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From: william@kaula.keck.hawaii.edu (William Lupton)
Newsgroups: comp.lang.idl-pvwave
Subject: Re: Problem with backing store under X windows
Message-ID: <12083@uhccux.uhcc.Hawaii.Edu>
Date: 22 Mar 91 02:03:19 GMT
References: <2676@bnlux0.bnl.gov>
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Organization: W. M. Keck Observatory (CARA), Kamuela, HI, USA
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In article <2676@bnlux0.bnl.gov>, rivers@bnlls1.nsls.bnl.gov (Mark Rivers)
writes...
> 
>I am having a problem with backing store in PV-WAVE 3.03 under X windows. The
>default backing store mechanism is supposed to be that PV-WAVE requests the
>server to do the backing store. This is also supposed to be the behavior for
>all subsequent windows created after a "DEVICE, RETAIN=1" command. However,
>neither of these work for me. I have used two different X windows devices,
>both of which I believe are capable of backing store: DECWindows on a
>VAXStation 3200 and a Tektronix XN11 terminal (which was set up to have backing
>store enabled). DEVICE, RETAIN=2 works, but is quite slow because PV-WAVE
>itself makes the backing store.
> 
>Has anyone else seen this problem and/or found a fix?

Running the same version of PV~WAVE as you on VAXstation 3100's we observe the
same behavior as you (and use RETAIN=2). I just assumed that the server didn't
support backing store.

We have recently borrowed a NCD X-terminal. Its X server can be configured to
provide backing store "on demand". With this setting, RETAIN=1 works and gives
instantaneous re-paint on window move, expose etc. Very nice.

So I suspect that the problem is that your X servers are not in fact configured
to provide backing store on demand.

		William Lupton (wlupton@keck.hawaii.edu)