Memory image support

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

// Stream handler to read from global variables
class VariableStream
{
    public $context;
    private $varname;
    private $position;

    function stream_open($path, $mode, $options, &$opened_path)
    {
        $url = parse_url($path);
        $this->varname = $url['host'];
        if(!isset($GLOBALS[$this->varname]))
        {
            trigger_error('Global variable '.$this->varname.' does not exist', E_USER_WARNING);
            return false;
        }
        $this->position = 0;
        return true;
    }

    function stream_read($count)
    {
        $ret = substr($GLOBALS[$this->varname], $this->position, $count);
        $this->position += strlen($ret);
        return $ret;
    }

    function stream_eof()
    {
        return $this->position >= strlen($GLOBALS[$this->varname]);
    }

    function stream_tell()
    {
        return $this->position;
    }

    function stream_seek($offset, $whence)
    {
        if($whence==SEEK_SET)
        {
            $this->position = $offset;
            return true;
        }
        return false;
    }
    
    function stream_stat()
    {
        return array();
    }
}

class PDF_MemImage extends FPDF
{
    function __construct($orientation='P', $unit='mm', $size='A4')
    {
        parent::__construct($orientation, $unit, $size);
        // Register var stream protocol
        stream_wrapper_register('var', 'VariableStream');
    }

    function MemImage($data, $x=null, $y=null, $w=0, $h=0, $link='')
    {
        // Display the image contained in $data
        $v = 'img'.md5($data);
        $GLOBALS[$v] = $data;
        $a = getimagesize('var://'.$v);
        if(!$a)
            $this->Error('Invalid image data');
        $type = substr(strstr($a['mime'],'/'),1);
        $this->Image('var://'.$v, $x, $y, $w, $h, $type, $link);
        unset($GLOBALS[$v]);
    }

    function GDImage($im, $x=null, $y=null, $w=0, $h=0, $link='')
    {
        // Display the GD image associated with $im
        ob_start();
        imagepng($im);
        $data = ob_get_clean();
        $this->MemImage($data, $x, $y, $w, $h, $link);
    }
}
?>

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

$pdf = new PDF_MemImage();
$pdf->AddPage();

// Load an image into a variable
$logo = file_get_contents('logo.jpg');
// Output it
$pdf->MemImage($logo, 50, 30);

// Create a GD graphics
$im = imagecreate(200, 150);
$bgcolor = imagecolorallocate($im, 255, 255, 255);
$bordercolor = imagecolorallocate($im, 0, 0, 0);
$color1 = imagecolorallocate($im, 255, 0, 0);
$color2 = imagecolorallocate($im, 0, 255, 0);
$color3 = imagecolorallocate($im, 0, 0, 255);
imagefilledrectangle($im, 0, 0, 199, 149, $bgcolor);
imagerectangle($im, 0, 0, 199, 149, $bordercolor);
imagefilledrectangle($im, 30, 100, 60, 148, $color1);
imagefilledrectangle($im, 80, 80, 110, 148, $color2);
imagefilledrectangle($im, 130, 40, 160, 148, $color3);
// Output it
$pdf->GDImage($im, 120, 25, 40);
imagedestroy($im);

$pdf->Output();
?>