[GRASS-dev] Re: [GRASS-user] need help with mac os x installation

[Michael Barton]

I did some experimentation with the lpr part of mapprint.tcl tonight. I'm
thinking that maybe I've done this before and come up with the same
result--and that is why I turned to ghostscript.

TclTk will output to a PS file that looks just fine when I open it.

However, just sending this to lpr (>>lpr file.ps) gives a very poor result.
The map is up against the upper right edges of the page, rather than being
centered. It is clipped on all edges but the bottom and clipped a
significant amount on the left side of the map (a side which is NOT against
the edge of a page).

Is there something I'm missing in sending this to lpr?

Michael


On 9/4/07 3:06 AM, "Glynn Clements" <glynn at gclements.plus.com> wrote:

> 
> William Kyngesburye wrote:
> 
>>> Yea. TclTk (at least the packages we use) doesn't have any good built in
>>> printing routines. I wrote one that is included in the GUI, but it needs
>>> ghostscript to translate from the native postscript of the canvas
>>> into print output.
> 
> On Unix, "print output" traditionally *is* PostScript.
> 
> The backbone of most Unix printing setups is the use of Ghostscript to
> make your printer look like a PostScript printer. If you happen to
> have an actual PostScript printer, the Ghostscript step is omitted.
> 
> There's no need for gis.m to invoke Ghostscript itself when printing;
> it can just feed PostScript to "lpr" (with CUPS, you can feed a lot of
> other formats, but PostScript is the one format which is likely to be
> accepted on non-CUPS systems).
> 
> Moreover, using gs to render to an image format then sending the image
> to lpr will invariably produce worse results than letting the printing
> system perform the rendering (or sending the data directly to a
> PostScript printer).
> 
>> I got to thinking about the GS license (it's GPL now) and I'll either
>> have to make it a separate download or find an existing Mac binary,
>> or maybe use an older AFPL GS.  Maybe there's an equivalent in the
>> system somewhere - it already uses CUPS for printing, maybe there's a
>> CLI postscript renderer...
> 
> "lpr file.ps" should work.
> 
>> Is your GUI printing use of GS the only thing in GRASS that uses it?
>> Does it generate an image, or print-ready postscript?
> 
> Looking at mapprint.tcl, it either:
> 
> 1. Generates an image and sends it to "lpr". (CUPS will first convert
> this to PostScript, then either invoke Ghostscript to convert it to
> the printer's raw image format or send it directly to a PostScript
> printer).
> 
> 2. Invokes gs with DEVICE set to a user-defined string. [This one
> looks wrong; it doesn't appear to send the output anywhere.]
> 
> 3. Generate a PDF.

__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton