1 #!/usr/bin/env python
2 '''
3 Copyright (C) 2005 Carsten Goetze c.goetze@tu-bs.de
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 '''
19 import random, math, inkex, simplepath
21 def calculateSubdivision(x1,y1,x2,y2,smoothness):
22 """ Calculate the vector from (x1,y1) to (x2,y2) """
23 x3 = x2 - x1
24 y3 = y2 - y1
25 """ Calculate the point half-way between the two points """
26 hx = x1 + x3/2
27 hy = y1 + y3/2
28 """ Calculate normalized vector perpendicular to the vector (x3,y3) """
29 length = math.sqrt(x3*x3 + y3*y3)
30 if length != 0:
31 nx = -y3/length
32 ny = x3/length
33 else:
34 nx = 1
35 ny = 0
36 """ Scale perpendicular vector by random factor """
37 r = random.uniform(-length/(1+smoothness),length/(1+smoothness))
38 nx = nx * r
39 ny = ny * r
40 """ add scaled perpendicular vector to the half-way point to get the final
41 displaced subdivision point """
42 x = hx + nx
43 y = hy + ny
44 return [x, y]
46 class PathFractalize(inkex.Effect):
47 def __init__(self):
48 inkex.Effect.__init__(self)
49 self.OptionParser.add_option("-s", "--subdivs",
50 action="store", type="int",
51 dest="subdivs", default="6",
52 help="Number of subdivisons")
53 self.OptionParser.add_option("-f", "--smooth",
54 action="store", type="float",
55 dest="smooth", default="4.0",
56 help="Smoothness of the subdivision")
57 def effect(self):
58 for id, node in self.selected.iteritems():
59 if node.tag == inkex.addNS('path','svg'):
60 d = node.get('d')
61 p = simplepath.parsePath(d)
63 a = []
64 first = 1
65 for cmd,params in p:
66 if cmd != 'Z':
67 if first == 1:
68 x1 = params[-2]
69 y1 = params[-1]
70 a.append(['M',params[-2:]])
71 first = 2
72 else :
73 x2 = params[-2]
74 y2 = params[-1]
75 self.fractalize(a,x1,y1,x2,y2,self.options.subdivs,self.options.smooth)
76 x1 = x2
77 y1 = y2
78 a.append(['L',params[-2:]])
80 node.set('d', simplepath.formatPath(a))
82 def fractalize(self,a,x1,y1,x2,y2,s,f):
83 subdivPoint = calculateSubdivision(x1,y1,x2,y2,f)
85 if s > 0 :
86 """ recursively subdivide the segment left of the subdivision point """
87 self.fractalize(a,x1,y1,subdivPoint[-2],subdivPoint[-1],s-1,f)
88 a.append(['L',subdivPoint])
89 """ recursively subdivide the segment right of the subdivision point """
90 self.fractalize(a,subdivPoint[-2],subdivPoint[-1],x2,y2,s-1,f)
92 e = PathFractalize()
93 e.affect()