Kochify
" RFE #1118728: fractal lines" was one of the reasons I thought it would be fun to work on extensions. This script is my implementation of a Koch's snowflake tool for Inkscape. The tool is built with two scripts. The first script loads the first selected path into a temporary file. The second script replaces each segment of the selected paths with a scaled and rotated copy of the path from the temporary file.
Loader script:
#!/usr/bin/env python
import math, tempfile, cPickle, inkex
def findend(d):
end = []
subPathStart = []
for cmd,params in d:
if cmd == 'M':
subPathStart = params[-2:]
if cmd == 'Z':
end = subPathStart[:]
else:
end = params[-2:]
return end
class LoadKochify(inkex.Effect):
def effect(self):
for id, node in self.selected.iteritems():
if node.tagName == 'path':
d = inkex.parsePath(node.attributes.getNamedItem('d').value)
start = d[0][1][-2:]
end = findend(d)
while start == end and len(d):
d = d[:-1]
end = findend(d)
if not end:
break
dx = end[0]-start[0]
dy = end[1]-start[1]
length = math.sqrt((dx**2) + (dy**2))
angle = math.atan2(dy,dx)
path = {'start': start, 'end': end,
'length': length, 'angle': angle, 'path': d}
f = open(tempfile.gettempdir() + '/kochify.bin', 'w')
cPickle.dump(path, f)
f.close()
break
e = LoadKochify()
e.affect()
Replacer script:
#!/usr/bin/env python
import math, tempfile, copy, cPickle, inkex
def findend(d):
end = []
subPathStart = []
for cmd,params in d:
if cmd == 'M':
subPathStart = params[-2:]
if cmd == 'Z':
end = subPathStart[:]
else:
end = params[-2:]
return end
class Kochify(inkex.Effect):
def effect(self):
try:
f = open(tempfile.gettempdir() + '/kochify.bin', 'r')
proto = cPickle.load(f)
f.close()
except:
return False
for id, node in self.selected.iteritems():
if node.tagName == 'path':
d = node.attributes.getNamedItem('d')
p = inkex.parsePath(d.value)
last = p[0][1][-2:]
subPathStart = []
cur = []
new = []
for i in range(len(p)):
rep = copy.deepcopy(proto['path'])
cmd, params = p[i]
if cmd == 'M':
subPathStart = params[-2:]
new.append(copy.deepcopy(p[i]))
continue
if cmd == 'Z':
cur = subPathStart[:]
else:
cur = params[-2:]
if last == cur:
continue
dx = cur[0]-last[0]
dy = cur[1]-last[1]
length = math.sqrt((dx**2) + (dy**2))
angle = math.atan2(dy,dx)
scale = length / proto['length']
rotate = angle - proto['angle']
inkex.scalePath(rep,scale,scale)
inkex.rotatePath(rep, rotate)
repend = findend(rep)
transx = cur[0] - repend[0]
transy = cur[1] - repend[1]
inkex.translatePath(rep, transx, transy)
new.extend(rep[1:])
last = cur[:]
d.value = inkex.formatPath(new)
e = Kochify()
e.affect()
Files:
