gl_readscreen, scrsave, icut, snapshot bug

[Tony Facca]

> Hmm...  I've had lots of trouble with scrsave giving spurious
> horizontal lines on our 4D/220GTX, but never vertical.  Also, the
> problem is not new.  I've seen it happen in previous releases.  If
> anyone has a workaround, I'd like to know.  On a couple occasions, it
> has cost me a several hours of work because I *thought* I was making
> good screen dumps.  Now, I'm more careful.

On the 320 and 340 VGX systems I have notices horizontal lines in all of
screen dumps saved with scrsave.  As a workaround, use pixel coordinates
in the command as follows:

	scrsave ~/screen.dump 1 1279 1 1023

You loose one row and one colomn of pixels, if you can live with that.
Also, someone had posted a nifty program to activate the "Print Screen"
key.  This comes in handy for a lot of applications which do not do there
own screen dumps when they are in full screen mode.

The program has been hacked up a bit, but it works pretty well:

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#!/usr/NeWS/bin/psh

%
% activate the 'Print Screen' key and bind it to the scrsave function.
%
% You can remove the '##' sign if you want to automatically spool the print
% to the Tektronix network printer.  Or change 'tek77' to your local network
% printer, you get the idea.   -- tony facca
%

systemdict begin

/ScreenPrinter {
    newprocessgroup
    createevent begin
	/Name 16#6F9E def	% PrintScreen key scan code
	/Action [/UpTransition /DownTransition] def
	/Exclusivity true def
	currentdict
    end expressinterest
    {
	awaitevent begin
	    Action /UpTransition eq {
		console rand (Saving screen%\n) fprintf
 	        (scrsave ~/screen.dump 1 1279 1 1023			     \
	 	 ; echo Screen saved as ~/screen.dump \ > /dev/console     \
##		 ; lp -dtek4693 ~/screen.dump				     \
		) forkunix
	    } if
            (Screen saved as screen.dump) print
	end
    } loop
} fork def

(Ready -- press 'Print Screen' for screen dump\n) print

end

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--
-----------------------------------------------------------------------------
Tony Facca   |   fsfacca at avelon.lerc.nasa.gov      |     phone: 216-433-8318
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      You are at Witt's end.  Passages lead off in *all* directions.