change types

1 files changed, 21 insertions, 16 deletions

diff --git a/raytracer.hs b/raytracer.hs
index b77445b..57427c2 100644
--- a/raytracer.hs
+++ b/raytracer.hs
@@ -4,6 +4,11 @@ import Data.Char
 -- P3 width height maxcolorval r g b r g b r g b ...
 -- max line length: 70
 
+
+type Angle = Double
+type ScreenCoord = (Angle, Angle)
+type Color = (Int, Int, Int)
+
 degrees = pi / 180
 
 eye = [0, 0, 2]
@@ -17,7 +22,7 @@ beta2 = -30 * degrees
 w = 1000
 h = 500
 
-oversampling = 2 -- each pixel is 2x2 rays
+oversampling = 1 -- each pixel is 2x2 rays
 ov_alphaoffset = ((alpha2 - alpha1) / (w-1)) / oversampling
 ov_betaoffset  = ((beta2 - beta1) / (h-1)) / oversampling
 
@@ -30,31 +35,31 @@ alphas = take (round w) [alpha1,(alpha1 + ((alpha2 - alpha1) / (w-1)))..]
 betas  = take (round h) [beta1,(beta1 + ((beta2 - beta1) / (h-1)))..]
 
 --                       intersect at  (x     , y     , depth )
-intersect_floor :: Double -> Double -> (Double, Double, Double)
-intersect_floor alpha beta
+intersect_floor :: ScreenCoord -> (Double, Double, Double)
+intersect_floor (alpha, beta)
         | beta < 0 = (-2 * (cos alpha) / (sin beta) - 2 * (cos beta) / (sin beta),
                       -2 * (sin alpha) / (sin beta),
                       -2 / (sin beta) )
         | otherwise = (0, 0, 0)
 
-floorcolor :: Double -> Double -> (Int, Int, Int)
-floorcolor alpha beta
+floorcolor :: ScreenCoord -> Color
+floorcolor (alpha, beta)
         | (round (x/8) `mod` 2) == (round (y/8) `mod` 2) = (attn, 0, 0)
         | otherwise              = (attn, attn, attn)
         where attn = max 0 (round (255 - 8*(sqrt t)))
-              (x, y, t) = intersect_floor alpha beta
+              (x, y, t) = intersect_floor (alpha, beta)
 
 -- blue is beautiful, but a green tint is nice too
-skycolor :: Double -> Double -> (Int, Int, Int)
-skycolor alpha beta = (60,
+skycolor :: ScreenCoord -> Color
+skycolor (alpha, beta) = (60,
             round ((sqrt (alpha/6)) / (sqrt (90 * degrees)) * 128),
             round ((sqrt beta) / (sqrt (90 * degrees)) * 255) )
 
-pixel_color :: Double -> Double -> (Int, Int, Int)
-pixel_color alpha beta
-        | beta > 0  = skycolor alpha beta
+pixel_color :: ScreenCoord -> Color
+pixel_color (alpha, beta)
+        | beta > 0  = skycolor (alpha, beta)
         | beta == 0 = (0, 255, 0)
-        | otherwise = floorcolor alpha beta
+        | otherwise = floorcolor (alpha, beta)
 
 cartProdTranspose xs ys = [(y,x) | x <- xs, y <- ys]
 cartProd xs ys = [(x,y) | x <- xs, y <- ys]
@@ -66,14 +71,14 @@ tuple2sum x y = (a1 + b1, a2 + b2)
                      (b1, b2) = y
 
 -- from one pixel (alpha, beta), get a list of oversampled pixels
-oversample :: (Double, Double) -> [(Double, Double)]
+oversample :: ScreenCoord -> [ScreenCoord]
 oversample (a,b) = map (tuple2sum (a,b)) (cartProd ov_alphaoffsets ov_betaoffsets)
 
 tuple3sum x y = (a1 + b1, a2 + b2, a3 + b3)
                where (a1, a2, a3) = x
                      (b1, b2, b3) = y
 
-coloraverage :: [(Int, Int, Int)] -> (Int, Int, Int)
+coloraverage :: [Color] -> Color
 coloraverage xs = ( round (fromIntegral s1/l),
                     round (fromIntegral s2/l),
                     round (fromIntegral s3/l) )
@@ -81,8 +86,8 @@ coloraverage xs = ( round (fromIntegral s1/l),
                           l = fromIntegral (length xs)
 
 -- calculate color of oversampled pixels
-ov_color :: [(Double, Double)] -> (Int, Int, Int)
-ov_color xs = coloraverage (map (uncurry pixel_color) xs)
+ov_color :: [ScreenCoord] -> Color
+ov_color xs = coloraverage (map pixel_color xs)
 
 -- list of list of (alpha, beta)-tuples
 ov_pixels = map oversample (cartProdTranspose betas alphas)