Sierpinski triangle in PostScript

sierpinksi.ps

%!PS-Adobe-3.0
%%Creator: Aaron Puchert
%%Title: The Spierpinski triangle
%%Pages: 1
%%PageOrder: Ascend

%%BeginProlog
% PAGE SETTINGS
/pageset {
	28.3464566 28.3464566 scale    % set cm = 1
	0.5 0.5 translate
	0 setlinewidth
} def

%----------
% MACRO
%----------

% sierpinski(n) draws a sierpinski triangle of order n
/sierpinski {
dup 0 gt
{	[0.5 0 0 0.5 0 0] concat dup 1 sub sierpinski
	[1 0 0 1 1 0] concat dup 1 sub sierpinski
	[1 0 0 1 -1 1] concat dup 1 sub sierpinski
	[2 0 0 2 0 -1] concat}
{	newpath
		0 0 moveto
		1 0 lineto
		0 1 lineto
	closepath
	fill}
ifelse pop} def
%%EndProlog

%%BeginSetup
<< /PageSize [596 843] >> setpagedevice  % A4
%%EndSetup

%----------------------------
% ACTUAL PAGE DEFINITION
%----------------------------
%%Page: 1 1
pageset
[20 0 10 300 sqrt 0 0] concat
9 sierpinski
showpage
%%EOF