Question

A few days ago, I started working with cocos2d. I really like the framework. I would like to create a game with cocos2d and have a probably simple question…

I am making a game with 4 characters, which all have similar characteristics, but have some different attributes like “type” and “points”. I’d like to subclass the sprites into one class which handles all their logic, drawing, and animation.

My question though, is how do I call the sprite class with say, a “type” parameter of 1, 2, 3, or 4 and then have the class draw the correct sprite into my scene with all of it’s individual logic?

Thanks!

Answer 1

You should have an Enemy class that contains properties of specific enemies and that are not type specific (like position, current health, a CCSprite instance?) and an EnemyType class that contains properties that are shared among all enemies of a specific type (max health, max speed, size, sprite filename). You should load your enemy types prior to loading the level, than instantiate each enemy using the appropriate type in the constructor.

For example if your enemy element in the level file looks like this

<enemy><type>spider</type>...more properties...</enemy>

The code (pseudo) would do something like

   EnemyType *enemyType = nil;
   if (typeElement.value == "spider")
   {
       enemyType = spiderType;
   }
   Enemy *newEnemy = [Enemy enemyWithType:enemyType];

Also the Enemy class should contain the CCSprite that represents it, not subclass it. An enemy is not a sprite, so unless I’m missing something, as i see it, an enemy should not inherit from a sprite. I’d read about when to contain and when to inherit.

EDIT:
Another nice post to read that seems very relevant and could communicate a few other things probably better than me.

Anyway, my intention was not to make you think you should just rethink your entire design. What i’m proposing is “better” MVC-wise, but it doesn’t mean it’s better for your game. If you spend all your time on “design correctness” you’ll never get a game done, especially if you’re just learning the cocos2d framework, i was actually making a learning project not too long ago and Steve McConnel himself would come over and slap me if he saw it.

If you’re working on a game alone and it’s a small project go ahead and subclass away if it’s going to be more manageable to you, everything, including “design correctness” needs to be properly quantified (except maybe usage of “goto” statements 🙂 ).