Merge pull request #212 from inkstitch/lexelby-fill-markers

fill start/end

12 files changed, 323 insertions, 129 deletions

diff --git a/lib/commands.py b/lib/commands.py
new file mode 100644
index 00000000..ec62d716
--- /dev/null
+++ b/lib/commands.py
@@ -0,0 +1,89 @@
+import inkex
+import cubicsuperpath
+
+from .svg import apply_transforms
+from .svg.tags import SVG_USE_TAG, SVG_SYMBOL_TAG, CONNECTION_START, CONNECTION_END, XLINK_HREF
+
+
+class Command(object):
+    def __init__(self, connector):
+        self.connector = connector
+        self.svg = self.connector.getroottree().getroot()
+
+        self.parse_command()
+
+    def get_node_by_url(self, url):
+        # url will be #path12345.  Find the object at the other end.
+
+        if url is None:
+            raise ValueError("url is None")
+
+        if not url.startswith('#'):
+            raise ValueError("invalid connection url: %s" % url)
+
+        id = url[1:]
+
+        try:
+            return self.svg.xpath(".//*[@id='%s']" % id)[0]
+        except (IndexError, AttributeError):
+            raise ValueError("could not find node by url %s" % id)
+
+    def parse_connector_path(self):
+        path = cubicsuperpath.parsePath(self.connector.get('d'))
+        return apply_transforms(path, self.connector)
+
+    def parse_command(self):
+        path = self.parse_connector_path()
+
+        neighbors = [
+            (self.get_node_by_url(self.connector.get(CONNECTION_START)), path[0][0][1]),
+            (self.get_node_by_url(self.connector.get(CONNECTION_END)), path[0][-1][1])
+        ]
+
+        if neighbors[0][0].tag != SVG_USE_TAG:
+            neighbors.reverse()
+
+        if neighbors[0][0].tag != SVG_USE_TAG:
+            raise ValueError("connector does not point to a use tag")
+
+        self.symbol = self.get_node_by_url(neighbors[0][0].get(XLINK_HREF))
+
+        if self.symbol.tag != SVG_SYMBOL_TAG:
+            raise ValueError("use points to non-symbol")
+
+        self.command = self.symbol.get('id')
+
+        if self.command.startswith('inkstitch_'):
+            self.command = self.command[10:]
+        else:
+            raise ValueError("symbol is not an Ink/Stitch command")
+
+        self.target = neighbors[1][0]
+        self.target_point = neighbors[1][1]
+
+    def __repr__(self):
+        return "Command('%s', %s)" % (self.command, self.target_point)
+
+def find_commands(node):
+    """Find the symbols this node is connected to and return them as Commands"""
+
+    # find all paths that have this object as a connection
+    xpath = ".//*[@inkscape:connection-start='#%(id)s' or @inkscape:connection-end='#%(id)s']" % dict(id=node.get('id'))
+    connectors = node.getroottree().getroot().xpath(xpath, namespaces=inkex.NSS)
+
+    # try to turn them into commands
+    commands = []
+    for connector in connectors:
+        try:
+            commands.append(Command(connector))
+        except ValueError:
+            import sys
+            import traceback
+            print >> sys.stderr, "not a Command:", connector.get('id'), traceback.format_exc()
+            # Parsing the connector failed, meaning it's not actually an Ink/Stitch command.
+            pass
+
+    return commands
+
+def is_command(node):
+    return CONNECTION_START in node.attrib or CONNECTION_END in node.attrib
diff --git a/lib/elements/auto_fill.py b/lib/elements/auto_fill.py
index 504bae2a..59816878 100644
--- a/lib/elements/auto_fill.py
+++ b/lib/elements/auto_fill.py
@@ -100,13 +100,28 @@ class AutoFill(Fill):
     def fill_shape(self):
         return self.shrink_or_grow_shape(self.expand)
 
+    def get_starting_point(self, last_patch):
+        # If there is a "fill_start" Command, then use that; otherwise pick
+        # the point closest to the end of the last patch.
+
+        if self.get_command('fill_start'):
+            return self.get_command('fill_start').target_point
+        elif last_patch:
+            return last_patch.stitches[-1]
+        else:
+            return None
+
+    def get_ending_point(self):
+        if self.get_command('fill_end'):
+            return self.get_command('fill_end').target_point
+        else:
+            return None
+
     def to_patches(self, last_patch):
         stitches = []
 
