Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!ucsd!ucsdhub!hp-sdd!hplabs!hpda!hpcuhb!hp-sde!hpcea!hpnmd!hpsrla!hpsadla!erik
From: erik@hpsadla.HP (Erik Kilk)
Newsgroups: comp.sys.mac.programmer
Subject: Re: flicker-free drawing
Message-ID: <5520002@hpsadla.HP>
Date: 28 Jul 88 18:28:55 GMT
References: <5727@orstcs.CS.ORST.EDU>
Lines: 15


In your case, you should be able to change the pen mode and take out
the EraseRect call.  Use the pen mode which copies both your white and
black bits (I don't have InsideMac here, but maybe it was srcbit or something.)

In general, you can get flicker free graphics by not
erasing before you draw.  The flicker comes from the small amount of
time that you have nothing drawn.  

Using various techniques, you should draw the new image over
the old image and then erase the old image.  Sometimes you are lucky 
and drawing the new image will erase the entire old one.  Othertimes
you have to calculate offscreen the overlap and erase it yourself.

Erik