slightly better reflections

1 files changed, 32 insertions, 14 deletions

diff --git a/raytracer.hs b/raytracer.hs
index 9f8a184..5b58bd3 100644
--- a/raytracer.hs
+++ b/raytracer.hs
@@ -37,8 +37,8 @@ spherepos = [72]
 spheres num = [ trace ("Sphere at " ++
                     show (round (80 * sin(num * degrees))) ++ "," ++
                     show (round (80 * cos(num * degrees))) ++ ",5" )
-            Sphere (80 * sin(num * degrees), 80 * cos(num * degrees), 5) 10 (255,60,0),
-            sphere1, sphere2]
+                Sphere (80 * sin(num * degrees), 80 * cos(num * degrees), 5) 10 (255,60,0),
+                sphere1, sphere2 ]
 
 writenum :: Double -> IO ()
 writenum num = trace ("Rendering " ++ show (filename $ round num))
@@ -55,10 +55,10 @@ beta2 = 120 * degrees
 
 floorscale = 4
 
-w = 192 * 8
-h = 108 * 8
+w = 192 * 4
+h = 108 * 4
 
-oversampling = 4 -- each pixel is oversampling^2 rays
+oversampling = 1 -- each pixel is oversampling^2 rays
 
 black :: Color
 black = (0,0,0)
@@ -95,7 +95,7 @@ spherical_proj (x,y,z) alpha beta dist = (x + dist*(sin beta * cos alpha),
                                           z + dist*cos beta)
 
 cart2spher :: Coord -> Direction
-cart2spher coord = (acos $ z/r, atan2 y x)
+cart2spher coord = ( atan2 y x, acos $ (-z/r))
                     where   (x, y, z) = coord
                             r = magnitude coord
 
@@ -107,14 +107,17 @@ spher2cart direction = (sin beta * cos alpha,
 
 -- reflection on sphere
 reflect :: Coord -> Direction -> Direction
-reflect normal _ = --trace ("a " ++ show alpha ++ " b " ++ show beta)
-                    cart2spher normal
+reflect normal incoming = (alph, beta)
                     where   (alpha, beta) = cart2spher normal
+                            b = spher2cart incoming
+                            n = normalise normal
+                            alph = degrees*(fromIntegral (alpha_i `mod` 360) + alpha_f)
+                            (alpha_i, alpha_f) = properFraction (alpha/degrees)
 
 reflect2 normal incoming = cart2spher $ ((1) `scale` a) `plus` b
-                        where   a = (b `dot` n) `scale` n
-                                b = spher2cart incoming
-                                n = normalise normal
+                    where   a = (b `dot` n) `scale` n
+                            b = spher2cart incoming
+                            n = normalise normal
 
 -- intersect sphere
 
@@ -129,13 +132,27 @@ discr source (alpha, beta) (Sphere centre radius _) = 4*(( aa * u + bb * v + cc
             bb = sin beta * sin alpha
             cc = cos beta
 
+--debug
+simplecolor (beta, alpha)
+            | 0   <= alph && alph < 90    =  (a,0,0)
+            | 90  <= alph && alph < 180   =  (0,a,0)
+            | 180 <= alph && alph < 270   =  (0,0,a)
+            | 270 <= alph && alph < 360   =  (a,a,0)
+            | otherwise                           =  (0,255,255)
+            where   a    = trace ("alpha " ++ show (alph)) (if beta > (90*degrees) then 28 else 255)
+                    alph = fromIntegral (alpha_i `mod` 360) + alpha_f
+                    (alpha_i, alpha_f) = properFraction (alpha/degrees)
+
 -- the intersect functions return (Coord, Distance, Color)
 -- distance = 0 means no intersection
 intersect_sphere :: Coord -> [Sphere] -> Direction -> Sphere -> (Double, Color)
 intersect_sphere source spheres (alpha, beta) (Sphere centre radius color)
         | delta > 0 =   (t,
                          attenuate_color 0.8 $
-                         pixel_color intersect_point subspheres reflection_angle
+                         pixel_color intersect_point [] reflection_angle
+                         --simplecolor reflection_angle
+                         --( round $ 200 * ((spher2cart (alpha, beta)) `dot` (normalise normal))
+                         --   ,0 ,0)
                         )
         | otherwise = (0, black)
             where   t = min ((-b - sqrt(delta)) / (2*a)) ((-b + sqrt(delta)) / (2*a))
@@ -149,7 +166,8 @@ intersect_sphere source spheres (alpha, beta) (Sphere centre radius color)
                     bb = sin beta * sin alpha
                     cc = cos beta
                     intersect_point = spherical_proj source alpha beta t
-                    reflection_angle = reflect (intersect_point `minus` centre) (alpha, beta)
+                    reflection_angle = reflect normal (alpha, beta)
+                    normal = centre `minus` intersect_point
                     subspheres = filter ((/=) (Sphere centre radius color)) spheres
 
 
@@ -176,7 +194,7 @@ intersect_floor :: Coord -> Direction -> (Coord, Double, Color)
 intersect_floor source (alpha, beta)
         | x > (-0.5) && x < 0.5  = ((x, y, z), t, (0, attn, attn)) -- x near 0 : cyan
         | y > (-0.5) && y < 0.5  = ((x, y, z), t, (attn, attn, 0)) -- y near 0 : yellow
-        | beta <= 90*degrees     = ((x, y, z), 0, checkerboard_pattern x y 128)
+        | beta <= 90*degrees     = ((x, y, z), 0, (128, 128, 128))--checkerboard_pattern x y 128)
         | otherwise              = ((x, y, z), t, checkerboard_pattern x y attn)
         where   attn = max 0 (round (255 - 4*(sqrt $ abs t)))
                 ((x, y, z), t) = intersect_point_floor source (alpha, beta)