package
{
    import Box2D.Collision.b2AABB;
    import Box2D.Collision.Shapes.b2CircleDef;
    import Box2D.Collision.Shapes.b2CircleShape;
    import Box2D.Collision.Shapes.b2PolygonDef;
    import Box2D.Collision.Shapes.b2PolygonShape;
    import Box2D.Collision.Shapes.b2Shape;
    import Box2D.Common.Math.b2Vec2;
    import Box2D.Dynamics.b2Body;
    import Box2D.Dynamics.b2BodyDef;
    import Box2D.Dynamics.b2World;
    import flash.display.Shape;
    import flash.display.Sprite;
    import flash.events.Event;

    /**
     * ...
     * @author Erlend Hofstad Langseth
     */
    public class Main extends Sprite
    {

        public function Main():void
        {
            if (stage) init();
            else addEventListener(Event.ADDED_TO_STAGE, init);
        }

        private var w:b2World;
        private function init(e:Event = null):void
        {
            removeEventListener(Event.ADDED_TO_STAGE, init);
            // entry point
            addChild(s);


            var bounding:b2AABB = new b2AABB();
            bounding.lowerBound.Set( - 100, - 100);
            bounding.upperBound.Set( 1000, 1000);
            w  = new b2World(bounding, new b2Vec2(0, -10), true);
            var groundBodyDef:b2BodyDef = new b2BodyDef();
            groundBodyDef.position.Set(400, 580);
            var groundBody:b2Body = w.CreateBody(groundBodyDef);
            var groundShapeDef:b2PolygonDef = new b2PolygonDef();
            groundShapeDef.SetAsBox(400, 20);
            groundBody.CreateShape(groundShapeDef);
            //
            var circleBodyDef:b2BodyDef = new b2BodyDef();
            circleBodyDef.position.Set(300, 200);
            var circleBody:b2Body = w.CreateBody(circleBodyDef);
            var circleDef:b2CircleDef = new b2CircleDef();
            circleDef.radius = 10;
            circleDef.density = 2;
            circleDef.friction = 0.5;
            circleBody.CreateShape(circleDef);
            addEventListener(Event.ENTER_FRAME, update);
        }

        private var s:Shape = new Shape();
        private function update(e:Event):void
        {

            trace("FRAM;E");
            w.Step(1 / 30, 10);

            // DRAW
            s.graphics.clear();
            s.graphics.lineStyle(1, 0xaaaaaa);
            s.graphics.beginFill(0x222222);

            var list:b2Body = w.GetBodyList();
            var shapeList:b2Shape;
            if (!list) return;
            do {
                shapeList = list.GetShapeList();
                if (shapeList) {
                    do {
                        drawShape(shapeList, list.GetPosition().x, list.GetPosition().y);
                    } while (shapeList = shapeList.GetNext());
                }
                //
            } while (list = list.GetNext());
        }
        private function drawShape(shape:b2Shape, x:int, y:int):void
        {
            if (shape is b2PolygonShape) {
                var polygon:b2PolygonShape = shape as b2PolygonShape;
                var ver:Array = polygon.GetVertices();
                delUndefined(ver);
                var vec:b2Vec2;
                for (var i:int = ver.length - 1; i >= 0; i --) {
                    vec = ver[i];
                    if (vec) {
                        trace(i, " : " , ver.length, vec.x, x, vec.y, y);
                        if (i == ver.length - 1) s.graphics.moveTo(vec.x + x, vec.y + y);
                        else s.graphics.lineTo(vec.x + x, vec.y + y);
                    }
                }
            } else if (shape is b2CircleShape) {
                var circle:b2CircleShape = shape as b2CircleShape;
                s.graphics.drawCircle(x, y, circle.GetRadius());
            }
        }
        private function delUndefined(array:Array):void
        {
            for (var i:int = array.length - 1; i >= 0; i --) {
                if (array[i] == undefined) {
                    array.splice(i, 1);
                }
            }
        }


    }

}