// Making use of A*
public List <Waypoint> FindPath(Waypoint start, Waypoint end)
{
Dictionary <int, Waypoint> closedList = new Dictionary <int, Waypoint>(); // Create a list containing nodes already seen (start is default)
List <Waypoint> openList = new List <Waypoint>()
{
start
}; // Create a list containing nodes seen but not assessed yet. Ordered as a priority queue
List <Waypoint> path = new List <Waypoint>(); // List containing all the nodes in the shortest path
List <Waypoint> currentLinks = new List <Waypoint>(); // Contains the neighbouring nodes to be assessed from the current node
Waypoint currentWaypoint = start;
// Init of the starting node
currentWaypoint.SetHeuristic(Mathf.Pow(end.gameObject.transform.position.x, 2) + Mathf.Pow(end.gameObject.transform.position.y, 2) + Mathf.Pow(end.gameObject.transform.position.z, 2));
currentWaypoint.AssignNodeValue(0);
currentWaypoint.AssignChild(null);
bool foundEnd = false;
int counter = 0;
while ((openList.Count > 0) && (!foundEnd))
{
currentWaypoint = RemoveHeap(openList);
closedList[currentWaypoint.num] = currentWaypoint;
currentLinks = currentWaypoint.GetConnectedNodes(); // Take all the nodes that the current node is connected to
counter += 6;
for (int i = 0; i < currentLinks.Count; i++)
{
counter += 2;
// Make sure it's not already in the closed list. Ignore it otherwise
if (!closedList.ContainsKey(currentLinks[i].num))//!closedList.Contains(currentLinks[i]))
{
// if (currentLinks[i].IsBlocked())
// closedList.Add(i, currentLinks[i]);
// else
// {
// Using Euclidean distance as heuristic function since waypoints are set at diff angles
float heuristic = Mathf.Pow(end.gameObject.transform.position.x - currentLinks[i].gameObject.transform.position.x, 2) + Mathf.Pow(end.gameObject.transform.position.y - currentLinks[i].gameObject.transform.position.y, 2) + Mathf.Pow(end.gameObject.transform.position.z - currentLinks[i].transform.position.z, 2);
float gValue = Mathf.Pow(currentLinks[i].gameObject.transform.position.x - currentWaypoint.gameObject.transform.position.x, 2) + Mathf.Pow(currentLinks[i].gameObject.transform.position.y - currentWaypoint.gameObject.transform.position.y, 2) + Mathf.Pow(currentLinks[i].gameObject.transform.position.z - currentWaypoint.transform.position.z, 2) + currentWaypoint.GetGVal();
//heuristic = 0f; // Turn this into Dijkstra's
counter += 5;
// If this item has not been seen OR if it has, that it has a higher cost value
if ((!openList.Contains(currentLinks[i]) || (openList.Contains(currentLinks[i]) && (currentLinks[i].GetNodeValue() > gValue + heuristic))))
{
currentLinks[i].AssignChild(currentWaypoint);
// Assign the distance to each node
currentLinks[i].SetHeuristic(Mathf.Sqrt(heuristic));
currentLinks[i].AssignNodeValue(gValue);
counter += 3;
AddHeap(openList, currentLinks[i]);
// }
}
}
counter++;
// If the end is found, exit
if (currentLinks[i] == end)
{
currentWaypoint = end;
end.target = code;
i = currentLinks.Count;
foundEnd = true;
counter += 3;
}
}
}
counter++;
// If a path was found, otherwise the path list will return empty
if (foundEnd)
{
while (currentWaypoint != null)
{
counter++;
path.Add(currentWaypoint);
currentWaypoint = currentWaypoint.GetChild();
}
path.Reverse(); // Or can implement as a stack
counter += path.Count;
}
//print("Total calc: " + counter);
return(path);
}
