Improve intersection test--fails sometimes

src/Picture.hs

@@ -72,9 +72,9 @@ blank = []
 
 polygon :: [Point2] -> Picture
 {-# INLINE polygon #-}
-polygon ps = map (f . zeroZ) $ polyToTris ps
+polygon ps = map f $ polyToTris ps
   where
-    f pos = Verx pos black [] 0 polyNum
+    f (V2 x y) = Verx (V3 x y 0) black [] 0 polyNum
 
 polygonZ :: [Point2] -> Float -> Picture
 {-# INLINE polygonZ #-}
@@ -191,7 +191,7 @@ scale3 a b (V3 x y z) = V3 (x*a) (y*b) z
 scale :: Float -> Float -> Picture -> Picture
 {-# INLINE scale #-}
 --scale x y = map . second . overPos $ scale3 x y
-scale x y = map $ overPos $ scale3 x y
+scale x = map . overPos . scale3 x
 
 rotate :: Float -> Picture -> Picture
 {-# INLINE rotate #-}