[IamBob]

So, I'm using:

Code:
int i = 0;
int result = 0;

srand(time(NULL));

for(i=0;i<MAX_DICE;i++) {
     result = rand()%MAX_DICE;
  [dice[i] setIntValue: ++result];  // ++result for 1-6 instead of 0-5
}

Is there a better way? It seems like what I get could be a little more random.

thanks in advance!

[typo]

[This message has been edited by IamBob (edited 02-13-2001).]

[lindberg]

Use srandom()/random() instead of srand()/rand(). *Much* better generator.

Other than that, dunno. You could try to seed the generator a bit more unpredictably, say maybe srandom(time(NULL) * getpid()), though I'm not sure how much that would help in your case.

Another thing to point out is that it may not be a good idea to keep re-seeding the generator -- it may seem this may make things "more random" but often it doesn't. Maybe try just seeding it once at the start of the program.

If MacOS X ever gets a /dev/[u]random, that would likely be the best way (though probably not the fastest). The Public Beta doesn't have it though.

[Mniot]

There was a patch posted on http://www.darwinfo.org/ a while ago that would give you a /dev/random
I didn't try to use it, but it might be interesting.

[IamBob]

I just tried what you suggested. Works great! Now I get to play around with it and see what I come up with!

Thanks!

[lgerbarg]

Originally posted by Mniot:
There was a patch posted on http://www.darwinfo.org/ a while ago that would give you a /dev/random
I didn't try to use it, but it might be interesting.

As the person who wrote /dev/random (well, I took a lot of it from FreeBSD) I can tell you that it will probably make it into OS X mainstream, but not until after 1.0. The code on my page has some potential stream corruption of the numbers that might allow for attacks, but I think the SMP races are clean. If you have any comments about quality random numbers in OS X please let me know.

Louis

[IamBob]

I ended up using a little of both.

Something like:

Code:
- (void)init
{
   srand(time(NULL) * MAX_DICE);
}

- (void)reSeed
{
   srandom(time(NULL) * rand()%MAX_DICE);
}

- (void)roll
{
int i=0;
int result = 0;
   
for(i=0;i<MAX_DICE;i++) {
     result = random()%MAX_DICE;
  [dice[i] setIntValue: ++result];
}

}

Then I reseed every so often to get a little extra randomness out of it. I wrote up a test that logs what I get with MAX_DICE equalling [input] and it looks pretty good.

Anyway, for what I'm doing this is plenty good enough. Check out what this went into here.