share/extensions/generate_voronoi.py

   1 #!/usr/bin/env python
   2 """
   3 Copyright (C) 2010 Alvin Penner, penner@vaxxine.com
   4
   5 - Voronoi Diagram algorithm and C code by Steven Fortune, 1987, http://ect.bell-labs.com/who/sjf/
   6 - Python translation to file voronoi.py by Bill Simons, 2005, http://www.oxfish.com/
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21
  22 """
  23 import random, inkex, simplestyle, gettext, voronoi
  24 _ = gettext.gettext
  25
  26 try:
  27     from subprocess import Popen, PIPE
  28 except:
  29     inkex.errormsg(_("Failed to import the subprocess module. Please report this as a bug at : https://bugs.launchpad.net/inkscape."))
  30     inkex.errormsg("Python version is : " + str(inkex.sys.version_info))
  31     exit()
  32
  33 def clip_line(x1, y1, x2, y2, w, h):
  34     if x1 < 0 and x2 < 0:
  35         return [0, 0, 0, 0]
  36     if x1 > w and x2 > w:
  37         return [0, 0, 0, 0]
  38     if x1 < 0:
  39         y1 = (y1*x2 - y2*x1)/(x2 - x1)
  40         x1 = 0
  41     if x2 < 0:
  42         y2 = (y1*x2 - y2*x1)/(x2 - x1)
  43         x2 = 0
  44     if x1 > w:
  45         y1 = y1 + (w - x1)*(y2 - y1)/(x2 - x1)
  46         x1 = w
  47     if x2 > w:
  48         y2 = y1 + (w - x1)*(y2 - y1)/(x2 - x1)
  49         x2 = w
  50     if y1 < 0 and y2 < 0:
  51         return [0, 0, 0, 0]
  52     if y1 > h and y2 > h:
  53         return [0, 0, 0, 0]
  54     if x1 == x2 and y1 == y2:
  55         return [0, 0, 0, 0]
  56     if y1 < 0:
  57         x1 = (x1*y2 - x2*y1)/(y2 - y1)
  58         y1 = 0
  59     if y2 < 0:
  60         x2 = (x1*y2 - x2*y1)/(y2 - y1)
  61         y2 = 0
  62     if y1 > h:
  63         x1 = x1 + (h - y1)*(x2 - x1)/(y2 - y1)
  64         y1 = h
  65     if y2 > h:
  66         x2 = x1 + (h - y1)*(x2 - x1)/(y2 - y1)
  67         y2 = h
  68     return [x1, y1, x2, y2]
  69
  70 class Pattern(inkex.Effect):
  71     def __init__(self):
  72         inkex.Effect.__init__(self)
  73         self.OptionParser.add_option("--size",
  74                         action="store", type="int",
  75                         dest="size", default=10,
  76                         help="Average size of cell (px)")
  77         self.OptionParser.add_option("--border",
  78                         action="store", type="int",
  79                         dest="border", default=0,
  80                         help="Size of Border (px)")
  81
  82     def effect(self):
  83         if not self.options.ids:
  84             inkex.errormsg(_("Please select an object"))
  85             exit()
  86         q = {'x':0,'y':0,'width':0,'height':0}  # query the bounding box of ids[0]
  87         for query in q.keys():
  88             p = Popen('inkscape --query-%s --query-id=%s "%s"' % (query, self.options.ids[0], self.args[-1]), shell=True, stdout=PIPE, stderr=PIPE)
  89             rc = p.wait()
  90             q[query] = float(p.stdout.read())
  91         defs = self.xpathSingle('/svg:svg//svg:defs')
  92         pattern = inkex.etree.SubElement(defs ,inkex.addNS('pattern','svg'))
  93         pattern.set('id', 'Voronoi' + str(random.randint(1, 9999)))
  94         pattern.set('width', str(q['width']))
  95         pattern.set('height', str(q['height']))
  96         pattern.set('patternTransform', 'translate(%s,%s)' % (q['x'], q['y']))
  97         pattern.set('patternUnits', 'userSpaceOnUse')
  98
  99         # generate random pattern of points
 100         c = voronoi.Context()
 101         pts = []
 102         b = float(self.options.border)          # width of border
 103         for i in range(int(q['width']*q['height']/self.options.size/self.options.size)):
 104             x = random.random()*q['width']
 105             y = random.random()*q['height']
 106             if b > 0:                           # duplicate border area
 107                 pts.append(voronoi.Site(x, y))
 108                 if x < b:
 109                     pts.append(voronoi.Site(x + q['width'], y))
 110                     if y < b:
 111                         pts.append(voronoi.Site(x + q['width'], y + q['height']))
 112                     if y > q['height'] - b:
