public override string ToString()
{
var white = WhiteNode.ToString() ?? EmptyNodeIndicator;
var black = BlackNode.ToString() ?? EmptyNodeIndicator;
return($"<{white} {black}>");
}
public Node Remove(T oldElement)
{
if (this.data.Equals(oldElement))
{
return(WhiteNode.GetSingleton());
}
return(this);
}
public Node Remove(T oldElement)
{
float positionX = oldElement.GetPositionX();
float positionY = oldElement.GetPositionY();
if (!myRegion.contains(oldElement))
{
if (isRootNode)
{
return(this);
}
throw new System.Exception("Element does not belong in this Grey Node");
}
for (int i = 0; i < nodes.Length; i++)
{
if (childRegions[i].contains(oldElement))
{
nodes[i] = nodes[i].Remove(oldElement);
}
}
if (isRootNode)
{
return(this);
}
int countBlackNodes = 0;
int countGreyNodes = 0;
Node lastBlackNode = null;
foreach (Node node in nodes)
{
if (node is GreyNode)
{
countGreyNodes++;
return(this);
}
else if (node is BlackNode)
{
countBlackNodes++;
lastBlackNode = node;
}
}
if (countBlackNodes == 0 && countGreyNodes == 0 && !isRootNode)
{
return(WhiteNode.GetSingleton());
}
else if (countBlackNodes == 1 && countGreyNodes == 0 && lastBlackNode != null && !isRootNode)
{
return(lastBlackNode);
}
return(this);
}
public GreyNode(Region region, bool rootNode = false)
{
if (region.width < 0 || region.height < 0)
{
throw new System.Exception("Invalid boundaries in GreyNode");
}
Node whiteSingleton = WhiteNode.GetSingleton();
nodes = new Node[4] {
whiteSingleton, whiteSingleton, whiteSingleton, whiteSingleton
};
this.isRootNode = rootNode;
myRegion = region;
childRegions = region.generateSubregions();
}
/**
* Create an image which is represented using a QuadTreeNode.
*
* @param size size of image
* @param center_x x coordinate of center
* @param center_y; y coordinate of center
* @param parent parent quad tree node
* @param quadrant the quadrant that the sub tree is in
* @param level the level of the tree
*/
public static QuadTreeNode createTree(int size, int center_x, int center_y, QuadTreeNode parent, Quadrant quadrant, int level)
{
QuadTreeNode node;
int intersect = checkIntersect(center_x, center_y, size);
size = size / 2;
if (intersect == 0 && size < 512)
{
node = new WhiteNode(quadrant, parent);
}
else if (intersect == 2)
{
node = new BlackNode(quadrant, parent);
}
else
{
if (level == 0)
{
node = new BlackNode(quadrant, parent);
}
else
{
node = new GreyNode(quadrant, parent);
QuadTreeNode sw = createTree(size, center_x - size, center_y - size, node,
Quadrant.cSouthWest, level - 1);
QuadTreeNode se = createTree(size, center_x + size, center_y - size, node,
Quadrant.cSouthEast, level - 1);
QuadTreeNode ne = createTree(size, center_x + size, center_y + size, node,
Quadrant.cNorthEast, level - 1);
QuadTreeNode nw = createTree(size, center_x - size, center_y + size, node,
Quadrant.cNorthWest, level - 1);
node.setChildren(nw, ne, sw, se);
}
}
return(node);
}
/**
* Create an image which is represented using a QuadTreeNode.
*
* @param size size of image
* @param center_x x coordinate of center
* @param center_y; y coordinate of center
* @param parent parent quad tree node
* @param quadrant the quadrant that the sub tree is in
* @param level the level of the tree
*/
public static QuadTreeNode createTree(int size, int center_x, int center_y, QuadTreeNode parent, Quadrant quadrant, int level)
{
QuadTreeNode node;
int intersect = checkIntersect(center_x, center_y, size);
size = size / 2;
if(intersect == 0 && size < 512)
{
node = new WhiteNode(quadrant, parent);
}
else if(intersect == 2)
{
node = new BlackNode(quadrant, parent);
}
else
{
if(level == 0)
{
node = new BlackNode(quadrant, parent);
}
else
{
node = new GreyNode(quadrant, parent);
QuadTreeNode sw = createTree(size, center_x - size, center_y - size, node,
Quadrant.cSouthWest, level - 1);
QuadTreeNode se = createTree(size, center_x + size, center_y - size, node,
Quadrant.cSouthEast, level - 1);
QuadTreeNode ne = createTree(size, center_x + size, center_y + size, node,
Quadrant.cNorthEast, level - 1);
QuadTreeNode nw = createTree(size, center_x - size, center_y + size, node,
Quadrant.cNorthWest, level - 1);
node.setChildren(nw, ne, sw, se);
}
}
return node;
}
