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- From: slchambe@athena.mit.edu (Stephen L Chamberlin)
- Subject: drawing synchronized to vertical retrace
- Message-ID: <1992Jul22.022319.4592@athena.mit.edu>
- Sender: news@athena.mit.edu (News system)
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- Organization: Massachusetts Institute of Technology
- References: <1992Jul21.161251.7693@midway.uchicago.edu> <D88-JWA.92Jul21225659@dront.nada.kth.se> <1992Jul21.231124.26354@midway.uchicago.edu>
- Date: Wed, 22 Jul 1992 02:23:19 GMT
- Lines: 15
-
- I'm trying to do some animation, and I want my drawing to be synchronized to
- the vertical retrace to avoid strange flicker problems. What's the simplest
- way to do this? I tried installing a vbl task that simply increments a global
- variable in my app every tick, and then synchronizing my drawing to changes in
- this tick counter variable. There may be an easier solution, I don't know. At
- any rate, I was unable to get the vbl task to work, because I couldn't seem to
- figure out how to use SetUpA5 and RestoreA5 as documented in IM 2. Think C 5.0
- complains that they are undefined. Did these traps get nuked somewhere since
- IM 2 was written? I believe that I should use SetUpA5 and RestoreA5 instead of
- SetUpA4 and RestoreA4 because my vbl task is part of an application, not an
- init. I've never done this before, though, so basically I don't have any idea
- what I'm doing. Any comments or advice would be appreciated. Thanks!
-
- Steve Chamberlin
- slchambe@athena.mit.edu
-