share/extensions/lindenmayer.py

   1 #!/usr/bin/env python
   2 '''
   3 Copyright (C) 2005 Aaron Spike, aaron@ekips.org
   4
   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.
   9
  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.
  14
  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 inkex, simplestyle, pturtle
  20
  21 class LSystem(inkex.Effect):
  22         def __init__(self):
  23                 inkex.Effect.__init__(self)
  24                 self.OptionParser.add_option("-o", "--order",
  25                                                 action="store", type="int",
  26                                                 dest="order", default=3,
  27                                                 help="number of iteration")
  28                 self.OptionParser.add_option("-a", "--angle",
  29                                                 action="store", type="float",
  30                                                 dest="angle", default=16.0,
  31                                                 help="angle for turn commands")
  32                 self.OptionParser.add_option("-s", "--step",
  33                                                 action="store", type="float",
  34                                                 dest="step", default=25.0,
  35                                                 help="step size")
  36                 self.OptionParser.add_option("-x", "--axiom",
  37                                                 action="store", type="string",
  38                                                 dest="axiom", default="++F",
  39                                                 help="initial state of system")
  40                 self.OptionParser.add_option("-r", "--rules",
  41                                                 action="store", type="string",
  42                                                 dest="rules", default="F=FF-[-F+F+F]+[+F-F-F]",
  43                                                 help="replacement rules")
  44                 self.stack = []
  45                 self.turtle = pturtle.pTurtle()
  46         def iterate(self):
  47                 self.rules = dict([i.split("=") for i in self.options.rules.upper().split(";") if i.count("=")==1])
  48                 self.__recurse(self.options.axiom.upper(),0)
  49                 return self.turtle.getPath()
  50         def __recurse(self,rule,level):
  51                 for c in rule:
  52                         if level < self.options.order:
  53                                 try:
  54                                         self.__recurse(self.rules[c],level+1)
  55                                 except KeyError:
  56                                         pass
  57
  58                         if c == 'F':
  59                                 self.turtle.pd()
  60                                 self.turtle.fd(self.options.step)
  61                         elif c == 'G':
  62                                 self.turtle.pu()
  63                                 self.turtle.fd(self.options.step)
  64                         elif c == '+':
  65                                 self.turtle.lt(self.options.angle)
  66                         elif c == '-':
  67                                 self.turtle.rt(self.options.angle)
  68                         elif c == '|':
  69                                 self.turtle.lt(180)
  70                         elif c == '[':
  71                                 self.stack.append([self.turtle.getpos(), self.turtle.getheading()])
  72                         elif c == ']':
  73                                 self.turtle.pu()
  74                                 pos,heading = self.stack.pop()
  75                                 self.turtle.setpos(pos)
  76                                 self.turtle.setheading(heading)
  77         def effect(self):
  78                 new = self.document.createElement('svg:path')
  79                 s = {'stroke-linejoin': 'miter', 'stroke-width': '1.0px',
  80                         'stroke-opacity': '1.0', 'fill-opacity': '1.0',
  81                         'stroke': '#000000', 'stroke-linecap': 'butt',
  82                         'fill': 'none'}
  83                 new.setAttribute('style', simplestyle.formatStyle(s))
  84                 new.setAttribute('d', self.iterate())
  85                 self.document.documentElement.appendChild(new)
  86
  87 e = LSystem()
  88 e.affect()