package
{
	import Box2D.Collision.Shapes.b2CircleDef;
	import Box2D.Collision.Shapes.b2PolygonDef;
	import Box2D.Collision.b2AABB;
	import Box2D.Common.Math.b2Vec2;
	import Box2D.Dynamics.b2Body;
	import Box2D.Dynamics.b2BodyDef;
	import Box2D.Dynamics.b2World;
 
	import flash.events.Event;
	import flash.events.KeyboardEvent;
	import flash.ui.Keyboard;
 
	import org.papervision3d.core.math.Matrix3D;
	import org.papervision3d.core.math.Number3D;
	import org.papervision3d.lights.PointLight3D;
	import org.papervision3d.materials.shadematerials.FlatShadeMaterial;
	import org.papervision3d.objects.DisplayObject3D;
	import org.papervision3d.objects.primitives.Sphere;
	import org.papervision3d.view.BasicView;
 
	[SWF(width="640", height="480", backgroundColor="#000000", frameRate="60")]
	public class RollingASphereWithTheKeyboardAndBox2D extends BasicView
	{
		private static const FORWARD:Number3D = new Number3D(0, 0, 1);
		private var WORLD_SCALE:Number = 30;
		private var WIDTH:Number = 640;
		private var HEIGHT:Number = 480;
 
		private var world:b2World;
 
		private var iterations:int = 10;
		private var timeStep:Number = 1.0/30.0;
 
		private var mainBody:b2Body;
 
 		private var isDown:Boolean = false;
		private var isUp:Boolean = false;
		private var isLeft:Boolean = false;
		private var isRight:Boolean = false;
 
		public function RollingASphereWithTheKeyboardAndBox2D()
		{
			setupPapervision3D();
			createWorld();
			createFloor();
			createCeiling();
			createWalls();
			createShapes();
 
			startRendering();
 
			stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownHandler);
			stage.addEventListener(KeyboardEvent.KEY_UP, keyUpHandler);
		}
 
		private function keyDownHandler(event:KeyboardEvent):void
		{
			switch(event.keyCode)
			{
				case Keyboard.DOWN:
					isDown = true;
					break;
				case Keyboard.UP:
					isUp = true;
					break;
				case Keyboard.LEFT:
					isLeft = true;
					break;
				case Keyboard.RIGHT:
					isRight = true;
					break;
			}
		}
 
		private function keyUpHandler(event:KeyboardEvent):void
		{
			switch(event.keyCode)
			{
				case Keyboard.DOWN:
					isDown = false;
					break;
				case Keyboard.UP:
					isUp = false;
					break;
				case Keyboard.LEFT:
					isLeft = false;
					break;
				case Keyboard.RIGHT:
					isRight = false;
					break;
			}
		}
 
 
		private function createWalls():void
		{
			 var wallShapeDef:b2PolygonDef = new b2PolygonDef();
			var wallBodyDef:b2BodyDef = new b2BodyDef();
			var wall:b2Body;
 
			//Left and Right Shape Definition
			wallShapeDef.SetAsBox(100/WORLD_SCALE, (HEIGHT+40)/WORLD_SCALE/2);
 
			// Left
			wallBodyDef.position = new b2Vec2(-95 / WORLD_SCALE, HEIGHT/WORLD_SCALE/2);
			wall = world.CreateBody(wallBodyDef);
			wall.CreateShape(wallShapeDef);
 
			// Right
			wallBodyDef.position = new b2Vec2((WIDTH+95) / WORLD_SCALE, HEIGHT/WORLD_SCALE/2);
			wall = world.CreateBody(wallBodyDef);
			wall.CreateShape(wallShapeDef);
		}
 
		private function setupPapervision3D():void
		{
			camera.y = -300;
			camera.z = -300;
		}
 
		private function createWorld():void {
			var worldBounds:b2AABB = new b2AABB();
			worldBounds.lowerBound = new b2Vec2( 0, 0 );
			worldBounds.upperBound = new b2Vec2(WIDTH/WORLD_SCALE, HEIGHT/WORLD_SCALE);
 
 			var gravity:b2Vec2 = new b2Vec2(0.0, 10.0);
			var sleep:Boolean = true;
 
			world = new b2World(worldBounds, gravity, sleep);
		}
 
		private function createFloor():void
		{
			// Create border of boxes
			var floorShapeDef:b2PolygonDef = new b2PolygonDef();
			var floorBodyDef:b2BodyDef = new b2BodyDef();
			var floor:b2Body;
 