-        if last_patch is None:
-            starting_point = None
-        else:
-            starting_point = last_patch.stitches[-1]
+        starting_point = self.get_starting_point(last_patch)
+        ending_point = self.get_ending_point()
 
         if self.fill_underlay:
             stitches.extend(auto_fill(self.underlay_shape,
@@ -126,6 +141,7 @@ class AutoFill(Fill):
                                   self.max_stitch_length,
                                   self.running_stitch_length,
                                   self.staggers,
-                                  starting_point))
+                                  starting_point,
+                                  ending_point))
 
         return [Patch(stitches=stitches, color=self.color)]
diff --git a/lib/elements/element.py b/lib/elements/element.py
index 39437c9f..3c31f1b0 100644
--- a/lib/elements/element.py
+++ b/lib/elements/element.py
@@ -4,7 +4,8 @@ from shapely import geometry as shgeo
 
 from ..i18n import _
 from ..utils import cache
-from ..svg import PIXELS_PER_MM, get_viewbox_transform, convert_length, get_doc_size
+from ..svg import PIXELS_PER_MM, convert_length, get_doc_size, apply_transforms
+from ..commands import find_commands
 
 # inkscape-provided utilities
 import simpletransform
@@ -171,10 +172,6 @@ class EmbroideryElement(object):
 
     @property
     def path(self):
-        return cubicsuperpath.parsePath(self.node.get("d"))
-
-    @cache
-    def parse_path(self):
         # A CSP is a  "cubic superpath".
         #
         # A "path" is a sequence of strung-together bezier curves.
@@ -202,22 +199,32 @@ class EmbroideryElement(object):
         # In a path, each element in the 3-tuple is itself a tuple of (x, y).
         # Tuples all the way down.  Hasn't anyone heard of using classes?
 
-        path = self.path
-
-        # start with the identity transform
-        transform = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0]]
+        return cubicsuperpath.parsePath(self.node.get("d"))
 
-        # combine this node's transform with all parent groups' transforms
-        transform = simpletransform.composeParents(self.node, transform)
+    @cache
+    def parse_path(self):
+        return apply_transforms(self.path, self.node)
 
-        # add in the transform implied by the viewBox
-        viewbox_transform = get_viewbox_transform(self.node.getroottree().getroot())
-        transform = simpletransform.composeTransform(viewbox_transform, transform)
+    @property
+    @cache
+    def commands(self):
+        return find_commands(self.node)
 
-        # apply the combined transform to this node's path
-        simpletransform.applyTransformToPath(transform, path)
+    @cache
+    def get_commands(self, command):
+        return [c for c in self.commands if c.command == command]
 
-        return path
+    @cache
+    def get_command(self, command):
+        commands = self.get_commands(command)
+
+        if len(commands) == 1:
+            return commands[0]
+        elif len(commands) > 1:
+            raise ValueError(_("%(id)s has more than one command of type '%(command)s' linked to it") %
+                                dict(id=self.node.get(id), command=command))
+        else:
+            return None
 
     def strip_control_points(self, subpath):
         return [point for control_before, point, control_after in subpath]
diff --git a/lib/elements/stroke.py b/lib/elements/stroke.py
index 5239f978..eca9e0ba 100644
--- a/lib/elements/stroke.py
+++ b/lib/elements/stroke.py
@@ -4,6 +4,7 @@ from .element import param, EmbroideryElement, Patch
 from ..i18n import _
 from ..utils import cache, Point
 from ..stitches import running_stitch
+from ..svg import parse_length_with_units
 
 warned_about_legacy_running_stitch = False
 
@@ -57,7 +58,7 @@ class Stroke(EmbroideryElement):
     def is_running_stitch(self):
         # using stroke width <= 0.5 pixels to indicate running stitch is deprecated in favor of dashed lines
 
