Allow creatures to path around chasms

src/Dodge/Placement/PlaceSpot.hs

@@ -148,11 +148,7 @@ placeSpotID rid ps pt w = case pt of
     PutNothing -> (0, w)
     PutID i -> (i, w)
     PutWorldUpdate f -> (0, w & f rid ps)
-    PutChasm ps' ->
-        ( 0
-        , w & gwWorld . cWorld . chasms .:~ map doShift ps'
-            & genRooms . ix rid . rmPos %~ filter (\rp -> not $ pointInPoly (_rpPos rp) ps')
-        )
+    PutChasm ps' -> (0, placeChasm w rid ps' $ map doShift ps')
     PutLabel{} -> (0, w)
   where
     p@(V2 px py) = _psPos ps
@@ -160,6 +156,15 @@ placeSpotID rid ps pt w = case pt of
     rot = _psRot ps
     doShift = shiftPointBy (p, rot)
 
+placeChasm :: GenWorld -> Int -> [Point2] -> [Point2] -> GenWorld
+placeChasm gw rid ps shiftps =
+    gw & gwWorld . cWorld . chasms .:~ shiftps
+        & genRooms . ix rid . rmPos %~ filter (\rp -> not $ pointInPoly (_rpPos rp) ps)
+        & gwWorld %~ f
+  where
+    f w = foldl' g w (loopPairs shiftps)
+    g w (x,y) = fst $ obstructPathsCrossing ChasmObstacle x y w
+
 --evaluateRandPS
 --    :: Int -> State StdGen PSType -> PlacementSpot -> GenWorld -> (Int, GenWorld)
 --evaluateRandPS rid rgen ps w = placeSpotID rid ps evaluatedType