Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!tdatirv!sarima
From: sarima@tdatirv.UUCP (Stanley Friesen)
Newsgroups: comp.windows.x
Subject: Re: PC X servers / backing store
Message-ID: <163@tdatirv.UUCP>
Date: 7 Mar 91 00:38:01 GMT
References: <9103032356.AA00215@devnull.Eng.Sun.COM> <952@boing.UUCP>
Reply-To: sarima@tdatirv.UUCP (Stanley Friesen)
Organization: Teradata Corp., Irvine
Lines: 20

In article <952@boing.UUCP> dale@boing.UUCP (Dale Luck) writes:
>I couldn't agree with you less on this last statement. Case in point:
>The Amiga guarentees backing store with it's SMART_REFRESH windows.
>The programmer is able to choose whether they can handle expose
>events or not. SIMPLE_REFRESH windows always generate expose events
>whenever it is uncovered. SMART_REFRESH windows do not.

Oh, aye, so it does, but read the fine print.  All of the memory has
to be allocated when the window is created, and I believe most of it
must be in memory accessible to the graphics chip (about 512K on older
systems).  You can only create a very few such windows before running
completely out of memory.  So, yes, it is possible, at tremendous cost
(only a few windows allowed, unless they are very small).

Now, if you will only have one or two apps running, and they only need
one or two SMART_REFRESH windows each, then this is fine.  BUT, for a
more general system, with reasonable limits, this is not good enough.
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uunet!tdatirv!sarima				(Stanley Friesen)