-        stroke_width = float(self.get_style("stroke-width", 1))
+        stroke_width, units = parse_length_with_units(self.get_style("stroke-width", "1"))
 
         if self.dashed:
             return True
diff --git a/lib/extensions/__init__.py b/lib/extensions/__init__.py
index 6d3e00d8..b8951e12 100644
--- a/lib/extensions/__init__.py
+++ b/lib/extensions/__init__.py
@@ -1,5 +1,5 @@
 from embroider import Embroider
-from palettes import Palettes
+from install import Install
 from params import Params
 from print_pdf import Print
 from simulate import Simulate
diff --git a/lib/extensions/base.py b/lib/extensions/base.py
index 831b6dc6..78f75cf1 100644
--- a/lib/extensions/base.py
+++ b/lib/extensions/base.py
@@ -7,6 +7,7 @@ from collections import MutableMapping
 from ..svg.tags import *
 from ..elements import AutoFill, Fill, Stroke, SatinColumn, Polyline, EmbroideryElement
 from ..utils import cache
+from ..commands import is_command
 
 
 SVG_METADATA_TAG = inkex.addNS("metadata", "svg")
@@ -165,7 +166,8 @@ class InkstitchExtension(inkex.Effect):
                         classes.append(Fill)
 
                 if element.get_style("stroke"):
-                    classes.append(Stroke)
+                    if not is_command(element.node):
+                        classes.append(Stroke)
 
                 if element.get_boolean_param("stroke_first", False):
                     classes.reverse()
diff --git a/lib/extensions/palettes.py b/lib/extensions/install.py
index f7a6c7a5..d55b96d0 100644
--- a/lib/extensions/palettes.py
+++ b/lib/extensions/install.py
@@ -1,3 +1,5 @@
+# -*- coding: UTF-8 -*-
+
 import sys
 import traceback
 import os
@@ -14,26 +16,26 @@ import inkex
 from ..utils import guess_inkscape_config_path
 
 
-class InstallPalettesFrame(wx.Frame):
+class InstallerFrame(wx.Frame):
     def __init__(self, *args, **kwargs):
         wx.Frame.__init__(self, *args, **kwargs)
 
-        default_path = os.path.join(guess_inkscape_config_path(), "palettes")
+        self.path = guess_inkscape_config_path()
 
         panel = wx.Panel(self)
         sizer = wx.BoxSizer(wx.VERTICAL)
 
-        text = wx.StaticText(panel, label=_("Directory in which to install palettes:"))
-        font = wx.Font(12, wx.DEFAULT, wx.NORMAL, wx.NORMAL)
-        text.SetFont(font)
-        sizer.Add(text, proportion=0, flag=wx.ALL|wx.EXPAND, border=10)
+        text_sizer = wx.BoxSizer(wx.HORIZONTAL)
 
-        path_sizer = wx.BoxSizer(wx.HORIZONTAL)
-        self.path_input = wx.TextCtrl(panel, wx.ID_ANY, value=default_path)
-        path_sizer.Add(self.path_input, proportion=3, flag=wx.RIGHT|wx.EXPAND, border=20)
-        chooser_button = wx.Button(panel, wx.ID_OPEN, _('Choose another directory...'))
-        path_sizer.Add(chooser_button, proportion=1, flag=wx.EXPAND)
-        sizer.Add(path_sizer, proportion=0, flag=wx.ALL|wx.EXPAND, border=10)
+        text = _('Ink/Stitch can install files ("add-ons") that make it easier to use Inkscape to create machine embroidery designs.  These add-ons will be installed:') + \
+                 "\n\n   • " + _("thread manufacturer color palettes") + \
+                 "\n   • " + _("Ink/Stitch visual commands (Object -> Symbols...)")
+
+        static_text = wx.StaticText(panel, label=text)
+        font = wx.Font(12, wx.DEFAULT, wx.NORMAL, wx.NORMAL)
+        static_text.SetFont(font)
+        text_sizer.Add(static_text, proportion=0, flag=wx.ALL|wx.EXPAND, border=10)
+        sizer.Add(text_sizer, proportion=3, flag=wx.ALL|wx.EXPAND, border=0)
 
         buttons_sizer = wx.BoxSizer(wx.HORIZONTAL)
         install_button = wx.Button(panel, wx.ID_ANY, _("Install"))
@@ -41,15 +43,11 @@ class InstallPalettesFrame(wx.Frame):
         buttons_sizer.Add(install_button, proportion=0, flag=wx.ALIGN_RIGHT|wx.ALL, border=5)
         cancel_button = wx.Button(panel, wx.ID_CANCEL, _("Cancel"))
         buttons_sizer.Add(cancel_button, proportion=0, flag=wx.ALIGN_RIGHT|wx.ALL, border=5)
-        sizer.Add(buttons_sizer, proportion=0, flag=wx.ALIGN_RIGHT)
-
-        outer_sizer = wx.BoxSizer(wx.HORIZONTAL)
-        outer_sizer.Add(sizer, proportion=0, flag=wx.ALIGN_CENTER_VERTICAL)
+        sizer.Add(buttons_sizer, proportion=1, flag=wx.ALIGN_RIGHT|wx.ALIGN_BOTTOM)
 
