Depth Manager

Question

Hello everyone. Here is a simple package with DepthManager, the question is in performance of it.
1) Create .fla AS3, size = 600x400, grey background.
2) Create in library a MovieClip, named THING, linkage = THING, and open it. Draw a 15-corner star in the centre of it. Fill by standart from-black-to-white linear gradient.
3) Set the name MAIN as main class of the document (don't forget save them all in one directory), open it, and paste there this code:
package 
       import flash.display.MovieClip;
          import flash.events.Event;
          import flash.events.MouseEvent;
          public class MAIN extends MovieClip
                   public var array_THINGS:Array = new Array();
                   public function MAIN()
                              var tmp_thing:MovieClip;
                              //BECAUSE I'M NOT GOING TO REMOVE THIS, I CAN USE ANONYMOUS FUNCTION
                              stage.addEventListener(MouseEvent.MOUSE_UP, function()
                                        //WE WILL CREATE SOME THINGS TO DISPLAY
                                        for(var i = 1; i <= 100; i++)
                                                  tmp_thing = new THING();
                                                  tmp_thing.x = Math.random() * 600;
                                                  tmp_thing.y = Math.random() * 400;
                                                  //LETS MAKE IT EASIER FOR PLAYER BY SETTING cacheAsBitmap TO true
                                                  tmp_thing.cacheAsBitmap = true;
                                                  addChild(tmp_thing);
                                                  array_THINGS.push({INSTANCE:tmp_thing});
                              stage.addEventListener(Event.ENTER_FRAME, function()
                                        ENTER_FRAME_1(); //USING DepthMan
                                        //ENTER_FRAME_2(); //NOT USING DepthMan
                                       //MAKE ONE OF THOSE FUNCTIONS IN // TO SEE THE DEFFERENCE IN FRAMERATE
                    private function ARRAY_THINGS_GET_POS_OF_OBJECT(element:*, index:int, arr:Array)
                              var thing_x = MovieClip(element.INSTANCE).x;
                              var thing_y = MovieClip(element.INSTANCE).y;
                              return {INSTANCE:element.INSTANCE, X:thing_x, Y:thing_y};
                    private function ENTER_FRAME_1()
                              var array_DETAILED_THINGS:Array = array_THINGS.map(ARRAY_THINGS_GET_POS_OF_OBJECT);
                              array_DETAILED_THINGS.sortOn(["Y", "X"], [Array.NUMERIC, Array.NUMERIC | Array.DESCENDING]);
                              for(var i in array_DETAILED_THINGS)
                                        var tmp_mc:MovieClip = MovieClip(array_DETAILED_THINGS[i].INSTANCE);
                                        tmp_mc.rotation += 7;
                                        tmp_mc.parent.setChildIndex(tmp_mc, i);
                    private function ENTER_FRAME_2()
                              for(var i in array_THINGS)
                                        var tmp_mc:MovieClip = MovieClip(array_THINGS[i].INSTANCE);
                                        tmp_mc.rotation += 7;
We click stage = we create 100 stars, each is rotated every frame.
Each frame the function ARRAY_THINGS_GET_POS_OF_OBJECT gets the position of the INSTANCE (it's a simple example, imagine that things may move, so the constant position will not suite).
Then things are sorted and reindexed.
Code works.
The main problem is:
With the ENTER_FRAME_1() turned ON (and ENTER_FRAME_2() turned off, ofcourse), the framerate is much lower, when 300 things (3 clicks) and more on the stage. We don't have so big decline, not using DepthManager (ENTER_FRAME_1() turned OFF and ENTER_FRAME_2() turned ON). And I don't even mention, that a star has not much dots to draw. So the problem is in setting indexes, or may be even in Array.map().
The tip is:
There is a way to use swapDepths, adding an EnterFrame function to each thing, which will "understand", if the thing is higher or lower(.y) from its neighbours, whose depths +1, -1. So it will be one check but by each star... 
