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#!/usr/bin/env python
# coding=utf-8
#
# Copyright (C) 2005 Aaron Spike, aaron@ekips.org
#
# 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 inkex
from inkex.paths import Move, Line, Curve, ZoneClose, Arc, Path, Vert, Horz, TepidQuadratic, Quadratic, Smooth
from inkex.transforms import Vector2d
from inkex.bezier import beziertatslope, beziersplitatt
class Motion(inkex.EffectExtension):
"""Generate a motion path"""
def add_arguments(self, pars):
pars.add_argument("-a", "--angle", type=float, default=45.0, \
help="direction of the motion vector")
pars.add_argument("-m", "--magnitude", type=float, default=100.0, \
help="magnitude of the motion vector")
@staticmethod
def makeface(last, segment, facegroup, delx, dely):
"""translate path segment along vector"""
elem = facegroup.add(inkex.PathElement())
npt = segment.translate([delx, dely])
# reverse direction of path segment
if isinstance(segment, Curve):
rev = Curve(npt.x3, npt.y3, npt.x2, npt.y2,
last[0] + delx, last[1] + dely
)
elif isinstance(segment, Line):
rev = Line(last[0] + delx, last[1] + dely)
else:
raise RuntimeError("Unexpected segment type {}".format(type(segment)))
elem.path = inkex.Path([
Move(last[0], last[1]),
segment,
npt.to_line(Vector2d()),
rev,
ZoneClose(),
])
def effect(self):
delx = math.cos(math.radians(self.options.angle)) * self.options.magnitude
dely = math.sin(math.radians(self.options.angle)) * self.options.magnitude
for node in self.svg.selection.filter(inkex.PathElement).values():
group = node.getparent().add(inkex.Group())
facegroup = group.add(inkex.Group())
group.append(node)
if node.transform:
group.transform = node.transform
node.transform = None
facegroup.style = node.style
for cmd_proxy in node.path.to_absolute().proxy_iterator():
self.process_segment(cmd_proxy, facegroup, delx, dely)
@staticmethod
def process_segment(cmd_proxy, facegroup, delx, dely):
"""Process each segments"""
segments = []
if isinstance(cmd_proxy.command, (Curve, Smooth, TepidQuadratic, Quadratic, Arc)):
prev = cmd_proxy.previous_end_point
for curve in cmd_proxy.to_curves():
bez = [prev] + curve.to_bez()
prev = curve.end_point(cmd_proxy.first_point, prev)
tees = [t for t in beziertatslope(bez, (dely, delx)) if 0 < t < 1]
tees.sort()
if len(tees) == 1:
one, two = beziersplitatt(bez, tees[0])
segments.append(Curve(*(one[1] + one[2] + one[3])))
segments.append(Curve(*(two[1] + two[2] + two[3])))
elif len(tees) == 2:
one, two = beziersplitatt(bez, tees[0])
two, three = beziersplitatt(two, tees[1])
segments.append(Curve(*(one[1] + one[2] + one[3])))
segments.append(Curve(*(two[1] + two[2] + two[3])))
segments.append(Curve(*(three[1] + three[2] + three[3])))
else:
segments.append(curve)
elif isinstance(cmd_proxy.command, (Line, Curve)):
segments.append(cmd_proxy.command)
elif isinstance(cmd_proxy.command, ZoneClose):
segments.append(Line(cmd_proxy.first_point.x, cmd_proxy.first_point.y))
elif isinstance(cmd_proxy.command, (Vert, Horz)):
segments.append(cmd_proxy.command.to_line(cmd_proxy.end_point))
for seg in Path([Move(*cmd_proxy.previous_end_point)] + segments).proxy_iterator():
if isinstance(seg.command, Move): continue
Motion.makeface(seg.previous_end_point, seg.command, facegroup, delx, dely)
if __name__ == '__main__':
Motion().run()
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