Updated chain paths extension to 0.6 release; added missing STLConverter executable

extensions/fablabchemnitz_chain_paths.inx

@@ -14,12 +14,13 @@
         <option value="px">px</option>
     </param>
     <param name="snap" type="boolean" _gui-text="Snap connecting ends together">false</param>
+	<param name="close" type="boolean" _gui-text="Close loops (start/end of the same path)">true</param>
     <!-- Keep in sync with chain_paths.py line 19 __version__ = ... -->
     <param name="about_version" type="description">
   
   
   https://github.com/fablabnbg/inkscape-chain-paths
-  Version 0.5</param>
+  Version 0.6</param>
     <effect needs-live-preview="false">
         <object-type>path</object-type>
         <effects-menu>

extensions/fablabchemnitz_chain_paths.py

@@ -16,23 +16,29 @@
 # 2015-11-16 jw, V0.3 -- all possible chains connected. Yeah
 # 2015-11-16 jw, V0.4 -- gui fully functional.
 # 2015-11-26 jw, V0.5 -- HACK to resolve some self-reversing path segments.
-#	https://github.com/fablabnbg/inkscape-chain-paths/issues/1
+#        https://github.com/fablabnbg/inkscape-chain-paths/issues/1
+# 2020-04-10 jw, V0.6 -- Close paths correctly. Self reversing path hack was too eager.
+#        Workaround for cubicsuperpath.parsePath/formatPath limitation.
+#        Started python3 compatibility.
 
-__version__ = '0.5'	# Keep in sync with chain_paths.inx ca line 22
+from __future__ import print_function
-__author__ = 'Juergen Weigert <juewei@fabmail.org>'
+
+__version__ = '0.6'        # Keep in sync with chain_paths.inx ca line 22
+__author__ = 'Juergen Weigert <juergen@fabmail.org>'
 
 import sys, os, shutil, time, logging, tempfile, math
+import re
 
 #debug = True
 debug = False
 
 # search path, so that inkscape libraries are found when we are standalone.
 sys_platform = sys.platform.lower()
-if sys_platform.startswith('win'):	# windows
+if sys_platform.startswith('win'):        # windows
   sys.path.append('C:\Program Files\Inkscape\share\extensions')
-elif sys_platform.startswith('darwin'):	# mac
+elif sys_platform.startswith('darwin'):   # mac
   sys.path.append('/Applications/Inkscape.app/Contents/Resources/extensions')
-else:   				# linux
+else:                                     # linux
   # if sys_platform.startswith('linux'):
   sys.path.append('/usr/share/inkscape/extensions')
 
@@ -44,11 +50,11 @@ inkex.localize()
 
 from optparse import SUPPRESS_HELP
 
-def uutounit(self,nn,uu):
+def uutounit(self, nn, uu):
   try:
-    return self.uutounit(nn,uu)		# inkscape 0.91
+    return self.uutounit(nn, uu)                # inkscape 0.91
   except:
-    return inkex.uutounit(nn,uu)	# inkscape 0.48
+    return inkex.uutounit(nn, uu)        # inkscape 0.48
 
 class ChainPaths(inkex.Effect):
   """
@@ -63,6 +69,7 @@ class ChainPaths(inkex.Effect):
     # as establishing a transform from the viewbox to the display.
     self.chain_epsilon = 0.01
     self.snap_ends = True
+    self.close_loops = True
     self.segments_done = {}
     self.min_missed_distance_sq = None
     self.chained_count = 0
@@ -71,21 +78,21 @@ class ChainPaths(inkex.Effect):
       self.tty = open("/dev/tty", 'w')
     except:
       try:
-        self.tty = open("CON:", 'w')	# windows. Does this work???
+        self.tty = open("CON:", 'w')        # windows. Does this work???
       except:
         self.tty = open(os.devnull, 'w')  # '/dev/null' for POSIX, 'nul' for Windows.
-    if debug: print >>self.tty, "__init__"
+    if debug: print("__init__", file=self.tty)
 
     self.OptionParser.add_option('-V', '--version',
           action = 'store_const', const=True, dest='version', default=False,
-          help='Just print version number ("'+__version__+'") and exit.')
+          help = 'Just print version number ("' + __version__ + '") and exit.')
     self.OptionParser.add_option('-s', '--snap', action='store', dest='snap_ends', type='inkbool', default=True, help='snap end-points together when connecting')
+    self.OptionParser.add_option('-c', '--close', action='store', dest='close_loops', type='inkbool', default=True, help='close loops (start/end of the same path)')
     self.OptionParser.add_option('-u', '--units', action='store', dest="units", type="string", default="mm", help="measurement unit for epsilon")
     self.OptionParser.add_option('-e', '--epsilon', action='store',
           type='float', dest='chain_epsilon', default=0.01, help="Max. distance to connect [mm]")
 
