@matter.js/brorand/index.js

Random number generator for browsers and node.js

var r;

module.exports = function rand(len) {
  if (!r)
    r = new Rand(null);

  return r.generate(len);
};

function Rand(rand) {
  this.rand = rand;
}
module.exports.Rand = Rand;

Rand.prototype.generate = function generate(len) {
  return this._rand(len);
};

// Emulate crypto API using randy
Rand.prototype._rand = function _rand(n) {
  if (this.rand.getBytes)
    return this.rand.getBytes(n);

  var res = new Uint8Array(n);
  for (var i = 0; i < res.length; i++)
    res[i] = this.rand.getByte();
  return res;
};

Rand.prototype._rand = function _rand(n) {
  var arr = new Uint8Array(n);
  self.crypto.getRandomValues(arr);
  return arr;
};