2010-01-11 Happy New Year!

In order to celebrate the new year properly, here is a python script to create an impossible triangle. Paste the code into a file (e.g. triangle.py), run it and pipe the result into an .svg file:
./triangle.py > triangle.svg

---

#!/usr/bin/env python

import math

w = 400
d = 40

class Point:
 def __init__(self, x, y):
  self.x = x
  self.y = y

frac = d / math.sqrt(3)
origin = Point(0.5*frac, w*math.sqrt(3)/2-d/2)
current = origin
a1 = Point(frac, d)
b1 = Point(2*frac, 0)
c1 = Point(5*frac, d)
d1 = Point(6*frac, 2*d)
a2 = Point(w-6*frac, 2*d)
b2 = Point(w-4*frac, 2*d)
c2 = Point(w-2*frac, 0)
d2 = Point(w-frac, d)
a3 = Point(w/2-frac, w/2*math.sqrt(3)-d)
b3 = Point(w/2+frac, w/2*math.sqrt(3)-d)
c3 = Point(w/2-frac, w/2*math.sqrt(3)-3*d)
d3 = Point(w/2, w/2*math.sqrt(3)-4*d)

def path(color, lineWidth, points):
 global current
 current = origin
 path = ''
 for p in points:
  path += '%f,%f ' % (p.x-current.x, -p.y+current.y)
  current = p
 return '<path style="fill: %s; stroke: #000000; stroke-width: %ipx; stroke-linecap: butt; stroke-linejoin: miter; stroke-opacity: 1" d="m %s z"/>' % (color, lineWidth, path)

print '<?xml version="1.0" standalone="no"?>'
print '<svg xmlns="http://www.w3.org/2000/svg" width="%i" height="%i" id="svg2" version="1.1">' % (w, w*math.sqrt(3)/2)
print path('#FF7F7F', 1, (b1, c2, d2, c1, d3, c3))
print path('#7FFF7F', 1, (d2, b3, a3, b2, d1, c1))
print path('#7F7FFF', 1, (a3, a1, b1, c3, a2, b2))
print path('none', 2, (b1, c2, d2, b3, a3 ,a1))
print '</svg>'

---

This is what it looks like: