[comp.sys.mac.programmer] Printer gripes

Christopher Tate <CXT105@psuvm.psu.edu> (04/17/91)

Neither the StyleWriter nor the Personal LaserWriter LS seem to support the
SetLineWidth PicComment.  Personally I find this rather frustrating, since it
means that even if I, as a programmer, go to the trouble to support high-
resolution PICT's, only a very few of the available printers will benefit
from my efforts.

The StyleWriter is Apple's highest resolution printer!  And still, the driver
doesn't support fine-line drawing.  As I understand it, the LaserWriter SC
*does* support SetLineWidth; is this correct?  If so, why couldn't the
relevant code have been incorporated into the new LS and StyleWriter drivers
also?

(Just a few more friendly neighborhood mutterings from this corner....)

-------
Christopher Tate                   |    somewhere i have never travelled,
cxt105@psuvm.psu.edu               |    gladly beyond any experience,
 ..!psuvax1!psuvm.bitnet!cxt105    |    your eyes have their silence.

leue@galen.crd.ge.com (Bill Leue) (04/17/91)

In article <91107.104212CXT105@psuvm.psu.edu> CXT105@psuvm.psu.edu (Christopher Tate) writes:
>Neither the StyleWriter nor the Personal LaserWriter LS seem to support the
>SetLineWidth PicComment.  Personally I find this rather frustrating, since it
>means that even if I, as a programmer, go to the trouble to support high-
>resolution PICT's, only a very few of the available printers will benefit
>from my efforts.
>
>The StyleWriter is Apple's highest resolution printer!  And still, the driver
>doesn't support fine-line drawing.  As I understand it, the LaserWriter SC
>*does* support SetLineWidth; is this correct?  If so, why couldn't the
>relevant code have been incorporated into the new LS and StyleWriter drivers
>also?

I'm not disputing your claim, Chris.  However, just for your info, when
using the StyleWriter with standard Mac applications which DO support fine
lines, such as MacDraw II, you do, in fact, get thin lines.  In fact,
hairlines look much better on the SW than on a Laser Printer, keeping
their width regardless of position, something that the Postscript drivers
don't always do.

I don't know whether MacDraw gets these fine lines using some other
mechanism than SetLineWidth, but anyway, the effect is as if it did.

-Bill Leue
leue@crd.ge.com

marshall@sdd.hp.com (Marshall Clow) (04/17/91)

In article <91107.104212CXT105@psuvm.psu.edu> Christopher Tate <CXT105@psuvm.psu.edu> writes:
>Neither the StyleWriter nor the Personal LaserWriter LS seem to support the
>SetLineWidth PicComment.  Personally I find this rather frustrating, since it
>means that even if I, as a programmer, go to the trouble to support high-
>resolution PICT's, only a very few of the available printers will benefit
>from my efforts.
>
>[more mutterings deleted]

I haven't played with either the StyleWriter or the PLW LS much, but a cursory
examination of the drivers indicates that they both support the PrGeneral
calls GetReslData and SetResl. See IM V-410. This allows you to print all
objects, not just lines and frames, at the printer's resoulution. Of course,
you have do do the scaling yourself, but that's not too much of a pain.

Marshall Clow
Hewlett Packard Color Imaging Division
Internet: marshall@sdd.hp.com
AppleLink: HP.Marshall
Phone: (619) 592-4151

CXT105@psuvm.psu.edu (Christopher Tate) (04/18/91)

marshall@sdd.hp.com (Marshall Clow) says:

>I haven't played with either the StyleWriter or the PLW LS much, but a cursory
>examination of the drivers indicates that they both support the PrGeneral
>calls GetReslData and SetResl. See IM V-410. This allows you to print all
>objects, not just lines and frames, at the printer's resoulution. Of course,
>you have do do the scaling yourself, but that's not too much of a pain.

and leue@galen.crd.ge.com (Bill Leue) says:

>I'm not disputing your claim, Chris.  However, just for your info, when
>using the StyleWriter with standard Mac applications which DO support fine
>lines, such as MacDraw II, you do, in fact, get thin lines.  In fact,
>hairlines look much better on the SW than on a Laser Printer, keeping
>their width regardless of position, something that the Postscript drivers
>don't always do.
>
>I don't know whether MacDraw gets these fine lines using some other
>mechanism than SetLineWidth, but anyway, the effect is as if it did.

