/// <summary>
/// Maps a RegionTree to a grid space. Uses a Greedy algorithm.
/// </summary>
/// <param name="r">The RegionTree used for the mapping</param>
/// <returns>Null if unsuccesful, a dictionary of Points & RegionTreeMarkers otherwise.</returns>
public override Dictionary<Point, RegionMarker> mapToWorld(RegionTree tree)
{
Dictionary<Point, RegionMarker> markers = new Dictionary<Point, RegionMarker>(); //will contain the RegionMarker objects for this world
Dictionary<RegionTreeNode, Point> parents = new Dictionary<RegionTreeNode, Point>(); //will contain every node that has already been given a location
List<RegionTreeNode> queue = new List<RegionTreeNode>(); //The list of nodes to be processed
Random generator = new Random(10); //Initializes a random number generator
queue.Add(tree.root); //Adds the root node to the queue
//While there are still nodes in the queue
while (queue.Count > 0)
{
RegionTreeNode currNode = queue.ElementAt(0); //The current node is the head of the queue
RegionTreeNode parent = currNode.Parent; //The parent of the current node
queue.AddRange(currNode.children); //Adds the children of the current node to the queue
queue.Remove(currNode); //Removes the current node from the queue
if (parent == null) //If the current node is the root of the tree
{
//Place root node at the origin
Point loc = new Point(0, 0);
RegionMarker marker = new RegionMarker(loc, false, false, false, false, currNode.region.environment.getName());
parents.Add(currNode, loc);
markers.Add(loc, marker);
}
else
{
//If the parent node of the current node is not in the Dictionary already, throw an Exception. Should never occur
if (!parents.ContainsKey(parent))
throw new Exception("Parent not in Dictionary");
Point parLoc = parents[parent]; //Gets the location of this node's parent node
bool success = false; //whether or not a placement can be found for this node
List<int> tried = new List<int>(); //The directions that have been tried so far
//Attempts to place the child node in one of the four directions, randomly chosen until succesful
while (!success || tried.Count < 4)
{
int direction = generator.Next(4); //Randomly generated direction
if (!tried.Contains(direction)) //If this direction has not already been done, add it to the list of tried directions
tried.Add(direction);
Point placement = parLoc; //The location of the placement. Initialized to the parent location
if (direction == 0) placement = RegionTreeMapper.getNorth(parLoc); //If north
else if (direction == 1) placement = RegionTreeMapper.getSouth(parLoc); //If south
else if (direction == 2) placement = RegionTreeMapper.getEast(parLoc); //If east
else if (direction == 3) placement = RegionTreeMapper.getWest(parLoc); //If west
success = !markers.ContainsKey(placement); //If the location of the chosen direction already has a node in it
if (success) //If the location is available
{
RegionMarker parentMarker = markers[parLoc]; //Get the marker of the parent
RegionMarker childMarker = new RegionMarker(placement, false, false, false, false, currNode.region.environment.getName()); //initializes a RegionMarker for this node
if (direction == 0) //If North
{
parentMarker.connectsTop = true; //Parent is connected at the top
childMarker.connectsBottom = true; //Child is connected at the bottom
}
else if (direction == 1) //If South
{
parentMarker.connectsBottom = true; //Parent is connected at the bottom
childMarker.connectsTop = true; //Child is connected at the top
}
else if (direction == 2) //If East
{
parentMarker.connectsRight = true; //Parent is connected at the right
childMarker.connectsLeft = true; //Child is connected at the left
}
else if (direction == 3) //If West
{
parentMarker.connectsLeft = true; //Parent is connected at the left
childMarker.connectsRight = true; //Child is connected at the right
}
parents.Add(currNode, placement); //Add the newly created node's location to the parents Dictionary
markers.Add(placement, childMarker); //Adds the newly created node to the markers
}
else //If the location is unavailable, the algorithm failed and returns null
return null;
}
}
}
return markers;
}
private void AddToDictionary(RegionMarker regionMarker)
{
KeyDictionary.Add(RegionMarkerCount.ToString(CultureInfo.InvariantCulture), regionMarker);
RegionMarkerCount++;
}
