/// <summary>
/// Finds a path from start to end.
/// </summary>
/// <param name="start">a start position</param>
/// <param name="target">a target position</param>
/// <returns></returns>
public List <Node> FindPath(Vector3 start, Vector3 target)
{
Heap <Node> openSet = new Heap <Node>(totalNodes);
List <Node> closedSet = new List <Node>();
List <Node> path = new List <Node>();
Node startNode = grid.GetNodeFromWorldPos(start);
Node targetNode = grid.GetNodeFromWorldPos(target);
// Returns an empty path if either of the ends is invalid
if (startNode == null || targetNode == null ||
startNode.isBlocked || targetNode.isBlocked)
{
return(path);
}
startNode.gCost = 0;
startNode.hCost = GetDistance(startNode, targetNode);
openSet.Add(startNode);
while (openSet.Count > 0)
{
Node currentNode = openSet.RemoveFirst();
closedSet.Add(currentNode);
currentNode.isInClosedSet = true;
if (currentNode == targetNode)
{
path = RetracePath(startNode, currentNode);
break;
}
else
{
foreach (Node neighbourNode in currentNode.neighbours)
{
if (!neighbourNode.isBlocked &&
!neighbourNode.isInClosedSet)
{
int newMovementCost =
currentNode.gCost +
GetDistance(currentNode, neighbourNode);
bool openListContainsNeighbour =
openSet.Contains(neighbourNode);
if (newMovementCost < neighbourNode.gCost ||
!openListContainsNeighbour)
{
neighbourNode.gCost = newMovementCost;
neighbourNode.hCost =
GetDistance(neighbourNode, targetNode);
neighbourNode.prevNode = currentNode;
if (!openListContainsNeighbour)
{
openSet.Add(neighbourNode);
}
else
{
openSet.UpdateItem(neighbourNode);
}
}
}
}
}
}
ResetClosedSet(closedSet);
return(path);
}
protected virtual void Update()
{
node = pathGridManager.GetNodeFromWorldPos(transform.position);
}