/// <summary>
/// Get the objects in this tree that intersect with the specified rectangle.
/// </summary>
/// <param name="searchRect">The rectangle to find objects in.</param>
/// <param name="results">A reference to a list that will be populated with the results.</param>
internal void GetObjects(BoundingBox2D searchRect, ref List <T> results)
{
// We can't do anything if the results list doesn't exist
if (results != null)
{
if (searchRect.Contains(this.rect))
{
// If the search area completely contains this quad, just get every object this quad and all it's children have
GetAllObjects(ref results);
}
else if (searchRect.Intersects(this.rect))
{
// Otherwise, if the quad isn't fully contained, only add objects that intersect with the search rectangle
if (objects != null)
{
for (int i = 0; i < objects.Count; i++)
{
if (searchRect.Intersects(objects[i].Data.BoundingBox2D))
{
results.Add(objects[i].Data);
}
}
}
// Get the objects for the search rectangle from the children
if (childTL != null)
{
childTL.GetObjects(searchRect, ref results);
childTR.GetObjects(searchRect, ref results);
childBL.GetObjects(searchRect, ref results);
childBR.GetObjects(searchRect, ref results);
}
}
}
}
/// <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.BoundingBox2D))
{
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
{
return;
}
}
if (objects == null ||
(childTL == null && objects.Count < 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);
}
}
}
