Find the intersection of a line with a plane: Difference between revisions

Content deleted Content added
Robbie (talk | contribs)
Added Java
Added Haskell
Line 132:
{{out}}
<pre>The ray intersects the plane at (0.000000,-5.000000,5.000000)</pre>
 
=={{header|Haskell}}==
{{trans|Kotlin}}
Note that V3 is implemented similarly in the external library [https://hackage.haskell.org/package/linear-1.20.7/docs/Linear-V3.html linear].
<lang Haskell>import Control.Applicative (liftA2)
import Text.Printf (printf)
 
data V3 a = V3 a a a
deriving Show
 
instance Functor V3 where
fmap f (V3 a b c) = V3 (f a) (f b) (f c)
 
instance Applicative V3 where
pure a = V3 a a a
V3 a b c <*> V3 d e f = V3 (a d) (b e) (c f)
 
instance Num a => Num (V3 a) where
(+) = liftA2 (+)
(-) = liftA2 (-)
(*) = liftA2 (*)
negate = fmap negate
abs = fmap abs
signum = fmap signum
fromInteger = pure . fromInteger
 
dot ::Num a => V3 a -> V3 a -> a
dot a b = x + y + z
where
V3 x y z = a * b
 
intersect :: Fractional a => V3 a -> V3 a -> V3 a -> V3 a -> V3 a
intersect rayVector rayPoint planeNormal planePoint =
rayPoint - rayVector * pure prod3
where
diff = rayPoint - planePoint
prod1 = diff `dot` planeNormal
prod2 = rayVector `dot` planeNormal
prod3 = prod1 / prod2
 
main = printf "The ray intersects the plane at (%f, %f, %f)\n" x y z
where
V3 x y z = intersect rv rp pn pp :: V3 Double
rv = V3 0 (-1) (-1)
rp = V3 0 0 10
pn = V3 0 0 1
pp = V3 0 0 5</lang>
{{out}}
<pre>The ray intersects the plane at (0.0, -5.0, 5.0)</pre>
 
 
=={{header|Java}}==