Package org.djutils.quadtree

Class QuadTree<T extends Envelope>

java.lang.Object

org.djutils.quadtree.QuadTree<T>

Type Parameters:

T - Type of object stored in this quad tree

All Implemented Interfaces:

Serializable, Iterable<T>, Collection<T>

public class QuadTree<T extends Envelope>
extends Object
implements Collection<T>, Serializable

Quad tree for 2D objects. For now, this implementation needs an ultimate outer bounding box. No part of any 2D string object may exceed that bounding box. A link to each stored 2D object will be stored in each sub-box that it intersects.

Author:

Peter Knoppers

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	QuadTree.SubTree<T extends Envelope>	Sub tree of a quad tree.

Constructor Summary

Constructors

Constructor	Description
QuadTree(int maximumLoad, double minimumSize, double left, double bottom, double right, double top)	Create a new QuadTree object (or a sub-tree).

Method Summary

Modifier and Type	Method	Description
boolean	add(T e)
boolean	addAll(Collection<? extends T> c)
void	clear()
boolean	contains(Object o)
boolean	containsAll(Collection<?> c)
String	dump(String indent)	Dump a quad tree.
int	getMaxLoad()	Return the number of objects at which it is time to try to re-balance.
double	getMinimumSize()	Return the minimum sub-tree rectangle size.
int	getSubTreeCount()	Return the total number of sub trees.
(package private) void	incrementSubTreeCount()	Increment the number of sub trees created.
boolean	isEmpty()
Iterator<T>	iterator()
Iterator<T>	iterator(Rectangle searchArea)	Find all elements intersecting a given bounding box.
boolean	remove(Object o)
boolean	removeAll(Collection<?> c)
boolean	retainAll(Collection<?> c)
int	size()
Object[]	toArray()
<T> T[]	toArray(T[] a)
String	toString()
String	toString(int expandDepth)	Make a textual description of this quad tree drilling down to the prescribed depth.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

equals, hashCode, parallelStream, removeIf, spliterator, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

QuadTree

public QuadTree(int maximumLoad,
                double minimumSize,
                double left,
                double bottom,
                double right,
                double top)

Create a new QuadTree object (or a sub-tree).

Parameters:

maximumLoad - int; number of elements at any level that warrants investigating if the tree can be re-balanced

minimumSize - double; minimum width or height of a sub tree Rectangle (smaller sub tree are never created)

left - double; the lowest X-coordinate that is allowed (inclusive)

bottom - double; the lowest Y-coordinate that is allowed (inclusive)

right - double; the highest X-coordinate that is allowed (exclusive)

top - double; the highest Y-coordinate that is allowed (exclusive)

Method Detail

getMaxLoad

public int getMaxLoad()

Return the number of objects at which it is time to try to re-balance.

Returns:

int; the number of objects at which it is time to try to re-balance

getMinimumSize

public double getMinimumSize()

Return the minimum sub-tree rectangle size.

Returns:

double; the minimum sub-tree rectangle size

size

public int size()

Specified by:

size in interface Collection<T extends Envelope>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<T extends Envelope>

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<T extends Envelope>

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Collection<T extends Envelope>

Specified by:

iterator in interface Iterable<T extends Envelope>

iterator

public Iterator<T> iterator(Rectangle searchArea)

Find all elements intersecting a given bounding box. This iterator cannot be used to remove elements, but the remove method can be safely called while the iterator is active.

Parameters:

searchArea - Rectangle; the bounding box

Returns:

Iterator<T>; iterator that returns all elements that intersect the given bounding box

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<T extends Envelope>

toArray

public <T> T[] toArray(T[] a)

Specified by:

toArray in interface Collection<T extends Envelope>

add

public boolean add(T e)

Specified by:

add in interface Collection<T extends Envelope>

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection<T extends Envelope>

containsAll

public boolean containsAll(Collection<?> c)

Specified by:

containsAll in interface Collection<T extends Envelope>

addAll

public boolean addAll(Collection<? extends T> c)

Specified by:

addAll in interface Collection<T extends Envelope>

removeAll

public boolean removeAll(Collection<?> c)

Specified by:

removeAll in interface Collection<T extends Envelope>

retainAll

public boolean retainAll(Collection<?> c)

Specified by:

retainAll in interface Collection<T extends Envelope>

clear

public void clear()

Specified by:

clear in interface Collection<T extends Envelope>

incrementSubTreeCount

void incrementSubTreeCount()

Increment the number of sub trees created.

getSubTreeCount

public int getSubTreeCount()

Return the total number of sub trees.

Returns:

int; the total number of sub trees

toString

public String toString()

Overrides:

toString in class Object

toString

public String toString(int expandDepth)

Make a textual description of this quad tree drilling down to the prescribed depth.

Parameters:

expandDepth - int; maximum depth to descend

Returns:

String; textual description of this quad tree

dump

public String dump(String indent)

Dump a quad tree.

Parameters:

indent - String; prefix for each output line

Returns:

String; textual description of this quad tree.