Question: How do I make the seed work for 2^32 or 2^64 numbers?

[AndrewMast]

How do I make the seed work for 2^32 or 2^64 numbers?

[josephg]

Sorry, I'm not sure I understand what you're trying to do.

On Friday, 26 February 2016, Andrew Mast notifications@github.com wrote:

How do I make the seed work for 2^32 or 2^64 numbers?

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Reply to this email directly or view it on GitHub
#15.

[AndrewMast]

How do I change this function to work for 2^32 or 2^64 numbers?

  // This isn't a very good seeding function, but it works ok. It supports 2^16
  // different seed values. Write something better if you need more seeds.
  module.seed = function(seed) {
    if(seed > 0 && seed < 1) {
      // Scale the seed out
      seed *= 65536;
    }

    seed = Math.floor(seed);
    if(seed < 256) {
      seed |= seed << 8;
    }

    for(var i = 0; i < 256; i++) {
      var v;
      if (i & 1) {
        v = p[i] ^ (seed & 255);
      } else {
        v = p[i] ^ ((seed>>8) & 255);
      }

      perm[i] = perm[i + 256] = v;
      gradP[i] = gradP[i + 256] = grad3[v % 12];
    }
  };

[josephg]

Why do you want that? Do you simply want more variety in the output?

[AndrewMast]

I want to be able use this:

String.prototype.hashCode = function() {
  var hash = 0, i, chr, len;
  if (this.length === 0) return hash;
  for (i = 0, len = this.length; i < len; i++) {
    chr   = this.charCodeAt(i);
    hash  = ((hash << 5) - hash) + chr;
    hash |= 0; // Convert to 32bit integer
  }
  return hash;
};

[AndrewMast]

So basically I want to know what to do with the module.seed to make it work with 2^32 numbers (So I can use noise.seed("seed".hashCode());)

[Squarific]

You can take your 2^32 number and divide it by 2^32 then use that.

[AndrewMast]

With this?

String.prototype.hashCode = function() {
  var hash = 0, i, chr, len;
  if (this.length === 0) return hash;
  for (i = 0, len = this.length; i < len; i++) {
    chr   = this.charCodeAt(i);
    hash  = ((hash << 5) - hash) + chr;
    hash |= 0; // Convert to 32bit integer
  }
  return hash / Math.pow(2, 32);
};

[Squarific]

This should work yes.