Use the angle value between the center/origin of your OSC and your touch coordinate, then separate out 8 conditions for each angle range you want.
int(angle(x1,y1,x2,y2)/8)= 1, simulate right
int(angle(x1,y1,x2,y2)/8)= 45, simulate right, simulate down
int(angle(x1,y1,x2,y2)/8)= 90, simulate down
...etc