Parametric Random Function For 2D Noise Generation

Question

I\'m attempting to generate infinite random terrain. The terrain should generate the same every time given the same seed.

I\'ve tried using Java\'s Random function,

Answer 1

You are looking for hashing function. Try one of those:

http://www.concentric.net/~ttwang/tech/inthash.htm

Here's example usage:

int hash32shift(int key)
{
  key = ~key + (key << 15); // key = (key << 15) - key - 1;
  key = key ^ (key >>> 12);
  key = key + (key << 2);
  key = key ^ (key >>> 4);
  key = key * 2057; // key = (key + (key << 3)) + (key << 11);
  key = key ^ (key >>> 16);
  return key;
}

int noise(int x, int y, int seed)
{
    return hash32shift(seed+hash32shift(x+hash32shift(y)));
}

And, it looks like this: