sc_vtb_pos
sc_vtb_seek(to, sc_vtb_pos(to,
pos = sc_vtb_pos(from, pos, cols1);
sc_vtb_seek(scp->history, sc_vtb_pos(scp->history,
pos = sc_vtb_pos(scp->history, pos, -scp->xsize);
scp->history_pos = sc_vtb_pos(scp->history, sc_vtb_tail(scp->history),
if (sc_vtb_pos(scp->history, scp->history_pos, -(scp->xsize*scp->ysize))
scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
scp->history_pos = sc_vtb_pos(scp->history, scp->history_pos,
int sc_vtb_pos(sc_vtb_t *vtb, int pos, int offset);