Geom2d.Rotation

This module contains a type class that can be used to modell data, that can be rotated by a given angle.

Documentation

class Rotation p where

Modells data that has an angle and can be rotated.

Minimal complete definition

rotate

Methods

angle :: (Floating a, RealFloat a, Ord a) => p a -> Maybe a

An object can return the orientation in space. If the object returns its orientation it should hold the following law:

fromMaybe True $ (==) <$> angle (r `rotate` x) <*> ((subtract pi).((`mod'` (2*pi)).(+pi).(+r)) <$> angle x)

Also angle should never return a value bigger than pi and smaller than `- pi`

fromMaybe True (fmap (\a -> a >= (- pi) && a <= pi) (angle x))

The default implementation is

angle _ = Nothing

rotate :: Floating a => a -> p a -> p a

Should rotate an object by a given angle.

Instances

Rotation Point'

(Rotation p, Point p) => Rotation (Shape p)

Rotation p => Rotation (Polygon p)

(Rotation p, Point p) => Rotation (Circle p)