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From: vrm@babcock.cerc.wvu.wvnet.edu (Vasile R. Montan)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Advice on icon animation wanted
Message-ID: <1119@babcock.cerc.wvu.wvnet.edu>
Date: 18 Dec 90 00:46:13 GMT
References: <47444@apple.Apple.COM>
Sender: news@cerc.wvu.wvnet.edu
Lines: 23

From article <47444@apple.Apple.COM>, by stevec@Apple.COM (Steve Christensen):
> In article <1116@babcock.cerc.wvu.wvnet.edu> un020070@vaxa.wvnet.edu writes:

[Deleted material in which I talk about plotting icons during the
vertical retrace interrupt] 
> You also can't draw from an interrupt routine because the heap may not be
> consistent, and QuickDraw uses the Memory Manager for regions.
Really?  One book that I saw (but don't own- I think it's called
Mac Programming Secrets) suggesting doing drawing during the VBL
to accomplish flicker-free animation.  Did the interrupt routine
somehow signal the main program that the VBL was going on?

>>Second question:  How do you draw an icon in XOR?  Is this possible
>>with the easy-to-use PlotIcon, or do I have to mess with some kind
>>of bit transfer? 
> Well, you should just be able to set the transfer mode to XOR and do the plot.
I tried this, and it didn't seem to work.  I couldn't get the transfer
mode to affect PlotIcon at all, which was why I wondered if there might
not be some special considerations.

Thank you!
--Kurisuto (who is not Vasile)
email un020070@vaxa.wvnet.edu