Using the physics engine

What should you do when you realize that your game needs to simulate real-world situations? You know that the answer is to use a physics engine. When you start using a physics engine, you have to use some new classes and methods. In this recipe, you will learn how to use the basic physics engine in Cocos2d-x.

How to do it...

1. Firstly, you have to create the physics world in your scene. You can create it by using the following code:

   Scene* HelloWorld::createScene()
   {
       auto scene = Scene::createWithPhysics();
       auto layer = HelloWorld::create();
       scene->addChild(layer);
   	return scene;
   }

2. Next, you have to add the physics bodies in the physics world. A physics body is not visible. It is a physical shape such as a square or a circle or a more complex shape. Here, let's create a square shape. You have to create it and set it to the sprite to be visible.

   bool HelloWorld::init()
   {
       if ( !Layer::init() )
       {
           return false;
       }
       Size visibleSize = Director...