Inter-letter justification

<?php
require('fpdf.php');

class PDF extends FPDF
{

function Justify($text, $w, $h)
{
    $tab_paragraphe = explode("\n", $text);
    $nb_paragraphe = count($tab_paragraphe);
    $j = 0;

    while ($j<$nb_paragraphe) {

        $paragraphe = $tab_paragraphe[$j];
        $tab_mot = explode(' ', $paragraphe);
        $nb_mot = count($tab_mot);

        // Handle strings longer than paragraph width
        $tab_mot2 = array();
        $k = 0;
        $l = 0;
        while ($k<$nb_mot) {

            $len_mot = strlen ($tab_mot[$k]);
            if ($len_mot<($w-5) )
            {
                $tab_mot2[$l] = $tab_mot[$k];
                $l++;    
            } else {
                $m=0;
                $chaine_lettre='';
                while ($m<$len_mot) {

                    $lettre = substr($tab_mot[$k], $m, 1);
                    $len_chaine_lettre = $this->GetStringWidth($chaine_lettre.$lettre);

                    if ($len_chaine_lettre>($w-7)) {
                        $tab_mot2[$l] = $chaine_lettre . '-';
                        $chaine_lettre = $lettre;
                        $l++;
                    } else {
                        $chaine_lettre .= $lettre;
                    }
                    $m++;
                }
                if ($chaine_lettre) {
                    $tab_mot2[$l] = $chaine_lettre;
                    $l++;
                }

            }
            $k++;
        }

        // Justified lines
        $nb_mot = count($tab_mot2);
        $i=0;
        $ligne = '';
        while ($i<$nb_mot) {

            $mot = $tab_mot2[$i];
            $len_ligne = $this->GetStringWidth($ligne . ' ' . $mot);

            if ($len_ligne>($w-5)) {

                $len_ligne = $this->GetStringWidth($ligne);
                $nb_carac = strlen ($ligne);
                $ecart = (($w-2) - $len_ligne) / $nb_carac;
                $this->_out(sprintf('BT %.3F Tc ET',$ecart*$this->k));
                $this->MultiCell($w,$h,$ligne);
                $ligne = $mot;

            } else {

                if ($ligne)
                {
                    $ligne .= ' ' . $mot;
                } else {
                    $ligne = $mot;
                }

            }
            $i++;
        }

        // Last line
        $this->_out('BT 0 Tc ET');
        $this->MultiCell($w,$h,$ligne);
        $j++;
    }
}

}
?>

<?php
require('justification.php');

$pdf=new PDF();
$pdf->AddPage();
$pdf->SetFont('Arial','',9);
$pdf->Cell(85,4,"EXAMPLE OF FUNCTION USAGE",1,1,'C');
$pdf->Write(4,"\nSource: http://www.swg-fr.com\n\n");
$text=file_get_contents('ex.txt');
$pdf->Justify($text,85,4);
$pdf->Output();
?>