Scene* HelloWorld::createScene(){    auto scene = Scene::createWithPhysics();    scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);    auto layer = HelloWorld::create();    scene->addChild(layer);    return scene;}bool HelloWorld::init(){    if ( !Layer::init() )    {        return false;    }    Size size = Director::getInstance()->getVisibleSize();    Vec2 origin = Director::getInstance()->getVisibleOrigin();    return true;}void HelloWorld::onEnter(){    addEdge();    addBall();}void HelloWorld::addEdge(){    Size size = Director::getInstance()->getVisibleSize();    Size liteSize=size;    liteSize.width-=10;    liteSize.height-=20;    auto edgeBox=PhysicsBody::createEdgeBox(liteSize);    auto node=Node::create();    node->setPosition(size.width/2,size.height/2);    node->setPhysicsBody(edgeBox);    addChild(node);}void HelloWorld::addBall(){    Size size = Director::getInstance()->getVisibleSize();    auto ball=Sprite::create("ball.png");    ball->setPosition(size.width/2,size.height/2);    ball->setPhysicsBody(PhysicsBody::createBox(ball->getContentSize()));    addChild(ball);}