PDF_begin_page()

(PHP 4, PECL pdflib >= 1.0.0)

Start new page[deprecated]

说明

PDF_begin_page(resource $pdfdoc,float $width,float $height): bool

Adds a new page to the document.成功时返回TRUE，或者在失败时返回FALSE。

This function is deprecated since PDFlib version 6, use PDF_begin_page_ext() instead.

I spent a lot of hours tweaking numbers in my PDF source, trying to nudge things the right way, and, invariably, really messing up big-time...
Then one day I realized that all these numbers were supposed to be (INCHES * 72).
Now my PDF code looks more like:
<?php
.
.
.
 pdf_begin_page($pdf, 8.5 * 72, 11 * 72);
.
. /* set up $helvetica as font */
.
 pdf_set_font($pdf, $helvetica, 9);
 $leading = pdf_get_value($pdf, 'leading');
 pdf_show_boxed($pdf, 0.5 * 72, 0.5 * 72, 4.0 * 72, $leading, 'left', '');
?>
0.0, 0.0 is at the bottom left.
8.5 * 72, 11 * 72 is at the top right.
Everything in between is in x.xx * 72 where x.xx is INCHES.
Suddenly, I can visualize the PDF while I'm typing.
Might work for you too.
Sample linked from:
http://l-i-e.com/resume.htm

Try this...
<?
function mm2pt($val){
  return floatval($val * 2.835016835017);
  }
$xpdf = pdf_new();
pdf_open_file($xpdf);
pdf_begin_page($xpdf, mm2pt(210), mm2pt(297));
// ...
?>

The DIN paper sizes below are rounded.
Theese functions returns exact paper sizes:
<?php
function paperheight($papername) {
 $name=strtolower($papername);
 switch($name) {
 case "dl": return 11/2.54*72;
 case "m65": return paperheight("c6");
 case "ledger": case "tabloid": return 17*72;
 case "legal": return paperwidth("ledger");
 case "letter": return 11*72;
 default: return paperwidth($name)*sqrt(2);
 }
}
function paperwidth($papername) {
 $name=strtolower($papername);
 switch($name) {
 case "dl": return 22/2.54*72;
 case "m65": return paperwidth("c5");
 case "ledger": case "tabloid": return 14*72;
 case "legal": case "letter": return paperheight("ledger")>>1;
 default:
  $i=strpos("ebca",$name{0});
  $j=substr($name,1);
  if($i!=false && ($j>0 || $j==="0"))
   return 100/(pow(2,($i+$j*4-1)/8))/2.54*72;
  else
   die("Unkown paper format: $papername");
 }
}
$paper = "A4";
$w = paperwidth($paper);
$h = paperheight($paper);
echo "$paper: $w ppt * $h ppt";
?>

The problem is that A4 is *NOT* exactly 210mm*297mm.
(Further more, the 2.835016835017 is incorrect. You convert from mm to pps by dividing by 25.4 and multiplying by 72. Hence the ratio is 2.83464566929133858267).
The code that I posted in may produces correct sizes.
(Except for the "m65" format, sorry. "m65" is the same as "dl", and should return the same values).