Jump to content
  • Advertisement

Archived

This topic is now archived and is closed to further replies.

Goober King

A stupid question

This topic is 6109 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Ok this is something I would look up but I lost all of my c books in the madness that has been my life as of late. I just need to know what function I can use to return a random number between 0-X. I though it was randomize(limit); but I cant seam to find where it is prototyped. Its been awhile since I used it and I just need it to fill my tile map with random tiles while I finnish building the engine.

Share this post


Link to post
Share on other sites
Advertisement
randomnr=rand()%100 ; // random number between 0->100

you also need the following line included :

srand((unsigned)time(NULL)) ;

and include time.h

Share this post


Link to post
Share on other sites
Be careful that the low-order bit of rand() are poorly random (if you take my meaning).

You actually want to do

x = 1 + (int)( 100.0 * rand() / ( 1.0 + RAND_MAX ) );

which will use the high order bits. Of course, it is slower, but it is more random.

cf Numerical Recipes, chapter 7, p277. (online at http://lib-www.lanl.gov/numerical/bookcpdf/c7-1.pdf )

Share this post


Link to post
Share on other sites
You might have to scale the number if you start at 1.

int GetRandomInteger( void )
{
int x; // random integer

x = ( rand() % 100 ) + 1; // generates a random number
// between 0-99, then adds 1 (1-100)
return x;
}

Share this post


Link to post
Share on other sites

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!