>General sort of question:
>
>I'm drawing a compass and need to determine the 'shortest' direction in which to rotate the compass (clockwise or anti-clockwise) between old and new bearings (in degrees).
>In most cases it is simple but when the old and new values span the 0 degree point those solutions don't work.....
>
>Anyone got a foolproof algorithm (language doesn't matter - just the logic)

Why not simply

dif=(angle2-angle1)%360
if dif>180
   dif=dif-360
endif