package {
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Dynamics.Joints.*;
	import Box2D.Dynamics.Contacts.*;
	import Box2D.Common.*;
	import Box2D.Common.Math.*;
	class custom_contact_listener extends b2ContactListener {
		override public function BeginContact(contact:b2Contact):void {
			// getting the fixtures that collided
			var fixtureA:b2Fixture=contact.GetFixtureA();
			var fixtureB:b2Fixture=contact.GetFixtureB();
			// if the fixture is a sensor, mark the parent body to be removed
			if (fixtureB.IsSensor()) {
				fixtureB.GetBody().SetUserData("remove");
			}
			if (fixtureA.IsSensor()) {
				fixtureA.GetBody().SetUserData("remove");
			}
		}
	}
}

//class custom_contact_listener
package 
{
    import Box2D.Dynamics.*;
    import Box2D.Dynamics.Contacts.*;
 
    internal class custom_contact_listener extends Box2D.Dynamics.b2ContactListener
    {
        public function custom_contact_listener()
        {
            super();
            return;
        }
 
        public override function BeginContact(arg1:Box2D.Dynamics.Contacts.b2Contact):void
        {
            var loc1:*=arg1.GetFixtureA();
            var loc2:*=arg1.GetFixtureB();
            if (loc2.IsSensor()) 
            {
                loc2.GetBody().SetUserData("remove");
            }
            if (loc1.IsSensor()) 
            {
                loc1.GetBody().SetUserData("remove");
            }
            return;
        }
    }
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.KeyboardEvent;
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Common.Math.*;
	public class ball02 extends Sprite {
		// world creation
		public var world:b2World=new b2World(new b2Vec2(0,10.0),true);
		public var world_scale:int=30;
		// the player
		public var player:b2Body;
		// force to apply to the player
		public var force:b2Vec2;
		// variables to store whether the keys are pressed or not
		// true = pressed;
		// false = unpressed
		public var left,right,up,down:Boolean=false;
		// declaring my custom contact listener class
		public var contact_listener=new custom_contact_listener();
		public function ball02():void {
			// assigning the contact listener to the world
			world.SetContactListener(contact_listener);
			// calling debug draw function
			debug_draw();
			// drawing the boundaries
			draw_box(250,400,500,10,false,"ground");
			draw_box(0,200,10,400,false,"left");
			draw_box(500,200,10,400,false,"right");
			draw_box(250,0,500,10,false,"roof");
			draw_box(250,200,300,10,false,"middle");
			// adding the player at 250,200
			add_player(250,350);
			// adding some coins
			for (var i:int = 1; i<=5; i++) {
				draw_coin(Math.random()*400+50,Math.random()*150+25,Math.random()*3+2);
			}
			// listeners needed for the game to work
			addEventListener(Event.ENTER_FRAME, update);
			stage.addEventListener(KeyboardEvent.KEY_DOWN,on_key_down);
			stage.addEventListener(KeyboardEvent.KEY_UP,on_key_up);
		}
		// according to the key pressed, set the proper variable to "true"
		public function on_key_down(e:KeyboardEvent):void {
			switch (e.keyCode) {
				case 37 :
					left=true;
					break;
				case 38 :
					up=true;
					break;
				case 39 :
					right=true;
					break;
				case 40 :
					down=true;
					break;
			}
		}
		// according to the key released, set the proper variable to "false"
		public function on_key_up(e:KeyboardEvent):void {
			switch (e.keyCode) {
				case 37 :
					left=false;
					break;
				case 38 :
					up=false;
					break;
				case 39 :
					right=false;
					break;
				case 40 :
					down=false;
					break;
			}
		}
		// function to draw a coin
		public function draw_coin(px,py,r):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			var my_circle:b2CircleShape=new b2CircleShape(r/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_circle;
			// look! it's a sensor!!
