/// <summary>
/// Pahtfinding using A*
/// </summary>
/// <returns>an arraylist with all the nodes to get to the target</returns>
private ArrayList NavigateToTarget()
{
if (target == null)
{
return(new ArrayList());
}
ArrayList closed = new ArrayList();
ArrayList open = new ArrayList();
NodeScript start = currentStartNode;
start.gScore = 0;
start.fScore = start.DistanceEstimate(start, target);
open.Add(start.gameObject);
while (open.Count > 0)
{
NodeScript currentNode;
float shortestDistance = float.MaxValue;
int shortestNeighbourIndex = 0;
for (int i = 0; i < open.Count; i++)
{
GameObject nodeEval = open[i] as GameObject;
nodeEval.GetComponent <NodeScript>().fScore = nodeEval.GetComponent <NodeScript>().DistanceEstimate(nodeEval.GetComponent <NodeScript>(), target);
if (nodeEval.GetComponent <NodeScript>().fScore < shortestDistance)
{
shortestDistance = nodeEval.GetComponent <NodeScript>().fScore;
shortestNeighbourIndex = i;
}
}
GameObject node = (GameObject)open[shortestNeighbourIndex] as GameObject;
currentNode = node.GetComponent <NodeScript>();
if (currentNode == target)
{
ArrayList path = ReconstructPath(currentNode);
//Restoring the infinity values to be better
for (int i = 0; i < game.nodes.Count; i++)
{
GameObject nodeEval = (GameObject)game.nodes[i] as GameObject;
nodeEval.GetComponent <NodeScript>().fScore = float.MaxValue;
nodeEval.GetComponent <NodeScript>().gScore = float.MaxValue;
nodeEval.GetComponent <NodeScript>().previousNode = null;
}
return(path);
}
open.Remove(currentNode.gameObject);
closed.Add(currentNode.gameObject);
for (int i = 0; i < currentNode.neighbours.Length; i++)
{
NodeScript neighbour = currentNode.neighbours[i].GetComponent <NodeScript>();
if (closed.Contains(neighbour.gameObject))
{
continue;
}
float tenativeGScore = currentNode.gScore + currentNode.distances[i];
if (!open.Contains(neighbour.gameObject))
{
open.Add(neighbour.gameObject);
}
else if (tenativeGScore >= neighbour.gScore)
{
continue;
}
neighbour.previousNode = currentNode;
neighbour.gScore = tenativeGScore;
neighbour.fScore = neighbour.gScore + neighbour.DistanceEstimate(neighbour, target);
}
}
return(new ArrayList()); //FAILURE
}
