Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!usc!apple!portal!cup.portal.com!schuster
From: schuster@cup.portal.com (Michael Alan Schuster)
Newsgroups: comp.lang.postscript
Subject: Re: Byte's fern postscript program
Message-ID: <35005@cup.portal.com>
Date: 18 Oct 90 22:21:34 GMT
References: <1990Oct18.182149.861@infonode.ingr.com>
Distribution: na
Organization: The Portal System (TM)
Lines: 55

>Has anyone gotten the fern postscript program to run?  It was
>published in Byte magazine a few months ago but seems to have
>one or more bugs in it.  I would like a copy of it if it has
>been fixed.  I recall that someone else posted a question
>similar to this shortly after the issue was on the newsstand,
>so you may want to post it here.

% Title: Fractal fern

% Copyright c 1990 by Don Lancaster and Synergetics, 3860 West First Street,
% Box 809, Thatcher AZ 85552. (602) 428-4073. All commercial rights reserved.
% Personal use permitted so long as this header remains present and intact.
% Show and Tell disk for Apple, Mac, or IBM costs $39.50. Free voice helpline.

%	X
%	

% This routine create a fractal fern.
% Additional details appear in Don Lancaster's LaserWriter Secrets text.

% Approximate NTX run time: Varies depending on numdot length.
% ....................................


/problistcreate {mark /counter 0 def probabilities {128 mul round cvi
{transforms counter get} repeat /counter counter 1 add def} forall
counttomark 128 sub neg dup 0 gt {[1 0 0 1 0 0] repeat} {pop} ifelse]
/problist exch def} bind def

/doit {problistcreate 1 1 20 {problist rand -24 bitshift get transform 2 copy
moveto 0.001 10 rlineto} repeat newpath numdots {problist rand -24 bitshift
get transform 2 copy moveto 0.001 0 rlineto stroke} repeat} bind def

%     ///   demo - remove before use   ///

/numdots 6000 def  % increase for denser image; descrease to print faster

/transforms   [
		[0 0 0 .16 0 0]
		[.2 .23 -.26 .22 0 1.6]
		[-.15 .26 .28 .24 0 .44]
		[.85 -.04 .04 .85 0 1.6]

	      ] def

/probabilities [.01 .07 .07 .85] def

1 setlinecap
0 setlinewidth
200 300 translate
30 dup scale

doit

showpage quit