Scene* HelloWorld::createScene(){    // ‘scene‘ is an autorelease object    auto scene = Scene::createWithPhysics();    scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);    // ‘layer‘ is an autorelease object    auto layer = HelloWorld::create();    // add layer as a child to scene    scene->addChild(layer);    // return the scene    return scene;}

void HelloWorld::onEnter(){    Layer::onEnter();    addEdge();}

void HelloWorld::addEdge(){    Size visibleSize=Director::getInstance()->getVisibleSize();    auto body=PhysicsBody::createEdgeBox(visibleSize);    auto node=Node::create();    node->setPhysicsBody(body);    node->setPosition(visibleSize.width/2,visibleSize.height/2);    addChild(node);}