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+#!/usr/bin/env python
+# coding=utf-8
+#
+# Copyright (C) 2005 Carsten Goetze c.goetze@tu-bs.de
+#
+# 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 math
+import random
+import inkex
+from inkex.paths import Move, Line
+
+def calculate_subdivision(smoothness, x1, y1, x2, y2):
+ # Calculate the vector from (x1,y1) to (x2,y2)
+ x3 = x2 - x1
+ y3 = y2 - y1
+ # Calculate the point half-way between the two points
+ hx = x1 + x3 / 2
+ hy = y1 + y3 / 2
+ # Calculate normalized vector perpendicular to the vector (x3,y3)
+ length = math.sqrt(x3 * x3 + y3 * y3)
+ if length != 0:
+ nx = -y3 / length
+ ny = x3 / length
+ else:
+ nx = 1
+ ny = 0
+ # Scale perpendicular vector by random factor """
+ r = random.uniform(-length / (1 + smoothness), length / (1 + smoothness))
+ nx = nx * r
+ ny = ny * r
+ # add scaled perpendicular vector to the half-way point to get the final displaced subdivision point
+ x = hx + nx
+ y = hy + ny
+ return (x, y)
+
+
+class Fractalize(inkex.EffectExtension):
+ def add_arguments(self, pars):
+ pars.add_argument("-s", "--subdivs", type=int, default="6",
+ help="Number of subdivisons")
+ pars.add_argument("-f", "--smooth", type=float, default="4.0",
+ help="Smoothness of the subdivision")
+
+ def effect(self):
+ for node in self.svg.selection.filter(inkex.PathElement).values():
+ path = node.path.to_absolute()
+ result = []
+ for cmd_proxy in path.proxy_iterator(): # type: inkex.Path.PathCommandProxy
+ prev = cmd_proxy.previous_end_point
+ end = cmd_proxy.end_point
+ if cmd_proxy.letter == 'M':
+ result.append(Move(*cmd_proxy.args))
+ else:
+ for seg in self.fractalize((prev.x, prev.y, end.x, end.y), self.options.subdivs,
+ self.options.smooth):
+ result.append(Line(*seg))
+ result.append(Line(end.x, end.y))
+
+ node.path = result
+
+ def fractalize(self, coords, subdivs, smooth):
+ """recursively subdivide the segments left and right of the subdivision"""
+ subdiv_point = calculate_subdivision(smooth, *coords)
+
+ if subdivs:
+ # recursively subdivide the segment left of the subdivision point
+ for left_seg in self.fractalize(coords[:2] + subdiv_point[-2:], subdivs - 1, smooth):
+ yield left_seg
+
+ yield subdiv_point
+
+ # recursively subdivide the segment right of the subdivision point
+ for right_seg in self.fractalize(subdiv_point[-2:] + coords[-2:], subdivs - 1, smooth):
+ yield right_seg
+
+if __name__ == '__main__':
+ Fractalize().run()