The methods setStageReference and removeStageReference have been removed from all Pixi classes. Objects no longer have stage properties, or references to the Stage object. This is because no reference to the Stage is required for any calculations, and Phaser can only have 1 Stage, so adding and removing references to it were superfluous actions.

Author: photonstorm

README.md

@@ -356,7 +356,7 @@ children except Groups. So now calculations are correct.
 used in the new getBounds function.
 * Corrected DisplayObjects default `_bounds` rect from (0, 0, 1, 1) to (0, 0, 0, 0).
 * Thanks to @fmflame for his hard work on the above (#2639 #2627)
-*
+* The methods `setStageReference` and `removeStageReference` have been removed from all Pixi classes. Objects no longer have `stage` properties, or references to the Stage object. This is because no reference to the Stage is required for any calculations, and Phaser can only have 1 Stage, so adding and removing references to it were superfluous actions.
 
 For changes in previous releases please see the extensive [Version History](https://github.com/photonstorm/phaser/blob/master/CHANGELOG.md).
 

src/pixi/display/DisplayObject.js

@@ -15,7 +15,7 @@
 * @class PIXI.DisplayObject
 * @constructor
 */
-PIXI.DisplayObject = function() {
+PIXI.DisplayObject = function () {
 
     /**
     * The coordinates, in pixels, of this DisplayObject, relative to its parent container.
@@ -116,15 +116,6 @@ PIXI.DisplayObject = function() {
     */
     this.parent = null;
 
-    /**
-    * The stage that this DisplayObject is connected to.
-    * 
-    * @property {PIXI.Stage} stage
-    * @default
-    * @readOnly
-    */
-    this.stage = null;
-
     /**
     * The multiplied alpha value of this DisplayObject. A value of 1 is fully opaque. A value of 0 is transparent.
     * This value is the calculated total, based on the alpha values of all parents of this DisplayObjects 
@@ -261,8 +252,7 @@ PIXI.DisplayObject.prototype = {
     /**
     * Destroy this DisplayObject.
     *
-    * Removes any cached sprites, sets renderable flag to false, and nulls references to the Stage, filters,
-    * bounds and mask.
+    * Removes any cached sprites, sets renderable flag to false, and nulls filters, bounds and mask.
     *
     * Also iteratively calls `destroy` on any children.
     *
@@ -284,7 +274,6 @@ PIXI.DisplayObject.prototype = {
 
         this.hitArea = null;
         this.parent = null;
-        this.stage = null;
         this.worldTransform = null;
         this.filterArea = null;
         this.renderable = false;
@@ -411,21 +400,6 @@ PIXI.DisplayObject.prototype = {
 
     },
 
-    /**
-    * Sets the root Stage object that this DisplayObject is connected to.
-    *
-    * @method PIXI.DisplayObject#setStageReference
-    * @param {Phaser.Stage} stage - The stage that the object will have as its current stage reference
-    * @return {PIXI.DisplayObject} - A reference to this DisplayObject.
-    */
-    setStageReference: function (stage)
-    {
-        this.stage = stage;
-
-        return this;
-
-    },
-
     /**
     * To be overridden by classes that require it.
     *