//// define basic operators for this class
#region IComparable (so nodes are sortable)
public int CompareTo(object obj)
{
AStarNodeDep other = (AStarNodeDep)obj;
float thisRank = this.heuristicCost + this.totalCost;
float otherRank = other.heuristicCost + other.totalCost;
return(thisRank.CompareTo(otherRank));
}
public static List <AStarNodeDep> FindPath(this AStarNodeDep[,] matrix, AStarNodeDep start, AStarNodeDep destination)
{
List <AStarNodeDep> edges = new List <AStarNodeDep>();
List <AStarNodeDep> path = new List <AStarNodeDep>();
// are start and destination the same?
if (start.Equals(destination))
{
path.Add(start);
return(path);
}
// update heuristic costs for all nodes in the matrix
foreach (AStarNodeDep node in matrix)
{
node.destination = destination.coordinate;
}
// build the path
edges.Add(start);
bool pathFound = false;
do
{
// sort the edges by heuristic
edges.Sort();
// select the first edge
AStarNodeDep selectedEdge = edges[0];
Vector2 edgeCoordinate = selectedEdge.coordinate.ToVector2();
// get all neighbors of the edge
List <AStarNodeDep> neighbors = new List <AStarNodeDep>();
neighbors = matrix.GetNeighborsOf((int)edgeCoordinate.x, (int)edgeCoordinate.y, 1);
// set the neighbors' parents to the edge
foreach (AStarNodeDep node in neighbors)
{
node.parent = selectedEdge;
}
// append all neighbors to the edge list
edges.AddUniques(neighbors);
// move the edge to the searched list
edges.Remove(selectedEdge);
pathFound = selectedEdge.Equals(destination);
} while (edges.Count > 0 && !pathFound);
if (pathFound)
{
AStarNodeDep node = destination;
do
{
path.Add(node);
node = node.parent;
} while (node != null);
return(path);
}
else
{
return(null);
}
}
//// A* operations
public bool CoordinateEquals(AStarNodeDep node)
{
return(this.CoordinateEquals(node.coordinate));
}
