function fromRotation(out, rad, axis) {
  var x = axis[0],
      y = axis[1],
      z = axis[2];
  var len = Math.sqrt(x * x + y * y + z * z);
  var s = void 0,
      c = void 0,
      t = void 0;

  if (Math.abs(len) < glMatrix.EPSILON) {
    return null;
  }

  len = 1 / len;
  x *= len;
  y *= len;
  z *= len;

  s = Math.sin(rad);
  c = Math.cos(rad);
  t = 1 - c;

  // Perform rotation-specific matrix multiplication
  out[0] = x * x * t + c;
  out[1] = y * x * t + z * s;
  out[2] = z * x * t - y * s;
  out[3] = 0;
  out[4] = x * y * t - z * s;
  out[5] = y * y * t + c;
  out[6] = z * y * t + x * s;
  out[7] = 0;
  out[8] = x * z * t + y * s;
  out[9] = y * z * t - x * s;
  out[10] = z * z * t + c;
  out[11] = 0;
  out[12] = 0;
  out[13] = 0;
  out[14] = 0;
  out[15] = 1;
  return out;
}
Creates a matrix from a given angle around a given axis
This is equivalent to (but much faster than):

    mat4.identity(dest);
    mat4.rotate(dest, dest, rad, axis);

@param {mat4} out mat4 receiving operation result
@param {Number} rad the angle to rotate the matrix by
@param {vec3} axis the axis to rotate around
@returns {mat4} out