Work towards cross-room placements

src/Dodge/Room/Link.hs

@@ -15,6 +15,7 @@ module Dodge.Room.Link
     , randomiseOutLinks
     , randomiseLinksBy
     , invShiftLinkBy
+    , setLastLinkToUsed
     ) where
 import Dodge.LevelGen
 import Dodge.Room.Data
@@ -105,3 +106,10 @@ shiftPathBy
     -> (Point2,Point2) 
     -> (Point2,Point2) 
 shiftPathBy s (p1,p2) = (shiftPointBy s p1, shiftPointBy s p2)
+
+setLastLinkToUsed :: Room -> Room
+setLastLinkToUsed rm = case _rmLinks rm of
+    (_:_) -> rm
+        & rmLinks %~ init
+        & rmUsedLinks %~ (uncurry InLink (last (_rmLinks rm)) :)
+    _ -> rm