code: public Vector3d reflect(double x, double y, double z, Vector3d dest) {
          double dot = this.dot(x, y, z);
          dest.x = this.x - (dot + dot) * x;
          dest.y = this.y - (dot + dot) * y;
          dest.z = this.z - (dot + dot) * z;
          return dest;
      }
docs: /* (non-Javadoc)
  @see org.joml.Vector3dc#reflect(double, double, double, org.joml.Vector3d)