-        panel.SetSizer(outer_sizer)
+        panel.SetSizer(sizer)
         panel.Layout()
 
-        chooser_button.Bind(wx.EVT_BUTTON, self.chooser_button_clicked)
         cancel_button.Bind(wx.EVT_BUTTON, self.cancel_button_clicked)
         install_button.Bind(wx.EVT_BUTTON, self.install_button_clicked)
 
@@ -57,36 +55,37 @@ class InstallPalettesFrame(wx.Frame):
         self.Destroy()
 
     def chooser_button_clicked(self, event):
-        dialog = wx.DirDialog(self, _("Choose Inkscape palettes directory"))
+        dialog = wx.DirDialog(self, _("Choose Inkscape directory"))
         if dialog.ShowModal() != wx.ID_CANCEL:
             self.path_input.SetValue(dialog.GetPath())
 
     def install_button_clicked(self, event):
         try:
-            self.install_palettes()
+            self.install_addons('palettes')
+            self.install_addons('symbols')
         except Exception, e:
             wx.MessageDialog(self,
-                             _('Thread palette installation failed') + ': \n' + traceback.format_exc(),
+                             _('Inkscape add-on installation failed') + ': \n' + traceback.format_exc(),
                              _('Installation Failed'),
                              wx.OK).ShowModal()
         else:
             wx.MessageDialog(self,
-                             _('Thread palette files have been installed.  Please restart Inkscape to load the new palettes.'),
+                             _('Inkscape add-on files have been installed.  Please restart Inkscape to load the new add-ons.'),
                              _('Installation Completed'),
                              wx.OK).ShowModal()
 
         self.Destroy()
 
-    def install_palettes(self):
-        path = self.path_input.GetValue()
-        palettes_dir = self.get_bundled_palettes_dir()
-        self.copy_files(glob(os.path.join(palettes_dir, "*")), path)
+    def install_addons(self, type):
+        path = os.path.join(self.path, type)
+        src_dir = self.get_bundled_dir(type)
+        self.copy_files(glob(os.path.join(src_dir, "*")), path)
 
-    def get_bundled_palettes_dir(self):
+    def get_bundled_dir(self, name):
         if getattr(sys, 'frozen', None) is not None:
-            return realpath(os.path.join(sys._MEIPASS, '..', 'palettes'))
+            return realpath(os.path.join(sys._MEIPASS, '..', name))
         else:
-            return os.path.join(dirname(realpath(__file__)), 'palettes')
+            return realpath(os.path.join(dirname(realpath(__file__)), '..', '..', name))
 
     if (sys.platform == "win32"):
         # If we try to just use shutil.copy it says the operation requires elevation.
@@ -104,9 +103,9 @@ class InstallPalettesFrame(wx.Frame):
             for palette_file in files:
                 shutil.copy(palette_file, dest)
 
-class Palettes(inkex.Effect):
+class Install(inkex.Effect):
     def effect(self):
         app = wx.App()
-        installer_frame = InstallPalettesFrame(None, title=_("Ink/Stitch Thread Palette Installer"), size=(450, 200))
+        installer_frame = InstallerFrame(None, title=_("Ink/Stitch Add-ons Installer"), size=(550, 250))
         installer_frame.Show()
         app.MainLoop()
diff --git a/lib/extensions/params.py b/lib/extensions/params.py
index 9d8de41b..58fedd6b 100644
--- a/lib/extensions/params.py
+++ b/lib/extensions/params.py
@@ -19,6 +19,7 @@ from ..stitch_plan import patches_to_stitch_plan
 from ..elements import EmbroideryElement, Fill, AutoFill, Stroke, SatinColumn
 from ..utils import save_stderr, restore_stderr
 from ..simulator import EmbroiderySimulator
+from ..commands import is_command
 
 
 def presets_path():
@@ -655,7 +656,7 @@ class Params(InkstitchExtension):
             classes.append(AutoFill)
             classes.append(Fill)
 
