in vector space

Synopsis

data Direction v n
_Dir :: Iso' (Direction v n) (v n)
direction :: v n -> Direction v n
dir :: v n -> Direction v n
fromDirection :: (Metric v, Floating n) => Direction v n -> v n
fromDir :: (Metric v, Floating n) => Direction v n -> v n
angleBetweenDirs :: (Metric v, Floating n, Ord n) => Direction v n -> Direction v n -> Angle n
dirBetween :: (Additive v, Num n) => Point v n -> Point v n -> Direction v n

Documentation

data Direction v n Source #

A vector is described by a Direction and a magnitude. So we can think of a Direction as a vector that has forgotten its magnitude. Directions can be used with fromDirection and the lenses provided by its instances.

Instances

Instances details

Functor v => Functor (Direction v) Source #
Instance details Defined in Diagrams.Direction Methods fmap :: (a -> b) -> Direction v a -> Direction v b # (<$) :: a -> Direction v b -> Direction v a #
HasPhi v => HasPhi (Direction v) Source #
Instance details Defined in Diagrams.Direction Methods _phi :: RealFloat n => Lens' (Direction v n) (Angle n) Source #
HasTheta v => HasTheta (Direction v) Source #
Instance details Defined in Diagrams.Direction Methods _theta :: RealFloat n => Lens' (Direction v n) (Angle n) Source #
Eq (v n) => Eq (Direction v n) Source #
Instance details Defined in Diagrams.Direction Methods (==) :: Direction v n -> Direction v n -> Bool # (/=) :: Direction v n -> Direction v n -> Bool #
Ord (v n) => Ord (Direction v n) Source #
Instance details Defined in Diagrams.Direction Methods compare :: Direction v n -> Direction v n -> Ordering # (<) :: Direction v n -> Direction v n -> Bool # (<=) :: Direction v n -> Direction v n -> Bool # (>) :: Direction v n -> Direction v n -> Bool # (>=) :: Direction v n -> Direction v n -> Bool # max :: Direction v n -> Direction v n -> Direction v n # min :: Direction v n -> Direction v n -> Direction v n #
Read (v n) => Read (Direction v n) Source #
Instance details Defined in Diagrams.Direction Methods readsPrec :: Int -> ReadS (Direction v n) # readList :: ReadS [Direction v n] # readPrec :: ReadPrec (Direction v n) # readListPrec :: ReadPrec [Direction v n] #
Show (v n) => Show (Direction v n) Source #
Instance details Defined in Diagrams.Direction Methods showsPrec :: Int -> Direction v n -> ShowS # show :: Direction v n -> String # showList :: [Direction v n] -> ShowS #
(V (v n) ~ v, N (v n) ~ n, Transformable (v n)) => Transformable (Direction v n) Source #
Instance details Defined in Diagrams.Direction Methods transform :: Transformation (V (Direction v n)) (N (Direction v n)) -> Direction v n -> Direction v n #
type V (Direction v n) Source #
Instance details Defined in Diagrams.Direction type V (Direction v n) = v
type N (Direction v n) Source #
Instance details Defined in Diagrams.Direction type N (Direction v n) = n

_Dir :: Iso' (Direction v n) (v n) Source #

_Dir is provided to allow efficient implementations of functions in particular vector-spaces, but should be used with care as it exposes too much information.

direction :: v n -> Direction v n Source #

direction v is the direction in which v points. Returns an unspecified value when given the zero vector as input.

dir :: v n -> Direction v n Source #

Synonym for direction.

fromDirection :: (Metric v, Floating n) => Direction v n -> v n Source #

fromDirection d is the unit vector in the direction d.

fromDir :: (Metric v, Floating n) => Direction v n -> v n Source #

Synonym for fromDirection.

angleBetweenDirs :: (Metric v, Floating n, Ord n) => Direction v n -> Direction v n -> Angle n Source #

compute the positive angle between the two directions in their common plane

dirBetween :: (Additive v, Num n) => Point v n -> Point v n -> Direction v n Source #

dirBetween p q returns the direction from p to q.