94 lines
4.1 KiB
Python
94 lines
4.1 KiB
Python
#!/usr/bin/env python
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"""
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Derived from the "envelope" extension by Aaron Spike, aaron@ekips.org
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By Apex 2011
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New version Jens Kober 2017
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""
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import inkex, cubicsuperpath, simpletransform
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from ffgeom import *
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class Project(inkex.Effect):
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def __init__(self):
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inkex.Effect.__init__(self)
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def effect(self):
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if len(self.options.ids) < 2:
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inkex.errormsg(_("This extension requires two selected paths. \nThe second path must be exactly two nodes long."))
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exit()
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#trafo is selected second
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obj = self.selected[self.options.ids[0]]
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trafo = self.selected[self.options.ids[1]]
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if trafo.tag == inkex.addNS('path','svg'):
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#distil trafo into two node points
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trafoPath = cubicsuperpath.parsePath(trafo.get('d'))
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t = trafo.get("transform")
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# if trafo has a transform, we need to translate the points to world coordinates first
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if t != None:
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m = simpletransform.parseTransform(t)
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simpletransform.applyTransformToPath(m,trafoPath)
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if len(trafoPath[0]) < 2:
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inkex.errormsg(_("This extension requires that the second selected path be two nodes long."))
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exit()
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trafoPath = [[Point(csp[1][0],csp[1][1]) for csp in subs] for subs in trafoPath][0][:2]
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#START HERE!!!
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# origin of mirror line
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ox = trafoPath[0]['x']
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oy = trafoPath[0]['y']
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# vector along mirror line
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vx = trafoPath[1]['x'] - ox
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vy = trafoPath[1]['y'] - oy
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# the transformation first translates the origin of the mirror line to [0 0], then rotates the mirror line onto the x-axis,
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# reflects everything over the x-axis, undoes the rotation, and finally undoes the translation
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# alpha = atan2(vy, vx);
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# [1 0 ox] [cos(alpha) -sin(alpha) 0] [1 0 0] [cos(-alpha) -sin(-alpha) 0] [1 0 -ox]
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# Transformation = [0 1 oy]*[sin(alpha) cos(alpha) 0]*[0 -1 0]*[sin(-alpha) cos(-alpha) 0]*[0 1 -oy]
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# [0 0 1] [ 0 0 1] [0 0 1] [ 0 0 1] [0 0 1]
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# after some simplifications (or using your favorite symbolic math software):
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# [(vx^2-vy^2)/(vx^2+vy^2) (2 vx vy)/(vx^2+vy^2) (2 vy (ox vy-oy vx))/(vx^2+vy^2)]
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# Transformation = [ (2 vx vy)/(vx^2+vy^2) -(vx^2-vy^2)/(vx^2+vy^2) -(2 vx (ox vy-oy vx))/(vx^2+vy^2)]
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# [ 0 0 1]
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denom = vx**2 + vy**2
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a00 = (vx**2 - vy**2) / denom
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a01 = (2 * vx * vy) / denom
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a02 = 2 * (ox * vy - oy * vx) / denom
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mat=[[a00, a01, vy * a02], [a01, -a00, -vx * a02]]
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simpletransform.applyTransformToNode(mat,obj)
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else:
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if trafo.tag == inkex.addNS('g','svg'):
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inkex.errormsg(_("The second selected object is a group, not a path.\nTry using the procedure Object->Ungroup."))
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else:
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inkex.errormsg(_("The second selected object is not a path.\nTry using the procedure Path->Object to Path."))
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exit()
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if __name__ == '__main__':
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e = Project()
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e.affect()
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# vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99 |