			my_fixture.isSensor=true;
			var world_body:b2Body=world.CreateBody(my_body);
			world_body.CreateFixture(my_fixture);
		}
		// simple function to draw a box
		public function draw_box(px,py,w,h,d,ud):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			if (d) {
				my_body.type=b2Body.b2_dynamicBody;
			}
			var my_box:b2PolygonShape = new b2PolygonShape();
			my_box.SetAsBox(w/2/world_scale, h/2/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_box;
			var world_body:b2Body=world.CreateBody(my_body);
			world_body.SetUserData(ud);
			world_body.CreateFixture(my_fixture);
		}
		// function to add the player
		public function add_player(px,py):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			my_body.type=b2Body.b2_dynamicBody;
			var my_circle:b2CircleShape=new b2CircleShape(10/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_circle;
			player=world.CreateBody(my_body);
			player.SetUserData("player");
			player.CreateFixture(my_fixture);
		}
		// debug draw
		public function debug_draw():void {
			var debug_draw:b2DebugDraw = new b2DebugDraw();
			var debug_sprite:Sprite = new Sprite();
			addChild(debug_sprite);
			debug_draw.SetSprite(debug_sprite);
			debug_draw.SetDrawScale(world_scale);
			debug_draw.SetFlags(b2DebugDraw.e_shapeBit);
			world.SetDebugDraw(debug_draw);
		}
		// function to be executed at every frame
		public function update(e:Event):void {
			// setting the force to null
			force=new b2Vec2(0,0);
			// according to the key(s) pressed, add the proper vector force
			if (left) {
				force.Add(new b2Vec2(-10,0));
			}
			if (right) {
				force.Add(new b2Vec2(10,0));
			}
			if (up) {
				force.Add(new b2Vec2(0,-20));
			}
			if (down) {
				force.Add(new b2Vec2(0,5));
			}
			// if there is any force, then apply it
			if (force.x||force.y) {
				player.ApplyForce(force,player.GetWorldCenter());
			}
			world.Step(1/30,10,10);
			world.ClearForces();
			// scanning through all bodies
			for (var worldbody:b2Body = world.GetBodyList(); worldbody; worldbody = worldbody.GetNext()) {
				// if a body is marked as "remove"...
				if (worldbody.GetUserData()=="remove") {
					// ... just remove it!!
					world.DestroyBody(worldbody);
				}
			}
			world.DrawDebugData();
		}
	}
}

package {
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Dynamics.Joints.*;
	import Box2D.Dynamics.Contacts.*;
	import Box2D.Common.*;
	import Box2D.Common.Math.*;
	class custom_contact_listener extends b2ContactListener {
		override public function BeginContact(contact:b2Contact):void {
			// getting the fixtures that collided
			var fixtureA:b2Fixture=contact.GetFixtureA();
			var fixtureB:b2Fixture=contact.GetFixtureB();
			// if the fixture is a sensor, mark the parent body to be removed
			if (fixtureB.IsSensor()) {
				fixtureB.GetBody().SetUserData("remove");
			}
			if (fixtureA.IsSensor()) {
				fixtureA.GetBody().SetUserData("remove");
			}
		}
		override public function PreSolve(contact:b2Contact, oldManifold:b2Manifold):void {
			// getting the fixtures that collided
			var fixtureA:b2Fixture=contact.GetFixtureA();
			var fixtureB:b2Fixture=contact.GetFixtureB();
			// variable to handle bodies y position
			var player_y_position:Number;
			var platform_y_position:Number;
			// checking if the collision bodies are the ones marked as "middle" and "player"
			if ((fixtureA.GetBody().GetUserData()=="middle" && fixtureB.GetBody().GetUserData()=="player")||(fixtureA.GetBody().GetUserData()=="player" && fixtureB.GetBody().GetUserData()=="middle")) {
				// determining if the fixtureA represents the platform ("middle") or the player
				switch (fixtureA.GetBody().GetUserData()) {
					case "middle" :
						// determining y positions
						player_y_position=fixtureB.GetBody().GetPosition().y*30;
						platform_y_position=fixtureA.GetBody().GetPosition().y*30;
						break;
					case "player" :
						// determining y positions
						player_y_position=fixtureA.GetBody().GetPosition().y*30;
						platform_y_position=fixtureB.GetBody().GetPosition().y*30;
<strong>						break;
				}
				// checking distance between bodies
				var distance = player_y_position-platform_y_position;
				// if the distance is greater than player radius + half of the platform height...
