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From: CXT105@psuvm.psu.edu (Christopher Tate)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Printer gripes
Message-ID: <91107.190347CXT105@psuvm.psu.edu>
Date: 17 Apr 91 23:03:47 GMT
References: <91107.104212CXT105@psuvm.psu.edu>
 <1991Apr17.160931.6408@sdd.hp.com>
Organization: Penn State University
Lines: 57

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