PPDs generated and installed, but now what? (Filter definitions)

[Michael R Sweet]

peer at baden-online.de wrote:
> ...
> Where do I find the interface specification which I need to create a
> filter for the low-level SLP printer language?

The following CUPS documentation:

     - Interface Design Description (IDD) for the PPD file and raster
       file formats.
     - Software Programmers Manual (SPM) for the filter interface
       (also "man filter")
     - CUPS DDK manual for some (limited) coverage of doing custom
       drivers.

> And hopefully some models I can base my filter on?

The rastertodymo source (part of CUPS) is probably your best bet,
since it already supports Dymo and Zebra command sets and can be
easily extended for others.

> Since I do not really know C yet, I plan to make a python script
> first. It could accept raster image data via STDIN and produce the
> resulting slp language commands and data via STDOUT. But I need the
> specification of the interface which I did not find so far.

Python (or any other scripting language) is a poor choice for a
raster printer driver due to the amount of data and bitwise
manipulations you typically do in a raster filter.  Also, we have
no Python bindings to the CUPS imaging library (which provides
the raster file support), so you'd have to reimplement the raster
library stuff in Python before you could even start writing the
driver.

In short, learn a little C and modify the rastertodymo code that
comes with CUPS to produce your new driver.

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Publishing Software        http://www.easysw.com