Allow creatures to path around chasms

src/Dodge/Path.hs

@@ -5,6 +5,7 @@ module Dodge.Path (
     makePathBetweenPs,
     --    , removePathsCrossing
     obstructPathsCrossing,
+    obstructPathsCrossing',
     pairsToGraph,
     getNodePos,
     walkableNodeNear,
@@ -44,6 +45,7 @@ makePathBetween = makePathUsing $ not . pathEdgeObstructed
 
 pathEdgeObstructed :: PathEdge -> Bool
 pathEdgeObstructed pe = DoorObstacle `Set.member` obs || BlockObstacle `Set.member` obs
+    || ChasmObstacle `Set.member` obs
   where
     obs = _peObstacles pe
 
@@ -158,6 +160,17 @@ obstructPathsCrossing obstacletype sp' ep w =
     updateedge gr (PathEdgeNodes x y pe) =
         insEdge (x, y, pe & peObstacles . at obstacletype ?~ ()) $ delEdge (x, y) gr
 
+obstructPathsCrossing' :: EdgeObstacle -> Point2 -> Point2 -> World 
+    -> World
+obstructPathsCrossing' obstacletype sp' ep w =
+     w & cWorld . pathGraph %~ updateedges
+  where
+    es = Set.filter edgecrosses $ pesNearSeg sp' ep w
+    edgecrosses (PathEdgeNodes _ _ pe) = isJust $ intersectSegSeg sp' ep (_peStart pe) (_peEnd pe)
+    updateedges gr = foldl' updateedge gr es
+    updateedge gr (PathEdgeNodes x y pe) =
+        insEdge (x, y, pe & peObstacles . at obstacletype ?~ ()) $ delEdge (x, y) gr
+
 snapToGrid :: Set (Point2,Point2) -> Set (Point2, Point2)
 snapToGrid = Set.map (over each (fmap (fromIntegral . f)))
   where