public void AddNeighbor(GraphNode <T> n, double cost)
{
this.edges.AddLast(new GraphEdge <T>(this, n, cost));
}
public GraphEdge(GraphNode <T> start, GraphNode <T> end, double cost)
{
this.start_node = start;
this.end_node = end;
this.cost = cost;
}
public virtual LinkedList <GraphNode <T> > ShortestPath(GraphNode <T> start_node, GraphNode <T> end_node)
{
examined_nodes.Clear();
curr_start_node = start_node;
curr_end_node = end_node;
open_nodes.Clear(); //clear both open and closed lists since they will be repopulated in this pathfinding step
closed_nodes.Clear();
this.StartNode = start_node; //start node for pathfinding step
resetCosts(); //reset all the costs
start_node.CostSoFar = 0;
DijkstraEvaluate();
//after the evaluation is done, each node has its cost and connections set
//starting at the end node and appending nodes by following the connections backwards allows us to build and return a list containing the nodes in the shortest path in order.
GraphNode <T> curr = end_node;
LinkedList <GraphNode <T> > node_order = new LinkedList <GraphNode <T> >();
while (curr != start_node)
{
node_order.AddFirst(curr);
curr = curr.Connection.Start;
}
node_order.AddFirst(curr);
return(node_order);
}
//shortest path using a*
public override LinkedList <GraphNode <T> > ShortestPath(GraphNode <T> start_node, GraphNode <T> end_node)
{
examined_nodes.Clear();
curr_start_node = start_node;
curr_end_node = end_node;
open_nodes.Clear(); //clear open and closed and reset all costs (costs so far)
closed_nodes.Clear();
this.StartNode = start_node;
resetCosts();
start_node.CostSoFar = 0;
//for each node compute its heuristic cost
foreach (GraphNode <T> n in nodes)
{
n.Heuristic = n.Value.ComputeHeuristic(end_node.Value);
}
//same node path construction as parent class
Evaluate(end_node);
GraphNode <T> curr = end_node;
LinkedList <GraphNode <T> > node_order = new LinkedList <GraphNode <T> >();
while (curr != start_node)
{
node_order.AddFirst(curr);
curr = curr.Connection.Start;
}
node_order.AddFirst(curr);
return(node_order);
}
public void Add(GraphNode <T> node)
{
nodes.AddLast(node);
}