				if (distance>-14.5) {
					// don't manage the contact
					contact.SetEnabled(false);
				}
			}
		}
	}
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.KeyboardEvent;
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Common.Math.*;
	public class ball02 extends Sprite {
		// world creation
		public var world:b2World=new b2World(new b2Vec2(0,10.0),true);
		public var world_scale:int=30;
		// the player
		public var player:b2Body;
		// force to apply to the player
		public var force:b2Vec2;
		// variables to store whether the keys are pressed or not
		// true = pressed;
		// false = unpressed
		public var left,right,up,down:Boolean=false;
		// declaring my custom contact listener class
		public var contact_listener=new custom_contact_listener();
		public function ball02():void {
			// assigning the contact listener to the world
			world.SetContactListener(contact_listener);
			// calling debug draw function
			debug_draw();
			// drawing the boundaries
			draw_box(250,400,500,10,false,"ground");
			draw_box(0,200,10,400,false,"left");
			draw_box(500,200,10,400,false,"right");
			draw_box(250,0,500,10,false,"roof");
			// adding the player at 250,200
			add_player(250,200);
			// adding some coins
			for (var i:int = 1; i<=5; i++) {
				draw_coin(Math.random()*400+50,Math.random()*300+50,Math.random()*3+2);
			}
			// listeners needed for the game to work
			addEventListener(Event.ENTER_FRAME, update);
			stage.addEventListener(KeyboardEvent.KEY_DOWN,on_key_down);
			stage.addEventListener(KeyboardEvent.KEY_UP,on_key_up);
		}
		// according to the key pressed, set the proper variable to "true"
		public function on_key_down(e:KeyboardEvent):void {
			switch (e.keyCode) {
				case 37 :
					left=true;
					break;
				case 38 :
					up=true;
					break;
				case 39 :
					right=true;
					break;
				case 40 :
					down=true;
					break;
			}
		}
		// according to the key released, set the proper variable to "false"
		public function on_key_up(e:KeyboardEvent):void {
			switch (e.keyCode) {
				case 37 :
					left=false;
					break;
				case 38 :
					up=false;
					break;
				case 39 :
					right=false;
					break;
				case 40 :
					down=false;
					break;
			}
		}
		// function to draw a coin
		public function draw_coin(px,py,r):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			var my_circle:b2CircleShape=new b2CircleShape(r/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_circle;
			// look! it's a sensor!!
			my_fixture.isSensor=true;
			var world_body:b2Body=world.CreateBody(my_body);
			world_body.CreateFixture(my_fixture);
		}
		// simple function to draw a box
		public function draw_box(px,py,w,h,d,ud):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			if (d) {
				my_body.type=b2Body.b2_dynamicBody;
			}
			var my_box:b2PolygonShape = new b2PolygonShape();
			my_box.SetAsBox(w/2/world_scale, h/2/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_box;
			var world_body:b2Body=world.CreateBody(my_body);
			world_body.SetUserData(ud);
			world_body.CreateFixture(my_fixture);
		}
		// function to add the player
		public function add_player(px,py):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			my_body.type=b2Body.b2_dynamicBody;
			var my_circle:b2CircleShape=new b2CircleShape(10/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_circle;
			player=world.CreateBody(my_body);
			player.CreateFixture(my_fixture);
		}
		// debug draw
		public function debug_draw():void {
			var debug_draw:b2DebugDraw = new b2DebugDraw();
			var debug_sprite:Sprite = new Sprite();
			addChild(debug_sprite);
			debug_draw.SetSprite(debug_sprite);
			debug_draw.SetDrawScale(world_scale);
			debug_draw.SetFlags(b2DebugDraw.e_shapeBit);
			world.SetDebugDraw(debug_draw);
		}
		// function to be executed at every frame
		public function update(e:Event):void {
			// setting the force to null
			force=new b2Vec2(0,0);
			// according to the key(s) pressed, add the proper vector force
			if (left) {
				force.Add(new b2Vec2(-10,0));
			}
			if (right) {
				force.Add(new b2Vec2(10,0));
			}
			if (up) {
				force.Add(new b2Vec2(0,-20));
			}
			if (down) {
				force.Add(new b2Vec2(0,5));
			}
			// if there is any force, then apply it
			if (force.x||force.y) {
				player.ApplyForce(force,player.GetWorldCenter());
			}
			world.Step(1/30,10,10);
			world.ClearForces();
			// scanning through all bodies
			for (var worldbody:b2Body = world.GetBodyList(); worldbody; worldbody = worldbody.GetNext()) {
				// if a body is marked as "remove"...
