    -- | Geometric functions concerning angles. If not otherwise specified, all angles are in radians.
    module Graphics.Gloss.Geometry.Angle
    	( degToRad
    	, radToDeg
    	, normaliseAngle )
    where

    -- | Convert degrees to radians
    {-# INLINE degToRad #-}
    degToRad :: Float -> Float
    degToRad d	= d * pi / 180

    -- | Convert radians to degrees
    {-# INLINE radToDeg #-}
    radToDeg :: Float -> Float
    radToDeg r	= r * 180 / pi

    -- | Normalise an angle to be between 0 and 2*pi radians
    {-# INLINE normaliseAngle #-}
    normaliseAngle :: Float -> Float
    normaliseAngle f
    	| f < 0
    	= normaliseAngle (f + 2 * pi)

    	| f > 2 * pi
    	= normaliseAngle (f - 2 * pi)

    	| otherwise
    	= f