/// <summary>
/// Moves to the next node
/// </summary>
/// <returns>True if the move to the next node was successful; otherwise false</returns>
public bool MoveNext()
{
if (this.current == null)
{
this.current = this.avlTree.GetFirstNode();
}
else
{
this.current = this.current.GetNextNode();
}
// Should check for an empty tree too :-)
if (this.current == null)
{
return(false);
}
return(true);
}
/// <summary>
/// Replace a node
/// </summary>
/// <param name="target">The node to replace</param>
/// <param name="source">The replacing node</param>
private static void Replace(AvlNode <T> target, AvlNode <T> source)
{
AvlNode <T> left = source.Left;
AvlNode <T> right = source.Right;
target.Balance = source.Balance;
target.Item = source.Item;
target.Left = left;
target.Right = right;
if (left != null)
{
left.Parent = target;
}
if (right != null)
{
right.Parent = target;
}
}
/// <summary>
/// Find child max height
/// </summary>
/// <param name="node">A node in the tree</param>
/// <returns>The height</returns>
private int RecursiveGetChildMaxHeight(AvlNode <T> node)
{
if (node == null)
{
return(0);
}
int leftHeight = 0;
if (node.Left != null)
{
leftHeight = this.RecursiveGetChildMaxHeight(node.Left);
}
int rightHeight = 0;
if (node.Right != null)
{
rightHeight = this.RecursiveGetChildMaxHeight(node.Right);
}
return(1 + Math.Max(leftHeight, rightHeight));
}
/// <summary>
/// Gets a node with the provided item
/// </summary>
/// <param name="item">An item to find</param>
/// <returns>The node with that item</returns>
protected AvlNode <T> GetNode(T item)
{
AvlNode <T> node = this.root;
while (node != null)
{
int compareResult = this.comparer.Compare(item, node.Item);
if (compareResult < 0)
{
node = node.Left;
}
else if (compareResult > 0)
{
node = node.Right;
}
else
{
return(node);
}
}
return(null);
}
/// <summary>
/// Removes a node
/// </summary>
/// <param name="item">item to remove</param>
/// <returns>True if successful; otherwise false</returns>
public virtual bool Remove(T item)
{
AvlNode <T> node = this.root;
while (node != null)
{
if (this.comparer.Compare(item, node.Item) < 0)
{
node = node.Left;
}
else if (this.comparer.Compare(item, node.Item) > 0)
{
node = node.Right;
}
else
{
this.RemoveNode(node);
return(true);
}
}
return(false);
}
/// <summary>
/// Gets a value indicating whether the tree contains an item
/// </summary>
/// <param name="item">The item to find</param>
/// <returns>True if the item is found; otherwise false;</returns>
public bool Contains(T item)
{
AvlNode <T> node = this.root;
while (node != null)
{
int compareResult = this.comparer.Compare(item, node.Item);
if (compareResult < 0)
{
node = node.Left;
}
else if (compareResult > 0)
{
node = node.Right;
}
else
{
return(true);
}
}
return(false);
}
/// <summary>
/// Iterate over each points to see if we can add it has a ConvexHull point.
/// It is specific by Quadrant to improve efficiency.
