/// <summary>
/// Find the closest room with the given argument
/// </summary>
/// <param name="currentRoom">The room to start the pathfinding from.</param>
/// <param name="rule">The lambda exprission for the room to find.</param>
/// <returns>A list with rooms, that form a path.</returns>
public List <Room> Find(Room currentRoom, FindPath rule)
{
List <RoomNode> queue = new List <RoomNode>();
List <RoomNode> visited = new List <RoomNode>();
RoomNode endNode = null;
// Add the current room.
queue.Add(new RoomNode(currentRoom, 0, null));
// Go through all the items in the queue
while (queue.Count > 0)
{
// Get the node with the lowest weight.
RoomNode current = queue.OrderBy(x => x.Weight).First();
// if the current room is the target room, were done.
if (rule(current.Room) == true)
{
endNode = current;
break;
}
// For every neighbor in the room.
foreach (Room room in current.Room.Neighbors.Values)
{
if (!UseElevator && room is ElevatorShaft && current.Room is ElevatorShaft)
{
continue;
}
// Returns this room from the queue or null when it is not yet in the queue.
RoomNode nodeToCheck = visited.Where(x => x.Room == room).FirstOrDefault();
// If the node is not yet visited.
if (nodeToCheck == null)
{
queue.Add(new RoomNode(room, current.Weight + room.Weight, current));
}
else
{
if (nodeToCheck.Weight > current.Weight + room.Weight)
{
nodeToCheck.PrevRoom = current;
nodeToCheck.Weight = current.Weight + room.Weight;
}
}
}
visited.Add(current);
queue.Remove(current);
}
// If no end node was found, return null.
if (endNode == null)
{
return(null);
}
// The path to follow
List <RoomNode> path = new List <RoomNode>();
// begin with the end node
path.Add(endNode);
// keep adding the previous node to the final path
while (true)
{
// the previous node
RoomNode node = path.Last().PrevRoom;
if (node != null)
{
path.Add(node);
}
else
{
break;
}
}
// reverse so that current room is start room, and end room is the last room.
return(path.Select(x => x.Room).Reverse().ToList());
}
public RoomNode(Room room, float weight, RoomNode prevRoom)
{
Room = room;
Weight = weight;
PrevRoom = prevRoom;
}