Box2D for Flash Games

Running the simulation

You need to run the simulation at every frame, so first of all you need a listener to be triggered at every frame.

1. Let's make some simple changes to our class:

   package {
     import flash.display.Sprite;
     import flash.events.Event;
     import Box2D.Dynamics.*;
     import Box2D.Collision.*;
     import Box2D.Collision.Shapes.*;
     import Box2D.Common.Math.*;
     public class Main extends Sprite {
       public function Main() {
         var gravity:b2Vec2=new b2Vec2(0,9.81);
         var sleep:Boolean=true;
         var world:b2World = new b2World(gravity,sleep);
         addEventListener(Event.ENTER_FRAME,updateWorld);
       }
       private function updateWorld(e:Event):void {
         trace("my awesome simulation runs here");
       }
     }
   }

   Nothing new, we just added an ENTER_FRAME event, but we needed it in order ...