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From: jim_d@cimcor.mn.org (Jim Dahlberg)
Newsgroups: comp.graphics
Subject: Re: Fractals
Summary: I have a curvetrace algorithm which traces around black regions.
Message-ID: <652@cimcor.mn.org>
Date: 26 Feb 89 22:58:07 GMT
References: <160.2404E090@muadib.FIDONET.ORG>
Organization: Grenier & friends, Forest Lake, MN
Lines: 28

In article <160.2404E090@muadib.FIDONET.ORG>, Mahesh.Neelakanta@f7.n369.z1.FIDONET.ORG (Mahesh Neelakanta) writes:
> 
>   I am at present reading the book that you mentioned.  I am not as 
> mathematically advanced as I would like to be in understanding the 
> proofs, etc that Mandelbrot has shown in his book.  I am basically just 
> looking for a fast way to skip the black areas in the fractal. I would 
> also like source code if anybody has any.
>  
>                                         - Mahesh

I just posted a program called JAM (Julian and Mandelbrot) to the
comp.binaries.ibm.pc group.  This program computes the set using a
curvetrace algorithm which traces around any region of a constant color
and then just fills the region with that color.  Imperfect results can
be obtained this way, but in practice it is virtually unnoticable.  And
the savings in time are worth it.  For perfect results, the program also
supports the old iterate-every-pixel algorithm if you want to spend the
time waiting for the result.  Source code is available (Turbo Basic). 
See the documentation.  The curvetrace routine is a fairly stand-alone
routine which was translated from an older Pascal version, so it should
be fairly easy to convert to other languages and Mandelbrot programs.

The program only supports the 16 color EGA 640 X 350 mode.  It also
supports a mouse.

    Jim Dahlberg
    Internet: jim_d@cimcor.mn.org
    UUCP:     uunet!rosevax!cimcor!jim_d