public void initializeMap()
{
Map = new Node[levelSize.I, levelSize.J];
for (int i = 0; i < levelSize.I; i++)
{
for (int j = 0; j < levelSize.J; j++)
{
Map[i, j] = new Node(informations.EndLocationIndex, new IndexPair(i, j));
}
}
}
private List<Node> GetAdjacentWalkableNodes(Node fromNode)
{
List<Node> walkableNodes = new List<Node>();
IEnumerable<IndexPair> nextLocations = GetAdjacentLocations(fromNode.Location);
foreach (var location in nextLocations)
{
int x = location.I;
int y = location.J;
// Stay within the grid's boundaries
if (x < 0 || x >= levelSize.I || y < 0 || y >= levelSize.J)
continue;
Node node = Map[x, y];
// Ignore non-walkable nodes
if (!node.walkable)
continue;
// Ignore already-closed nodes
if (node.State == NodeState.Closed)
continue;
// Already-open nodes are only added to the list if their G-value is lower going via this route.
if (node.State == NodeState.Open)
{
float traversalCost = Node.GetTraversalCost(node.Location, node.ParentNode.Location);
float gTemp = fromNode.G + traversalCost;
if (gTemp < node.G)
{
node.ParentNode = fromNode;
walkableNodes.Add(node);
}
}
else
{
// If it's untested, set the parent and flag it as 'Open' for consideration
node.ParentNode = fromNode;
node.State = NodeState.Open;
walkableNodes.Add(node);
}
}
return walkableNodes;
}
public PathFinder(RouteInformation informations)
{
levelSize = MapLoader.LevelDimensions;
this.informations = informations;
initializeMap();
startNode = Map[informations.StartLocationIndex.I, informations.StartLocationIndex.J];
startNode.State = NodeState.Open;
endNode = Map[informations.EndLocationIndex.I, informations.EndLocationIndex.J];
}
/// <summary>
/// returns true if(the path leads to the destination and false if the path leads to dead end
/// </summary>
/// <param name="currentNode"></param>
/// <returns></returns>
private bool Search(Node currentNode)
{
// Set the current node to Closed since it cannot be traversed more than once
currentNode.State = NodeState.Closed;
List<Node> nextNodes = GetAdjacentWalkableNodes(currentNode);
// Sort by F-value so that the shortest possible routes are considered first
nextNodes.Sort((node1, node2) => node1.F.CompareTo(node2.F));
foreach (var nextNode in nextNodes)
{
// Check whether the end node has been reached
if (nextNode.Location == this.endNode.Location)
{
return true;
}
else
{
// If not, check the next set of nodes
if (Search(nextNode)) // Note: Recurses back into Search(Node)
return true;
}
}
// The method returns false if this path leads to be a dead end
return false;
}
