Improve room clip testing

src/Geometry.hs

@@ -226,9 +226,14 @@ polysIntersect (p:ps) (q:qs)
   where 
     pairs1 = zip (p:ps) (ps++[p])
     pairs2 = zip (q:qs) (qs++[q])
+polysIntersect _ _ = False
 
-polysIntersect [] _ = False
-polysIntersect _ [] = False
+-- | Test whether two polygons intersect or if one is contained in the other.
+polysOverlap :: [Point2] -> [Point2] -> Bool
+polysOverlap (p:ps) (q:qs) = polysIntersect (p:ps) (q:qs) 
+    || pointInPolygon p (q:qs)
+    || pointInPolygon q (p:ps)
+polysOverlap _ _ = False
 
 -- | Test whether any polygons from a first list intersect with any polygons from
 -- a second list.