module.exports = normalize

/**
 * Normalize a vec4
 *
 * @param {vec4} out the receiving vector
 * @param {vec4} a vector to normalize
 * @returns {vec4} out
 */
function normalize (out, a) {
  var x = a[0],
    y = a[1],
    z = a[2],
    w = a[3]
  var len = x * x + y * y + z * z + w * w
  if (len > 0) {
    len = 1 / Math.sqrt(len)
    out[0] = x * len
    out[1] = y * len
    out[2] = z * len
    out[3] = w * len
  }
  return out
}