Align Text Within a Fixed Space Using imageTTFbbox() in PHP

<?php//  w  w w . ja  va2 s .  c o  m
header("Content-type: image/gif");
$height = 100;
$width = 200;
$fontsize = 50;
$text = "www.java2s.com";
$image = imagecreate( $width, $height );
$red = imagecolorallocate($image, 255,0,0);
$blue = imagecolorallocate($image, 0,0,255 );
$font = "ARIALBD.TTF";
$textwidth = $width;
$textheight;

while ( 1 ){
    $box = imageTTFbbox( $fontsize, 0, $font, $text );
    $textwidth =  abs( $box[2] );
    $textbodyheight = ( abs($box[7]) )-2;
    if ( $textwidth < $width - 20 )
        break;
    $fontsize--;
}
$gifXcenter = (int) ( $width/2 );
$gifYcenter = (int) ( $height/2 );
imageTTFtext($image, $fontsize, 0,(int) ($gifXcenter-($textwidth/2)),(int)($gifYcenter+(($textbodyheight)/2) ),
             $blue, $font, $text );
imagegif($image);
?>