Improve level generation speed

src/Geometry.hs

@@ -199,6 +199,17 @@ polyToTris (a:as) = go a as
     go _ _ = []
 polyToTris _ = []
 
+polyToTris' :: [s] -> [s]
+{-# INLINE polyToTris' #-}
+polyToTris' [] = []
+polyToTris' (a:as) = prependTwo a as
+
+prependTwo :: a -> [a] -> [a]
+prependTwo _   [] = []
+prependTwo _   [_] = []
+prependTwo sep (x:y:xs) = sep : x : y : prependTwo sep (y:xs)
+
+
 -- | Return n equidistant points on a circle with a radius of 600.
 nRays :: Int -> [Point2]
 nRays n = take n $ iterate (rotateV (2*pi/fromIntegral n)) (V2 600 0)