If on each frame update, I pick a randomized number, if this number is greater than 100000, then I let the object appear, is it an efficient or good way?

Thanks

Jack

that for sure will not work because the probability from the random object is less than 1% which is a super low drop rate assuming

if your number was used in my approach stated below.

What you can do is achieve a 50% drop rate. This is written in Java:

Random random = new Random();

if(random.nextInt(2) == 1)

{

// add your item to the screen

}

nextInt method returns an integer number between 0(inclusive) and 2(exclusive)

So it basically returns either 0 or a 1 which is 50% or (1/(total possibilties))

Not the most efficient way, but it would work. In SFML, you could do something like this: Create a timer, get a random number using rand() between x and n, and set the timer to go off after the random number of seconds is up. After the timer goes off, you would execute whatever you wanted to happen.

Here is a link to the SFML Timer page so you can learn more about it: http://www.sfml-dev.org/documentation/2.0/classsf_1_1Time.php.

If you're not using SFML, I'm sure you could easily apply it to another API.

Typically you would use float [0..1) for probability.

However, let me point something else out to you:

If on each frame update, I pick a randomized number...

I'm stressing on that particular sentence. This is a poor way to do any probability. Regardless of how low the probability is, counting it on each frame update means it will happen very often! If you say 1% chance of event X happening, and your game runs at 100fps, guess what happens? In one second, event X will occur.

That's not what you want, right? Rather than counting it every frame, pick a more deterministic occurence of when you are going to count the probability. Something like on a button press or on every second.