/// </summary>
/// <param name="point">a point</param>
//// [MethodImpl(MethodImplOptions.AggressiveInlining)]
internal override void ProcessPoint(ref MutablePoint point)
{
this.CurrentNode = this.Root;
AvlNode <MutablePoint> currentPrevious = null;
AvlNode <MutablePoint> currentNext = null;
while (this.CurrentNode != null)
{
var insertionSide = Side.Unknown;
if (point.X > this.CurrentNode.Item.X)
{
if (this.CurrentNode.Left != null)
{
this.CurrentNode = this.CurrentNode.Left;
continue;
}
currentPrevious = this.CurrentNode.GetPreviousNode();
if (CanQuickReject(ref point, ref currentPrevious.Item))
{
return;
}
if (!this.IsPointToTheRightOfOthers(currentPrevious.Item, this.CurrentNode.Item, point))
{
return;
}
// Ensure to have no duplicate
if (this.CurrentNode.Item == point)
{
return;
}
insertionSide = Side.Left;
}
else if (point.X < this.CurrentNode.Item.X)
{
if (this.CurrentNode.Right != null)
{
this.CurrentNode = this.CurrentNode.Right;
continue;
}
currentNext = this.CurrentNode.GetNextNode();
if (CanQuickReject(ref point, ref currentNext.Item))
{
return;
}
if (!this.IsPointToTheRightOfOthers(this.CurrentNode.Item, currentNext.Item, point))
{
return;
}
// Ensure to have no duplicate
if (this.CurrentNode.Item == point)
{
continue;
}
insertionSide = Side.Right;
}
else
{
if (point.Y <= this.CurrentNode.Item.Y)
{
return; // invalid point
}
// Replace CurrentNode point with point
this.CurrentNode.Item = point;
this.InvalidateNeighbors(this.CurrentNode.GetPreviousNode(), this.CurrentNode, this.CurrentNode.GetNextNode());
return;
}
// We should insert the point
// Try to optimize and verify if can replace a node instead insertion to minimize tree balancing
if (insertionSide == Side.Right)
{
currentPrevious = this.CurrentNode.GetPreviousNode();
if (currentPrevious != null && !this.IsPointToTheRightOfOthers(currentPrevious.Item, point, this.CurrentNode.Item))
{
this.CurrentNode.Item = point;
this.InvalidateNeighbors(currentPrevious, this.CurrentNode, currentNext);
return;
}
var nextNext = currentNext.GetNextNode();
if (nextNext != null && !this.IsPointToTheRightOfOthers(point, nextNext.Item, currentNext.Item))
{
currentNext.Item = point;
this.InvalidateNeighbors(null, currentNext, nextNext);
return;
}
}
else
{
// Left
currentNext = this.CurrentNode.GetNextNode();
if (currentNext != null && !this.IsPointToTheRightOfOthers(point, currentNext.Item, this.CurrentNode.Item))
{
this.CurrentNode.Item = point;
this.InvalidateNeighbors(currentPrevious, this.CurrentNode, currentNext);
return;
}
var previousPrevious = currentPrevious.GetPreviousNode();
if (previousPrevious != null && !this.IsPointToTheRightOfOthers(previousPrevious.Item, point, currentPrevious.Item))
{
currentPrevious.Item = point;
this.InvalidateNeighbors(previousPrevious, currentPrevious, null);
return;
}
}
// Should insert but no invalidation is required. (That's why we need to insert... can't replace an adjacent neighbor)
AvlNode <MutablePoint> newNode = new AvlNode <MutablePoint>();
if (insertionSide == Side.Right)
{
newNode.Parent = this.CurrentNode;
newNode.Item = point;
this.CurrentNode.Right = newNode;
this.AddBalance(newNode.Parent, -1);
}
else
{
// Left
newNode.Parent = this.CurrentNode;
newNode.Item = point;
this.CurrentNode.Left = newNode;
this.AddBalance(newNode.Parent, 1);
}
return;
}
}
/// <summary>
/// Removes a node
/// </summary>
/// <param name="node">node to remove</param>
protected void RemoveNode(AvlNode <T> node)
{
this.count--;
AvlNode <T> left = node.Left;
AvlNode <T> right = node.Right;
if (left == null)
{
if (right == null)
{
if (node == this.root)
{
this.root = null;
}
else
{
if (node.Parent.Left == node)
{
node.Parent.Left = null;
this.RemoveBalance(node.Parent, -1);
}
else if (node.Parent.Right == node)