			//bottom shape definition
			floorShapeDef.SetAsBox((WIDTH+40)/WORLD_SCALE/2, 100/WORLD_SCALE);
 
			// Bottom
			floorBodyDef.position = new b2Vec2(WIDTH/WORLD_SCALE/2, (HEIGHT+95)/WORLD_SCALE);
			floor = world.CreateBody(floorBodyDef);
			floor.CreateShape(floorShapeDef);
 
			floor.SetMassFromShapes();
		}
 
		private function createCeiling():void
		{
			var ceilingShapeDef:b2PolygonDef = new b2PolygonDef();
			var ceilingBodyDef:b2BodyDef = new b2BodyDef();
			var ceiling:b2Body;
			//Top and bottom shape definition
			ceilingShapeDef.SetAsBox((WIDTH+40)/WORLD_SCALE/2, 100/WORLD_SCALE);
 
			// Top
			ceilingBodyDef.position = new b2Vec2(WIDTH/WORLD_SCALE/2, -95/WORLD_SCALE);
			ceiling = world.CreateBody(ceilingBodyDef);
			ceiling.CreateShape(ceilingShapeDef);
		}
 
		private function createShapes():void
		{
			var light:PointLight3D = new PointLight3D();
			for (var i:Number = 0; i < 20; i++)
			{
				//radius for physics circle and sphere
				var radius:Number = Math.random() * 50 + 10;
 
				var bodyDef:b2BodyDef = new b2BodyDef();
				//random position toward the top of the stage
				bodyDef.position = new b2Vec2(Math.random() * WIDTH / WORLD_SCALE, Math.random() * HEIGHT /WORLD_SCALE);
 
				var body:b2Body = world.CreateBody(bodyDef);
 
				var shapeDef:b2CircleDef = new b2CircleDef();
				shapeDef.radius = radius/WORLD_SCALE;
				shapeDef.density = 1;
				shapeDef.friction = .7;
				shapeDef.restitution = .7;
				body.CreateShape(shapeDef);
				body.SetMassFromShapes();
 				var flatShadeMaterial:FlatShadeMaterial = new FlatShadeMaterial(light, Math.random() * 0xffffff, 0x111111);
				var sphere:Sphere = new Sphere(flatShadeMaterial, radius);
 
				scene.addChild(sphere);
				body.m_userData = sphere;
 
				mainBody = body;
			}
		}
 
		override protected function onRenderTick(event:Event=null):void
		{
			if(isDown) mainBody.m_linearVelocity.y += .2;
			if(isUp) mainBody.m_linearVelocity.y -= .2;
			if(isLeft) mainBody.m_linearVelocity.x -= .2;
			if(isRight) mainBody.m_linearVelocity.x += .2;
 
			//sets the position of any DisplayObject3D to the body position
			for (var bb:b2Body = world.m_bodyList; bb; bb = bb.m_next)
			{
				var gravityOffset:b2Vec2 = world.m_gravity.Copy();
				gravityOffset.Multiply(-bb.m_mass);
				bb.ApplyForce(gravityOffset, bb.GetWorldCenter() );
                if (bb.m_userData is DisplayObject3D)
                {
                        bb.m_userData.x = bb.GetPosition().x * WORLD_SCALE - WIDTH * .5;
                        bb.m_userData.y = -bb.GetPosition().y * WORLD_SCALE + HEIGHT * .5;
                        var distance:Number = Math.sqrt(bb.m_linearVelocity.x * bb.m_linearVelocity.x + bb.m_linearVelocity.y * bb.m_linearVelocity.y);
 
						var rotationAxis:Number3D = Number3D.cross(new Number3D(bb.m_linearVelocity.x, bb.m_linearVelocity.y, 0), FORWARD);
						rotationAxis.normalize();
 
						var rotationMatrix:Matrix3D = Matrix3D.rotationMatrix(rotationAxis.x, -rotationAxis.y, rotationAxis.z, distance/30);
 
						bb.m_userData.transform.calculateMultiply3x3(rotationMatrix, bb.m_userData.transform);
                }
			}
			renderer.renderScene(scene, camera, viewport);
			world.Step(timeStep, iterations);
		}
	}
}