				if (worldbody.GetUserData()=="remove") {
					// ... just remove it!!
					world.DestroyBody(worldbody);
				}
			}
			world.DrawDebugData();
		}
	}
}

package {
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Dynamics.Joints.*;
	import Box2D.Dynamics.Contacts.*;
	import Box2D.Common.*;
	import Box2D.Common.Math.*;
	class custom_contact_listener extends b2ContactListener {
		override public function BeginContact(contact:b2Contact):void {
			// getting the fixtures that collided
			var fixtureA:b2Fixture=contact.GetFixtureA();
			var fixtureB:b2Fixture=contact.GetFixtureB();
			// if the fixture is a sensor, mark the parent body to be removed
			if (fixtureB.IsSensor()) {
				fixtureB.GetBody().SetUserData("remove");
			}
			if (fixtureA.IsSensor()) {
				fixtureA.GetBody().SetUserData("remove");
			}
		}
	}
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.KeyboardEvent;
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Common.Math.*;
	public class ball01 extends Sprite {
		// world creation
		public var world:b2World=new b2World(new b2Vec2(0,10.0),true);
		public var world_scale:int=30;
		// the player
		public var player:b2Body;
		// force to apply to the player
		public var force:b2Vec2;
		// variables to store whether the keys are pressed or not
		// true = pressed;
		// false = unpressed
		public var left,right,up,down:Boolean=false;
		public function ball01():void {
			// calling thebug draw function
			debug_draw();
			// drawing the boundaries
			draw_box(250,400,500,10,false,"ground");
			draw_box(0,200,10,400,false,"left");
			draw_box(500,200,10,400,false,"right");
			draw_box(250,0,500,10,false,"roof");
			// adding the player at 250,200
			// some listeners
			add_player(250,200);
			addEventListener(Event.ENTER_FRAME, update);
			stage.addEventListener(KeyboardEvent.KEY_DOWN,on_key_down);
			stage.addEventListener(KeyboardEvent.KEY_UP,on_key_up);
		}
		// according to the key pressed, set the proper variable to "true"
		public function on_key_down(e:KeyboardEvent):void {
			switch (e.keyCode) {
				case 37 :
					left=true;
					break;
				case 38 :
					up=true;
					break;
				case 39 :
					right=true;
					break;
				case 40 :
					down=true;
					break;
			}
		}
		// according to the key released, set the proper variable to "false"
		public function on_key_up(e:KeyboardEvent):void {
			switch (e.keyCode) {
				case 37 :
					left=false;
					break;
				case 38 :
					up=false;
					break;
				case 39 :
					right=false;
					break;
				case 40 :
					down=false;
					break;
			}
		}
		// simple function to draw a box
		public function draw_box(px,py,w,h,d,ud):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			if (d) {
				my_body.type=b2Body.b2_dynamicBody;
			}
			var my_box:b2PolygonShape = new b2PolygonShape();
			my_box.SetAsBox(w/2/world_scale, h/2/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_box;
			var world_body:b2Body=world.CreateBody(my_body);
			world_body.SetUserData(ud);
			world_body.CreateFixture(my_fixture);
		}
		// function to add the player
		public function add_player(px,py):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			my_body.type=b2Body.b2_dynamicBody;
			var my_circle:b2CircleShape=new b2CircleShape(10/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_circle;
			player=world.CreateBody(my_body);
			player.CreateFixture(my_fixture);
		}
		// debug draw
		public function debug_draw():void {
			var debug_draw:b2DebugDraw = new b2DebugDraw();
			var debug_sprite:Sprite = new Sprite();
			addChild(debug_sprite);
			debug_draw.SetSprite(debug_sprite);
			debug_draw.SetDrawScale(world_scale);
