[Desktop_printing] PPD settings vs IPP options

Michael Sweet mike at easysw.com
Wed Feb 15 06:34:05 PST 2006

Johannes Meixner wrote:
> ...
> As far as I know CUPS may not support sub-groups but even only two
> groups should help a lot to have all top-level options in one group
> and all the low-level options in an "expert" group.

The API supports it, but sub-group support is disabled because
some vendors have abused this functionality beyond belief -
Xerox, in particular, has several PPD files with a separate
sub-group for every option!

If there is consensus that sub-groups are wanted and useful,
then we'll re-enable the code that supports it in CUPS.

> Why do you need a seperated full-bleed option at all in the PPD?
> If a *.FullBleed media size was choosen, then the full-bleed
> printing mode must be activated in any case - or what do I miss?

There *is* an outstanding issue WRT to multiple PageSize/Region
options with the same dimensions in Ghostscript right now.
Basically, when you insert:

     <</PageSize[595 842]>>setpagedevice

in the PostScript data stream, Ghostscript looks up the closest
page size in the PPD file to determine the proper imageable area.
This means that the first matching size wins, so you are stuck
advertising the full-bleed margins and then dropping raster data
in the driver to clip to the non-full-bleed margins.

What we've added in CUPS 1.2 is a new cupsPageSizeName attribute
in the page header - this allows the RIP and app to embed both the
dimensions and size name in the page device dictionary so that the
correct margins are used.  In addition, a new
cupsBorderlessScalingFactor attribute (already supported in MacOS X)
is available to slightly increase the size of the page to create a
bleed over area (if the developer doesn't just want to repeat the
last color value out an extra mm or so...)

Anyways, once the first CUPS 1.2 beta is out (almost there! :), I'll
be adding support for all of this to ESP Ghostscript, at which point
we'll have a 8.15.2 release (with other bug fixes) followed by the
integration with GPL GS 8.50.

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

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