-        if element.get_style("stroke"):
+        if element.get_style("stroke") and not is_command(node):
             classes.append(Stroke)
 
             if element.get_style("stroke-dasharray") is None:
diff --git a/lib/stitches/auto_fill.py b/lib/stitches/auto_fill.py
index 518a2812..6326ced2 100644
--- a/lib/stitches/auto_fill.py
+++ b/lib/stitches/auto_fill.py
@@ -2,7 +2,7 @@ import sys
 import shapely
 import networkx
 import math
-from itertools import groupby
+from itertools import groupby, izip
 from collections import deque
 
 from .fill import intersect_region_with_grating, row_num, stitch_row
@@ -14,18 +14,38 @@ from ..utils.geometry import Point as InkstitchPoint
 class MaxQueueLengthExceeded(Exception):
     pass
 
+class PathEdge(object):
+    OUTLINE_KEYS = ("outline", "extra", "initial")
+    SEGMENT_KEY = "segment"
 
-def auto_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, running_stitch_length, staggers, starting_point=None):
+    def __init__(self, nodes, key):
+        self.nodes = nodes
+        self._sorted_nodes = tuple(sorted(self.nodes))
+        self.key = key
+
+    def __getitem__(self, item):
+        return self.nodes[item]
+
+    def __hash__(self):
+        return hash((self._sorted_nodes, self.key))
+
+    def __eq__(self, other):
+        return self._sorted_nodes == other._sorted_nodes and self.key == other.key
+
+    def is_outline(self):
+        return self.key in self.OUTLINE_KEYS
+
+    def is_segment(self):
+        return self.key == self.SEGMENT_KEY
+
+def auto_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, running_stitch_length, staggers, starting_point, ending_point=None):
     stitches = []
 
     rows_of_segments = intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing)
     segments = [segment for row in rows_of_segments for segment in row]
 
     graph = build_graph(shape, segments, angle, row_spacing)
-    path = find_stitch_path(graph, segments)
-
-    if starting_point:
-        stitches.extend(connect_points(shape, starting_point, path[0][0], running_stitch_length))
+    path = find_stitch_path(graph, segments, starting_point, ending_point)
 
     stitches.extend(path_to_stitches(graph, path, shape, angle, row_spacing, max_stitch_length, running_stitch_length, staggers))
 
@@ -134,8 +154,6 @@ def build_graph(shape, segments, angle, row_spacing):
         else:
             edge_set = 1
 
-        #print >> sys.stderr, outline_index, "es", edge_set, "rn", row_num, inkstitch.Point(*nodes[0]) * self.north(angle), inkstitch.Point(*nodes[1]) * self.north(angle)
-
         # add an edge between each successive node
         for i, (node1, node2) in enumerate(zip(nodes, nodes[1:] + [nodes[0]])):
             graph.add_edge(node1, node2, key="outline")
@@ -157,14 +175,20 @@ def node_list_to_edge_list(node_list):
 
 def bfs_for_loop(graph, starting_node, max_queue_length=2000):
     to_search = deque()
-    to_search.appendleft(([starting_node], set(), 0))
+    to_search.append((None, set()))
 
     while to_search:
         if len(to_search) > max_queue_length:
             raise MaxQueueLengthExceeded()
 
-        path, visited_edges, visited_segments = to_search.pop()
-        ending_node = path[-1]
+        path, visited_edges = to_search.pop()
+
+        if path is None:
+            # This is the very first time through the loop, so initialize.
+            path = []
+            ending_node = starting_node
+        else:
+            ending_node = path[-1][-1]
 
         # get a list of neighbors paired with the key of the edge I can follow to get there
         neighbors = [
@@ -178,26 +202,21 @@ def bfs_for_loop(graph, starting_node, max_queue_length=2000):
 
         for next_node, key in neighbors:
             # skip if I've already followed this edge
-            edge = (tuple(sorted((ending_node, next_node))), key)
+            edge = PathEdge((ending_node, next_node), key)
             if edge in visited_edges:
                 continue
 
