RosettaCodeData/Task/Draw-a-sphere/Haskell/draw-a-sphere-2.hs
2023-07-01 13:44:08 -04:00

16 lines
526 B
Haskell

import Data.List (genericLength)
shades = ".:!*oe%#&@"
n = genericLength shades
dot a b = sum $ zipWith (*) a b
normalize x = (/ sqrt (x `dot` x)) <$> x
sphere r k amb light = unlines $
[ [ if x*x + y*y <= r*r
then let vec = normalize [x, y, sqrt (r*r-x*x-y*y)]
b = (light `dot` vec) ** k + amb
intensity = (1 - b)*(n - 1)
in shades !! round ((0 `max` intensity) `min` n)
else ' '
| y <- map (/2.12) [- 2*r - 0.5 .. 2*r + 0.5] ]
| x <- [ - r - 0.5 .. r + 0.5] ]