Thank you very much ROJO! Works now.
Now there's one thing, I don't understand. Shouldn't the angle keep the same (reversed or right), if it is calling angle() with the same order on every frame?
I mean, the angle from center to x/y might be 10, then angle from x/y to center would be 190?. And that should be true for every frame, no?
EDIT: So it should just swap the angles once the first time it is called wrong.