Path: utzoo!censor!geac!jtsv16!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!bloom-beacon!EXPO.LCS.MIT.EDU!converse
From: converse@EXPO.LCS.MIT.EDU (Donna Converse)
Newsgroups: comp.windows.x
Subject: Re: Can two color windows be highlighted at on time?
Message-ID: <8908030017.AA19889@expo.lcs.mit.edu>
Date: 3 Aug 89 00:17:24 GMT
References: <26899@srcsip.UUCP>
Organization: X Consortium, MIT Laboratory for Computer Science
Lines: 32


>   We are running two applications at the same time, with output on
> the color screen of a SUN/3.  Since we need to photograph the output
> of  both simulataneously, both windows must be ( excuse me if my 
> terminology isn't correct ) active at the same time ( I guess ).
> 
>   The problem is now that when the pointer is on one, the other gets
> some weird color mapping.  

Your two applications use two different colormaps.  When one 
application is active, its own colormap is installed, causing
the previously installed colormap to be uninstalled, and therefore 
the weird colors in the other window.

The display can show n distinct colors simultaneously; say n = 256.
If you count each distinct color among both applications, and there
are more than n, you won't be able to display the images simultaneously.
Together, they require more colormap cells than your hardware provides.

On the other hand, suppose they could use the same colormap.  You could
modify the application(s) to use a single shared (read-only) colormap.
Or, *maybe*, you could use xwd and xwud, *maybe*, to show both images
simultaneously, in the default colormap.

... double exposure?

Donna Converse
converse@expo.lcs.mit.edu



------- End of Unsent Draft