hash2d - javascript version of the cheap 2D hash often used in GLSL shaders

hash2d.js

  // returns a number with the fractional part of the given number
  function fract(num) {
    return num - Math.floor(num);
  }

  // hash2d - not repeatable or stable between platforms
  function hash2d(x, y) {
    return fract(43758.5453 * Math.sin(x * 78.233 - 12.9898 * y));
  }
  
  // hash2d with integer return scaled to a range
  function hash2dInt(x, y, low, high) {
    return Math.floor(hash2d(x, y) * (high - low + 1)) + low;
  }