share/extensions/addnodes.py

   1 #!/usr/bin/env python
   2 '''
   3 This extension either adds nodes to a path so that
   4     a) no segment is longer than a maximum value
   5     or
   6     b) so that each segment is divided into a given number of equal segments
   7
   8 Copyright (C) 2005,2007 Aaron Spike, aaron@ekips.org
   9
  10 This program is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2 of the License, or
  13 (at your option) any later version.
  14
  15 This program is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with this program; if not, write to the Free Software
  22 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 '''
  24
  25 import inkex
  26 import cubicsuperpath, simplestyle, copy, math, re, bezmisc
  27
  28 def numsegs(csp):
  29     return sum([len(p)-1 for p in csp])
  30 def tpoint((x1,y1), (x2,y2), t = 0.5):
  31     return [x1+t*(x2-x1),y1+t*(y2-y1)]
  32 def cspbezsplit(sp1, sp2, t = 0.5):
  33     m1=tpoint(sp1[1],sp1[2],t)
  34     m2=tpoint(sp1[2],sp2[0],t)
  35     m3=tpoint(sp2[0],sp2[1],t)
  36     m4=tpoint(m1,m2,t)
  37     m5=tpoint(m2,m3,t)
  38     m=tpoint(m4,m5,t)
  39     return [[sp1[0][:],sp1[1][:],m1], [m4,m,m5], [m3,sp2[1][:],sp2[2][:]]]
  40 def cspbezsplitatlength(sp1, sp2, l = 0.5, tolerance = 0.001):
  41     bez = (sp1[1][:],sp1[2][:],sp2[0][:],sp2[1][:])
  42     t = bezmisc.beziertatlength(bez, l, tolerance)
  43     return cspbezsplit(sp1, sp2, t)
  44 def cspseglength(sp1,sp2, tolerance = 0.001):
  45     bez = (sp1[1][:],sp1[2][:],sp2[0][:],sp2[1][:])
  46     return bezmisc.bezierlength(bez, tolerance)
  47 def csplength(csp):
  48     total = 0
  49     lengths = []
  50     for sp in csp:
  51         lengths.append([])
  52         for i in xrange(1,len(sp)):
  53             l = cspseglength(sp[i-1],sp[i])
  54             lengths[-1].append(l)
  55             total += l
  56     return lengths, total
  57 def numlengths(csplen):
  58     retval = 0
  59     for sp in csplen:
  60         for l in sp:
  61             if l > 0:
  62                 retval += 1
  63     return retval
  64
  65 class SplitIt(inkex.Effect):
  66     def __init__(self):
  67         inkex.Effect.__init__(self)
  68         self.OptionParser.add_option("--segments",
  69                         action="store", type="int",
  70                         dest="segments", default=2,
  71                         help="Number of segments to divide the path into")
  72         self.OptionParser.add_option("--max",
  73                         action="store", type="float",
  74                         dest="max", default=2,
  75                         help="Number of segments to divide the path into")
  76         self.OptionParser.add_option("--method",
  77                         action="store", type="string",
  78                         dest="method", default='',
  79                         help="The kind of division to perform")
  80
  81     def effect(self):
  82
  83         for id, node in self.selected.iteritems():
  84             if node.tag == inkex.addNS('path','svg'):
  85                 p = cubicsuperpath.parsePath(node.get('d'))
  86
  87                 #lens, total = csplength(p)
  88                 #avg = total/numlengths(lens)
  89                 #inkex.debug("average segment length: %s" % avg)
  90
  91                 new = []
  92                 for sub in p:
  93                     new.append([sub[0][:]])
  94                     i = 1
  95                     while i <= len(sub)-1:
  96                         length = cspseglength(new[-1][-1], sub[i])
  97
  98                         if self.options.method == 'bynum':
  99                             splits = self.options.segments
 100                         else:
 101                             splits = math.ceil(length/self.options.max)
 102
 103                         for s in xrange(int(splits),1,-1):
 104                             new[-1][-1], next, sub[i] = cspbezsplitatlength(new[-1][-1], sub[i], 1.0/s)
 105                             new[-1].append(next[:])
 106                         new[-1].append(sub[i])
 107                         i+=1
 108
 109                 node.set('d',cubicsuperpath.formatPath(new))
 110
 111 if __name__ == '__main__':
 112     e = SplitIt()
 113     e.affect()
 114
 115
 116 # vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99