convert2dashes.py revision b93ce4197e7f5026a1c8deeb79cbd00aa3f86d91
#!/usr/bin/env python
'''
This extension converts a path into a dashed line using 'stroke-dasharray'
It is a modification of the file addnodes.py
Copyright (C) 2005,2007 Aaron Spike, aaron@ekips.org
Copyright (C) 2009 Alvin Penner, penner@vaxxine.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
'''
import inkex, cubicsuperpath, bezmisc, simplestyle
def tpoint((x1,y1), (x2,y2), t = 0.5):
return [x1+t*(x2-x1),y1+t*(y2-y1)]
def cspbezsplit(sp1, sp2, t = 0.5):
m1=tpoint(sp1[1],sp1[2],t)
m2=tpoint(sp1[2],sp2[0],t)
m3=tpoint(sp2[0],sp2[1],t)
m4=tpoint(m1,m2,t)
m5=tpoint(m2,m3,t)
m=tpoint(m4,m5,t)
return [[sp1[0][:],sp1[1][:],m1], [m4,m,m5], [m3,sp2[1][:],sp2[2][:]]]
def cspbezsplitatlength(sp1, sp2, l = 0.5, tolerance = 0.001):
bez = (sp1[1][:],sp1[2][:],sp2[0][:],sp2[1][:])
t = bezmisc.beziertatlength(bez, l, tolerance)
return cspbezsplit(sp1, sp2, t)
def cspseglength(sp1,sp2, tolerance = 0.001):
bez = (sp1[1][:],sp1[2][:],sp2[0][:],sp2[1][:])
return bezmisc.bezierlength(bez, tolerance)
class SplitIt(inkex.Effect):
def __init__(self):
inkex.Effect.__init__(self)
def effect(self):
for id, node in self.selected.iteritems():
if node.tag == inkex.addNS('path','svg'):
dashes = []
style = simplestyle.parseStyle(node.get('style'))
if style.has_key('stroke-dasharray'):
if style['stroke-dasharray'].find(',') > 0:
dashes = [float (dash) for dash in style['stroke-dasharray'].split(',')]
if dashes:
p = cubicsuperpath.parsePath(node.get('d'))
new = []
for sub in p:
idash = 0
dash = dashes[0]
length = 0
new.append([sub[0][:]])
i = 1
while i < len(sub):
dash = dash - length
length = cspseglength(new[-1][-1], sub[i])
while dash < length:
new[-1][-1], next, sub[i] = cspbezsplitatlength(new[-1][-1], sub[i], dash/length)
if idash % 2: # create a gap
new.append([next[:]])
else: # splice the curve
new[-1].append(next[:])
length = length - dash
idash = (idash + 1) % len(dashes)
dash = dashes[idash]
if idash % 2:
new.append([sub[i]])
else:
new[-1].append(sub[i])
i+=1
node.set('d',cubicsuperpath.formatPath(new))
if __name__ == '__main__':
e = SplitIt()
e.affect()
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