			debug_draw.SetFlags(b2DebugDraw.e_shapeBit);
			world.SetDebugDraw(debug_draw);
		}
		// functiojn to be executed at every frame
		public function update(e:Event):void {
			// setting the force to null
			force=new b2Vec2(0,0);
			// according to the key(s) pressed, add the proper vector force
			if (left) {
				force.Add(new b2Vec2(-10,0));
			}
			if (right) {
				force.Add(new b2Vec2(10,0));
			}
			if (up) {
				force.Add(new b2Vec2(0,-20));
			}
			if (down) {
				force.Add(new b2Vec2(0,5));
			}
			// if there is any force, then apply it
			if (force.x||force.y) {
				player.ApplyForce(force,player.GetWorldCenter());
			}
			world.Step(1/30,10,10);
			world.ClearForces();
			world.DrawDebugData();
		}
	}
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Common.Math.*;
	public class forces extends Sprite {
		public var world:b2World=new b2World(new b2Vec2(0,10.0),true);
		public var world_scale:int=30;
		public function forces():void {
			debug_draw();
			draw_box(250,400,500,10,false,"ground");
			draw_box(100,100,10,10,true,"left");
			draw_box(250,100,10,10,true,"middle");
			draw_box(400,100,10,10,true,"right");
			addEventListener(Event.ENTER_FRAME, update);
			stage.addEventListener(MouseEvent.CLICK,applyforces);
		}
		public function draw_box(px,py,w,h,d,ud):void {
			var my_body:b2BodyDef= new b2BodyDef();
			my_body.position.Set(px/world_scale, py/world_scale);
			if (d) {
				my_body.type=b2Body.b2_dynamicBody;
			}
			var my_box:b2PolygonShape = new b2PolygonShape();
			my_box.SetAsBox(w/2/world_scale, h/2/world_scale);
			var my_fixture:b2FixtureDef = new b2FixtureDef();
			my_fixture.shape=my_box;
			var world_body:b2Body=world.CreateBody(my_body);
			world_body.SetUserData(ud);
			world_body.CreateFixture(my_fixture);
		}
		public function debug_draw():void {
			var debug_draw:b2DebugDraw = new b2DebugDraw();
			var debug_sprite:Sprite = new Sprite();
			addChild(debug_sprite);
			debug_draw.SetSprite(debug_sprite);
			debug_draw.SetDrawScale(world_scale);
			debug_draw.SetFlags(b2DebugDraw.e_shapeBit);
			world.SetDebugDraw(debug_draw);
		}
		public function applyforces(e:MouseEvent):void {
			var force:b2Vec2;
			for (var worldbody:b2Body = world.GetBodyList(); worldbody; worldbody = worldbody.GetNext()) {
				switch (worldbody.GetUserData()) {
					case "left" :
						force=new b2Vec2(0,-450);
						worldbody.ApplyForce(force,worldbody.GetWorldCenter());
						break;
					case "middle" :
						force=new b2Vec2(0,-15);
						worldbody.ApplyImpulse(force,worldbody.GetWorldCenter());
						break;
					case "right" :
						force=new b2Vec2(0,-15);
						worldbody.SetAwake(true);
						worldbody.SetLinearVelocity(force);
						break;
				}
			}
		}
		public function update(e:Event):void {
			world.Step(1/30,10,10);
			world.ClearForces();
			world.DrawDebugData();
		}
	}
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	public class pixel_engine extends Sprite {
		public var ball_radius:int;
		public var precision:int=120;
		public var degrees_to_radians:Number=0.0174532925;
		public var x_speed:Number=0;
		public var y_speed:Number=0;
		public var friction:Number=0.9;
		public var max_speed:int=15;
		public var gravity:Number=0.98;
		public var steps=2;
		public var ball:ball_mc = new ball_mc();
		public var terrain:terrain_mc = new terrain_mc();
		public function pixel_engine():void {
			addChild(ball);
			ball.x=250;
			ball_radius=ball.width/2;
			addChild(terrain);
			addEventListener(Event.ENTER_FRAME, update);
			stage.addEventListener(MouseEvent.MOUSE_DOWN, reverse_gravity);
		}
		private function reverse_gravity(event:MouseEvent):void {
