class Entity {
public:
      void render() {
          _graphic->render();
      }
        
protected:
      Graphic* _graphic;
};

class Graphic {
public:
      virtual void render() = 0;
};

class Image : public Graphic {
public:
      void render() {
          // Выводим графику
      }
};

class Sprite : public Entity {
      Sprite() {
          _graphic = new Image;
      }
};

int main()
{
      Entity* entity = new Sprite;
      entity->render();

      return 0;
}

  // Define the gravity vector.
  b2Vec2 gravity(0.0f, -10.0f);

// Construct a world object, which will hold and simulate the rigid bodies.
b2World world(gravity);

// Define the ground body.
b2BodyDef groundBodyDef;
groundBodyDef.position.Set(0.0f, -10.0f);

// Call the body factory which allocates memory for the ground body
// from a pool and creates the ground box shape (also from a pool).
// The body is also added to the world.
b2Body* groundBody = world.CreateBody(&groundBodyDef);

// Define the ground box shape.
b2PolygonShape groundBox;

// The extents are the half-widths of the box.
groundBox.SetAsBox(50.0f, 10.0f);

// Add the ground fixture to the ground body.
groundBody->CreateFixture(&groundBox, 0.0f);

B2World world(0.0f, -10.0f);
B2Rect ground(0.0f, -10.0f, 100.0f, 20.0f);
world.add(&ground);