Initial pass at shadows from level geometry

src/Picture.hs

@@ -47,6 +47,7 @@ module Picture
     )
   where
 import Geometry
+import Geometry.Vector3D
 import Geometry.Data
 import Picture.Data
 
@@ -148,12 +149,6 @@ scale :: Float -> Float -> Picture -> Picture
 {-# INLINE scale #-}
 scale x y = OverPic (scale3 x y) id
 
-rotate3 :: Float -> Point3 -> Point3
-{-# INLINE rotate3 #-}
-rotate3 a (x,y,z) = (x',y',z)
-  where 
-    (x',y') = rotateV a (x,y)
-
 rotate :: Float -> Picture -> Picture
 {-# INLINE rotate #-}
 rotate a = OverPic (rotate3 a) id