FFLAG
board[cbp->c_vertex].s_flg |= FFLAG << cbp->c_dir;
bmask = (BFLAG | FFLAG | MFLAG) << r;
if (fsp->s_flg & (FFLAG << r))
board[tcbp->c_vertex].s_flg |= FFLAG << tcbp->c_dir;