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From: mlab2@kuhub.cc.ukans.edu
Newsgroups: comp.sys.mac.programmer
Subject: Re: Copybits ok for mac classic and SE but hangs on Mac II's!
Message-ID: <28385.27aebeb8@kuhub.cc.ukans.edu>
Date: 5 Feb 91 20:18:32 GMT
References: <1991Feb05.021813.17710@mthvax.cs.miami.edu>
Organization: University of Kansas Academic Computing Services
Lines: 20

In article <1991Feb05.021813.17710@mthvax.cs.miami.edu>, rsherman@mthvax.cs.miami.edu (Roby Sherman) writes:
> I'm confused (ok, I mean MORE than usual!) my  friend and I have written a
> routine to draw to an offscreen bitmap and copy to a visable window.
> 
> This routine works flawlessly on the Mac plus, classic, se, etc. But it will
> hang any Mac II (or the LC) even if they are set to B/W mode. Why?
> 
> -- Roby
> 
> -- 
> Roby Sherman    |  rsherman@mthvax.cs.miami.edu

I seem to recall a similar experience.  I believe the II was very picky about
the current GrafPort and the clipping region on CopyBits calls.  If your
graphic you are transfering is not completely within the rectangle of the port
you may transfer garbage or crash.  Make sure every offscreen port has a
clipping region set to its bounds and try making different ports current during
the CopyBits.

john calhoun