utf_off2cells(unsigned off, unsigned max_off)
{
    return (off + 1 < max_off && ScreenLines[off + 1] == 0) ? 2 : 1;
}
utf_off2cells(unsigned off, unsigned max_off)
{
    return (off + 1 < max_off && ScreenLines[off + 1] == 0) ? 2 : 1;
}