Re: [Groff] Proposal for raster graphics extensions to gpic

[Werner LEMBERG]

> > The next thing on the agenda would be to do changes to groff. This
> > will allow support for devices other than postscript. I think the
> > best way is to introduce a new general escape sequence for
> > handling images, akin to the \X'ps: import ...'. But that will
> > really be a technicality, the groff user will only need to concern
> > herself about the gpic image object.
> 
> Hmm, A new escape sequence is probably not needed; I can imagine
> that e.g.
> 
>   \X'pnm: import ...'
> 
> will do the trick, and it is up to the device driver to interpret
> this correctly.  The only necessary command would be a pendant to
> `.psbb', e.g. `.pnmbb', to get the bounding box of the image.  The
> appropriate macro would be then called `.PNMPIC'.

After some more thinking, I propose the following:

  . Change readsize_pbm to readsize_pam, the (new) `mother' of all pnm
    formats.  See pam(5) for more details.

  . Move the routines readsize_{pam,ps} into the libgroff library,
    unifying it with the code for gtroff's `.psbb' request (which
    should also be moved into libgroff).

  . It should be straightforward to implement a `.pambb' request for
    gtroff.

  . Use the \X'pam: ...' syntax (or perhaps a more general
    \X'image: <format>: ...') to pass the image to the device driver.

What do you think?


   Werner


PS: Please use `diff -u' relative to the current CVS.