Time for action – implementing GameSprite

With the header out of the way, all we need to do is implement our methods.

1. Select the GameSprite.cpp file and let's start on the instantiation logic of the class:

   #include "GameSprite.h"
   
   GameSprite::GameSprite(void){
       _vector = Vec2(0,0);
   }
   
   GameSprite::~GameSprite(void){
   }
   
   GameSprite* GameSprite::gameSpriteWithFile(const char * pszFileName) {
      auto sprite = new GameSprite();
      if (sprite && sprite->initWithFile(pszFileName)) {
             sprite->autorelease();
             return sprite;
      }
      CC_SAFE_DELETE(sprite);
      return sprite = nullptr;
   }

2. Next we need to override the Node method setPosition. We need to make sure that whenever we change the position of the sprite, the new value is also used by _nextPosition:

   void GameSprite::setPosition(const Point& pos) {
       Sprite::setPosition(pos);
       if (!_nextPosition.equals(pos)) {
           _nextPosition = pos;
       }
   }

3. And finally, we implement our new method to retrieve the radius...