Brand new highly optimised QuadTree added, populated by the game loop and world ready to be queried as often as you want in your game loop, without creating hundreds of new QuadTrees each frame.

src/physics/arcade/ArcadePhysics.js

@@ -8,9 +8,16 @@ Phaser.Physics.Arcade = function (game) {
 	this.bounds = new Phaser.Rectangle(0, 0, game.world.width, game.world.height);
 
 	/**
+	* Used by the QuadTree to set the maximum number of objects
 	* @type {number}
 	*/
-	this.worldDivisions = 6;
+	this.maxObjects = 10;
+
+	/**
+	* Used by the QuadTree to set the maximum number of levels
+	* @type {number}
+	*/
+	this.maxLevels = 4;
 
     this.LEFT = 0x0001;
     this.RIGHT = 0x0010;
@@ -25,6 +32,8 @@ Phaser.Physics.Arcade = function (game) {
 	this.OVERLAP_BIAS = 4;
 	this.TILE_OVERLAP = false;
 
+	this.quadTree = null;
+
 	//	avoid gc spikes by caching these values for re-use
 	this._obj1Bounds = new Phaser.Rectangle;
 	this._obj2Bounds = new Phaser.Rectangle;
@@ -126,6 +135,20 @@ Phaser.Physics.Arcade.prototype = {
 
         return velocity;
 
+    },
+
+    preUpdate: function () {
+
+    	//	Create our tree which all of the Physics bodies will add themselves to
+    	this.quadTree = new Phaser.QuadTree(this.game.world.bounds.x, this.game.world.bounds.y, this.game.world.bounds.width, this.game.world.bounds.height, this.maxObjects, this.maxLevels);
+
+    },
+
+    postUpdate: function () {
+
+    	//	Clear the tree ready for the next update
+    	this.quadTree.clear();
+
     },
 
      /**
@@ -139,28 +162,6 @@ Phaser.Physics.Arcade.prototype = {
      */
     overlap: function (object1, object2, notifyCallback, processCallback) {
 
-        if (object1 == null)
-        {
-            object1 = this._game.world.group;
-        }
-
-        if (object2 == object1)
-        {
-            object2 = null;
-        }
-
-        Phaser.QuadTree.divisions = this.worldDivisions;
-
-        var quadTree = new Phaser.QuadTree(this._game.world.bounds.x, this._game.world.bounds.y, this._game.world.bounds.width, this._game.world.bounds.height);
-
-        quadTree.load(object1, object2, notifyCallback, processCallback);
-
-        var result = quadTree.execute();
-
-        quadTree.destroy();
-
-        quadTree = null;
-
         return result;
 
     },

src/physics/arcade/Body.js

@@ -58,6 +58,8 @@ Phaser.Physics.Arcade.Body = function (sprite) {
     this.allowRotation = false;
     this.allowGravity = true;
 
+    this.collideWorldBounds = false;
+
 	this.lastX = sprite.x;
 	this.lastY = sprite.y;
 
@@ -91,10 +93,50 @@ Phaser.Physics.Arcade.Body.prototype = {
 		this.bounds.x = this.x;
 		this.bounds.y = this.y;
 
+		if (this.allowCollisions & this.ANY)
+		{
+			this.game.physics.quadTree.insert(this);
+		}
+
+	},
+
+	checkWorldBounds: function () {
+
+		if (this.bounds.x < this.game.world.bounds.x)
+		{
+			this.x = this.game.world.bounds.x;
+			this.velocity.x *= -1;
+			this.velocity.x *= this.bounce.x;
+		}
+		else if (this.bounds.right > this.game.world.bounds.right)
+		{
+			this.x = this.game.world.bounds.right - this.width;
+			this.velocity.x *= -1;
+			this.velocity.x *= this.bounce.x;
+		}
+
+		if (this.bounds.y < this.game.world.bounds.y)
+		{
+			this.y = this.game.world.bounds.y;
+			this.velocity.y *= -1;
+			this.velocity.y *= this.bounce.y;
+		}
+		else if (this.bounds.bottom > this.game.world.bounds.bottom)
+		{
+			this.y = this.game.world.bounds.bottom - this.height;
+			this.velocity.y *= -1;
+			this.velocity.y *= this.bounce.y;
+		}
+
 	},
 
 	postUpdate: function () {
 
+		if (this.collideWorldBounds)
+		{
+			this.checkWorldBounds();
+		}
+
 		this.sprite.x = this.x - this.offset.x + (this.sprite.anchor.x * this.width);
 		this.sprite.y = this.y - this.offset.y + (this.sprite.anchor.y * this.height);
 
@@ -122,6 +164,7 @@ Phaser.Physics.Arcade.Body.prototype = {
 
 	},
 
+	/*
     hullWidth: function () {
 
         if (this.deltaX() > 0)
@@ -173,6 +216,7 @@ Phaser.Physics.Arcade.Body.prototype = {
         }
 
     },
+    */
 
     deltaAbsX: function () {
         return (this.deltaX() > 0 ? this.deltaX() : -this.deltaX());