Maintainer	diagrams-discuss@googlegroups.com
Safe Haskell	None

Diagrams.TwoD.Types

Contents

2D Euclidean space
Angles

Description

Basic types for two-dimensional Euclidean space.

Synopsis

2D Euclidean space

data R2 Source

The two-dimensional Euclidean vector space R^2. This type is intentionally abstract.

To construct a vector, use r2, or ^& (from Diagrams.Coordinates):

 r2 (3,4) :: R2
 3 ^& 4    :: R2

Note that Diagrams.Coordinates is not re-exported by Diagrams.Prelude and must be explicitly imported.

To construct the vector from the origin to a point p, use p .-. origin.
To convert a vector v into the point obtained by following v from the origin, use origin .+^ v.
To convert a vector back into a pair of components, use unv2 or coords (from Diagrams.Coordinates). These are typically used in conjunction with the ViewPatterns extension:

 foo (unr2 -> (x,y)) = ...
 foo (coords -> x :& y) = ...

Constructors

R2 !Double !Double

Instances

Eq R2
Fractional R2
Num R2
Ord R2
Read R2
Show R2
Typeable R2
Transformable R2
Wrapped R2	Lens wrapped isomorphisms for R2.
HasBasis R2
VectorSpace R2
InnerSpace R2
AdditiveGroup R2
HasY P2
HasY R2
HasX P2
HasX R2
Coordinates R2
Rewrapped R2 R2
Traced (FixedSegment R2)
Traced (Trail R2)
Traced (Path R2)
Traced (Segment Closed R2)
Renderable (Path R2) b => TrailLike (QDiagram b R2 Any)

r2 :: (Double, Double) -> R2 Source

Construct a 2D vector from a pair of components. See also &.

unr2 :: R2 -> (Double, Double)Source

Convert a 2D vector back into a pair of components. See also coords.

mkR2 :: Double -> Double -> R2 Source

Curried form of r2.

r2Iso :: Iso' R2 (Double, Double)Source

type P2 = Point R2 Source

Points in R^2. This type is intentionally abstract.

To construct a point, use p2, or ^& (see Diagrams.Coordinates):

 p2 (3,4)  :: P2
 3 ^& 4    :: P2

To construct a point from a vector v, use origin .+^ v.
To convert a point p into the vector from the origin to p, use p .-. origin.
To convert a point back into a pair of coordinates, use unp2, or coords (from Diagrams.Coordinates). It's common to use these in conjunction with the ViewPatterns extension:

 foo (unp2 -> (x,y)) = ...
 foo (coords -> x :& y) = ...

p2 :: (Double, Double) -> P2 Source

Construct a 2D point from a pair of coordinates. See also ^&.

mkP2 :: Double -> Double -> P2 Source

Curried form of p2.

unp2 :: P2 -> (Double, Double)Source

Convert a 2D point back into a pair of coordinates. See also coords.

p2Iso :: Iso' P2 (Double, Double)Source

type T2 = Transformation R2 Source

Transformations in R^2.

Angles

data Angle Source

Angles can be expressed in a variety of units. Internally, they are represented in radians.

Instances

Enum Angle
Eq Angle
Ord Angle
Read Angle
Show Angle
VectorSpace Angle
AdditiveGroup Angle

rad :: Iso' Angle Double Source

The radian measure of an Angle a can be accessed as a ^. rad. A new Angle can be defined in radians as pi @@ rad.

turn :: Iso' Angle Double Source

The measure of an Angle a in full circles can be accessed as a ^. turn. A new Angle of one-half circle can be defined in as 1/2 @@ turn.

deg :: Iso' Angle Double Source

The degree measure of an Angle a can be accessed as a ^. deg. A new Angle can be defined in degrees as 180 @@ deg.

fullTurn :: Angle Source

An angle representing one full turn.

fullCircle :: Angle Source

Deprecated synonym for fullTurn, retained for backwards compatibility.

angleRatio :: Angle -> Angle -> Double Source

Calculate ratio between two angles.

(@@) :: b -> Iso' a b -> aSource

30 @@ deg is an Angle of the given measure and units.

More generally, @@ reverses the Iso' on its right, and applies the Iso' to the value on the left. Angles are the motivating example where this order improves readability.