🚀 go-pugleaf

this was just posted to clc - it's a little bit older and I hope there's
nothing to copy left, but it's to nice to keep it secret ;-)

-- 
Patrick Dockhorn	       Forschungszentrum Informatik, Karlsruhe/Germany.
INTERNET: dockhorn@fzi.de      There are two rules for success in life:
BITNET  : ukew@dkauni2.bitnet  Rule 1:  Don't tell people everything you know.


%!
% ============================================================================
% Generate a fractal fern by first creating a table of 128 different transformations based on the required
% probablilities. This table is then used to build up the final fern. The first 20 dots are thrown out to
% give the stange attractor time to start strange attracting. It takes a mere 28 data values to completely
% define this fractal image.

% References: Lancaster, Don. Some Assembly Required, PostScript Insider Secrets. Byte, July 1990. 300.
% ============================================================================

/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

% ============================================================================

/numdots 100000 def	% increase for denser image; decrease to print faster

/transforms
[
	[0 0 0 0.16 0 0]
	[0.2 0.23 -0.26 0.22 0 1.6]
	[-0.15 0.26 0.28 0.24 0 0.44]
	[0.85 -0.04 0.04 0.85 0 1.6]
] def

/probabilities [0.01 0.07 0.07 0.85] def

1 setlinecap
0 setlinewidth
200 300 translate
30 dup scale

doit
showpage
quit

% ============================================================================