module Vector where

import Graphics.UI.GLUT

normalize :: Floating a => Vector3 a -> Vector3 a
normalize (Vector3 x y z) =
      Vector3 (x/d) (y/d) (z/d)
   where d = sqrt (x*x+y*y+z*z)

prod (Vector3 x1 y1 z1) (Vector3 x2 y2 z2) =
     Vector3 (y1 * z2 - z1 * y2)
        (z1 * x2 - x1 * z2)
        (x1 * y2 - y1 * x2)

xmove (Vector3 x y z) incr = Vector3 (x+incr) y z
ymove (Vector3 x y z) incr = Vector3 x (y+incr) z
zmove (Vector3 x y z) incr = Vector3 x y (z+incr)

xpart (Vector3 x _ _) = x
ypart (Vector3 _ y _) = y
zpart (Vector3 _ _ z) = z

instance Floating a => Num (Vector3 a) where
    (Vector3 x1 y1 z1) + (Vector3 x2 y2 z2) = Vector3 (x1 + x2) (y1 + y2) (z1 + z2)
    (Vector3 x1 y1 z1) * (Vector3 x2 y2 z2) =
      Vector3 (y1 * z2 - z1 * y2)
         (z1 * x2 - x1 * z2)
         (x1 * y2 - y1 * x2)
    (Vector3 x1 y1 z1) - (Vector3 x2 y2 z2) = Vector3 (x1 - x2) (y1 - y2) (z1 - z2)
    negate (Vector3 x y z) = Vector3 (-x) (-y) (-z)
    fromInteger i = Vector3 (fromInteger i) 0 0

    -- dummy definitions
    abs v = v
    signum (Vector3 0 0 0) = 0
    signum _          = 1