IEnumerator CheckIfPathExists(Vector2 startPos, Vector2 targetPos) { bool pathSuccess = false; //Get the nodes for respective world space positions. Node startNode = Grid.NodeFromWorldPoint(startPos); Node targetNode = Grid.NodeFromWorldPoint(targetPos); //Create open set and closed set. Open set for nodes that haven't been examined yet, closed set for nodes that have. Heap <Node> openSet = new Heap <Node>(grid.MaxSize); HashSet <Node> closedSet = new HashSet <Node>(); //Add start node to openSet openSet.Add(startNode); while (openSet.Count > 0) { Node currentNode = openSet.RemoveFirst(); closedSet.Add(currentNode); //We've found the target if (currentNode == targetNode) { pathSuccess = true; break; } //Find all neighbouring nodes. List <Node> neighbours = new List <Node>(); neighbours = Grid.GetNeighbourNodes(currentNode); foreach (Node neighbour in neighbours) { //If the node is walkable or it is in the closed set, then continue to the next if (!neighbour.walkable || closedSet.Contains(neighbour)) { continue; } int newMovementCostToNeighbour = currentNode.gCost + GetDistance(currentNode, neighbour); if (newMovementCostToNeighbour < neighbour.gCost || !openSet.Contains(neighbour)) { neighbour.gCost = newMovementCostToNeighbour; neighbour.hCost = GetDistance(neighbour, targetNode); neighbour.parent = currentNode; if (!openSet.Contains(neighbour)) { openSet.Add(neighbour); } } } } yield return(null); requestManager.FinishedCheckingPath(null, pathSuccess); }