fractalize.py revision 659d437ab1fa196d010c1e92b009b608b8e8b086
#!/usr/bin/env python
'''
Copyright (C) 2005 Carsten Goetze c.goetze@tu-bs.de
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
'''
import random, math, inkex, simplepath
def calculateSubdivision(x1,y1,x2,y2,smoothness):
""" Calculate the vector from (x1,y1) to (x2,y2) """
x3 = x2 - x1
y3 = y2 - y1
""" Calculate the point half-way between the two points """
hx = x1 + x3/2
hy = y1 + y3/2
""" Calculate normalized vector perpendicular to the vector (x3,y3) """
length = math.sqrt(x3*x3 + y3*y3)
nx = -y3/length
ny = x3/length
""" Scale perpendicular vector by random factor """
r = random.uniform(-length/(1+smoothness),length/(1+smoothness))
nx = nx * r
ny = ny * r
""" add scaled perpendicular vector to the half-way point to get the final
displaced subdivision point """
x = hx + nx
y = hy + ny
return [x, y]
class PathFractalize(inkex.Effect):
def __init__(self):
inkex.Effect.__init__(self)
self.OptionParser.add_option("-s", "--subdivs",
action="store", type="int",
dest="subdivs", default="6",
help="Number of subdivisons")
self.OptionParser.add_option("-f", "--smooth",
action="store", type="float",
dest="smooth", default="4.0",
help="Smoothness of the subdivision")
def effect(self):
for id, node in self.selected.iteritems():
if node.tag == inkex.addNS('path','svg'):
d = node.get('d')
p = simplepath.parsePath(d)
a = []
first = 1
for cmd,params in p:
if cmd != 'Z':
if first == 1:
x1 = params[-2]
y1 = params[-1]
a.append(['M',params[-2:]])
first = 2
else :
x2 = params[-2]
y2 = params[-1]
self.fractalize(a,x1,y1,x2,y2,self.options.subdivs,self.options.smooth)
x1 = x2
y1 = y2
a.append(['L',params[-2:]])
node.set('d', simplepath.formatPath(a))
def fractalize(self,a,x1,y1,x2,y2,s,f):
subdivPoint = calculateSubdivision(x1,y1,x2,y2,f)
if s > 0 :
""" recursively subdivide the segment left of the subdivision point """
self.fractalize(a,x1,y1,subdivPoint[-2],subdivPoint[-1],s-1,f)
a.append(['L',subdivPoint])
""" recursively subdivide the segment right of the subdivision point """
self.fractalize(a,subdivPoint[-2],subdivPoint[-1],x2,y2,s-1,f)
e = PathFractalize()
e.affect()