[Desktop_printing] Just how much of OpenPrinting Vector is in ESP ghostscript?

[Osamu MIHARA]

Todd,

on 2006/06/27 5:28 Fujinaka, Todd said the following:
> It's going to take me a while longer to figure out the structure of the
> code (if I figure out the structure of the code) and it appears that
> OpenPrinting Vector could still be a moving target. I figure I'd better
> just ask, how much of OpenPrinting Vector is in ESP ghostscript?

Currently, opvp/oprp ("glue code" for vector driver) version 1.05 is in 
the latest ESP-GS. Opvp/oprp 1.05 is fully functional and has been 
tested with vector printer drivers from Canon (LIPS4, LIPS LX and CAPT), 
Epson (ESP/Page), and NEC (NPDL) and has no major problems as long as I 
know.

> And if
> was a printer manufacturer, how much more would I need to create an
> OpenPrinting Vector filter for my printer?

Source code for the driver has 3000 to 5000 lines, of course it depends 
on the PDL and driver implementation.  And, other than the driver, you 
need to prepare ppd file to use under CUPS.  The implementation team 
prepares a null driver, which is a skeleton code of driver and just 
outputs message when each driver API is called.   You may write driver 
based on this null driver or other implementation from printer vendors.

Here is a good post from Till mentioning driver implementation.
http://lists.osdl.org/pipermail/desktop_printing/2006/000713.html

Other information, including source code, can be got from 
http://opfc.sourceforge.jp.

Writing vector driver takes more effort than raster drivers such as IJS 
or GS native driver.  But you might be able to more advantage, such as 
performance.  Also, the driver is not only for ghostscript.  When the 
spooling file format is transited to PDF in the future, you do not need 
to writer another driver for your printer.  The same driver can be used 
for PDF renderer, which has been introduced in the Printing Summit.
http://groups.osdl.org/apps/group_public/download.php/2294/2006-04-11-FSG_OP_Japan_Implementation.pdf

-- Osamu MIHARA