使用FPDF生成PDF时设置行数

I'm using the library FPDF to generate a PDF based on a query. The code i have currently creates a three column layout on a landscape A4 page. I want to be able to specify a set number of rows for each column before creating a new column.

Does anyone know how to specific a number of rows each column has? Currently, it's stopping at 34 rows and I would like it to be 49.

The code I have so far is:

var $col = 0;

function SetCol($col)
{
    // Move position to a column
    $this->col = $col;
    $x = 60+$col*65;
    $this->SetLeftMargin($x);
    $this->SetX($x);
}

function AcceptPageBreak()
{
    if($this->col<2)
    {
        // Go to next column
        $this->SetCol($this->col+1);
        $this->SetY(10);
        return false;
    }
    else
    {
        // Go back to first column and issue page break
        $this->SetCol(0);
        return true;
    }
}

global $pdf;
  $title_line_height = 10;
  $content_line_height = 8;

  $pdf->AddPage('L');
  $pdf->SetFont( 'Arial', '', 42 );

  $header = array('Order Number', 'Full name (Billing)', 'Draw #');

  foreach($header as $col) {
    $pdf->SetFont( 'Arial', '', 8);
    $pdf->Cell(40,2,$col,1);
  }

  $pdf->Ln();

  foreach( $log as $row ) {
        $pdf->SetFont( 'Arial', '', 8 );
        $pdf->Cell(40,5,$row->orderid, 1);
        $pdf->Cell(40,5, $row->firstname .' '. $row->lastname, 1);
        $pdf->Cell(40,5,$row->ticketid,1);
        $pdf->Ln();
      }
    }
}
$pdf->Output('D','atomic_smash_fpdf_tutorial.pdf');