public PathFinder(PathFindingParameters parameters)
{
this.parameters = parameters;
InitNodes(parameters.Map);
this.startNode = this.nodes[parameters.StartLocation.X, parameters.StartLocation.Y];
this.destinationNode = this.nodes[parameters.EndLocation.X, parameters.EndLocation.Y];
this.startNode.State = PathNodeState.Possible;
}
private bool SearchPath(PathNode currentNode)
{
currentNode.State = PathNodeState.Included;
List<PathNode> nextNodes = GetWalkableNodes(currentNode);
nextNodes.Sort((node1, node2) => node1.CostTotal.CompareTo(node2.CostTotal));
foreach (PathNode nextNode in nextNodes)
{
if (nextNode.Location == this.destinationNode.Location)
{
return true;
}
else
{
if (SearchPath(nextNode))
return true;
}
}
// no path found
return false;
}
private List<PathNode> GetWalkableNodes(PathNode currentNode)
{
List<PathNode> walkables = new List<PathNode>();
IEnumerable<Point> nextLocations;
if (currentNode.Location.Y == 1)
{
nextLocations = new Point[] { new Point(destinationNode.Location.X, destinationNode.Location.Y) };
}
else
{
nextLocations = GetAdjacentLocations(currentNode.Location);
}
foreach (Point location in nextLocations)
{
int x = location.X;
int y = location.Y;
if (x < 0 || x >= this.width || y < 0 || y >= this.heigth)
continue;
PathNode node = this.nodes[x, y];
// check if tower is not walkable or already in the path
if (!node.Walkable || node.State == PathNodeState.Included)
continue;
// Check if path goes between 2 towers
if (x != currentNode.Location.X && y != currentNode.Location.Y && y != 0)
{
if (!this.nodes[x, currentNode.Location.Y].Walkable || !this.nodes[currentNode.Location.X, y].Walkable)
continue;
}
if (node.State == PathNodeState.Possible)
{
float cost = PathNode.GetCost(node.Location, node.ParentNode.Location);
float tmp = currentNode.CostFromStart + cost;
// Nodes are only added to the list if their cost is lower going via this route
if (tmp < node.CostFromStart)
{
node.ParentNode = currentNode;
walkables.Add(node);
}
}
else
{
// Untested node -> set parent and consider it for the path
node.ParentNode = currentNode;
node.State = PathNodeState.Possible;
walkables.Add(node);
}
}
return walkables;
}