Copyright	(C) 2015 Dimitri Sabadie
License	BSD3
Maintainer	Dimitri Sabadie <dimitri.sabadie@gmail.com>
Stability	experimental
Portability	portable
Safe Haskell	None
Language	Haskell2010

Data.Spline.Key

Contents

Key type
Interpolation

Description

Synopsis

data Key a
- = Hold a
- | Linear a
- | Cosine a
- | CubicHermite a
- | Bezier a a a
keyValue :: Key a -> a
interpolateKeys :: (Additive a, Floating s) => s -> Key (a s) -> Key (a s) -> a s
normalizeSampling :: Fractional s => (a s -> s) -> s -> Key (a s) -> Key (a s) -> s

Key type

data Key a Source #

A Key is a point on the spline with extra information added. It can be, for instance, left and right handles for a Bezier curve, or whatever the interpolation might need.

Hold v is used to express no interpolation and holds its latest value until the next key.

Linear v represents a linear interpolation until the next key.

Cosine v represents a cosine interpolation until the next key.

CubicHermite v represents a cubic hermitian interpolation until the next key.

Bezier l v r represents a cubic Bezier interpolation, where l refers to the input – left – tangent of the key and r is the output – right – tangent of the key.

Constructors

Hold a
Linear a
Cosine a
CubicHermite a
Bezier a a a

Instances

Functor Key Source #
Instance details Defined in Data.Spline.Key Methods fmap :: (a -> b) -> Key a -> Key b # (<$) :: a -> Key b -> Key a #
Eq a => Eq (Key a) Source #
Instance details Defined in Data.Spline.Key Methods (==) :: Key a -> Key a -> Bool # (/=) :: Key a -> Key a -> Bool #
Show a => Show (Key a) Source #
Instance details Defined in Data.Spline.Key Methods showsPrec :: Int -> Key a -> ShowS # show :: Key a -> String # showList :: [Key a] -> ShowS #
FromJSON a => FromJSON (Key a) Source #
Instance details Defined in Data.Spline.Key Methods parseJSON :: Value -> Parser (Key a) parseJSONList :: Value -> Parser [Key a]
ToJSON a => ToJSON (Key a) Source #
Instance details Defined in Data.Spline.Key Methods toJSON :: Key a -> Value toEncoding :: Key a -> Encoding toJSONList :: [Key a] -> Value toEncodingList :: [Key a] -> Encoding

keyValue :: Key a -> a Source #

Extract the value out of a Key.

Interpolation

interpolateKeys :: (Additive a, Floating s) => s -> Key (a s) -> Key (a s) -> a s Source #

interpolateKeys t start end interpolates between start and end using s as a normalized sampling value.

Satisfies the following laws:

  interpolateKeys 0 start _ = start
  interpolateKeys 1 _ end   = end

normalizeSampling :: Fractional s => (a s -> s) -> s -> Key (a s) -> Key (a s) -> s Source #

Normalize a sampling value by clamping and scaling it between two Keys.

The following laws should be satisfied in order to get a coherent output:

  sampler :: a s -> s

  sampler (keyValue k1) s= sampler (keyValue k0)
  0 <= normalizeSampling sampler s k0 k1 <= 1