Casual Game Development
Reinitializing an Instance
http://blog.pettomato.com/?p=19

Occasionally, I want to reuse an object without having to create a new instance from scratch. Creating an instance with the new operator can be prohibitively expensive if you have to do it a lot. For example, I'm working on a project where a firework explodes into several dozen sparks. If I was to create that many new instances at the same time, the game would stick on that frame for too long. After testing a variety of convoluted solutions, I discovered that the answer is actually quite simple.

Example Class

Actionscript
1. class SomeClass{
2.   public var Initialize:Function = SomeClass; // points to the constructor.
3.   public var someProperty:Number;
4.   public function SomeClass(arg1){
5.     someProperty = arg1;
6.   }
7. }

Now, I have created a new variable that points to the constructor function. By calling Initialize(), I can re-run the constructor without having to create a new instance. As long as all the member variables are initialized in the constructor, the object should be good as new.

Example Usage

Actionscript
1. var a = new SomeClass(3);
2. trace(a.someProperty); // 3
3. a.Initialize(7);
4. trace(a.someProperty); // 7
5.  

This solution works best if you can maintain a pool of instances, and grab a free instance when you need it. For my firework project, I create around 200 sparks up front because I know that is the maximum that I will ever use at one time. Then, instead of creating and deleting sparks during the game, I just borrow them from the pool and return them when I'm done.

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