Re: [Groff] PDFPIC macro

[Keith Marshall]

Resurrecting a three year old thread ...

On 21/09/14 05:38, Werner LEMBERG wrote:
>>> A good starting point may be to implement a C/C++ library function,
>>> to extract the MediaBox properties; that would open the gate to a
>>> possible pdfbb request, which gtroff.exe could process internally.
>>
>> Alternatively, we could modify the existing implementation of .psbb,
>> such that it will discriminate on `%!PS-Adobe-´ or `%PDF-´ as
>> initial file content, then DTRT wrt parsing a `%%BoundingBox:´ or
>> `/MediaBox´ record accordingly.
> 
> Good idea!

You may recall that I did begin to explore possibilities, at the time, 
but then life ... explicitly a protracted visit to Australia and New 
Zealand, followed by too many other priorities on return ... got in the 
way.  I've now found a bit of time to revisit it, and have posted some 
prototypical code at https://osdn.net/users/keith/pf/groff-psbb/files

Although I did, initially, consider a C++ solution, I'd actually given 
up on that idea, before heading off to the antipodes; I now believe a 
lex scanner, coupled with a minimal yacc parser to drive it, offers a 
much more practical implementation.  The mechanism for integrating it 
into groff is illustrated in t-psbb.cpp, (which compiles to a free 
standing test program for the lex/yacc code).  At present, it seems to 
work for EPS and regular PDF files, (but not for linearised PDF); I 
have yet to implement handling for the effect of the /Rotate operation 
on PDF /MediaBox properties ... I'd like some agreed understanding of 
exactly what transformation that should represent, before I proceed.  
Also, should /CropBox, /BleedBox, /TrimBox, or /ArtBox be considered 
to have any relevance, in this context?

Does anyone foresee any possible difficulties in incorporating such a  
solution into groff, before I pursue it further?

-- 
Regards,
Keith.