Fix bug when forming convex hull of game room bounds

src/Picture.hs

@@ -5,6 +5,7 @@ module Picture
     , module Color
     , blank
     , polygon
+    , polygonWire
     , polygonZ
     , polygonCol
     , poly3
@@ -56,6 +57,10 @@ blank :: Picture
 {-# INLINE blank #-}
 blank = []
 
+polygonWire :: [Point2] -> Picture
+{-# INLINE polygonWire #-}
+polygonWire ps = line (ps ++ [head ps])
+
 polygon :: [Point2] -> Picture
 {-# INLINE polygon #-}
 polygon ps = map f $ polyToTris ps