I undestand how the machine work.
Ok
Point A X0Y0
Point B X600Y600 to go back to A X0Y0 easy when are only 3 .points..code line easy

Point A X0Y0
Between the points are from start to end 43578 points complicate shape
Point B X600Y600 from hire to go back (from end to start) through all 43578 to Point A
Like ping-pong move. ...