			gravity*=-1;
		}
		public function update(e : Event):void {
			if (ball.y>400) {
				ball.y-=400;
			}
			if (ball.y<0) {
				ball.y+=400;
			}
			for (var j:int = 1; j<=steps; j++) {
				var number_of_collisions:int=0;
				var sum_x_collision:Number=0;
				var sum_y_collision:Number=0;
				if (x_speed>max_speed) {
					x_speed=max_speed;
				} else {
					if (x_speed<max_speed*-1) {
						x_speed=- max_speed;
					}
				}
				if (y_speed>max_speed) {
					y_speed=max_speed;
				} else {
					if (y_speed<max_speed*-1) {
						y_speed=- max_speed;
					}
				}
				ball.x=ball.x+x_speed/steps;
				ball.y=ball.y+y_speed/steps;
				y_speed=y_speed+gravity/steps;
				for (var i:int=1; i<=precision; i++) {
					var x_test:Number=ball.x+ball_radius*Math.sin(i*360/precision*degrees_to_radians);
					var y_test:Number=ball.y-ball_radius*Math.cos(i*360/precision*degrees_to_radians);
					if (terrain.hitTestPoint(x_test,y_test,true)) {
						number_of_collisions++;
						sum_x_collision=sum_x_collision+x_test;
						sum_y_collision=sum_y_collision+y_test;
					}
				}
				var average_x:Number=sum_x_collision/number_of_collisions;
				var average_y:Number=sum_y_collision/number_of_collisions;
				if (number_of_collisions>0) {
					var collision_angle:Number=Math.atan2(ball.x-average_x,ball.y-average_y)/degrees_to_radians*-1+90;
					var collision_x:Number = ball.x - ball_radius * Math.sin((collision_angle + 90) * degrees_to_radians);
					var collision_y:Number = ball.y + ball_radius * Math.cos((collision_angle + 90) * degrees_to_radians);
					var delta_x:Number = (collision_x - ball.x) / ball_radius * -1;
					var delta_y:Number = (collision_y - ball.y) / ball_radius * -1;
					var speed:Number=Math.sqrt(x_speed*x_speed+y_speed*y_speed)*friction;
					var bounce:Number=Math.atan2(x_speed,y_speed)/degrees_to_radians*-1;
					var ricochet:Number=2*collision_angle-bounce-180;
					x_speed=Math.sin(ricochet*degrees_to_radians)*speed;
					y_speed=- Math.cos(ricochet*degrees_to_radians)*speed;
					while (terrain.hitTestPoint(collision_x, collision_y,true)) {
						ball.x=ball.x+delta_x;
						ball.y=ball.y+delta_y;
						collision_x=ball.x-delta_x*ball_radius;
						collision_y=ball.y-delta_y*ball_radius;
					}
				}
			}
		}
	}
}

package {
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.KeyboardEvent;
	//
	import Box2D.Dynamics.*;
	import Box2D.Collision.*;
	import Box2D.Collision.Shapes.*;
	import Box2D.Common.Math.*;
	import Box2D.Dynamics.Joints.*;
	// partigen libraries
	import com.desuade.partigen.emitters.*;
	import com.desuade.partigen.renderers.*;
	public class partigen extends Sprite {
		public var world:b2World;
		public var car_body:b2Body;
		public var front_wheel:b2Body;
		public var rear_wheel:b2Body;
		public var front_motor:b2RevoluteJointDef = new b2RevoluteJointDef();
		public var rear_motor:b2RevoluteJointDef = new b2RevoluteJointDef();
		public var fixtureDef:b2FixtureDef = new b2FixtureDef();
		public var rear_motor_added:b2RevoluteJoint;
		public var front_motor_added:b2RevoluteJoint;
		// partigen variables
		public var the_particle:particle_mc = new particle_mc();
		var particle_emitter:Emitter = new Emitter();
		public function partigen() {
			world=new b2World(new b2Vec2(0,10.0),true);
			debug_draw();
			var body:b2Body;
			var bodyDef:b2BodyDef= new b2BodyDef();
			var boxDef:b2PolygonShape = new b2PolygonShape();
			var circleDef:b2CircleShape=new b2CircleShape(20/30);
			var revoluteJointDef:b2RevoluteJointDef = new b2RevoluteJointDef();
			bodyDef.position.Set(250/30, 200/30);
			boxDef.SetAsBox(600/30, 20/30);
			fixtureDef.shape=boxDef;
