lib/a_star: fix check for max_cost (is more reliable)

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/a_star.nit b/lib/a_star.nit
index 1f25f00..0c81a48 100644 (file)
--- a/lib/a_star.nit
+++ b/lib/a_star.nit
@@ -93,7 +93,7 @@ class Node
        # Main functionnality, returns path from `self` to `dest`
        fun path_to(dest: Node, max_cost: Int, context: PathContext): nullable Path[N]
        do
-               var cost: Int = 0
+               var cost = 0
 
                var nbr_buckets = context.worst_cost + context.worst_heuristic_cost + 1
                var buckets = new Array[List[Node]].with_capacity(nbr_buckets)
@@ -110,7 +110,7 @@ class Node
                self.last_pathfinding_evocation = graph.pathfinding_current_evocation
                self.best_cost_up_to = 0
 
-               while cost < max_cost do
+               loop
                        var frontier_node: nullable Node = null
 
                        var bucket_searched: Int = 0
@@ -122,6 +122,7 @@ class Node
                                if current_bucket.is_empty then # move to next bucket
                                        debug "b {cost} {cost % nbr_buckets} {buckets[cost % nbr_buckets].hash}"
                                        cost += 1
+                                       if cost > max_cost then return null
                                        bucket_searched += 1
 
                                        if bucket_searched > nbr_buckets then break
@@ -179,9 +180,6 @@ class Node
                                end
                        end
                end
-
-               # costs over max
-               return null
        end
 
        # Find closes node with matching caracteristic