/**
 * Created with IntelliJ IDEA.
 * User: VirtualMaestro
 * Date: 11.03.12
 */
package tests
{
    import flash.display.Sprite;
    import flash.events.Event;

    import nape.geom.Vec2;
    import nape.phys.Body;
    import nape.phys.BodyType;
    import nape.phys.Material;
    import nape.shape.Circle;
    import nape.shape.Polygon;

    [SWF(width=800, height=600, backgroundColor=0xdddddd, frameRate=30)]
    public class TestDampening extends Sprite
    {
        static public const APP_WIDTH:int = 800;
        static public const APP_HEIGHT:int = 600;

        private var _core:InitNape;
        private var _frameRate:Number = 30;
        private var _timeStep:Number = 1 / _frameRate;

        public function TestDampening(initNape:InitNape = null)
        {
            _core = initNape;

            if (_core == null)
            {
                _core = new InitNape(APP_WIDTH, APP_HEIGHT, _frameRate, 10);
                addChild(_core);
            }

            init();
        }

        private function init():void
        {
            _core.space().gravity.setxy(0, 0);

            createWalls();
            createActor();
            initWorldDampening();

            addEventListener(Event.ENTER_FRAME, update);
        }

        private function createWalls():void
        {
            var upWall:Body = new Body(BodyType.STATIC, new Vec2(APP_WIDTH / 2, 50));
            upWall.shapes.add(new Polygon(Polygon.box(APP_WIDTH, 50)));
            upWall.space = _core.space();

            var bottomWall:Body = new Body(BodyType.STATIC, new Vec2(APP_WIDTH / 2, APP_HEIGHT - 50));
            bottomWall.shapes.add(new Polygon(Polygon.box(APP_WIDTH, 50)));
            bottomWall.space = _core.space();

            var leftWall:Body = new Body(BodyType.STATIC, new Vec2(50, APP_HEIGHT / 2));
            leftWall.shapes.add(new Polygon(Polygon.box(50, APP_HEIGHT)));
            leftWall.space = _core.space();

            var rightWall:Body = new Body(BodyType.STATIC, new Vec2(APP_WIDTH - 50, APP_HEIGHT / 2));
            rightWall.shapes.add(new Polygon(Polygon.box(50, APP_HEIGHT)));
            rightWall.space = _core.space();
        }

        private var _actor:Body;
        private var _linearDampening:Number = Math.abs(Math.random()); // 0- полное отсутсвие торможения - до бесконечности
        private var _angularDampening:Number = Math.abs(Math.random()); // 0- полное отсутсвие торможения - до бесконечности

        private function createActor():void
        {
            _actor = new Body(BodyType.DYNAMIC, new Vec2(APP_WIDTH / 2, APP_HEIGHT / 2));
            _actor.shapes.add(new Circle(20, null, new Material(0.5)));
            _actor.space = _core.space();

            var linVel:int = 300;
            var angVel:int = 30;
            _actor.velocity.setxy(linVel, linVel);
            _actor.angularVel = angVel;
        }

        private function initWorldDampening():void
        {
            _core.space().worldLinearDrag = _linearDampening;
            _core.space().worldAngularDrag = _angularDampening;
        }

        private function update(event:Event):void
        {
            var vel:Vec2 = _actor.velocity;
            var velX:int = 0;
            var velY:int = 0;
            var ang:int = 0;

            velX = (vel.x + ((-1) * vel.x * _linearDampening * _timeStep)) * 1000;
            velY = (vel.y + ((-1) * vel.y * _linearDampening * _timeStep)) * 1000;
            vel.x = velX / 1000.0;
            vel.y = velY / 1000.0;

            ang = (_actor.angularVel + ((-1) * _actor.angularVel * _angularDampening * _timeStep)) * 1000;
            _actor.angularVel = ang / 1000.0;

            trace("vel x/y: " + _actor.velocity.x + "/" + _actor.velocity.y + "; ang: " + _actor.angularVel);
        }
    }
}