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From: envbvs@epb2.lbl.gov (Brian V. Smith)
Newsgroups: comp.windows.x
Subject: Re:  XCopyPlane() on color Vaxstation 2000s
Message-ID: <4096@helios.ee.lbl.gov>
Date: 1 Nov 89 20:19:32 GMT
References: <8911010656.AA19525@Larry.McRCIM.McGill.EDU>
Sender: usenet@helios.ee.lbl.gov
Reply-To: envbvs@epb2.lbl.gov (Brian V. Smith)
Organization: Lawrence Berkeley Laboratory
Lines: 55

In article <8911010656.AA19525@Larry.McRCIM.McGill.EDU>,
mouse@LARRY.MCRCIM.MCGILL.EDU (der Mouse) writes:
< 
< Good, you've avoided the first problem.  (But you've already created
< another, probably without realizing it.)
< 
< >        gcval.foreground=BlackPixel(disp,0);
< >        gcval.background=WhitePixel(disp,0);
< 
< Not that it's related to your problem, but this sort of assumption is a
< common headache of mine.  Not everybody runs black-on-white!
<

I wanted to use black and white as to simplify the problem for debugging
purposes. At least I didn't use 1 and 0! 8-)
 
< >        XMapRaised(disp,win);
< 
< >        XSelectInput(disp, win, ExposureMask|ButtonPressMask|KeyPressMask);
< >        for (;;)
< > [...read events and redraw stuff upon an Expose event...]
< 
< Suppose the server generates Expose events from the MapRaised before it
< acts on the SelectInput?  Guess what that will do...
< 

You're right - I should reverse the XMapRaised and XSelectInput.  
But that isn't the problem.  Read on.

< By the way, you needn't XFlush after drawing; XNextEvent will flush for
< you if necessary.

Right again.  I wasn't leaving anything to chance since it wasn't working.
 
< Why is there a difference?  I can only guess, and it wouldn't even be
< an informed guess, because I've never even seen a DEC server.  So your
< guess is at least as good as and probably better than mine.

The problem is that the Xqdss server (color vaxstation)s has several
bugs related to this and other problems (stippling, for example).
Several people have given me some ideas and I thank all who have responded.

One fix is to apply a patch file available on expo.lcs.mit.edu (18.30.0.212)
that has been available since Sep 2, which fixes these problems.
The other is to use DECwindows UWS2.1, which, as some claim is faster anyway.

The patch file on expo (contrib/Xqdss.patch1.Z) seems to fix the problem.
Thanks again to all who responded to my problem.

Maybe we'll try UWS2.1 (if we can figure out how to use our existing
fonts 8-)  )
_____________________________________
Brian V. Smith    (bvsmith@lbl.gov)
Lawrence Berkeley Laboratory
I don't speak for LBL, these non-opinions are all mine.