package
{
import flash.display.*;
import mx.collections.*;
import mx.core.*;
public class GameObjectManager
{
// double buffer
public var backBuffer:BitmapData;
// colour to use to clear backbuffer with
public var clearColor:uint = 0xFF0043AB;
// static instance
protected static var instance:GameObjectManager = null;
// the last frame time
protected var lastFrame:Date;
// a collection of the GameObjects
protected var gameObjects:ArrayCollection = new ArrayCollection();
// a collection where new GameObjects are placed, to avoid adding items
// to gameObjects while in the gameObjects collection while it is in a loop
protected var newGameObjects:ArrayCollection = new ArrayCollection();
// a collection where removed GameObjects are placed, to avoid removing items
// to gameObjects while in the gameObjects collection while it is in a loop
protected var removedGameObjects:ArrayCollection = new ArrayCollection();
static public function get Instance():GameObjectManager
{
if ( instance == null )
instance = new GameObjectManager();
return instance;
}
public function GameObjectManager()
{
if ( instance != null )
throw new Error( "Only one Singleton instance should be instantiated" );
backBuffer = new BitmapData(Application.application.width, Application.application.height, false);
}
public function startup():void
{
lastFrame = new Date();
new Bounce().startupBounce();
}
public function shutdown():void
{
shutdownAll();
}
public function enterFrame():void
{
// Calculate the time since the last frame
var thisFrame:Date = new Date();
var seconds:Number = (thisFrame.getTime() - lastFrame.getTime())/1000.0;
lastFrame = thisFrame;
removeDeletedGameObjects();
insertNewGameObjects();
// now allow objects to update themselves
for each (var gameObject:GameObject in gameObjects)
{
if (gameObject.inuse)
gameObject.enterFrame(seconds);
}
drawObjects();
}
protected function drawObjects():void
{
backBuffer.fillRect(backBuffer.rect, clearColor);
// draw the objects
for each (var gameObject:GameObject in gameObjects)
{
if (gameObject.inuse)
gameObject.copyToBackBuffer(backBuffer);
}
}
public function addGameObject(gameObject:GameObject):void
{
newGameObjects.addItem(gameObject);
}
public function removeGameObject(gameObject:GameObject):void
{
removedGameObjects.addItem(gameObject);
}
protected function shutdownAll():void
{
// don't dispose objects twice
for each (var gameObject:GameObject in gameObjects)
{
var found:Boolean = false;
for each (var removedObject:GameObject in removedGameObjects)
{
if (removedObject == gameObject)
{
found = true;
break;
}
}
if (!found)
gameObject.shutdown();
}
}
protected function insertNewGameObjects():void
{
for each (var gameObject:GameObject in newGameObjects)
{
for (var i:int = 0; i < gameObjects.length; ++i)
{
if (gameObjects.getItemAt(i).zOrder > gameObject.zOrder ||
gameObjects.getItemAt(i).zOrder == -1)
break;
}
gameObjects.addItemAt(gameObject, i);
}
newGameObjects.removeAll();
}
protected function removeDeletedGameObjects():void
{
// insert the object accordng to it's z position
for each (var removedObject:GameObject in removedGameObjects)
{
var i:int = 0;
for (i = 0; i < gameObjects.length; ++i)
{
if (gameObjects.getItemAt(i) == removedObject)
{
gameObjects.removeItemAt(i);
break;
}
}
}
removedGameObjects.removeAll();
}
}
}
