function displayError($msg)
{
//ttf from jpgraph
$ttf = new TTF();
$ttf->SetUserFont('dejavu-lgc/DejaVuLGCSans.ttf', 'dejavu-lgc/DejaVuLGCSans-Bold.ttf', 'dejavu-lgc/DejaVuLGCSans-Oblique.ttf', 'dejavu-lgc/DejaVuLGCSans-BoldOblique.ttf');
//Calculate the baseline
// @see http://www.php.net/manual/fr/function.imagettfbbox.php#75333
//this should be above baseline
$test2 = "H";
//some of these additional letters should go below it
$test3 = "Hjgqp";
//get the dimension for these two:
$box2 = imageTTFBbox(10, 0, $ttf->File(FF_USERFONT), $test2);
$box3 = imageTTFBbox(10, 0, $ttf->File(FF_USERFONT), $test3);
$baseline = abs(abs($box2[5]) + abs($box2[1]) - (abs($box3[5]) + abs($box3[1])));
$bbox = imageTTFBbox(10, 0, $ttf->File(FF_USERFONT), $msg);
if ($im = @imagecreate($bbox[2] - $bbox[6], $bbox[3] - $bbox[5])) {
$background_color = imagecolorallocate($im, 255, 255, 255);
$text_color = imagecolorallocate($im, 64, 64, 64);
imagettftext($im, 10, 0, 0, $bbox[3] - $bbox[5] - $baseline, $text_color, $ttf->File(FF_USERFONT), $msg);
header("Content-type: image/png");
imagepng($im);
imagedestroy($im);
}
}