 113                         pts.append(voronoi.Site(x + q['width'], y - q['height']))
 114                 if x > q['width'] - b:
 115                     pts.append(voronoi.Site(x - q['width'], y))
 116                     if y < b:
 117                         pts.append(voronoi.Site(x - q['width'], y + q['height']))
 118                     if y > q['height'] - b:
 119                         pts.append(voronoi.Site(x - q['width'], y - q['height']))
 120                 if y < b:
 121                     pts.append(voronoi.Site(x, y + q['height']))
 122                 if y > q['height'] - b:
 123                     pts.append(voronoi.Site(x, y - q['height']))
 124             elif x > -b and y > -b and x < q['width'] + b and y < q['height'] + b:
 125                 pts.append(voronoi.Site(x, y))  # leave border area blank
 126             # dot = inkex.etree.SubElement(pattern, inkex.addNS('rect','svg'))
 127             # dot.set('x', str(x-1))
 128             # dot.set('y', str(y-1))
 129             # dot.set('width', '2')
 130             # dot.set('height', '2')
 131         if len(pts) < 3:
 132             inkex.errormsg("Please choose a larger object, or smaller cell size")
 133             exit()
 134
 135         # plot Voronoi diagram
 136         sl = voronoi.SiteList(pts)
 137         voronoi.voronoi(sl, c)
 138         path = ""
 139         for edge in c.edges:
 140             if edge[1] >= 0 and edge[2] >= 0:       # two vertices
 141                 [x1, y1, x2, y2] = clip_line(c.vertices[edge[1]][0], c.vertices[edge[1]][1], c.vertices[edge[2]][0], c.vertices[edge[2]][1], q['width'], q['height'])
 142             elif edge[1] >= 0:                      # only one vertex
 143                 if c.lines[edge[0]][1] == 0:        # vertical line
 144                     xtemp = c.lines[edge[0]][2]/c.lines[edge[0]][0]
 145                     if c.vertices[edge[1]][1] > q['height']/2:
 146                         ytemp = q['height']
 147                     else:
 148                         ytemp = 0
 149                 else:
 150                     xtemp = q['width']
 151                     ytemp = (c.lines[edge[0]][2] - q['width']*c.lines[edge[0]][0])/c.lines[edge[0]][1]
 152                 [x1, y1, x2, y2] = clip_line(c.vertices[edge[1]][0], c.vertices[edge[1]][1], xtemp, ytemp, q['width'], q['height'])
 153             elif edge[2] >= 0:                      # only one vertex
 154                 if c.lines[edge[0]][1] == 0:        # vertical line
 155                     xtemp = c.lines[edge[0]][2]/c.lines[edge[0]][0]
 156                     if c.vertices[edge[2]][1] > q['height']/2:
 157                         ytemp = q['height']
 158                     else:
 159                         ytemp = 0
 160                 else:
 161                     xtemp = 0
 162                     ytemp = c.lines[edge[0]][2]/c.lines[edge[0]][1]
 163                 [x1, y1, x2, y2] = clip_line(xtemp, ytemp, c.vertices[edge[2]][0], c.vertices[edge[2]][1], q['width'], q['height'])
 164             if x1 or x2 or y1 or y2:
 165                 path += 'M %.3f,%.3f %.3f,%.3f ' % (x1, y1, x2, y2)
 166
 167         attribs = {'d': path, 'style': 'stroke:#000000'}
 168         inkex.etree.SubElement(pattern, inkex.addNS('path', 'svg'), attribs)
 169
 170         # link selected object to pattern
 171         obj = self.selected[self.options.ids[0]]
 172         style = {}
 173         if obj.attrib.has_key('style'):
 174             style = simplestyle.parseStyle(obj.attrib['style'])
 175         style['fill'] = 'url(#%s)' % pattern.get('id')
 176         obj.attrib['style'] = simplestyle.formatStyle(style)
 177         if obj.tag == inkex.addNS('g', 'svg'):
 178             for node in obj:
 179                 style = {}
 180                 if node.attrib.has_key('style'):
 181                     style = simplestyle.parseStyle(node.attrib['style'])
 182                 style['fill'] = 'url(#%s)' % pattern.get('id')
 183                 node.attrib['style'] = simplestyle.formatStyle(style)
 184
 185 if __name__ == '__main__':
 186     e = Pattern()
 187     e.affect()
 188
 189 # vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99