autorun: fix networkx no path (#2645)

lib/stitches/auto_run.py

@@ -5,23 +5,22 @@
 
 from collections import defaultdict
 
+import inkex
 import networkx as nx
 from shapely.geometry import LineString, MultiLineString, MultiPoint, Point
 from shapely.ops import nearest_points, substring, unary_union
 
-import inkex
-
 from ..commands import add_commands
 from ..elements import Stroke
 from ..i18n import _
 from ..svg import PIXELS_PER_MM, generate_unique_id
 from ..svg.tags import INKSCAPE_LABEL, INKSTITCH_ATTRIBS
+from ..utils.threading import check_stop_flag
 from .utils.autoroute import (add_elements_to_group, add_jumps,
                               create_new_group, find_path,
                               get_starting_and_ending_nodes,
                               preserve_original_groups,
                               remove_original_elements)
-from ..utils.threading import check_stop_flag
 
 
 class LineSegments:

lib/stitches/utils/autoroute.py

@@ -83,42 +83,70 @@ def add_jumps(graph, elements, preserve_order):
     Jump stitches are added to ensure that all elements can be reached.  Only the
     minimal number and length of jumps necessary will be added.
     """
-
     if preserve_order:
-        # For each sequential pair of elements, find the shortest possible jump
-        # stitch between them and add it.  The directions of these new edges
-        # will enforce stitching the elements in order.
-
-        for element1, element2 in zip(elements[:-1], elements[1:]):
-            check_stop_flag()
-
-            potential_edges = []
-
-            nodes1 = get_nodes_on_element(graph, element1)
-            nodes2 = get_nodes_on_element(graph, element2)
-
-            for node1 in nodes1:
-                for node2 in nodes2:
-                    point1 = graph.nodes[node1]['point']
-                    point2 = graph.nodes[node2]['point']
-                    potential_edges.append((point1, point2))
-
-            if potential_edges:
-                edge = min(potential_edges, key=lambda p1_p2: p1_p2[0].distance(p1_p2[1]))
-                graph.add_edge(str(edge[0]), str(edge[1]), jump=True)
+        _add_ordered_jumps(graph, elements)
     else:
-        # networkx makes this super-easy!  k_edge_agumentation tells us what edges
-        # we need to add to ensure that the graph is fully connected.  We give it a
-        # set of possible edges that it can consider adding (avail).  Each edge has
-        # a weight, which we'll set as the length of the jump stitch.  The
-        # algorithm will minimize the total length of jump stitches added.
-        for jump in nx.k_edge_augmentation(graph, 1, avail=list(possible_jumps(graph))):
-            check_stop_flag()
-            graph.add_edge(*jump, jump=True)
-
+        _add_unordered_jumps(graph, elements)
     return graph
 
 
+def _add_ordered_jumps(graph, elements):
+    # For each sequential pair of elements, find the shortest possible jump
+    # stitch between them and add it.  The directions of these new edges
+    # will enforce stitching the elements in order.
+    for element1, element2 in zip(elements[:-1], elements[1:]):
+        check_stop_flag()
+        _insert_smallest_jump(graph, element1, element2)
+
+    # add jumps between subpath too, we do not care about directions here
+    for element in elements:
+        check_stop_flag()
+        geoms = list(element.as_multi_line_string().geoms)
+        i = 0
+        for line1 in geoms:
+            for line2 in geoms[i+1:]:
+                if line1.distance(line2) == 0:
+                    continue
+                node1, node2 = nearest_points(line1, line2)
+                _insert_jump(graph, node1, node2)
+            i += 1
+
+
+def _insert_smallest_jump(graph, element1, element2):
+    potential_edges = []
+
+    nodes1 = get_nodes_on_element(graph, element1)
+    nodes2 = get_nodes_on_element(graph, element2)
+
+    for node1 in nodes1:
+        for node2 in nodes2:
+            point1 = graph.nodes[node1]['point']
+            point2 = graph.nodes[node2]['point']
+            potential_edges.append((point1, point2))
+
+    if potential_edges:
+        edge = min(potential_edges, key=lambda p1_p2: p1_p2[0].distance(p1_p2[1]))
+        graph.add_edge(str(edge[0]), str(edge[1]), jump=True)
+
+
+def _insert_jump(graph, node1, node2):
+    graph.add_node(str(node1), point=node1)
+    graph.add_node(str(node2), point=node2)
+    graph.add_edge(str(node1), str(node2), jump=True)
+    graph.add_edge(str(node2), str(node1), jump=True)
+
+
+def _add_unordered_jumps(graph, elements):
+    # networkx makes this super-easy!  k_edge_agumentation tells us what edges
+    # we need to add to ensure that the graph is fully connected.  We give it a
+    # set of possible edges that it can consider adding (avail).  Each edge has
+    # a weight, which we'll set as the length of the jump stitch.  The
+    # algorithm will minimize the total length of jump stitches added.
+    for jump in nx.k_edge_augmentation(graph, 1, avail=list(possible_jumps(graph))):
+        check_stop_flag()
+        graph.add_edge(*jump, jump=True)
+
+
 def possible_jumps(graph):
     """All possible jump stitches in the graph with their lengths.