if (_fade_in)
{
    _alpha = lerp(_alpha, 1, 0.06);
    for (var i = 0; i < array_length(_grid_lines); i++)
    {
        var grid_line = _grid_lines[i];
        grid_line.set_alpha(_alpha);
        grid_line.y = lerp(grid_line.y, grid_line.ystart, 0.14);
    }
    if (_alpha >= 1)
        _fade_in = false;
}