stop_look
STATIC int stop_look(struct item *, char, int, int);
if (stop_look(itemp, ch, row - r, c - col))
if (stop_look(itemp, ch, r - row, col - c))
if (stop_look(itemp, ch, col - c, row - r))
if (stop_look(itemp, ch, c - col, r - row))