{
node.Parent.Right = null;
this.RemoveBalance(node.Parent, 1);
}
}
}
else
{
Replace(node, right);
this.RemoveBalance(node, 0);
}
}
else if (right == null)
{
Replace(node, left);
this.RemoveBalance(node, 0);
}
else
{
AvlNode <T> successor = right;
if (successor.Left == null)
{
AvlNode <T> parent = node.Parent;
successor.Parent = parent;
successor.Left = left;
successor.Balance = node.Balance;
left.Parent = successor;
if (node == this.root)
{
this.root = successor;
}
else
{
if (parent.Left == node)
{
parent.Left = successor;
}
else
{
parent.Right = successor;
}
}
this.RemoveBalance(successor, 1);
}
else
{
while (successor.Left != null)
{
successor = successor.Left;
}
AvlNode <T> parent = node.Parent;
AvlNode <T> successorParent = successor.Parent;
AvlNode <T> successorRight = successor.Right;
if (successorParent.Left == successor)
{
successorParent.Left = successorRight;
}
else
{
successorParent.Right = successorRight;
}
if (successorRight != null)
{
successorRight.Parent = successorParent;
}
successor.Parent = parent;
successor.Left = left;
successor.Balance = node.Balance;
successor.Right = right;
right.Parent = successor;
left.Parent = successor;
if (node == this.root)
{
this.root = successor;
}
else
{
if (parent.Left == node)
{
parent.Left = successor;
}
else
{
parent.Right = successor;
}
}
this.RemoveBalance(successorParent, -1);
}
}
}
/// <summary>
/// Copies to an array
/// </summary>
/// <param name="array">The array to copy to</param>
/// <param name="index">start point</param>
/// <param name="count">number of items to copy</param>
public void CopyTo(T[] array, int index, int count)
{
if (array == null)
{
throw new ArgumentNullException("'array' can't be null");
}
if (index < 0)
{
throw new ArgumentException("'index' can't be null");
}
if (count < 0)
{
throw new ArgumentOutOfRangeException("'count' should be greater or equal to 0");
}
if (index > array.Length || count > array.Length - index)
{
throw new ArgumentException("The array size is not big enough to get all items");
}
if (count == 0)
{
return;
}
int indexIter = 0;
int indexArray = 0;
AvlNode <T> current = this.GetFirstNode();
while (current.GetNextNode() != null)
{
if (indexIter >= index)
{
array[indexArray] = current.Item;
indexArray++;
count--;
if (count == 0)
{
return;
}
}
indexIter++;
}
/*
* foreach (AvlNode<T> node in this.Nodes())
* {
* if (indexIter >= index)
* {
* array[indexArray] = node.Item;
* indexArray++;
* count--;
* if (count == 0)
* {
* return;
* }
* }
*
* indexIter++;
* }*/
}
/// <inheritdoc/>
public void Clear()
{
this.root = null;
this.count = 0;
}
/// <summary>
/// Resets the enumerator
/// </summary>
public void Reset()
{
this.current = null;
}
protected void InvalidateNeighbors(AvlNode <MutablePoint> pointPrevious, AvlNode <MutablePoint> pointNew, AvlNode <MutablePoint> pointNext)
{
bool invalidPoint;
if (pointPrevious != null)
{
AvlNode <MutablePoint> previousPrevious = pointPrevious.GetPreviousNode();
for (; ;)
{
if (previousPrevious == null)
{
break;
}
invalidPoint = !this.IsPointToTheRightOfOthers(previousPrevious.Item, pointNew.Item, pointPrevious.Item);
if (!invalidPoint)
{
break;
}
MutablePoint pointPrevPrev = previousPrevious.Item;
this.RemoveNode(pointPrevious);
pointPrevious = this.GetNode(pointPrevPrev);
previousPrevious = pointPrevious.GetPreviousNode();
}
}
// Invalidate next(s)
if (pointNext != null)
{
AvlNode <MutablePoint> nextNext = pointNext.GetNextNode();
for (; ;)
{
if (nextNext == null)
{
break;
}
invalidPoint = !this.IsPointToTheRightOfOthers(pointNew.Item, nextNext.Item, pointNext.Item);
if (!invalidPoint)
{
break;
}
MutablePoint pointNextNext = nextNext.Item;
this.RemoveNode(pointNext);
pointNext = this.GetNode(pointNextNext);
nextNext = pointNext.GetNextNode();
}
}
}
