Add more sounds

src/Geometry/Vector3D.hs

@@ -4,6 +4,7 @@ module Geometry.Vector3D
 import Geometry.Vector
 import Geometry.Data
 
+import qualified Control.Foldl as L
 import Data.List
 
 infixl 6 +.+.+, -.-.-
@@ -27,7 +28,7 @@ V3 x1 y1 z1 -.-.- V3 x2 y2 z2 =
     !y = y1 - y2
     !z = z1 - z2
   in V3 x y z
-{- | 3D scalar multiplication.  -}
+{- | 3D scalar multiplication. Strict. -}
 (*.*.*) :: Float -> Point3 -> Point3
 {-# INLINE (*.*.*) #-}
 a *.*.* (V3 x2 y2 z2) =
@@ -112,7 +113,8 @@ orderAround3 v ps = sortOn (argV . prj) ps
     prj p = V2 (dotV3 xdir p) (dotV3 ydir p)
 
 vCen3 :: [Point3] -> Point3
-vCen3 ps = (1 / fromIntegral (length ps)) *.*.* foldr (+.+.+) (V3 0 0 0) ps 
+vCen3 = L.fold $ (/) <$> L.sum <*> L.genericLength
+--vCen3 ps = (1 / fromIntegral (length ps)) *.*.* foldr (+.+.+) (V3 0 0 0) ps 
 
 dotV3 :: Point3 -> Point3 -> Float
 dotV3 (V3 x y z) (V3 a b c) = x*a + y*b + z*c