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111 lines
3.3 KiB
111 lines
3.3 KiB
module Main where
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import Control.Monad (mapM)
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import Control.Monad.Random
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import Data.Ix
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import Data.Maybe
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import Debug.Trace
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import Hittable
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import Linear.V2
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import Linear.V3
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import Linear.Vector
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import Maths
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import Ray
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import Text.Printf
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type Color = (Double, Double, Double)
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type Coord = (Int, Int)
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type ImageDimensions = (Int, Int)
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type ViewPortDimensions = (Double, Double)
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-- TODO
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-- DONE add multiple samples per pixel
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-- fix coordinate system
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-- DONE fix random number generator
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backgroundColor = V3 0.0 0.0 0.0
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getRayColor :: (Shape s, RandomGen g) => [s] -> Int -> Ray Double -> Rand g (V3 Double)
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getRayColor ws d r = do
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let h = getBestHit (mapMaybe (testHit r) ws)
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v <- getRayColor' r h ws d
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return v
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getRayColor' :: (Shape s, RandomGen g) => Ray Double -> Maybe Hit -> [s] -> Int -> Rand g (V3 Double)
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getRayColor' (Ray o d) Nothing _ _ = do return $ colorGradient (unitVector d)
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getRayColor' (Ray o d) _ _ 0 = do return $ colorGradient (unitVector d)
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getRayColor' (Ray o d) (Just (Hit t p n)) ws depth =
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do
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r <- randV3
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let target = p ^+^ colorWithNormal (unitVector n) ^+^ r
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nextVal <- getRayColor ws (depth - 1) (Ray p (target ^-^ p))
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return (0.5 *^ nextVal)
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colorGradient :: V3 Double -> V3 Double
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colorGradient (V3 x y z) = do
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let t = 0.5 * (y + 1.0)
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(1.0 - t) *^ V3 1.0 1.0 1.0 + t *^ V3 0.5 0.7 1.0
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-- testHit needs to take into account other hits, not here
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getBestHit [] = Nothing
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getBestHit (h : hs) = Just (getBestHit' hs h)
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getBestHit' :: [Hit] -> Hit -> Hit
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getBestHit' (h : hs) bestHit =
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-- always pick closest hit to camera
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if root h < root bestHit
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then getBestHit' hs h
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else getBestHit' hs bestHit
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getBestHit' [] hit = hit
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colorWithNormal :: V3 Double -> V3 Double
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colorWithNormal v = 0.5 *^ (v ^+^ V3 1.0 1.0 1.0)
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rayTrace :: (Shape s) => (Int, Int) -> ImageDimensions -> ViewPortDimensions -> [s] -> IO (V3 Double)
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rayTrace (x, y) (w, h) (vw, vh) world = do
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evalRandIO (getRayColor world 50 $ buildRay (xf * (vw / wf)) (yf * (vh / hf)))
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where
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xf = fromIntegral x
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yf = fromIntegral y
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wf = fromIntegral (w - 1)
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hf = fromIntegral (h - 1)
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clamp :: Double -> Double -> Double -> Double
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clamp x mi ma
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| x < mi = mi
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| x > ma = ma
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| otherwise = x
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colorToString :: Color -> IO ()
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colorToString (x, y, z) = tupToString (xr, yr, zr)
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where
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-- scale 1
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scale = 1.0
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xr = truncate ((clamp (sqrt (x * scale)) 0.0 0.999) * 256.0)
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yr = truncate ((clamp (sqrt (y * scale)) 0.0 0.999) * 256.0)
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zr = truncate ((clamp (sqrt (z * scale)) 0.0 0.999) * 256.0)
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tupToString :: (Show a) => (a, a, a) -> IO ()
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tupToString (x, y, z) = putStrLn (show x ++ " " ++ show y ++ " " ++ show z)
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v3ToColor :: V3 Double -> Color
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v3ToColor (V3 x y z) = (x, y, z)
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main :: IO ()
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main = do
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let w = 400
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let h = 400
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-- weirdly, the bottom circle appears on top and bottom
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-- Circle (V3 0.0 (-10.05) 1.0) 5]
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let world = [Circle (V3 0.0 0.0 (-1.0)) 0.25, Circle (V3 0.0 (-10.25) (-1.0)) 10]
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let coords = reverse $ range ((-1 * (w `div` 2), -1 * (h `div` 2)), ((w `div` 2) - 1, (h `div` 2) - 1)) -- "canvas"
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colors <- mapM (\x -> rayTrace x (w, h) (1.0, 1.0) world) coords
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let convertedColors = map v3ToColor colors
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putStrLn "P3"
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putStrLn (show w ++ " " ++ show h)
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putStrLn "255"
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mapM_ colorToString convertedColors
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mapM_ print convertedColors
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