public void SetRoute(RouteResult route)
{
// if we're instructed to move to this tile, we're here!
if (route.nodes.Count <= 0)
{
return;
}
startMoveTime = Time.deltaTime;
currentNodeIndex = 0;
// assume we're on the starting Node
currentNode = route.nodes[0];
targetNode = route.nodes[1];
}
/// <summary>
/// Given a starting and ending node, determine the
/// shortest path between the two
/// </summary>
/// <param name="start">The starting node</param>
/// <param name="end">The ending node</param>
/// <returns>A RouteResult</returns>
public RouteResult Route(Node start, Node end, bool diagonal = true)
{
// create the result object
RouteResult result = new RouteResult();
// create the path for the starting node
Path startPath = new Path {
cheapestPathCost = 0
};
startPath.nodes.Add(start);
// add that path to the dict
paths.Add(start.GetInstanceID(), startPath);
// create a stack of nodes and queue the starting node
Stack nodes = new Stack();
nodes.Push(start);
// while we have nodes...
while (nodes.Count > 0)
{
Node current = nodes.Pop() as Node;
// retrieve the path for this node if exists in the dictionary
pathForKey(current.GetInstanceID(), out Path currentPath);
// mark this node as visited in the path
currentPath.visited = true;
// list of nodes to sort and prioritize next
List <Node> nextNodes = new List <Node>();
// for each one fo the nodes neighbors, supporting
// both diagonal and direct:
List <Node> neighbors = current.directNeighbors;
if (diagonal)
{
neighbors = current.neighbors;
}
foreach (Node neighborNode in neighbors)
{
// in the event that a neighbor node gets
// removed while pathing or a neighbor is occupied
if (neighborNode == null || neighborNode.Occupied)
{
continue;
}
// create a new path for this neighbor
pathForKey(neighborNode.GetInstanceID(), out Path neighborPath);
// determine the cost to get to this node
int cost = currentPath.cheapestPathCost + neighborNode.cost;
// if the calculated cost is less than the current n.cost (defaults to int.max),
// update this as the shortest path to this node
if (cost < neighborPath.cheapestPathCost)
{
neighborPath.cheapestPathCost = cost;
neighborPath.nodes.Clear();
// add all nodes in current path to this neighbors nodes
foreach (Node shortestNode in currentPath.nodes)
{
neighborPath.nodes.Add(shortestNode);
}
// now add this node as well
neighborPath.nodes.Add(neighborNode);
}
// if this node isn't visited, add it to
// nextNodes to be sorted and processed
if (!neighborPath.visited)
{
nextNodes.Add(neighborNode);
}
}
// sort all neighbor nodes that haven't been processed
// by their distance to the end node and add them to
// the stack
nextNodes = prioritizeNodes(nextNodes, start, end);
foreach (Node nextNode in nextNodes)
{
nodes.Push(nextNode);
}
// if this is the end node, set the result and return
if (current == end)
{
result.cost = currentPath.cheapestPathCost;
result.nodes = currentPath.nodes;
return(result);
}
}
// if no return, return empty result...
return(result);
}