			fixtureDef.friction=1;
			fixtureDef.density=1;
			body=world.CreateBody(bodyDef);
			body.CreateFixture(fixtureDef);
			bodyDef.position.Set(0/30, 200/30);
			boxDef.SetAsBox(50/30, 50/30);
			fixtureDef.shape=boxDef;
			fixtureDef.friction=1;
			fixtureDef.density=1;
			body=world.CreateBody(bodyDef);
			body.CreateFixture(fixtureDef);
			bodyDef.position.Set(500/30, 200/30);
			boxDef.SetAsBox(50/30, 50/30);
			fixtureDef.shape=boxDef;
			fixtureDef.friction=1;
			fixtureDef.density=1;
			body=world.CreateBody(bodyDef);
			body.CreateFixture(fixtureDef);
			bodyDef.position.Set(250/30, 90/30);
			bodyDef.type=b2Body.b2_dynamicBody;
			bodyDef.userData = new Sprite();
			boxDef.SetAsBox(50/30, 10/30);
			fixtureDef.shape=boxDef;
			fixtureDef.density=1;
			fixtureDef.friction=1;
			fixtureDef.restitution=0.1;
			car_body=world.CreateBody(bodyDef);
			car_body.CreateFixture(fixtureDef);
			fixtureDef.density=1;
			fixtureDef.friction=5;
			fixtureDef.density=0.1;
			fixtureDef.shape=circleDef;
			bodyDef.allowSleep=false;
			bodyDef.position.Set(car_body.GetWorldCenter().x + 40/30, car_body.GetWorldCenter().y);
			front_wheel=world.CreateBody(bodyDef);
			front_wheel.CreateFixture(fixtureDef);
			bodyDef.position.Set(car_body.GetWorldCenter().x - 40/30, car_body.GetWorldCenter().y);
			rear_wheel=world.CreateBody(bodyDef);
			rear_wheel.CreateFixture(fixtureDef);
			front_motor.enableMotor=true;
			front_motor.maxMotorTorque=10;
			front_motor.Initialize(car_body, front_wheel, front_wheel.GetWorldCenter());
			front_motor_added=world.CreateJoint(front_motor) as b2RevoluteJoint;
			rear_motor.enableMotor=true;
			rear_motor.maxMotorTorque=1;
			rear_motor.Initialize(car_body, rear_wheel, rear_wheel.GetWorldCenter());
			rear_motor_added=world.CreateJoint(rear_motor) as b2RevoluteJoint;
			addEventListener(Event.ENTER_FRAME, update);
			stage.addEventListener(KeyboardEvent.KEY_DOWN, key_down);
			// partigen code
			var particle_container:Sprite = new Sprite();
			addChild(particle_container);
			var particle_renderer:Renderer=new StandardRenderer(particle_container,'top');
			particle_emitter.renderer=particle_renderer;
			particle_emitter.particle=particle_mc;
			var emmx:XML = 
			<IDEEmitter particle="particle_mc" eps="10" burst="2" life="1" lifeSpread="*0.5" group="GroupParticle" groupAmount="0" groupProximity="10" angle="0" angleSpread="*360">
			  <Controllers>
			    <EmitterController/>
			    <ParticleController>
			      <ParticleTweenController duration="0" property="rotation">
			        <KeyframeContainer tweenClass="BasicTween" precision="0">
			          <Keyframe position="0" ease="linear" spread="*200" label="begin"/>
			          <Keyframe position="1" ease="linear" value="0" spread="*100" label="end"/>
			        </KeyframeContainer>
			      </ParticleTweenController>
			      <ParticlePhysicsController duration="0" flip="false" useAngle="true" property="x">
			        <ParticleTweenController duration="0" property="velocity">
			          <KeyframeContainer tweenClass="BasicTween" precision="1">
			            <Keyframe position="0" ease="linear" value="3" spread="*0" label="begin"/>
			            <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			          </KeyframeContainer>
			        </ParticleTweenController>
			        <ParticleTweenController duration="0" property="acceleration">
			          <KeyframeContainer tweenClass="BasicTween" precision="2">
			            <Keyframe position="0" ease="linear" spread="*0" label="begin"/>
			            <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			          </KeyframeContainer>
