[gs-bugs] [Bug 689757] Extra square characters rendering PDF file

bugs.ghostscript.com-bugzilla-daemon at ghostscript.com bugs.ghostscript.com-bugzilla-daemon at ghostscript.com
Wed Apr 9 07:41:02 PDT 2008


------- Additional Comments From ken.sharp at artifex.com  2008-04-09 07:41 -------

I've spent quite some time trying to work out what prompts Acrobat to render a
/.notdef glyph, and when it doesn't. I haven't been able to draw any
conclusions, but I do have some negative information.

Starting with a file produced by Distiller, the /.notdef glyphs are not rendered
in Acrobat. Its not the font name, changing the standard 'base 14' name to
something totally different makes no difference. Making the font symbolic has no
effect, adding the /.notdef glyph to a /Differences in the Encoding has no effect.

Starting with the output of pdfwrite, the /.notdef glyphs are rendered in
Acrobat. Making the font non-symbolic and removing the direct reference to
/.notdef from the /Encoding causes Acrobat to stop rendering the /.notdef glyphs.

Whenever Acrobat elides the /.notdef it appears to still use the width of the
original glyph, if it is specified in a /Widths array. If there is no /Widths
array, it seems to use the width of the /.notdef glyph.

I've got a patch which I'm just completing testing which addresses the 'issue'.
It introduces a new command line switch RENDERTTNOTDEF, which the PDF
interpreter uses to set a user parameter '\RenderTTNotdef'. The default
behaviour is to render /.notdef glyphs when in PostScript and NOT render them
when interpreting a PDF file.

The reason this is a switch, is because Acrobat does still render /.notdef
glyphs, I just can't work out the rules it is using.

I've checked the behaviour of all the prior issues that Leonardo mentions, and
done a trawl through the database for other cases. There were surprisingly few,
most are related to encoding problems and the presence of the /.notdef was to be
expected. I did find three other case, 687387, 688315 and 687929. All render as
per Acrobat with the patch, and display boxes as reported without.

------- You are receiving this mail because: -------
You are the QA contact for the bug, or are watching the QA contact.

More information about the gs-bugs mailing list