   def version(self):
-    print "hiuhu"
     return __version__
   def author(self):
     return __author__
@@ -112,7 +119,7 @@ class ChainPaths(inkex.Effect):
     if not id in self.segments_done:
       self.segments_done[id] = {}
     self.segments_done[id][n] = True
-    if debug: print >>self.tty, "done", id, n, msg
+    if debug: print("done", id, n, msg, file=self.tty)
 
   def is_segment_done(self, id, n):
     if not id in self.segments_done:
@@ -128,9 +135,9 @@ class ChainPaths(inkex.Effect):
       p2 = seg2[0]
       # fuse p1 and p2 to create one new point:
       # first handle from p1, point coordinates averaged, second handle from p2
-      seg.append([ [ p1[0][0]             ,  p1[0][1]             ],
+      seg.append([ [  p1[0][0]                 ,  p1[0][1]                  ],
-                   [(p1[1][0]+p2[1][0])*.5, (p1[1][1]+p2[1][1])*.5],
+                   [ (p1[1][0] + p2[1][0]) * .5, (p1[1][1] + p2[1][1]) * .5 ],
-		   [          p2[2][0]    ,           p2[2][1]    ] ])
+                   [             p2[2][0]      ,             p2[2][1]       ] ])
       seg.extend(seg2[1:])
     else:
       seg = seg1[:]
@@ -156,14 +163,15 @@ class ChainPaths(inkex.Effect):
 
   def effect(self):
     if self.options.version:
-      print __version__
+      print(__version__)
       sys.exit(0)
 
     self.calc_unit_factor(self.options.units)
 
     if self.options.snap_ends     is not None: self.snap_ends     = self.options.snap_ends
+    if self.options.close_loops   is not None: self.close_loops   = self.options.close_loops
     if self.options.chain_epsilon is not None: self.chain_epsilon = self.options.chain_epsilon
-    if self.chain_epsilon < 0.001: self.chain_epsilon = 0.001	# keep a minimum.
+    if self.chain_epsilon < 0.001: self.chain_epsilon = 0.001        # keep a minimum.
     self.eps_sq = self.chain_epsilon * self.unit_factor * self.chain_epsilon * self.unit_factor
 
     if not len(self.selected.items()):
@@ -172,36 +180,35 @@ class ChainPaths(inkex.Effect):
 
     segments = []
     for id, node in self.selected.iteritems():
-      if node.tag != inkex.addNS('path','svg'):
+      if node.tag != inkex.addNS('path', 'svg'):
-        inkex.errormsg(_("Object "+id+" is not a path. Try\n  - Path->Object to Path\n  - Object->Ungroup"))
+        inkex.errormsg(_("Object " + id + " is not a path. Try\n  - Path->Object to Path\n  - Object->Ungroup"))
         return
-      if debug: print >>self.tty, "id="+str(id), "tag="+str(node.tag)
+      if debug: print("id=" + str(id), "tag=" + str(node.tag), file=self.tty)
       path_d = cubicsuperpath.parsePath(node.get('d'))
       sub_idx = -1
       for sub in path_d:
         sub_idx += 1
-	# sub=[[[200.0, 300.0], [200.0, 300.0], [175.0, 290.0]], [[175.0, 265.0], [220.37694, 256.99876], [175.0, 240.0]], [[175.0, 215.0], [200.0, 200.0], [200.0, 200.0]]]
+        # sub = [[[200.0, 300.0], [200.0, 300.0], [175.0, 290.0]], [[175.0, 265.0], [220.37694, 256.99876], [175.0, 240.0]], [[175.0, 215.0], [200.0, 200.0], [200.0, 200.0]]]
-	# this is a path of three points. All the bezier handles are included. the Structure is:
+        # this is a path of three points. All the bezier handles are included. the Structure is:
-	# [[handle0_x, point0, handle0_1], [handle1_0, point1, handle1_2], [handle2_1, point2, handle2_x]]
+        # [[handle0_OUT, point0, handle0_1], [handle1_0, point1, handle1_2], [handle2_1, point2, handle2_OUT]]
-        if debug: print >>self.tty, "   sub="+str(sub)
+        # the _OUT handles at the end of the path are ignored. The data structure has them identical to their points.
-	end1=[sub[0][1][0],sub[0][1][1]]
+        #
-	end2=[sub[-1][1][0],sub[-1][1][1]]
+        if debug: print("   sub=" + str(sub), file=self.tty)
+        end1 = [sub[ 0][1][0], sub[ 0][1][1]]
+        end2 = [sub[-1][1][0], sub[-1][1][1]]
 
