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From: rener@cs.eur.nl (Rene Roelofs)
Newsgroups: comp.lang.pascal
Subject: Re: flicker-free animation with TP
Message-ID: <1990May9.104756.3645@cs.eur.nl>
Date: 9 May 90 10:47:56 GMT
References: <90.127.13:27:55@ira.uka.de>
Organization: Erasmus Universiteit Rotterdam, dept. CS (Informatica)
Lines: 29

>Some days ago, one of you asked for a solution to do fast flicker-free
>animation in TurboPascal. I myself had the same problem and circumvented it by
>a simple technique called "page-flipping": nearly every graphic card has 2
>independent graphic pages, so it is possible to draw at one page while showing
>the other. If the "background" page is finished, you just "flip" the pages:
>thus, at any time all actions take place in the background and you get a smooth
>animation!

This is a good demo and contains some usefull hints to get the
flicker out of my game. But since I use more then yust one moving
sprite on my screen and a lot of background (most of them random)
items, I am looking for somekind of COPYVIDEOPAGE. 
This can then be used to avoid a lot of double drawing in both
videopages and should be used as follow.

   Copyvideopage( 0, 1);
   updatepage_1;
   showpage_1;
   copyvideopage( 1, 0);
   updatepage_0
   etc...

Does anybody have any suggestions to create such a routine?

-- 
    |-----\                        Rene Roelofs 
    |     |                        Dept. of Computer Science
   /|-----/                        Erasmus University Rotterdam, The Netherlands
   \|  \                           uucp: mcvax!hp4nl!eurtrx!euraiv1!rener          /|    \