cocos2d for iPhone

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

1. 

   fms
   Member

   Hello,

   I want to have a random int number between 4 and 8.
   Right now I'm using arc4random and I wrote it in my init method but the thing is that I get always the same number. For example if by the time I started the scene the number was 5, it is always 5 throughout the scene.

   Do I have to put that code inside a method?

   Posted 9 months ago #
2. 

   fms
   Member

   By the way, I'm using that random number as the interval for a scheduled method

   Posted 9 months ago #
3. 

   skyhawk
   Member

   you need to seed your random number generator.

   Posted 9 months ago #
4. 

   bagibyte
   Member

   First of all, you need to seed the randomizer.

   srand(time(NULL));

   Then, you can call to get a number between 4 - 8.

   rand() % 5 + 4

   This works for me.

   Posted 9 months ago #
5. 

   fms
   Member

   How can I do that?

   And something else, I've been reading a little and arc4random is supposedly different than rand() because you don't have to seed arc4random().

   Is that true?

   Posted 9 months ago #
6. 

   crmagicxxx
   Member

   Yes, you don't have to seed arc4random(). But you say that you use that random number as the interval for a scheduled method and that's why you see same number afterwards. When you schedule method with random number, you have to unschedule it inside that method and schedule it again with another random number

   Pseudo code:
   

   init {
   schedule "myMethod" interval:(arc4random()%5 + 4)
   }
   myMethod {
   unschedule "myMethod"
   some other code
   schedule "myMethod" interval:(arc4random()%5 + 4)
   }

   Posted 9 months ago #
7. 

   bagibyte
   Member

   Never tried arc4random() so couldn't tell you how.

   Posted 9 months ago #
8. 

   fms
   Member

   Thanks for all the replies.

   I have a random float generator and that one is in my init method. I also use that float number as interval for another scheduled method and it actually works.

   Do you think that arc4random() only uses the first number to schedule all the time and that CCRANDOM_0_1 does work the way I want?

   Posted 9 months ago #
9. 

   crmagicxxx
   Member

   Do you think that arc4random() only uses the first number to schedule all the time and that CCRANDOM_0_1 does work the way I want?

   No, I think you're doing something wrong. Post your code

   Posted 9 months ago #
10. 

    fms
    Member

    Ok crmagicxxx I just did it the way you suggested and it seems to work fine. Thank you.

    In another scene what I did is scheduling a method in charge of only generating the random number and I used this number to schedule another method and it worked also.

    But there was one scene where I had to use your procedure.

    Thanks

    Posted 9 months ago #

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