-	while ((len(sub) > 1) and self.near_ends(end1, end2)):
+        # Remove trivial self revesal when building candidate segments list.
-	  if debug: print >>self.tty, "splitting self-reversing path, length:", len(sub)
+        if ((len(sub) == 3) and self.near_ends(end1, end2)):
-	  ## We split the path and generate more snippets.
+          if debug: print("dropping segment from self-reversing path, length:", len(sub), file=self.tty)
-	  splitp=[sub[-2][1][0],sub[-2][1][1]]
+          sub.pop()
-	  segments.append({'id': id, 'n': sub_idx, 'end1': splitp, 'end2':end2, 'seg': [sub[-2],sub[-1]]})
+          end2 = [sub[-1][1][0], sub[-1][1][1]]
-	  sub_idx += 1
-	  sub.pop()
-	  end2=splitp
 
-	segments.append({'id': id, 'n': sub_idx, 'end1': end1, 'end2':end2, 'seg': sub})
+        segments.append({'id': id, 'n': sub_idx, 'end1': end1, 'end2':end2, 'seg': sub})
-      if node.get(inkex.addNS('type','sodipodi')):
+      if node.get(inkex.addNS('type', 'sodipodi')):
         del node.attrib[inkex.addNS('type', 'sodipodi')]
-    if debug: print >>self.tty, "-------- seen:"
+    if debug: print("-------- seen:", file=self.tty)
     for s in segments:
-      if debug: print >>self.tty, s['id'],s['n'],s['end1'],s['end2']
+      if debug: print(s['id'], s['n'], s['end1'], s['end2'], file=self.tty)
 
     # chain the segments
     obsoleted = 0
@@ -209,68 +216,103 @@ class ChainPaths(inkex.Effect):
     for id, node in self.selected.iteritems():
       # path_style = simplestyle.parseStyle(node.get('style'))
       path_d = cubicsuperpath.parsePath(node.get('d'))
-      new=[]
+      # ATTENTION: for parsePath() it is the same, if first and last point coincide, or if the path is really closed.
+      path_closed = True if re.search("z\s*$", node.get('d')) else False
+      new = []
       cur_idx = -1
-      for cur in path_d:
+      for chain in path_d:
         cur_idx += 1
-	if not self.is_segment_done(id, cur_idx):
+        if not self.is_segment_done(id, cur_idx):
-	  # quadratic algorithm: we check both ends of the current segment.
+          # quadratic algorithm: we check both ends of the current segment.
-	  # If one of them is near another known end from the segments list, we
+          # If one of them is near another known end from the segments list, we
-	  # chain this segment to the current segment and remove it from the
+          # chain this segment to the current segment and remove it from the
-	  # list,
+          # list,
-	  # end1-end1 or end2-end2: The new segment is reversed.
+          # end1-end1 or end2-end2: The new segment is reversed.
-	  # end1-end2: The new segment is prepended to the current segment.
+          # end1-end2: The new segment is prepended to the current segment.
-	  # end2-end1: The new segment is appended to the current segment.
+          # end2-end1: The new segment is appended to the current segment.
-	  self.set_segment_done(id, cur_idx, "output")	# do not cross with ourselves.
+          self.set_segment_done(id, cur_idx, "output")        # do not cross with ourselves.
-	  end1=[cur[0][1][0],cur[0][1][1]]
+          end1 = [chain[ 0][1][0], chain[ 0][1][1]]
-	  end2=[cur[-1][1][0],cur[-1][1][1]]
+          end2 = [chain[-1][1][0], chain[-1][1][1]]
-	  segments_idx = 0
-	  while segments_idx < len(segments):
-	    seg = segments[segments_idx]
-	    if self.is_segment_done(seg['id'], seg['n']):
-	      segments_idx += 1
-	      continue
 
-	    if (self.near_ends(end1, seg['end1']) or
+          # Remove trivial self revesal when doing the actual chain operation.
-	        self.near_ends(end2, seg['end2'])):
+          if ((len(chain) == 3) and self.near_ends(end1, end2)):
-	      seg['seg'] = self.reverse_segment(seg['seg'])
+            chain.pop()
-	      seg['end1'],seg['end2'] = seg['end2'],seg['end1']
+            end2 = [chain[-1][1][0], chain[-1][1][1]]
-	      if debug: print >>self.tty, "reversed seg", seg['id'], seg['n']
 
-	    if self.near_ends(end1, seg['end2']):
+          segments_idx = 0
-	      # prepend seg to cur
+          while segments_idx < len(segments):
-	      self.set_segment_done(seg['id'], seg['n'], 'prepended to '+id+' '+str(cur_idx))
+            seg = segments[segments_idx]
-	      cur = self.link_segments(seg['seg'], cur)
+            if self.is_segment_done(seg['id'], seg['n']):
-	      end1=[cur[0][1][0],cur[0][1][1]]
+              segments_idx += 1
-	      segments_idx = 0
+              continue
-	      continue
 