			        </ParticleTweenController>
			        <ParticleTweenController duration="0" property="friction">
			          <KeyframeContainer tweenClass="BasicTween" precision="2">
			            <Keyframe position="0" ease="linear" spread="*0" label="begin"/>
			            <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			          </KeyframeContainer>
			        </ParticleTweenController>
			      </ParticlePhysicsController>
			      <ParticleTweenController duration="0" property="alpha">
			        <KeyframeContainer tweenClass="BasicTween" precision="2">
			          <Keyframe position="0" ease="linear" value="0.1" spread="*0.8" label="begin"/>
			          <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			        </KeyframeContainer>
			      </ParticleTweenController>
			      <ParticleTweenController duration="0" property="scale">
			        <KeyframeContainer tweenClass="BasicTween" precision="2">
			          <Keyframe position="0" ease="linear" value="0.3" spread="*0.5" label="begin"/>
			          <Keyframe position="1" ease="linear" value="0" spread="*0" label="end"/>
			        </KeyframeContainer>
			      </ParticleTweenController>
			      <ParticlePhysicsController duration="0" flip="true" useAngle="true" property="y">
			        <ParticleTweenController duration="0" property="velocity">
			          <KeyframeContainer tweenClass="BasicTween" precision="1">
			            <Keyframe position="0" ease="linear" value="3" spread="*0" label="begin"/>
			            <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			          </KeyframeContainer>
			        </ParticleTweenController>
			        <ParticleTweenController duration="0" property="acceleration">
			          <KeyframeContainer tweenClass="BasicTween" precision="2">
			            <Keyframe position="0" ease="linear" spread="*0" label="begin"/>
			            <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			          </KeyframeContainer>
			        </ParticleTweenController>
			        <ParticleTweenController duration="0" property="friction">
			          <KeyframeContainer tweenClass="BasicTween" precision="2">
			            <Keyframe position="0" ease="linear" spread="*0" label="begin"/>
			            <Keyframe position="1" ease="linear" spread="*0" label="end"/>
			          </KeyframeContainer>
			        </ParticleTweenController>
			      </ParticlePhysicsController>
			    </ParticleController>
			  </Controllers>
			</IDEEmitter>;
			particle_emitter.fromXML(emmx);
			particle_emitter.start();
		}
		public function key_down(event:KeyboardEvent):void {
			switch (event.keyCode) {
				case 39 :
					rear_motor_added.SetMotorSpeed(10);
					front_motor_added.SetMotorSpeed(10);
					break;
				case 37 :
					rear_motor_added.SetMotorSpeed(-10);
					front_motor_added.SetMotorSpeed(-10);
					break;
			}
		}
		public function debug_draw():void {
			var m_sprite:Sprite;
			m_sprite = new Sprite();
			addChild(m_sprite);
			var dbgDraw:b2DebugDraw = new b2DebugDraw();
			var dbgSprite:Sprite = new Sprite();
			m_sprite.addChild(dbgSprite);
			dbgDraw.SetSprite(m_sprite);
			dbgDraw.SetDrawScale(30);
			dbgDraw.SetFillAlpha(0.5);
			dbgDraw.SetLineThickness(1);
			dbgDraw.SetFlags(b2DebugDraw.e_shapeBit);
			world.SetDebugDraw(dbgDraw);
		}
		public function update(e : Event):void {
			world.Step(1/30,10,10);
			world.ClearForces();
			world.DrawDebugData();
			for (var bb:b2Body = world.GetBodyList(); bb; bb = bb.GetNext()) {
				if (bb.GetUserData()) {
					particle_emitter.x=bb.GetPosition().x*30;
					particle_emitter.y=bb.GetPosition().y*30;
				}
			}
		}
	}
}