Re: [ft-devel] Type 1 dictionary information

[Chris Liddell]

On 27/10/11 10:48, Werner LEMBERG wrote:
>> [...]  For reasons I won't bore you with, we do need to be able to
>> create a (fairly) valid Postscript type 1 font dictionary which can
>> be seen by the Postscript interpreter.  We're only talking about
>> Type 1 streams from PDF files, in Postscript jobs we have to
>> continue to use the PS interpreter.
> 
> Is there a difference between a Type 1 font coming from a PDF and a PS
> file?

Basically, we're seeing Type 1 streams from PDF files which are simply
broken Postscript, but are close enough to satisfy the simplified Type 1
specific parsing rules used in the likes of FT's parser (or the one used
in Acrobat.....). So we're seeing streams, for example, that don't call
the definefont operator, or fail to prefix dictionary keys with a "/",
leave objects on the operand stack they shouldn't and so on.

We know FT is happy with these things, because mupdf, xpdf, poppler and
so on all read the jobs fine.

It's increasingly a problem that people are generating PDFs with very
limited reference to the various specifications involved, and simply
hack it until it opens in Acrobat, xpdf or other random PDF viewer. The
vast majority of which are not built on a Postscript interpreter, so
they don't spot problems like these - then we (Ghostscript) get shouted
at because we do trip over these issues.

> Whatever, your idea sounds useful, so please provide patches.

Thanks, I'll get started on it properly - I didn't want to devote much
time to it in case it wasn't required/wanted.

Chris