/// <summary>
/// Subdivide this QuadTree and move it's children into the appropriate Quads where applicable.
/// </summary>
private void Subdivide()
{
// We've reached capacity, subdivide...
PrecisePoint size = new PrecisePoint(rect.Width / 2.0d, rect.Height / 2.0d);
PrecisePoint mid = new PrecisePoint(rect.X + size.X, rect.Y + size.Y);
childTL = new QuadTreeNode <T>(this, new PreciseRectangle(rect.Left, rect.Top, size.X, size.Y));
childTR = new QuadTreeNode <T>(this, new PreciseRectangle(mid.X, rect.Top, size.X, size.Y));
childBL = new QuadTreeNode <T>(this, new PreciseRectangle(rect.Left, mid.Y, size.X, size.Y));
childBR = new QuadTreeNode <T>(this, new PreciseRectangle(mid.X, mid.Y, size.X, size.Y));
// If they're completely contained by the quad, bump objects down
for (int i = 0; i < objects.Count; i++)
{
QuadTreeNode <T> destTree = GetDestinationTree(objects[i]);
if (destTree != this)
{
// Insert to the appropriate tree, remove the object, and back up one in the loop
destTree.Insert(objects[i]);
Remove(objects[i]);
i--;
}
}
}
private void Relocate(QuadTreeObject <T> item)
{
// Are we still inside our parent?
if (QuadRect.Contains(item.Data.QuadBounds))
{
// Good, have we moved inside any of our children?
if (childTL != null)
{
QuadTreeNode <T> dest = GetDestinationTree(item);
if (item.Owner != dest)
{
// Delete the item from this quad and add it to our child
// Note: Do NOT clean during this call, it can potentially delete our destination quad
QuadTreeNode <T> formerOwner = item.Owner;
Delete(item, false);
dest.Insert(item);
// Clean up ourselves
formerOwner.CleanUpwards();
}
}
}
else
{
// We don't fit here anymore, move up, if we can
if (parent != null)
{
parent.Relocate(item);
}
}
}
///<summary>
///Adds an item to the <see cref="T:System.Collections.Generic.ICollection`1" />.
///</summary>
///
///<param name="item">The object to add to the <see cref="T:System.Collections.Generic.ICollection`1" />.</param>
///<exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1" /> is read-only.</exception>
public void Add(T item)
{
lock (objLock) {
QuadTreeObject <T> wrappedObject = new QuadTreeObject <T>(item);
wrappedDictionary.Add(item, wrappedObject);
quadTreeRoot.Insert(wrappedObject);
}
}
/// <summary>
/// Insert an item into this QuadTree object.
/// </summary>
/// <param name="item">The item to insert.</param>
internal void Insert(QuadTreeObject <T> item)
{
// If this quad doesn't contain the items rectangle, do nothing, unless we are the root
if (!rect.Contains(item.Data.QuadBounds))
{
//System.Diagnostics.Debug.Assert(parent == null, "We are not the root, and this object doesn't fit here. How did we get here?");
if (parent == null)
{
// This object is outside of the QuadTree bounds, we should add it at the root level
Add(item);
}
else
{
parent.Insert(item);
return;
}
}
if (objects == null ||
(childTL == null && objects.Count + 1 <= maxObjectsPerNode))
{
// If there's room to add the object, just add it
Add(item);
}
else
{
// No quads, create them and bump objects down where appropriate
if (childTL == null)
{
Subdivide();
}
// Find out which tree this object should go in and add it there
QuadTreeNode <T> destTree = GetDestinationTree(item);
if (destTree == this)
{
Add(item);
}
else
{
destTree.Insert(item);
}
}
}