-	    if self.near_ends(end2, seg['end1']):
+            if (self.near_ends(end1, seg['end1']) or
-	      # append seg to cur
+                self.near_ends(end2, seg['end2'])):
-	      self.set_segment_done(seg['id'], seg['n'], 'appended to '+id+' '+str(cur_idx))
+              seg['seg'] = self.reverse_segment(seg['seg'])
-	      cur = self.link_segments(cur, seg['seg'])
+              seg['end1'], seg['end2'] = seg['end2'], seg['end1']
-	      end2=[cur[-1][1][0],cur[-1][1][1]]
+              if debug: print("reversed seg", seg['id'], seg['n'], file=self.tty)
-	      segments_idx = 0
-	      continue
 
-	    segments_idx += 1
+            if self.near_ends(end1, seg['end2']):
+              # prepend seg to chain
+              self.set_segment_done(seg['id'], seg['n'], 'prepended to ' + id + ' ' + str(cur_idx))
+              chain = self.link_segments(seg['seg'], chain)
+              end1 = [chain[0][1][0], chain[0][1][1]]
+              segments_idx = 0          # this chain changed. re-visit all candidate
+              continue
 
-	  new.append(cur)
+            if self.near_ends(end2, seg['end1']):
+              # append seg to chain
+              self.set_segment_done(seg['id'], seg['n'], 'appended to ' + id + ' ' + str(cur_idx))
+              chain = self.link_segments(chain, seg['seg'])
+              end2 = [chain[-1][1][0], chain[-1][1][1]]
+              segments_idx = 0          # this chain changed. re-visit all candidate
+              continue
+
+            segments_idx += 1
+
+          # Now all joinable segments are joined.
+          # Finally, we can check, if the resulting path is a closed path:
+          # Closing a path here, isolates it from the rest.
+          # But as we prefer to make the chain as long as possible, we close late.
+          if self.near_ends(end1, end2) and not path_closed and self.close_loops:
+              if debug: print("closing closeable loop", id, file=self.tty)
+              if self.snap_ends:
+                  # move first point to mid position
+                  x1n = (chain[0][1][0] + chain[-1][1][0]) * 0.5
+                  y1n = (chain[0][1][1] + chain[-1][1][1]) * 0.5
+                  chain[0][1][0], chain[0][1][1] = x1n, y1n
+                  # merge handle of the last point to the handle of the first point
+                  dx0e = chain[-1][0][0] - chain[-1][1][0]
+                  dy0e = chain[-1][0][1] - chain[-1][1][1]
+                  if debug: print("handle diff: ", dx0e, dy0e, file=self.tty)
+                  # FIXME: this does not work. cubicsuperpath.formatPath() ignores this handle.
+                  chain[0][0][0], chain[0][0][1] = x1n+dx0e, y1n+dy0e
+                  # drop last point
+                  chain.pop()
+                  end2 = [chain[-1][1][0], chain[-1][1][1]]
+              path_closed = True
+              self.chained_count +=1
+
+          new.append(chain)
 
       if not len(new):
         # node.clear()
         node.getparent().remove(node)
-	obsoleted += 1
+        obsoleted += 1
-        if debug: print >>self.tty, "Path node obsoleted:", id
+        if debug: print("Path node obsoleted:", id, file=self.tty)
       else:
         remaining += 1
-        node.set('d',cubicsuperpath.formatPath(new))
+        # BUG: All previously closed loops, are open, after we convert them back with cubicsuperpath.formatPath()
+        p_fmt = cubicsuperpath.formatPath(new)
+        if path_closed: p_fmt += " z"
+        if debug: print("new path :", p_fmt, file=self.tty)
+        node.set('d', p_fmt)
 
     # statistics:
-    print >>self.tty, "Path nodes obsoleted:", obsoleted, "\nPath nodes remaining:", remaining
+    if debug: print("Path nodes obsoleted:", obsoleted, "\nPath nodes remaining:", remaining, file=self.tty)
     if self.min_missed_distance_sq is not None:
-      print >>self.tty, "min_missed_distance:", math.sqrt(float(self.min_missed_distance_sq))/self.unit_factor, '>', self.chain_epsilon, self.options.units
+      if debug: print("min_missed_distance:", math.sqrt(float(self.min_missed_distance_sq))/self.unit_factor, '>', self.chain_epsilon, self.options.units, file=self.tty)
-    print >>self.tty, "Successful link operations: ", self.chained_count
+    if debug: print("Successful link operations: ", self.chained_count, file=self.tty)
 
 if __name__ == '__main__':
         e = ChainPaths()