rroom
int rroom(int, int);
if (!rroom(sdx * d, sdy * d))
if (!rroom(sdx * ((d * adx) / ady), sdy * d) ||
!rroom(sdx * ((d * adx - 1) / ady + 1), sdy * d))
if (!rroom(sdx * d, sdy * ((d * ady) / adx)) ||
!rroom(sdx * d, sdy * ((d * ady - 1) / adx + 1)))