title: PDF font mapping error
body: <p>While rendering a PDF file generated by PDFCreator 0.9.x. I noticed it contains an error in the character mapping. Now, an error in a PDF file is nothing to be wondered about, Acrobat does wonders in rendering faulty PDF files hence a lot of PDF generators create PDFs that do not adhere fully to the PDF standard.</p>
  
  <p>I trief to create a small example file: <a href="http://test.continuit.nl/temp/Document.pdf" rel="nofollow">http://test.continuit.nl/temp/Document.pdf</a></p>
  
  <p>The single page renders a single glyph (a capital A) using a Tj command (See stream 5 0 obj). The font selected (7 0 obj) contains a font with a single glyph embedded. So far so good. The char is referenced by char #1. Given the Encoding of the font it contains a Differences part: [ 1 /A ]. Thus char 1 -> character /A. Now in the embedded subset font there is a cmap that matches no glyph at character 65 (eg capital A) the cmap section of the font does define the character in exactly the order in the PDF file Font -> Encoding -> Differences array.</p>
  
  <p>It looks like the character mapping / encoding is done twice. Only Files from PDFCreator 0.9.x seem to be affected.</p>
  
  <p>My question is: Is this correct (or did I make a mistake and is the PDF correct) and what would you do to detect this situation in order to solve the rendering problem.</p>
  
  <p>Note: I do need to be able to render these PDFs..</p>
  
  <p><em>Solution</em></p>
  
  <p>In the ISO32000 file there is a remark that symbolic TrueType fonts (flag bit 3 is on in the font descriptor) the encoding is not allowed and you should IGNORE it, using a simple 1on1 encoding always. SO all in all, if it is a symbolic font, I ignore the Encoding object altogether and this solves the problem.</p>