diff options
Diffstat (limited to 'share/extensions/generate_voronoi.py')
| -rwxr-xr-x | share/extensions/generate_voronoi.py | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/share/extensions/generate_voronoi.py b/share/extensions/generate_voronoi.py new file mode 100755 index 0000000..b2ac9dd --- /dev/null +++ b/share/extensions/generate_voronoi.py @@ -0,0 +1,180 @@ +#!/usr/bin/env python +# coding=utf-8 +# +# Copyright (C) 2010 Alvin Penner, penner@vaxxine.com +# +# - Voronoi Diagram algorithm and C code by Steven Fortune, 1987, http://ect.bell-labs.com/who/sjf/ +# - Python translation to file voronoi.py by Bill Simons, 2005, http://www.oxfish.com/ +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +# + +import random + +import inkex +from inkex import PathElement, Pattern + +import voronoi + +def clip_line(x1, y1, x2, y2, w, h): + if x1 < 0 and x2 < 0: + return [0, 0, 0, 0] + if x1 > w and x2 > w: + return [0, 0, 0, 0] + if x1 < 0: + y1 = (y1 * x2 - y2 * x1) / (x2 - x1) + x1 = 0 + if x2 < 0: + y2 = (y1 * x2 - y2 * x1) / (x2 - x1) + x2 = 0 + if x1 > w: + y1 = y1 + (w - x1) * (y2 - y1) / (x2 - x1) + x1 = w + if x2 > w: + y2 = y1 + (w - x1) * (y2 - y1) / (x2 - x1) + x2 = w + if y1 < 0 and y2 < 0: + return [0, 0, 0, 0] + if y1 > h and y2 > h: + return [0, 0, 0, 0] + if x1 == x2 and y1 == y2: + return [0, 0, 0, 0] + if y1 < 0: + x1 = (x1 * y2 - x2 * y1) / (y2 - y1) + y1 = 0 + if y2 < 0: + x2 = (x1 * y2 - x2 * y1) / (y2 - y1) + y2 = 0 + if y1 > h: + x1 = x1 + (h - y1) * (x2 - x1) / (y2 - y1) + y1 = h + if y2 > h: + x2 = x1 + (h - y1) * (x2 - x1) / (y2 - y1) + y2 = h + return [x1, y1, x2, y2] + + +class GenerateVoronoi(inkex.EffectExtension): + def add_arguments(self, pars): + pars.add_argument("--tab") + pars.add_argument("--size", type=int, default=10, help="Average size of cell (px)") + pars.add_argument("--border", type=int, default=0, help="Size of Border (px)") + + def effect(self): + if not self.options.ids: + return inkex.errormsg(_("Please select an object")) + scale = self.svg.unittouu('1px') # convert to document units + self.options.size *= scale + self.options.border *= scale + obj = self.svg.selection.first() + bbox = obj.bounding_box() + mat = obj.composed_transform().matrix + pattern = self.svg.defs.add(Pattern()) + pattern.set_random_id('Voronoi') + pattern.set('width', str(bbox.width)) + pattern.set('height', str(bbox.height)) + pattern.set('patternUnits', 'userSpaceOnUse') + pattern.patternTransform.add_translate(bbox.left - mat[0][2], bbox.top - mat[1][2]) + + # generate random pattern of points + c = voronoi.Context() + pts = [] + b = float(self.options.border) # width of border + for i in range(int(bbox.width * bbox.height / self.options.size / self.options.size)): + x = random.random() * bbox.width + y = random.random() * bbox.height + if b > 0: # duplicate border area + pts.append(voronoi.Site(x, y)) + if x < b: + pts.append(voronoi.Site(x + bbox.width, y)) + if y < b: + pts.append(voronoi.Site(x + bbox.width, y + bbox.height)) + if y > bbox.height - b: + pts.append(voronoi.Site(x + bbox.width, y - bbox.height)) + if x > bbox.width - b: + pts.append(voronoi.Site(x - bbox.width, y)) + if y < b: + pts.append(voronoi.Site(x - bbox.width, y + bbox.height)) + if y > bbox.height - b: + pts.append(voronoi.Site(x - bbox.width, y - bbox.height)) + if y < b: + pts.append(voronoi.Site(x, y + bbox.height)) + if y > bbox.height - b: + pts.append(voronoi.Site(x, y - bbox.height)) + elif x > -b and y > -b and x < bbox.width + b and y < bbox.height + b: + pts.append(voronoi.Site(x, y)) # leave border area blank + # dot = pattern.add(inkex.Rectangle()) + # dot.set('x', str(x-1)) + # dot.set('y', str(y-1)) + # dot.set('width', '2') + # dot.set('height', '2') + if len(pts) < 3: + return inkex.errormsg("Please choose a larger object, or smaller cell size") + + # plot Voronoi diagram + sl = voronoi.SiteList(pts) + voronoi.voronoi(sl, c) + path = "" + for edge in c.edges: + if edge[1] >= 0 and edge[2] >= 0: # two vertices + [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], bbox.width, bbox.height) + elif edge[1] >= 0: # only one vertex + if c.lines[edge[0]][1] == 0: # vertical line + xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0] + if c.vertices[edge[1]][1] > bbox.height / 2: + ytemp = bbox.height + else: + ytemp = 0 + else: + xtemp = bbox.width + ytemp = (c.lines[edge[0]][2] - bbox.width * c.lines[edge[0]][0]) / c.lines[edge[0]][1] + [x1, y1, x2, y2] = clip_line(c.vertices[edge[1]][0], c.vertices[edge[1]][1], xtemp, ytemp, bbox.width, bbox.height) + elif edge[2] >= 0: # only one vertex + if edge[0] >= len(c.lines): + xtemp = 0 + ytemp = 0 + elif c.lines[edge[0]][1] == 0: # vertical line + xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0] + if c.vertices[edge[2]][1] > bbox.height / 2: + ytemp = bbox.height + else: + ytemp = 0 + else: + xtemp = 0 + ytemp = c.lines[edge[0]][2] / c.lines[edge[0]][1] + [x1, y1, x2, y2] = clip_line(xtemp, ytemp, c.vertices[edge[2]][0], c.vertices[edge[2]][1], bbox.width, bbox.height) + if x1 or x2 or y1 or y2: + path += 'M %.3f,%.3f %.3f,%.3f ' % (x1, y1, x2, y2) + + patternstyle = {'stroke': '#000000', 'stroke-width': str(scale)} + attribs = {'d': path, 'style': str(inkex.Style(patternstyle))} + pattern.append(PathElement(**attribs)) + + # link selected object to pattern + style = {} + if 'style' in obj.attrib: + style = dict(inkex.Style.parse_str(obj.attrib['style'])) + style['fill'] = 'url(#%s)' % pattern.get('id') + obj.attrib['style'] = str(inkex.Style(style)) + if isinstance(obj, inkex.Group): + for node in obj: + style = {} + if 'style' in node.attrib: + style = dict(inkex.Style.parse_str(node.attrib['style'])) + style['fill'] = 'url(#%s)' % pattern.get('id') + node.attrib['style'] = str(inkex.Style(style)) + +if __name__ == '__main__': + GenerateVoronoi().run() |