RIGHTBTN
? (LEFTBTN | RIGHTBTN) : 0);
return ((x < tp->edge.center ? LEFTBTN : RIGHTBTN) ^ tp->sbtnswap);
? (RIGHTBTN ^ tp->sbtnswap) : MIDDLEBTN);
if (btn == (LEFTBTN | RIGHTBTN))
return (contacts == 2 ? RIGHTBTN : (contacts == 3 ? MIDDLEBTN : 0));