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);
}