#!/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 obj.style["fill"] = pattern if isinstance(obj, inkex.Group): for node in obj: node.style["fill"] = pattern if __name__ == "__main__": GenerateVoronoi().run()