I suspect that MacDraw does indeed use the PrGeneral() facilities for
application-defined addressable resolution.  I *do* know that the
StyleWriter uses them, from first-hand experience.  And I'll agree that
the output is quite impressive, though a trifle prone to horizontal
streaking at the top and bottom edges of the print head.  Even the
fine vertical lines come out straight!

However, let me clarify:  the practical upshot of the StyleWriter and
the PLW LS drivers not supporting the "SetLineWidth" PicComment is that
when printing a PICT which contains embedded line width information via
the SetLineWidth mechanism, that information will be ignored.  For example,
in the documentation to my graphics toy-application "Lissart," I have a
couple of PICT's extracted from the EPSF files that Lissart generates.
Those PICT's have fine lines specified via SetLineWidth.  On a PostScript
LaserWriter, the PICT's are rendered with fine lines, allowing the reader
to see the detail of the images -- which is the point of having the
illustrations in the first place; they represent the progressive evolution
of an image that variation in the parameters causes.

However, the PLW LS and the StyleWriter don't support this, so even though
they offer top-of-the-line resolution, I feel that their functionality in
dealing with *portable* image representations is sorely lacking.  They're
not PostScript, so EPSF is useless; they don't support SetLineWidth, so
PICT's won't have any fine-line adjustment utilized -- all that's left is
to print images directly from the generating application, which can take
advantage of the Print Manager routines for optimizing resolution.  But
this isn't always what you want....

Oh, well.  I apologize for taking up so much bandwidth on this; it's just
irritating to see (IMHO) regression in the technology offered to the
market.

-------
Christopher Tate          | "The soldier came knocking upon the Queen's door;
                          |  He said 'I am not fighting for you anymore....'"
cxt105@psuvm.psu.edu      |
cxt105@psuvm.bitnet       |                          -- Suzanne Vega

omh@cs.brown.edu (Owen M. Hartnett) (04/19/91)

Can we assume therefore from this discussion that applications which now
use the picComment should now use the PrGeneral stuff?  Or should we use
picComment on PostScript devices and PrGeneral for non PS?

Enquiring mimes want to know.

-Owen

Owen Hartnett				omh@cs.brown.edu.CSNET
Brown University Computer Science	omh@cs.brown.edu
					uunet!brunix!omh
"Don't wait up for me tonight because I won't be home for a month."

gurgle@well.sf.ca.us (Pete Gontier) (04/21/91)

In article <91107.190347CXT105@psuvm.psu.edu> CXT105@psuvm.psu.edu (Christopher Tate) writes:
>However, let me clarify:  the practical upshot of the StyleWriter and
>the PLW LS drivers not supporting the "SetLineWidth" PicComment is that
>when printing a PICT which contains embedded line width information via
>the SetLineWidth mechanism, that information will be ignored.

I complained to DTS about this when the printers were in beta. Unfortunately,
our seed was too late for the print shop to do anything about it. At this
point, the feature can't even be added, because the powers that be are
concerned that developers will start using special case code to determine
whether they have a late enough version of the driver to use SetLineWidth.
(If the version is too early, the theory goes, developers might want to
dot the line instead of making it thin.) Such version-checking, of course,
would be done differently by every developer, because there is no standard
facility for getting the version of a printer driver. (This is probably a
bad idea anyway; getting version info means you know what printer and
driver you're printing to, which is another black art in the first place.)
-- 
 Pete Gontier, gurgle@well.sf.ca.us
 Software Imagineer, Kiwi Software, Inc.