Phaser.QuadTree = function (x, y, width, height, maxObjects, maxLevels, level){ 
this.maxObjects = maxObjects || 10; 
this.maxLevels = maxLevels || 4; 
this.level = level || 0; 
this.bounds = { 
x: Math.round(x),
y: Math.round(y),
width: width,
height: height,
subWidth: Math.floor(width / 2),
subHeight: Math.floor(height / 2),
right: Math.round(x) + Math.floor(width / 2),
bottom: Math.round(y) + Math.floor(height / 2)}
; 
this.objects = [] ; 
this.nodes = [] ; 
} 
; 
Phaser.QuadTree.prototype = { 
populate: function (group){ 
group.forEach(this.populateHandler, this, true ); 
} 
,
populateHandler: function (sprite){ 
if (sprite.body && sprite.body.checkCollision.none === false  && sprite.alive) { 
this.insert(sprite.body); 
} 
} 
,
split: function (){ 
this.level++ ; 
this.nodes[0] = new Phaser.QuadTree(this.bounds.right, this.bounds.y, this.bounds.subWidth, this.bounds.subHeight, this.maxObjects, this.maxLevels, this.level); 
this.nodes[1] = new Phaser.QuadTree(this.bounds.x, this.bounds.y, this.bounds.subWidth, this.bounds.subHeight, this.maxObjects, this.maxLevels, this.level); 
this.nodes[2] = new Phaser.QuadTree(this.bounds.x, this.bounds.bottom, this.bounds.subWidth, this.bounds.subHeight, this.maxObjects, this.maxLevels, this.level); 
this.nodes[3] = new Phaser.QuadTree(this.bounds.right, this.bounds.bottom, this.bounds.subWidth, this.bounds.subHeight, this.maxObjects, this.maxLevels, this.level); 
} 
,
insert: function (body){ 
var i = 0; 
var index; 
if (this.nodes[0] != null ) { 
index = this.getIndex(body); 
if (index !== -1) { 
this.nodes[index].insert(body); 
return ; 
} 
} 
this.objects.push(body); 
if (_AN_Read_length('length', this.objects) > this.maxObjects && this.level < this.maxLevels) { 
if (this.nodes[0] == null ) { 
this.split(); 
} 
while (i < _AN_Read_length('length', this.objects)){ 
index = this.getIndex(this.objects[i]); 
if (index !== -1) { 
this.nodes[index].insert(this.objects.splice(i, 1)[0]); 
} 
 else { 
i++ ; 
} 
} 
} 
} 
,
getIndex: function (rect){ 
var index = -1; 
if (rect.x < this.bounds.right && rect.right < this.bounds.right) { 
if ((rect.y < this.bounds.bottom && rect.bottom < this.bounds.bottom)) { 
index = 1; 
} 
 else if ((rect.y > this.bounds.bottom)) { 
index = 2; 
} 
} 
 else if (rect.x > this.bounds.right) { 
if ((rect.y < this.bounds.bottom && rect.bottom < this.bounds.bottom)) { 
index = 0; 
} 
 else if ((rect.y > this.bounds.bottom)) { 
index = 3; 
} 
} 
return index; 
} 
,
retrieve: function (sprite){ 
var returnObjects = this.objects; 
sprite.body.quadTreeIndex = this.getIndex(sprite.body); 
if (this.nodes[0]) { 
if (sprite.body.quadTreeIndex !== -1) { 
returnObjects = returnObjects.concat(this.nodes[sprite.body.quadTreeIndex].retrieve(sprite)); 
} 
 else { 
returnObjects = returnObjects.concat(this.nodes[0].retrieve(sprite)); 
returnObjects = returnObjects.concat(this.nodes[1].retrieve(sprite)); 
returnObjects = returnObjects.concat(this.nodes[2].retrieve(sprite)); 
returnObjects = returnObjects.concat(this.nodes[3].retrieve(sprite)); 
} 
} 
return returnObjects; 
} 
,
clear: function (){ 
this.objects = [] ; 
for (var i = 0, len = _AN_Read_length('length', this.nodes); 
i < len; i++ ){ 
if (this.nodes[i]) { 
_AN_Call_clear('clear', this.nodes[i]); 
delete this.nodes[i]; 
} 
} 
} 
}
; 
Phaser.QuadTree.prototype.constructor = Phaser.QuadTree;