Use Zend PDF to Load Multiple PDFs and Draw on Each One - php

Question

I'm trying to use zend pdf to load multiple pdfs from file (each a 1 page pdf) then draw text, images etc. onto each one. Ideally the drawn text and images would be added within a function. However when I try to do some basic draw it comes back with an error in the pdf. The code works perfectly fine until I try draw text onto the page.
require_once 'zendframework/library/Zend/Loader/Autoloader.php';
include 'form-structures.php'; //
$loader = Zend_Loader_Autoloader::getInstance();
$pdfMerged = new Zend_Pdf();
//load pdf
$loadedpdf = Zend_Pdf::load("form-url.pdf");
//clone pdf
$page1 = clone $loadedpdf->pages[0];
// add text etc.
$page1->drawText('Some text...', 400, 500);
drawmore($page1);
//merge pdf
$pdfMerged->pages[] = $page1;
// do again
$loadedpdf = Zend_Pdf::load("form-url.pdf");
$page = clone $loadedpdf->pages[0];
$pdfMerged->pages[] = $page;
echo $pdfMerged->render();
The form-structure.php file is below with a function to draw something extra on the page:
function drawmore($page)
{
$page->drawText("Height is: 600px", 300,800);
return $page;
}

Answer 1

Resolved.
Zend PDF can't draw text on the screen unless you already specified the font.
I just added:
$page1->setFont(Zend_Pdf_Font::fontWithName(Zend_Pdf_Font::FONT_HELVETICA), 20);
and it fixed the error.