-            new_path = path + [next_node]
-
-            if key == "segment":
-                new_visited_segments = visited_segments + 1
-            else:
-                new_visited_segments = visited_segments
+            new_path = path + [edge]
 
             if next_node == starting_node:
                 # ignore trivial loops (down and back a doubled edge)
                 if len(new_path) > 3:
-                    return node_list_to_edge_list(new_path), new_visited_segments
+                    return new_path
 
             new_visited_edges = visited_edges.copy()
             new_visited_edges.add(edge)
 
-            to_search.appendleft((new_path, new_visited_edges, new_visited_segments))
+            to_search.appendleft((new_path, new_visited_edges))
 
 
 def find_loop(graph, starting_nodes):
@@ -216,14 +235,6 @@ def find_loop(graph, starting_nodes):
     somewhere else.
     """
 
-    #loop = self.simple_loop(graph, starting_nodes[-2])
-
-    #if loop:
-    #    print >> sys.stderr, "simple_loop success"
-    #    starting_nodes.pop()
-    #    starting_nodes.pop()
-    #    return loop
-
     loop = None
     retry = []
     max_queue_length = 2000
@@ -231,7 +242,6 @@ def find_loop(graph, starting_nodes):
     while not loop:
         while not loop and starting_nodes:
             starting_node = starting_nodes.pop()
-            #print >> sys.stderr, "find loop from", starting_node
 
             try:
                 # Note: if bfs_for_loop() returns None, no loop can be
@@ -240,12 +250,7 @@ def find_loop(graph, starting_nodes):
                 # case we discard that node and try the next.
                 loop = bfs_for_loop(graph, starting_node, max_queue_length)
 
-                #if not loop:
-                    #print >> dbg, "failed on", starting_node
-                    #dbg.flush()
             except MaxQueueLengthExceeded:
-                #print >> dbg, "gave up on", starting_node
-                #dbg.flush()
                 # We're giving up on this node for now.  We could try
                 # this node again later, so add it to the bottm of the
                 # stack.
@@ -272,7 +277,7 @@ def insert_loop(path, loop):
     start and end point.  The points will be specified in order, such
     that they will look like this:
 
-    ((p1, p2), (p2, p3), (p3, p4) ... (pn, p1))
+    ((p1, p2), (p2, p3), (p3, p4), ...)
 
     path will be modified in place.
     """
@@ -282,11 +287,59 @@ def insert_loop(path, loop):
     for i, (start, end) in enumerate(path):
         if start == loop_start:
             break
+    else:
+        # if we didn't find the start of the loop in the list at all, it must
+        # be the endpoint of the last segment
+        i += 1
 
     path[i:i] = loop
 
+def nearest_node_on_outline(graph, point, outline_index=0):
+    point = shapely.geometry.Point(*point)
+    outline_nodes = [node for node, data in graph.nodes(data=True) if data['index'] == outline_index]
+    nearest = min(outline_nodes, key=lambda node: shapely.geometry.Point(*node).distance(point))
 
-def find_stitch_path(graph, segments):
+    return nearest
+
+def get_outline_nodes(graph, outline_index=0):
+    outline_nodes = [(node, data['projection']) \
+                     for node, data \
+                     in graph.nodes(data=True) \
+                     if data['index'] == outline_index]
+    outline_nodes.sort(key=lambda (node, projection): projection)
+    outline_nodes = [node for node, data in outline_nodes]
+
+    return outline_nodes
+
+def find_initial_path(graph, starting_point, ending_point=None):
+    starting_node = nearest_node_on_outline(graph, starting_point)
+
+    if ending_point is None:
+        # If they didn't give an ending point, pick either neighboring node
+        # along the outline -- doesn't matter which.  We do this because
+        # the algorithm requires we start with _some_ path.
+        neighbors = [n for n, keys in graph.adj[starting_node].iteritems() if 'outline' in keys]
+        return [PathEdge((starting_node, neighbors[0]), "initial")]
+    else:
+        ending_node = nearest_node_on_outline(graph, ending_point)
+        outline_nodes = get_outline_nodes(graph)
+
+        # Multiply the outline_nodes list by 2 (duplicate it) because
+        # the ending_node may occur first.
+        outline_nodes *= 2
+        start_index = outline_nodes.index(starting_node)
+        end_index = outline_nodes.index(ending_node, start_index)
+        nodes = outline_nodes[start_index:end_index + 1]
+
+        # we have a series of sequential points, but we need to
+        # turn it into an edge list
+        path = []
+        for start, end in izip(nodes[:-1], nodes[1:]):
+            path.append(PathEdge((start, end), "initial"))
+
+        return path
+
+def find_stitch_path(graph, segments, starting_point=None, ending_point=None):
     """find a path that visits every grating segment exactly once
 
