Re: [Gnome-print] Re: [Gimp-print-devel] An introduction to gnome-print (fwd)

[Ben Woodard <ben valinux com>]

> Ben Woodard wrote:
> > ...
> > Very simple. In the LPD setup that I have been working on you can
> > insert arbitrary filters into the processing path. That is what I
> > took pstops and turned it into ppdfilt for. I stick it in the filter
> > path just before something is sent to the printer and voila I have
> > PPD support. I figure I can get ppdfilt or another program to do the
> > same sort of thing without much trouble for binary non-PS files.
> > Then I just stick it in the filter chain after gs and viola limited
> > PPD support for non-PS printers.
> 
> Again - why bother with this?  You can make a *real* PPD file that
> sets the options supported by the GS drivers, use pstops/ppdfilt to
> *insert the options for the driver*, and then pass the filtered file
> to GS.  Then GS will produce a printer-specific output stream that
> can be sent to a printer.

There are two problems with this:

1) GS drivers doen't support all the features that printers are
capable of and from my initial assement quite a few of them are going
to be non-trivial to implement. I only spent a couple days in the GS
code. I might have missed something but it is rather difficult code to
grok. Mentally shifting between the C code with huge number of macro
expansions and the PS code that defines much of the operating
environment that the PS runs with was quite a challenge.

2) I'm assuming that whether I believe that PS should be the meta file
format or not I am going to get BLOBs (Big Lumps of Binary data -- I
like the acronym ;-) ) dumped into the spooler. The idea was to deal
with the fact that I will get BLOBs not to try to force the world to
do it the way that I think it should be done.

> 
> Depending on the printer driver, you may get all of the functionality
> you need; if not, it is *easy* to add new options to drivers (see
> the CUPS GS driver for how easy it is)

I will look how you did it. I'm quite ready to believe that I missed
something obvious in GS or that I approached it at completely the
wrong level to see how to do it.

> 
> -- 
> ______________________________________________________________________
> Michael Sweet, Easy Software Products                  mike@easysw.com
> Printing Software for UNIX                       http://www.easysw.com