The question is:
Will it work faster? Or there is another way to make all this RUN?)

Answer 1

I have actually had a chance to play around with it now
and with 400 stars my ENTER_FRAME_1() runs at 10 fps and so does ENTER_FRAME2()
I am using
package
          import flash.display.MovieClip;
          import flash.events.Event;
          import flash.events.MouseEvent;
          public class MAIN extends MovieClip
                    public var array_THINGS:Array = new Array();
                    private var stats:Stats = new Stats();
                    public function MAIN()
                              stage.addEventListener(MouseEvent.CLICK, mouseUpHandler);
                              stage.addEventListener(Event.ENTER_FRAME, enterFrameHandler);
                    private function mouseUpHandler(e:MouseEvent):void
                              var tmp_thing:THING;
                              //WE WILL CREATE SOME THINGS TO DISPLAY
                              for (var i = 1; i <= 100; i++)
                                        tmp_thing = new THING();
                                        tmp_thing.x = Math.random() * 600;
                                        tmp_thing.y = Math.random() * 400;
                                        //LETS MAKE IT EASIER FOR PLAYER BY SETTING cacheAsBitmap TO true
                                        tmp_thing.cacheAsBitmap = true;
                                        addChild(tmp_thing);
                                        array_THINGS.push(tmp_thing);
                              array_THINGS.sortOn(["y", "x"], Array.NUMERIC | Array.DESCENDING);
                              for (var j in array_THINGS)
                                        var tmp_mc:THING = THING(array_THINGS[j]);
                                        tmp_mc.parent.setChildIndex(tmp_mc, j);
                              addChild(stats);
                    private function enterFrameHandler(e:Event):void
                              ENTER_FRAME_1(); //USING DepthMan
                              //ENTER_FRAME_2(); //NOT USING DepthMan
                              //MAKE ONE OF THOSE FUNCTIONS IN // TO SEE THE DEFFERENCE IN FRAMERATE
                    private function ENTER_FRAME_1()
                              for (var i in array_THINGS)
                                        var tmp_mc:THING = THING(array_THINGS[i]);
                                        tmp_mc.rotation += 7;
                    private function ENTER_FRAME_2()
                              for (var i in array_THINGS)
                                        var tmp_mc:THING = THING(array_THINGS[i]);
                                        tmp_mc.rotation += 7;
and a copy of MrDoobs stats class
* stats.as
* https://github.com/mrdoob/Hi-ReS-Stats
* Released under MIT license:
* http://www.opensource.org/licenses/mit-license.php
* How to use:
*          addChild( new Stats() );
package {
          import flash.display.BitmapData;
          import flash.display.Sprite;
          import flash.events.Event;
          import flash.events.MouseEvent;
          import flash.geom.Matrix;
          import flash.geom.Rectangle;
          import flash.system.System;
          import flash.text.StyleSheet;
          import flash.text.TextField;
          import flash.utils.getTimer;
          public class Stats extends Sprite {
                    protected const WIDTH : uint = 70;
                    protected const HEIGHT : uint = 100;
                    protected var xml : XML;
                    protected var text : TextField;
                    protected var style : StyleSheet;
                    protected var timer : uint;
                    protected var fps : uint;
                    protected var ms : uint;
                    protected var ms_prev : uint;
                    protected var mem : Number;
                    protected var mem_max : Number;
                    protected var graph : BitmapData;
                    protected var rectangle : Rectangle;
                    protected var fps_graph : uint;
                    protected var mem_graph : uint;
                    protected var mem_max_graph : uint;
                    protected var colors : Colors = new Colors();
                     * <b>Stats</b> FPS, MS and MEM, all in one.
