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From: hultquis@orville.nas.nasa.gov (Jeff P.M. Hultquist)
Newsgroups: comp.sys.sgi
Subject: screen-save with colormap and RGB modes
Message-ID: <3599@amelia.nas.nasa.gov>
Date: 27 Oct 89 04:22:35 GMT
Sender: news@amelia.nas.nasa.gov
Reply-To: hultquis@orville.nas.nasa.gov (Jeff P.M. Hultquist)
Organization: NASA Ames Research Center, Moffett Field, CA
Lines: 25

I am using a Personal Iris running IRIX 3.1 ...

For making screen-dumps, I have been using the program 'scrsave' 
(which is in '/usr/people/4Dgifts/...').  This works fine for
windows which are in colormap mode, but it doesn't grab the proper
color-components for windows which are using RGBmode.  The source
for 'scrsave.c' contains a call to 'gl_readscreen', which appears 
to be intended to handle pixels regardless of their display mode.
This function is not listed in the man pages; however, it *is* in
'/usr/lib/libgl.a'.

So ... what gives? 

   * Can I find the displayed color of a pixel regardless
	of its display mode?
   * If so, how?
   * If gl_readscreen is the right thing to be using for this,
	why is my copy broken?  

Solutions (or even hints) will be warmly welcomed; 
send mail to me and I will summarize.
--
Jeff Hultquist
     hultquis@nas.nasa.gov
     (415) 694-4970