<?

$url = $_REQUEST['url']; // URL for code to
$text = isset($_REQUEST['text']) ? $_REQUEST['text'] : ''; // message to display below barcode
$overlay = $_REQUEST['overlay'];
$hash_track = isset($_REQUEST['hash']) ? $_REQUEST['hash'] : '';
  
//Add the Hash symbol to the beginning of the hash code
if(isset($hash_track)) $hash_track = "#" . $hash_track;
  
//google chart API URL
$image = "http://chart.apis.google.com/chart?cht=qr&chs=500x500&chl=" . $url . $hash_track . "&chld=h";
$font = 'ARIAL.TTF';
 
//Get the QR code image from google
$background = imagecreatefrompng($image);
$swidth = imagesx($background);
$sheight = imagesy($background);
 
//if a logo is defined, overlay it on top of the QR code
//Important: overlay image needs to be a png
if(isset($overlay))
{
    $overlay = imagecreatefrompng($overlay); //get image
    imagealphablending($background, true); //needed if logo has transparent layer
    $owidth = imagesx($overlay); //get the heigh and width of the overlay image
    $oheight = imagesy($overlay);
    imagecopy($background, $overlay, ($swidth/2) - ($owidth/2), ($sheight/2) - ($oheight/2), 0, 0, $owidth, $oheight); //paste it on top
}
 
//If text field isn't blank, draw it in below the code
if(isset($text))
{
    $font_color = imagecolorallocate($background, 0, 0, 0); // set font color
    if(strlen($text) >= 15)
    {
        //split string in two, down the middle
        $half = (int) ( (strlen($text) / 2) ); // cast to int incase str length is odd
        $left = trim(substr($text, 0, $half));
        $right = trim(substr($text, $half));
    
        // Write Text
        imagettftext($background, 9, 0, 35, 176, $font_color, $font, $left);
        imagettftext($background, 9, 0, 35, 186, $font_color, $font, $right);
    } else {
        // Write Text
        imagettftext($background, 9, 0, 35, 172, $font_color, $font, $text);
    }
}
 
 
// Output header and final image
header("Content-type: image/png");
header("Content-Disposition: filename=" . $image);
imagepng($background);
  
// Destroy the images
imagedestroy($background);
imagedestroy($overlay); 
?>