I m a little bit confused about inheritence. I created an enemy class and calling enemies with a vector like this:

class enemy
{
public:
    sf::RectangleShape rect;
    float bottom, left, right, top;
    sf::Texture enemytexture;
    sf::Sprite enemysprite;

    enemy(sf::Vector2f position, sf::Vector2f size, sf::Color color)
    {
        rect.setPosition(position);
        rect.setSize(size);
        rect.setFillColor(color);
        enemytexture.loadFromFile("npc1.png");
        enemysprite.setTexture(enemytexture);
    }

    void update(){
        //////}
    };

    class goblin : public enemy
    {
    public:
        goblin(sf::Vector2f position, sf::Vector2f size, sf::Color color);
        void update()
        {
            enemytexture.loadFromFile("npc2.png");
            enemysprite.setTexture(enemytexture);
        };
    };

    std::vector<std::unique_ptr<enemy>> enemies1;

    enemies1.emplace_back(std::unique_ptr<enemy>(
        new enemy(sf::Vector2f(100, 100), sf::Vector2f(15, 10), sf::Color(255, 255, 255, 255))));

    enemies1.emplace_back(std::unique_ptr<enemy>(new goblin::enemy(
        sf::Vector2f(100, 100), sf::Vector2f(15, 10), sf::Color(255, 255, 255, 255))));

But i would like to draw different enemies and sprites like goblin etc. With this sample i draw only npc1.png for enemy and goblin classes. Is it possible to do that or do i need create another class? I searched some tutorials about inheritence but i cannot solve my problem. Plz i will appreciate for every suggestion or help.

CodePudding user response：

Add virtual vefore void update in enemy; under the zero overhead principle, C does not implement dynamic dispatch unless you ask for it.

Also add virtual ~enemy()=default; so the derived class data is properly cleaned up.

CodePudding user response：

class enemy
{
public:
  /* snip */

  // add a virtual dtor to the base class
  virtual ~enemy() {}

  // declare your base class methods as virtual 
  virtual void draw() {}
  virtual void update() {}
};

class goblin : public enemy
{
public:
  // and now in the derived class, you can overload 
  // the methods for that type
  void draw() override {
    // code to draw goblin
  }
  void update() override {
    // code to update goblin
  }
};

// all of your games enemies
std::vector<std::unique_ptr<enemy>> enemies1;

// now you can draw all of your enemies in one go
void drawAll() {
   for(const auto& ptr : enemies1) {
      ptr->draw();
   }
}

// of update your enemies in one go
void updateAll() {
   for(const auto& ptr : enemies1) {
      ptr->update();
   }
}