Difference between revisions of "Library for colours"
Jump to navigation
Jump to search
m (Ooops! Meant to press preview, not save...) |
(add link to hackag) |
||
| (2 intermediate revisions by one other user not shown) | |||
| Line 1: | Line 1: | ||
[[Category:Code]] |
[[Category:Code]] |
||
| + | ''See also the more sophisticated [http://hackage.haskell.org/package/colour colour package] on Hackage.'' |
||
| ⚫ | |||
| + | |||
| ⚫ | |||
<haskell> |
<haskell> |
||
| Line 42: | Line 44: | ||
cclip :: Colour -> Colour |
cclip :: Colour -> Colour |
||
cclip = cmap clip |
cclip = cmap clip |
||
| − | |||
| − | quantinize :: Int -> Double -> Int |
||
| − | quantinize max v = floor (v * (fromIntegral max)) |
||
</haskell> |
</haskell> |
||
Latest revision as of 22:40, 8 December 2010
See also the more sophisticated colour package on Hackage.
Simple thing for working on colours in the RGB colours space. (The intention being that each component is in the interval 0 ≤ x ≤ 1.) You could just use tuples, but this library provides simple colour arithmetic.
module Colour where
data Colour = Colour {red, green, blue :: Double} deriving (Eq, Show)
cmap :: (Double -> Double) -> Colour -> Colour
cmap f (Colour r g b) = Colour (f r) (f g) (f b)
czip :: (Double -> Double -> Double) -> Colour -> Colour -> Colour
czip f (Colour r1 g1 b1) (Colour r2 g2 b2) = Colour (f r1 r2) (f g1 g2) (f b1 b2)
cfold :: (Double -> Double -> Double) -> Colour -> Double
cfold f (Colour r g b) = r `f` g `f` b
cpromote :: Double -> Colour
cpromote x = Colour x x x
instance Num Colour where
(+) = czip (+)
(-) = czip (-)
(*) = czip (*)
negate = cmap negate
abs = cmap abs
signum = cmap signum
fromInteger x = cpromote (fromInteger x)
instance Fractional Colour where
(/) = czip (/)
recip = cmap recip
fromRational x = cpromote (fromRational x)
clip :: (Num n, Ord n) => n -> n
clip n
| n < 0 = 0
| n > 1 = 1
| otherwise = n
cclip :: Colour -> Colour
cclip = cmap clip