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From: anderson@SECS.ucsc.edu
Newsgroups: comp.sys.mac.programmer
Subject: Problems with color animation
Message-ID: <17477@darkstar.ucsc.edu>
Date: 26 Jun 91 19:44:02 GMT
Sender: usenet@darkstar.ucsc.edu
Reply-To: anderson@SECS.ucsc.edu
Organization: UCSC Molecular Engineering Laboratory
Lines: 32

Would some kind reader please take the time to help me retain my sanity?
I am in the process of porting an MSDOS molecular dynamics animation viewer
to the Mac.  This program uses offscreen drawing to give smooth animation.
I have been able to get good results on the Mac in monochrome by drawing to
an offscreen bitmap and then using CopyBits to move it to the window.  The 
problem comes when I try to use color.  I  have been able to get the drawing
to the offscreen bitmap and I can copy it to the screen but I get a terrible
flicker.  I have used SlotVInstall to try to synch the copybits to the
vertical retrace but it didn't cure the problem.  I have waded through 
Inside Macintosh I-V, the Mac Technical Notes, and the Usnet Mac Programmer's 
Guide and I have run out of ideas on what to try next.
HELPPPPPPP!!!!!!!!

The size of the bitmap may be a contributing factor.  I am using the full 
screen for the drawings so my first question is whether or not it is possible
to do the copybits fast enough  on this large a bitmap?

The program is  written in C (about 125K of source code).  Originally written
with Turbo C++ 1.0 for MSDOS, porting to the Mac using Think C 4.0.
Using a Mac IIx for the port to Mac.

While I am reasonably experienced  with C, this is my first attempt at writing
a program for the Mac so please show some mercy if I have overlooked  an
obvious answer.

Sample source code in any language would help but C would be most useful.

Gary D. Anderson
Department of Chemistry
University of California
Santa Cruz, CA   95060
anderson@secs.ucsc.edu