flip = (out, plane) => {
  out[0] = -plane[0]
  out[1] = -plane[1]
  out[2] = -plane[2]
  out[3] = -plane[3]
  return out
}
Flip the given plane.

@param {plane} out - receiving plane
@param {plane} plane - plane to flip
@return {plane} out
@alias module:modeling/maths/plane.flip