cocos2d for iPhone

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

1. 

   Osiris
   Member

   Hopefully this is an intelligent question, forgive me if its not.

   I have an an emitter I created called "addMonster" within this routine, everytime I add an alien to the screen, I'm adding the object to a NSMutableArray. Later in my collisions and in my callFunc in my actions, im directing to a routine that removes these sprites from game play.

   I am trying [enemy removeObject: monster]; where "monster" is the pointer id of the sprite that is being used in the function.

   its apparently not the same as the pointer id that was originally placed in the array? Im not sure how to get the original id to remove that particular alien from the array.

   any pointers?

   Posted 2 years ago #
2. 

   Osiris
   Member

   Sometimes when testing, I get an exception referring to this array too...

   *** Terminating app due to uncaught exception 'NSGenericException', reason: '*** Collection <NSCFArray: 0x5181b70> was mutated while being enumerated.'

   im not sure what that means, but its when I'm calling the [enemy removeObject:monster] when it detected a collision between the alien ship and a bullet. It doesnt seem to happen every time.

   Posted 2 years ago #
3. 

   lgoss007
   Member

   Are you trying to remove the monster in a loop? It would help to see the code around that remove call. The exception looks something like you're looping through the array and trying to change the array (possibly the remove?) during the loop..

   Posted 2 years ago #
4. 

   Osiris
   Member

   yes I have tracked it to a look where I am

   for(Sprite *monster in enemy) {
       ....
       stuff
       ...
       [enemy removeObject: monster];
       monster = nil;
   }

   I'm guessing thats not the proper way and I can logistically see why, but i'm new and I'm having trouble seeing how to do it differently.

   Posted 2 years ago #
5. 

   Osiris
   Member

   everyone looks at my code and cringes.... Osiris hides head in shame....

   but its coming along.. I have figured out enough to store default settings between scenes and how to have and call different scenes as cut scenes and such... I'm proud of my little game so far.

   Posted 2 years ago #
6. 

   adpro
   Member

   I was going to say the same thing.

   A hint. If you're removing it from a loop, make sure you order your array so you're removing the last object.

   Also, you can add a tag and remove it by tag as well. That's usually pretty easy and seems to remove any possible issues with trying to remove stuff that has already been removed.

   Either way, if you're removing stuff in a loop, you might end up trying to remove something that has already been removed. Using tags or sorting your array so you remove the objects at the end of the array (loop in reverse order (x--;)).

   Posted 2 years ago #
7. 

   adpro
   Member

   Another thing,

   Be sure to use cleanup:YES when removing!!!

   Posted 2 years ago #
8. 

   jd
   Member

   I don't think you should remove from the loop while you iterate over it.

   Posted 2 years ago #
9. 

   natanavra
   Member

   The exception is for changing the array when looping through it, I'd suggest something like this:

   `NSMutableArray *removeArr = [[NSMutableArray alloc] init];
   for ( Monster *spr in enemy ) {
   //stuff...
   [self removeChild: spr cleanup:YES];
   [removeArr addObject: spr];
   }
   [enemy remove ObjectsFromArray: removeArr];
   [removeArr removeAllObjects];
   [removeArr release]; `

   Note:
   - Me: "Ohhh god! Writing code from the iPhone is a pain, especially when attempting to fall asleep..."
   Hope this helps, btw is there a bactick anywhere in the iPhone keyboard? hate copy pasting backticks...

   Posted 2 years ago #
10. 

    Osiris
    Member

    Ahh I see

    Adding the sprites to be removed to a defacto "remove queue" --- Cool, I like it. Thanks! I'll give that a twirl.

    Posted 2 years ago #
11. 

    Osiris
    Member

    I dont understand the use of "[self removeChild: spr cleanup:YES];" I was using "[enemy removeObject:spr]" but I just thought we decided that was bad?

    Posted 2 years ago #
12. 

    Codemattic
    Moderator

    also read:

    http://www.cocos2d-iphone.org/forum/topic/1382

    QcMat and bsharp42 had some solutions to this problem.

    Good luck, Codemattic

    Posted 2 years ago #
13. 

    Osiris
    Member

    or are you removing the sprite from the node?

    Posted 2 years ago #
14. 

    Osiris
    Member

    @natanavra - Thanks - That seems to work perfectly in my preliminary tests. There is still so much to learn about, especially memory management and when its appropriate to CLEANUP and releast and =nil and all that... so much to learn.

    Posted 2 years ago #

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