title: Move bitmap ship on canvas with finger without jump
body: <p>I try to move a bitmap on canvas with ACTION_MOVE and event.getX/Y()
  It works fine, but when i put finger on screen the ship jump in my finger position.
  How can i move it withoit this jump?
  for exemple: my ship is in position X=5. I put finger in position X=7 and after drag it from X=7 to X=10. The ship jump from X=5 to X=7 and after follow my finger from X=7 to X=10;
  But i want that: when i put finger in X=7 the ship stay in X=5 and when i drag finger from X=7 to X=10 the ship translate from x=5 to X=8 where 8=10-7+5.   </p>