Question

public float randomNumber(float x, float y, Random rnd)
{
    //Return a random number between 0 - 1
}

So my problem is I need the random number to be related to x and y. If I pass in x = 10, y = 5 and I get out 0.34567f when I pass in x = 10, y = 5 a second time I need a result of 0.34567f again. Does anyone know a way of doing this?

EDIT: Based on the responses below I realize I left something out. The reason I pass in the Random object is because it has been pre-seeded elsewhere. So if I pass in x = 10, y = 5 for a random object with a seed of 50 and get out 0.34567f doing the same thing with a Random object with a seed of 51 should give me something different.

Answer 1

You can use them as a seed:

int seed = 
    BitConverter.ToInt32(BitConverter.GetBytes(
        x * 17 + y
    ));
new Random(seed).NextDouble();