                    public function Stats() : void {
                              mem_max = 0;
                              xml = <xml><fps>FPS:</fps><ms>MS:</ms><mem>MEM:</mem><memMax>MAX:</memMax></xml>;
                              style = new StyleSheet();
                              style.setStyle('xml', {fontSize:'9px', fontFamily:'_sans', leading:'-2px'});
                              style.setStyle('fps', {color: hex2css(colors.fps)});
                              style.setStyle('ms', {color: hex2css(colors.ms)});
                              style.setStyle('mem', {color: hex2css(colors.mem)});
                              style.setStyle('memMax', {color: hex2css(colors.memmax)});
                              text = new TextField();
                              text.width = WIDTH;
                              text.height = 50;
                              text.styleSheet = style;
                              text.condenseWhite = true;
                              text.selectable = false;
                              text.mouseEnabled = false;
                              rectangle = new Rectangle(WIDTH - 1, 0, 1, HEIGHT - 50);
                              addEventListener(Event.ADDED_TO_STAGE, init, false, 0, true);
                              addEventListener(Event.REMOVED_FROM_STAGE, destroy, false, 0, true);
                    private function init(e : Event) : void {
                              graphics.beginFill(colors.bg);
                              graphics.drawRect(0, 0, WIDTH, HEIGHT);
                              graphics.endFill();
                              addChild(text);
                              graph = new BitmapData(WIDTH, HEIGHT - 50, false, colors.bg);
                              graphics.beginBitmapFill(graph, new Matrix(1, 0, 0, 1, 0, 50));
                              graphics.drawRect(0, 50, WIDTH, HEIGHT - 50);
                              addEventListener(MouseEvent.CLICK, onClick);
                              addEventListener(Event.ENTER_FRAME, update);
                    private function destroy(e : Event) : void {
                              graphics.clear();
                              while(numChildren > 0)
                                        removeChildAt(0);
                              graph.dispose();
                              removeEventListener(MouseEvent.CLICK, onClick);
                              removeEventListener(Event.ENTER_FRAME, update);
                    private function update(e : Event) : void {
                              timer = getTimer();
                              if( timer - 1000 > ms_prev ) {
                                        ms_prev = timer;
                                        mem = Number((System.totalMemory * 0.000000954).toFixed(3));
                                        mem_max = mem_max > mem ? mem_max : mem;
                                        fps_graph = Math.min(graph.height, ( fps / stage.frameRate ) * graph.height);
                                        mem_graph = Math.min(graph.height, Math.sqrt(Math.sqrt(mem * 5000))) - 2;
                                        mem_max_graph = Math.min(graph.height, Math.sqrt(Math.sqrt(mem_max * 5000))) - 2;
                                        graph.scroll(-1, 0);
                                        graph.fillRect(rectangle, colors.bg);
                                        graph.setPixel(graph.width - 1, graph.height - fps_graph, colors.fps);
                                        graph.setPixel(graph.width - 1, graph.height - ( ( timer - ms ) >> 1 ), colors.ms);
                                        graph.setPixel(graph.width - 1, graph.height - mem_graph, colors.mem);
                                        graph.setPixel(graph.width - 1, graph.height - mem_max_graph, colors.memmax);
                                        xml.fps = "FPS: " + fps + " / " + stage.frameRate;
                                        xml.mem = "MEM: " + mem;
                                        xml.memMax = "MAX: " + mem_max;
                                        fps = 0;
                              fps++;
                              xml.ms = "MS: " + (timer - ms);
                              ms = timer;
                              text.htmlText = xml;
                    private function onClick(e : MouseEvent) : void {
                              mouseY / height > .5 ? stage.frameRate-- : stage.frameRate++;
                              xml.fps = "FPS: " + fps + " / " + stage.frameRate; 
                              text.htmlText = xml;
                    // .. Utils
                    private function hex2css( color : int ) : String {
                              return "#" + color.toString(16);
class Colors {
          public var bg : uint = 0x000033;
          public var fps : uint = 0xffff00;
          public var ms : uint = 0x00ff00;
          public var mem : uint = 0x00ffff;
          public var memmax : uint = 0xff0070;