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diff --git a/share/extensions/rubberstretch.py b/share/extensions/rubberstretch.py
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+#!/usr/bin/env python
+# coding=utf-8
+#
+# Copyright (C) 2006 Jean-Francois Barraud, barraud@math.univ-lille1.fr
+#
+# 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.
+#
+"""
+Distorts selected paths, stretching it vertically while squeezing horizontally.
+
+Amount is controlled by ratio parameter.
+
+Curve gives further effect by bunching the surface towards the ends.
+"""
+
+from inkex.utils import X, Y
+from pathmodifier import Diffeo
+import inkex
+
+
+class RubberStretch(Diffeo):
+ """Distort selected paths"""
+
+ ratio = property(lambda self: -(self.options.ratio / 100))
+ curve = property(lambda self: min(self.options.curve / 100, 0.99))
+
+ def add_arguments(self, pars):
+ pars.add_argument("-r", "--ratio", type=float, default=25)
+ pars.add_argument("-c", "--curve", type=float, default=25)
+
+ def applyDiffeo(self, bpt, vects=()):
+ for vect in vects:
+ vect[0] -= bpt[0]
+ vect[1] -= bpt[1]
+ vect[1] *= -1
+ bpt[1] *= -1
+ bx0 = self.bbox.center.x
+ by0 = -self.bbox.center.y
+
+ x, y = (bpt[0] - bx0), (bpt[1] - by0)
+ sx1 = (
+ 1
+ + self.curve
+ * (x / (self.bbox.width / 2) + 1)
+ * (x / (self.bbox.width / 2) - 1)
+ ) * 2**self.ratio
+ sy1 = (
+ 1
+ + self.curve
+ * (y / (self.bbox.height / 2) + 1)
+ * (y / (self.bbox.height / 2) - 1)
+ ) * 2**self.ratio
+ bpt[0] = bx0 + x * sy1
+ bpt[1] = by0 + y / sx1
+ for vect in vects:
+ dx_dx = sy1
+ dx_dy = (
+ x
+ * 2
+ * self.curve
+ * y
+ / self.bbox.height
+ / self.bbox.height
+ * 2**self.ratio
+ )
+ dy_dx = (
+ -y
+ * 2
+ * self.curve
+ * x
+ / self.bbox.width
+ / self.bbox.width
+ * 2**self.ratio
+ / sx1
+ / sx1
+ )
+ dy_dy = 1 / sx1
+ vect[0] = dx_dx * vect[X] + dx_dy * vect[Y]
+ vect[1] = dy_dx * vect[X] + dy_dy * vect[Y]
+
+ # --spherify
+ # s=((x*x+y*y)/(w*w+h*h))**(-a/2)
+ # bpt[0]=x0+s*x
+ # bpt[1]=y0+s*y
+ # for v in vects:
+ # dx,dy=v
+ # v[0]=(1-a/2/(x*x+y*y)*2*x*x)*s*dx+( -a/2/(x*x+y*y)*2*y*x)*s*dy
+ # v[1]=( -a/2/(x*x+y*y)*2*x*y)*s*dx+(1-a/2/(x*x+y*y)*2*y*y)*s*dy
+
+ for vect in vects:
+ vect[0] += bpt[0]
+ vect[1] += bpt[1]
+ vect[1] *= -1
+ bpt[1] *= -1
+
+
+if __name__ == "__main__":
+ RubberStretch().run()