cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   tape2
   Member

   I'm totally new to Objective-C, so this might all be stupidly obvious.

   I want to create and keep track of a bunch of objects (for example bullets). This is the code I'm currently using to create them.

   for (int n=0; n<NUM_BULLETS; n++)
   {
   bullets[n] = [[BulletSprite alloc] init];
   [self addChild:bullets[n]];
   }

   I also want to be able to reach the bullets I've created. For example, when I want to remove the bullets i use this:

   for (int n=0; n<NUM_BULLETS; n++)
   {
   [bullets[n] die];
   }

   This works, but I get a warning "'Sprite' may not respond to '-die'", which I don't understand. I was messing around until I got it to work, but I don't think this is the proper way.

   My question is: what is the 'right' way to create a bunch of objects and to send a message to each of them?

   Posted 2 years ago #
2. 

   Joao Caxaria
   Member

   is your bullets a Sprite[] or a BulletSprite[]?

   Posted 2 years ago #
3. 

   tape2
   Member

   A Sprite, i guess? Like this:

   @interface BulletSprite : Sprite
   {
   //stuff here
   }

   -(void) die;

   Posted 2 years ago #
4. 

   tape2
   Member

   Oh wait, bullets[] should be an array containing the objects. At least, that's how I used to do it in Actionscript :-) I have no idea if this is the right approach.

   Posted 2 years ago #
5. 

   Codemattic
   Moderator

   tape2, you can iterate through a layer's children, so you could put all your bullets in a specific layer you create just for bullets.

   myBulletLayer.children will return an NSArray of bullets in that layer.

   This is only good for you if in your game you can put all bullets in a single layer. If not, you can do like you are doing and keep a separate array just for bullets, but now you have extra work bc you have to make sure when you remove a bullet from cocos, you also remove it from your array, etc...

   Also, using a c based array is fine. But if you dont know about NSArray, read up on them here:

   http://developer.apple.com/DOCUMENTATION/Cocoa/Reference/Foundation/Classes/NSArray_Class/Reference/Reference.html#//apple_ref/occ/cl/NSArray

   http://developer.apple.com/DOCUMENTATION/Cocoa/Reference/Foundation/Classes/NSMutableArray_Class/Reference/Reference.html

   Posted 2 years ago #
6. 

   tape2
   Member

   That's very helpful, thanks! I'll try it using a layer.

   Posted 2 years ago #
7. 

   crmagicxxx
   Member

   Even if you don't use different Layer, you can set unique TAG for all your bullets, and then when you iterate through self.children, just compare TAGS to find your bullets. Of course if you have tons of other objects on that layer, it could slow down the process...

   Posted 2 years ago #

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