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module Main where
import Data.Bifunctor (Bifunctor, bimap)
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL
import qualified Data.Text as T
import Data.Word (Word8)
import PFM
import Vec
clamp :: PFMColour -> PPMColour
clamp (PFMColour ri gi bi) =
PPMColour (f ri) (f gi) (f bi)
where
v s = s * 255.0
f s = if v s > 255.0 then 255 else fromInteger (round (v s))
clamp _ = undefined
clampImage :: PFMImage -> PPMImage
clampImage (PFMImage w h c) =
PPMImage w h $ fmap clamp <$> c
bmap :: (Bifunctor f) => (a -> b) -> f a a -> f b b
bmap f = bimap f f
uncurry3 :: (a -> b -> c -> d) -> (a, b, c) -> d
uncurry3 f (a, b, c) = f a b c
colourCorrect :: Double -> Double
colourCorrect = (+0.5) . (/2)
toCircle :: ((Int, Int) -> Vec Double) -> Int -> [[(Int, Int)]] -> [[PFMColour]]
toCircle f v m =
fmap toCol <$> m
where
toCol val = if dist val <= v ^ (2 :: Int)
then uncurry3 PFMColour (unVec $ realToFrac . colourCorrect <$> f val)
else PFMColour 0 0 0--0.5 0.5 1.0
dist = add . bmap ((^(2 :: Int)) . (v-))
add (an, bn) = an + bn
circleImage :: ((Int, Int) -> Vec Double) -> Int -> PFMImage
circleImage f s = PFMImage s s $ toCircle f ((s - 1) `div` 2)
[ [ (y, x) | x <- [0..s-1] ] | y <- reverse [0..s-1] ]
revColour :: PFMImage -> PFMImage
revColour (PFMImage w h i) =
PFMImage w h $ reverse i
main :: IO ()
main = do
let i = circleImage (normalise 511) 511
BL.writeFile "normal.ppm" . encodePPM . clampImage $ i
BL.writeFile "normal.pfm" . encode . revColour $ i
let r = circleImage (reflect 511 (Vec (0, 0, 1))) 511
BL.writeFile "reflect.ppm" . encodePPM . clampImage $ r
BL.writeFile "reflect.pfm" . encode . revColour $ r
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