x=R*Math.sin(cta);
y=R*Math.cos(cta); // jamming the on drag codes
i made a yellow object which is on (x000, y000) seems to be able to drag.
i think the fixed relation
x=R*Math.sin(cta);
y=R*Math.cos(cta);
does not allow on drag.
let me look at it more closely ;D