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From: rap@dana.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: New IBMs?  Amiga runs circles...
Message-ID: <140@dana.UUCP>
Date: Tue, 7-Apr-87 13:02:02 EST
Article-I.D.: dana.140
Posted: Tue Apr  7 13:02:02 1987
Date-Received: Sat, 11-Apr-87 00:30:40 EST
References: <1825@vax135.UUCP>
Organization: Dana Computer, Inc., Sunnyvale, CA
Lines: 26
Summary: and circles could really be faster...

In article <1825@vax135.UUCP>, cjp@vax135.UUCP (Charles Poirier) writes:
> I glimpsed one of the new IBMs on TV this morning (don't know which one),
> it was running a "circles" demo.  They were drawing circles at about
> 2 per second.  My stock Amiga can run ellipses (not just circles),
> in a full-screen window at over 10 per second, and much faster
> in smaller windows.  This is IBM's 1988 machine?  I think
> the Amiga is not in any trouble from this quarter.
> 
> 	Charles Poirier

I talked to DUCK at one of the BADGE meetings recently and he mentioned
that all of the circle code actually uses WritePixel.  It could have
been faster (and someday somebody will make it faster, I'm sure) but
the pressures of the release time only allowed the crew to just barely
get the code into 1.2.   The benefit of doing it exactly the way the
code is now is that it gave the Amiga one-dot-mode, which allows
the blitter to be used most efficiently for filling the ellipses.

I can envision at a future time somebody allocating a background
bitmap, rendering (and filling) the ellipse in the background by the 
most efficient method available, then blitting (ClipBlitTransparent?)
the resultant ellipse into the target area.  I would assume that the
result would be faster than the writepixel-per-dot than is now done?

Rob Peck	hplabs!dana!rap
.