share/extensions/motion.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 math, inkex, simplestyle, simplepath, bezmisc
  20
  21 class Motion(inkex.Effect):
  22     def __init__(self):
  23         inkex.Effect.__init__(self)
  24         self.OptionParser.add_option("-a", "--angle",
  25                         action="store", type="float",
  26                         dest="angle", default=45.0,
  27                         help="direction of the motion vector")
  28         self.OptionParser.add_option("-m", "--magnitude",
  29                         action="store", type="float",
  30                         dest="magnitude", default=100.0,
  31                         help="magnitude of the motion vector")
  32
  33     def makeface(self,last,(cmd, params)):
  34         a = []
  35         a.append(['M',last[:]])
  36         a.append([cmd, params[:]])
  37
  38         #translate path segment along vector
  39         np = params[:]
  40         defs = simplepath.pathdefs[cmd]
  41         for i in range(defs[1]):
  42             if defs[3][i] == 'x':
  43                 np[i] += self.vx
  44             elif defs[3][i] == 'y':
  45                 np[i] += self.vy
  46
  47         a.append(['L',[np[-2],np[-1]]])
  48
  49         #reverse direction of path segment
  50         np[-2:] = last[0]+self.vx,last[1]+self.vy
  51         if cmd == 'C':
  52             c1 = np[:2], np[2:4] = np[2:4], np[:2]
  53         a.append([cmd,np[:]])
  54
  55         a.append(['Z',[]])
  56         face = self.document.createElement('svg:path')
  57         self.facegroup.appendChild(face)
  58         face.setAttribute('d', simplepath.formatPath(a))
  59
  60
  61     def effect(self):
  62         self.vx = math.cos(math.radians(self.options.angle))*self.options.magnitude
  63         self.vy = math.sin(math.radians(self.options.angle))*self.options.magnitude
  64         for id, node in self.selected.iteritems():
  65             if node.tagName == 'path':
  66                 group = self.document.createElement('svg:g')
  67                 self.facegroup = self.document.createElement('svg:g')
  68                 node.parentNode.appendChild(group)
  69                 group.appendChild(self.facegroup)
  70                 group.appendChild(node)
  71
  72                 try:
  73                     t = node.attributes.getNamedItem('transform').value
  74                     group.setAttribute('transform', t)
  75                     node.attributes.getNamedItem('transform').value=""
  76                 except AttributeError:
  77                     pass
  78
  79                 s = node.attributes.getNamedItem('style').value
  80                 self.facegroup.setAttribute('style', s)
  81
  82                 p = simplepath.parsePath(node.attributes.getNamedItem('d').value)
  83                 for cmd,params in p:
  84                     tees = []
  85                     if cmd == 'C':
  86                         bez = (last,params[:2],params[2:4],params[-2:])
  87                         tees = [t for t in bezmisc.beziertatslope(bez,(self.vy,self.vx)) if 0<t<1]
  88                         tees.sort()
  89
  90                     segments = []
  91                     if len(tees) == 0 and cmd in ['L','C']:
  92                             segments.append([cmd,params[:]])
  93                     elif len(tees) == 1:
  94                             one,two = bezmisc.beziersplitatt(bez,tees[0])
  95                             segments.append([cmd,list(one[1]+one[2]+one[3])])
  96                             segments.append([cmd,list(two[1]+two[2]+two[3])])
  97                     elif len(tees) == 2:
  98                             one,two = bezmisc.beziersplitatt(bez,tees[0])
  99                             two,three = bezmisc.beziersplitatt(two,tees[1])
 100                             segments.append([cmd,list(one[1]+one[2]+one[3])])
 101                             segments.append([cmd,list(two[1]+two[2]+two[3])])
 102                             segments.append([cmd,list(three[1]+three[2]+three[3])])
 103
 104                     for seg in segments:
 105                         self.makeface(last,seg)
 106                         last = seg[1][-2:]
 107
 108                     if cmd == 'M':
 109                         subPathStart = params[-2:]
 110                     if cmd == 'Z':
 111                         last = subPathStart
 112                     else:
 113                         last = params[-2:]
 114
 115 e = Motion()
 116 e.affect()