Understanding GameObject Inheritance in C# with FlameBullet and Player Classes

1. FlameBullet - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - int age; - Color color; - public void Update(); // Methods - public void Draw(); Player - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - Vector2 bulletVel; - double xPart, yPart; - public void Update(); // Methods - public void Draw();

2. Find all the common attributes and methods… FlameBullet - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - int age; - Color color; - public void Update(); // Methods - public void Draw(); Player - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - Vector2 bulletVel; - double xPart, yPart; - public void Update(); // Methods - public void Draw();

3. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - int age; - Color color; - public void Update(); // Methods - public void Draw(); Player : GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - Vector2 bulletVel; - double xPart, yPart; - public void Update(); // Methods - public void Draw();

4. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - int age; - Color color; - public void Update(); // Methods - public void Draw(); Player : GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - Vector2 bulletVel; - double xPart, yPart; - public void Update(); // Methods - public void Draw();

5. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - int age; // Attributes - Color color; - public void Update(); // Methods - public void Draw(); Player : GameObject - Vector2 bulletVel; // Attributes - double xPart, yPart; - public void Update(); // Methods - public void Draw(); This class has 8 attributes! - inherited 6 - added 2 more This class has 9 attributes! - inherited 6 - added 3 more

6. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - int age; // Attributes - Color color; - public void Update(); // Methods - public void Draw(); Player : GameObject - Vector2 bulletVel; // Attributes - double xPart, yPart; - public void Update(); // Methods - public void Draw();

7. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - int age; // Attributes - Color color; Player : GameObject - Vector2 bulletVel; // Attributes - double xPart, yPart; This class has 8 attributes and 2 methods This class has 9 attributes and 2 methods

8. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - int age; // Attributes - Color color; Player : GameObject - Vector2 bulletVel; // Attributes - double xPart, yPart; • What if we don’t like the methods we inherited? • Game objects usually update differently • Fancier draw?

9. GameObject - Texture2D tex; // Attributes - Rectangle rect; - Vector2 pos, origin; - double rotation; - boolisAlive; - Game1 mainGame; - public void Update(); // Methods - public void Draw(); FlameBullet : GameObject - int age; // Attributes - Color color; - public void Update(); // New code - public void Draw(); Player : GameObject - Vector2 bulletVel; // Attributes - double xPart, yPart; - public void Update(); // New code - public void Draw(); • We override those methods: • “Redefine” those methods • New (specific) code

10. Inheritance • “Absorbing” the properties from another class • Benefits • Good design (organization) • Smaller code • Maintainable code! • To “override” a method is to “redefine” it

11. Access Modifiers in C# • public – “everyone” can see it (i.e. access it) • private – only the class that defined it can see it • protected – can be seen only by the class that defined it or any child classes • internal – we won’t talk about this…

12. Why not? GameObject Man : GameObject - string name; // Attributes - … - public void Update(); // Overridden - public void Draw(); - public void Run(); // new Wolf : GameObject - intnumTeeth; // Attributes - … - public void Update(); // Overridden - public void Draw(); - public void Run(); // new WolfMan : Man, Wolf - public void Run(); // ????

13. “Diamond of Death” GameObject Man : GameObject - string name; // Attributes - … - public void Update(); // Overridden - public void Draw(); - public void Run(); // new Wolf : GameObject - intnumTeeth; // Attributes - … - public void Update(); // Overridden - public void Draw(); - public void Run(); // new WolfMan : Man, Wolf - public void Run(); // ????

14. Inheritance • You inherit from your grandparent too! Object GameObject Weapon Enemy Bow Bow Magic Orc Poodle Professor