     Theoretically, we just need to find an Eulerian Path in the graph.
@@ -294,13 +347,14 @@ def find_stitch_path(graph, segments):
     The edges on the outline of the region are only there to help us get
     from one grating segment to the next.
 
-    We'll build a "cycle" (a path that ends where it starts) using
-    Hierholzer's algorithm.  We'll stop once we've visited every grating
-    segment.
+    We'll build a Eulerian Path using Hierholzer's algorithm.  A true
+    Eulerian Path would visit every single edge (including all the extras
+    we inserted in build_graph()),but we'll stop short once we've visited
+    every grating segment since that's all we really care about.
 
     Hierholzer's algorithm says to select an arbitrary starting node at
     each step.  In order to produce a reasonable stitch path, we'll select
-    the vertex carefully such that we get back-and-forth traversal like
+    the starting node carefully such that we get back-and-forth traversal like
     mowing a lawn.
 
     To do this, we'll use a simple heuristic: try to start from nodes in
@@ -313,40 +367,42 @@ def find_stitch_path(graph, segments):
     segments_visited = 0
     nodes_visited = deque()
 
-    # start with a simple loop: down one segment and then back along the
-    # outer border to the starting point.
-    path = [segments[0], list(reversed(segments[0]))]
+    if starting_point is None:
+        starting_point = segments[0][0]
+
+    path = find_initial_path(graph, starting_point, ending_point)
 
-    graph.remove_edges_from(path)
+    # Our graph is Eulerian: every node has an even degree.  An Eulerian graph
+    # must have an Eulerian Circuit which visits every edge and ends where it
+    # starts.
+    #
+    # However, we're starting with a path and _not_ removing the edges of that
+    # path from the graph.  By doing this, we're implicitly adding those edges
+    # to the graph, after which the starting and ending point (and only those
+    # two) will now have odd degree.  A graph that's Eulerian except for two
+    # nodes must have an Eulerian Path that starts and ends at those two nodes.
+    # That's how we force the starting and ending point.
 
-    segments_visited += 1
-    nodes_visited.extend(segments[0])
+    nodes_visited.append(path[0][0])
 
     while segments_visited < num_segments:
-        result = find_loop(graph, nodes_visited)
+        loop = find_loop(graph, nodes_visited)
 
-        if not result:
+        if not loop:
             print >> sys.stderr, _("Unexpected error while generating fill stitches. Please send your SVG file to lexelby@github.")
             break
 
-        loop, segments = result
-
-        #print >> dbg, "found loop:", loop
-        #dbg.flush()
-
-        segments_visited += segments
-        nodes_visited += [edge[0] for edge in loop]
+        segments_visited += sum(1 for edge in loop if edge.is_segment())
+        nodes_visited.extend(edge[0] for edge in loop)
         graph.remove_edges_from(loop)
 
         insert_loop(path, loop)
 
-        #if segments_visited >= 12:
-        #    break
-
-    # Now we have a loop that covers every grating segment.  It returns to
-    # where it started, which is unnecessary, so we'll snip the last bit off.
-    #while original_graph.has_edge(*path[-1], key="outline"):
-    #    path.pop()
+    if ending_point is None:
+        # If they didn't specify an ending point, then the end of the path travels
+        # around the outline back to the start (see find_initial_path()). This
+        # isn't necessary, so remove it.
+        trim_end(path)
 
     return path
 
@@ -363,10 +419,10 @@ def collapse_sequential_outline_edges(graph, path):
     new_path = []
 
     for edge in path:
-        if graph.has_edge(*edge, key="segment"):
+        if edge.is_segment():
             if start_of_run:
                 # close off the last run
-                new_path.append((start_of_run, edge[0]))
+                new_path.append(PathEdge((start_of_run, edge[0]), "collapsed"))
                 start_of_run = None
 
             new_path.append(edge)
@@ -376,7 +432,7 @@ def collapse_sequential_outline_edges(graph, path):
 
     if start_of_run:
         # if we were still in a run, close it off
-        new_path.append((start_of_run, edge[1]))
+        new_path.append(PathEdge((start_of_run, edge[1]), "collapsed"))
 
     return new_path
 
@@ -416,9 +472,6 @@ def connect_points(shape, start, end, running_stitch_length):
     direction = math.copysign(1.0, distance)
     one_stitch = running_stitch_length * direction
 
