[comp.windows.news] Changing device characteristics in NeWS

paul@ppgbms (Paul Matz) (12/01/88)

	We would like to use NeWS to generate printed output.  Hard copy of
display data could be generated in a number of ways.  One way would be by
shipping the postscript code and data parts of our NeWS programs directly to
a postscript printer.  Another would be by using screendump or writecanvas to
create raster files that could be run through a raster-to-postscript filter on
the way to a postscript printer.
	However, these solutions are too costly, considering the cost of a
postscript laser printer.  In addition, either method would most likely be 
very slow, because of the amount of data points that would need to be
transmitted to the printer.
	What seems like the most promising approach, so far, is the new
video  HP laser printer interface technology.  An AT bus card contains a
bitmap of memory, and that data is transmitted via a video signal to
another interface card in the laser printer.
	What this requires is the ability to format output data for devices
with different characteristics than the main display device.  It seems that
NeWS has this ability intrinsicly;  The fact that it works on displays of 
different resolutions shows this to be the case.  The question is:

 Is there any way to specify the display device characteristics
 from outside NeWS, at the application level?

	As a example, visualize an application, which runs under
NeWS that generates a formatted report that contains text and graphics.
If it could open an "unmapped" canvas and re-define that canvas's color 
and resolution characteristics (color to monochrome, monitor resolution
to 300 dpi), it could generate the report on that canvas, page by page, 
writing the resultant canvases, via the "writecanvas" command, to a file.
That file could then be written to the output mechanism mentioned above,
so long as the device characteristics match.  During the process, other
NeWS applications running on the display device would still need to operate
normally.


	Anyone who has ported NeWS must have some idea whether any of this
is feasible.  As an aside, is there a filter available for converting 
image/raster files to HP LaserJet compatible output on a 386i? 

   Please send any responses to:  ppgbms!paul
   in addition to posting responses.
    
    Thanks (wishful thinking)
    Regards,    
                     
        Paul Matz
            PPG Biomedical Systems 
                Pleasantville, NY. 
                    914-741-4685 
                        ppgbms!paul 

mr@ritd.co.UK (12/13/88)

Sorry to be a spoiler (and I hope that I am wrong) but last time that
I read the NeWS licence it specifically precluded using NeWS to drive
a printer. A nice gotcha - does Sun own shares in any printer companies?