module.exports = distance

/**
 * Calculates the euclidian distance between two vec4's
 *
 * @param {vec4} a the first operand
 * @param {vec4} b the second operand
 * @returns {Number} distance between a and b
 */
function distance (a, b) {
  var x = b[0] - a[0],
    y = b[1] - a[1],
    z = b[2] - a[2],
    w = b[3] - a[3]
  return Math.sqrt(x * x + y * y + z * z + w * w)
}