-    #print >> dbg, "connect_points:", outline_index, start, end, distance, stitches, direction
-    #dbg.flush()
-
     stitches = [InkstitchPoint(*outline.interpolate(pos).coords[0])]
 
     for i in xrange(num_stitches):
@@ -430,11 +483,11 @@ def connect_points(shape, start, end, running_stitch_length):
     if (end - stitches[-1]).length() > 0.1 * PIXELS_PER_MM:
         stitches.append(end)
 
-    #print >> dbg, "end connect_points"
-    #dbg.flush()
-
     return stitches
 
+def trim_end(path):
+    while path and path[-1].is_outline():
+        path.pop()
 
 def path_to_stitches(graph, path, shape, angle, row_spacing, max_stitch_length, running_stitch_length, staggers):
     path = collapse_sequential_outline_edges(graph, path)
@@ -442,7 +495,7 @@ def path_to_stitches(graph, path, shape, angle, row_spacing, max_stitch_length,
     stitches = []
 
     for edge in path:
-        if graph.has_edge(*edge, key="segment"):
+        if edge.is_segment():
             stitch_row(stitches, edge[0], edge[1], angle, row_spacing, max_stitch_length, staggers)
         else:
             stitches.extend(connect_points(shape, edge[0], edge[1], running_stitch_length))
diff --git a/lib/svg/__init__.py b/lib/svg/__init__.py
index 1895bba4..50543b1b 100644
--- a/lib/svg/__init__.py
+++ b/lib/svg/__init__.py
@@ -1,2 +1,3 @@
 from .svg import color_block_to_point_lists, render_stitch_plan
 from .units import *
+from .path import apply_transforms
diff --git a/lib/svg/path.py b/lib/svg/path.py
new file mode 100644
index 00000000..a8012774
--- /dev/null
+++ b/lib/svg/path.py
@@ -0,0 +1,20 @@
+import simpletransform
+import cubicsuperpath
+
+from .units import get_viewbox_transform
+
+def apply_transforms(path, node):
+    # start with the identity transform
+    transform = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0]]
+
+    # combine this node's transform with all parent groups' transforms
+    transform = simpletransform.composeParents(node, transform)
+
+    # add in the transform implied by the viewBox
+    viewbox_transform = get_viewbox_transform(node.getroottree().getroot())
+    transform = simpletransform.composeTransform(viewbox_transform, transform)
+
+    # apply the combined transform to this node's path
+    simpletransform.applyTransformToPath(transform, path)
+
+    return path
diff --git a/lib/svg/tags.py b/lib/svg/tags.py
index fee59957..5488608c 100644
--- a/lib/svg/tags.py
+++ b/lib/svg/tags.py
@@ -5,8 +5,13 @@ SVG_PATH_TAG = inkex.addNS('path', 'svg')
 SVG_POLYLINE_TAG = inkex.addNS('polyline', 'svg')
 SVG_DEFS_TAG = inkex.addNS('defs', 'svg')
 SVG_GROUP_TAG = inkex.addNS('g', 'svg')
+SVG_SYMBOL_TAG = inkex.addNS('symbol', 'svg')
+SVG_USE_TAG = inkex.addNS('use', 'svg')
 
 INKSCAPE_LABEL = inkex.addNS('label', 'inkscape')
 INKSCAPE_GROUPMODE = inkex.addNS('groupmode', 'inkscape')
+CONNECTION_START = inkex.addNS('connection-start', 'inkscape')
+CONNECTION_END = inkex.addNS('connection-end', 'inkscape')
+XLINK_HREF = inkex.addNS('href', 'xlink')
 
 EMBROIDERABLE_TAGS = (SVG_PATH_TAG, SVG_POLYLINE_TAG)