public static extern int rot_matrix_to_quaternion(ref int handle, ref JKTYPE.RotMatrix rot_matrix, ref JKTYPE.Quaternion quaternion);
 public static extern int rot_matrix_to_rpy(ref int handle, ref JKTYPE.RotMatrix rot_matrix, ref JKTYPE.Rpy rpy);
 public static extern int quaternion_to_rot_matrix(ref int handle, ref JKTYPE.Quaternion quaternion, ref JKTYPE.RotMatrix rot_matrix);
 public static extern int rpy_to_rot_matrix(ref int handle, ref JKTYPE.Rpy rpy, ref JKTYPE.RotMatrix rot_matrix);