From: Sam Moore <matches@ucc.asn.au>
Date: Thu, 29 May 2014 12:37:42 +0000 (+0800)
Subject: Koch's snowflake, now in PostScript!
X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fsam.git;a=commitdiff_plain;h=4c0361848c4fa9ccc9d4f100385f2d92728ad341

Koch's snowflake, now in PostScript!

It is amazing.
---

diff --git a/figures/koch.ps b/figures/koch.ps
new file mode 100644
index 0000000..45f88b2
--- /dev/null
+++ b/figures/koch.ps
@@ -0,0 +1,66 @@
+%!PS-Adobe-3.0 EPSF-3.0
+%%BoundingBox: -40 -40 140 120
+% Generates a koch snowflake, or crashes your pdf viewer, whichever you prefer.
+
+
+% Usage:
+% x1 y1 x2 y2 iterations koch x1 y1 ... x2 y2
+/koch {
+	20 dict begin
+	/iteration exch def
+	/y2 exch def
+	/x2 exch def
+	/y1 exch def
+	/x1 exch def
+	/dy y2 y1 sub def
+	/dx x2 x1 sub def
+	/dist dx dx mul dy dy mul add sqrt def
+	/nx 0 dy sub dist div def
+	/ny dx dist div def
+
+	/xA dx 3 div x1 add def
+	/yA dy 3 div y1 add def 
+	/xB dist 3 div nx mul dx 2 div add x1 add def
+	/yB dist 3 div ny mul dy 2 div add y1 add def
+	/xC dx 3 div 2 mul x1 add def
+	/yC dy 3 div 2 mul y1 add def 
+	
+	iteration 0 gt
+	{
+		/next_iteration iteration 1 sub def
+
+		x1 y1 xA yA next_iteration koch
+		xA yA xB yB next_iteration koch
+		xB yB xC yC next_iteration koch
+		xC yC x2 y2 next_iteration koch
+		%xB debug
+	}
+	{
+		x1 y1 moveto x2 y2 lineto
+		
+	} ifelse
+	end
+} def
+
+/debug { moveto 20 string cvs  show} bind def
+/Coronet findfont 12 scalefont setfont % Fancy font!
+
+% End prolog
+
+
+% Draw some text and the initial triangle faintly
+0.9 0.9 1 setrgbcolor
+(Koch's) 38 40 debug
+(Snowflake) 28 28 debug
+1E-6 setlinewidth
+0 0 moveto 50 100 lineto 100 0 lineto 0 0 lineto stroke
+
+/iterations 7 def % Define to the desired number of iterations to crash your pdf viewer
+0 0 1 setrgbcolor
+0 0 moveto
+0 0 50 100 iterations koch 
+50 100 100 0 iterations koch
+100 0 0 0 iterations koch closepath
+fill 
+
+showpage