Rewrite force lock stitch extension (#3559)

* rewrite force lock stitch extension
* do not add forced lock stitch before color change

2 files changed, 75 insertions, 51 deletions

diff --git a/lib/elements/satin_column.py b/lib/elements/satin_column.py
index 3aa54f90..de04579c 100644
--- a/lib/elements/satin_column.py
+++ b/lib/elements/satin_column.py
@@ -1807,6 +1807,8 @@ class SatinColumn(EmbroideryElement):
 
     @property
     def first_stitch(self):
+        if self.start_at_nearest_point:
+            return None
         return shgeo.Point(self.flattened_rails[0].coords[0])
 
     def start_point(self, last_stitch_group):
diff --git a/lib/extensions/lettering_force_lock_stitches.py b/lib/extensions/lettering_force_lock_stitches.py
index c835bc72..16f81227 100644
--- a/lib/extensions/lettering_force_lock_stitches.py
+++ b/lib/extensions/lettering_force_lock_stitches.py
@@ -6,9 +6,11 @@
 import inkex
 from shapely.geometry import Point
 
+from ..elements.utils import iterate_nodes, nodes_to_elements
 from ..i18n import _
+from ..marker import has_marker
 from ..svg import PIXELS_PER_MM
-from ..svg.tags import INKSTITCH_ATTRIBS
+from ..svg.tags import EMBROIDERABLE_TAGS
 from .base import InkstitchExtension
 
 
@@ -22,6 +24,7 @@ class LetteringForceLockStitches(InkstitchExtension):
         InkstitchExtension.__init__(self, *args, **kwargs)
         self.arg_parser.add_argument("--notebook")
         self.arg_parser.add_argument("-s", "--satin_only", type=inkex.Boolean, dest="satin_only")
+        self.arg_parser.add_argument("-d", "--distance", type=inkex.Boolean, dest="distance")
         self.arg_parser.add_argument("-a", "--max_distance", type=float, default=3, dest="max_distance")
         self.arg_parser.add_argument("-i", "--min_distance", type=float, default=1, dest="min_distance")
         self.arg_parser.add_argument("-l", "--last_element", type=inkex.Boolean, dest="last_element")
@@ -30,56 +33,75 @@ class LetteringForceLockStitches(InkstitchExtension):
         if self.options.max_distance < self.options.min_distance:
             inkex.errormssg(_("The maximum value is smaller than the minimum value."))
 
-        # Set glyph layers to be visible. We don't want them to be ignored by self.elements
-        self._update_layer_visibility('inline')
-
-        # mark last elements of a glyph
-        xpath = ".//svg:g[@inkscape:groupmode='layer']//svg:path[last()]"
-        last_elements = self.document.xpath(xpath, namespaces=inkex.NSS)
-        for last_element in last_elements:
-            last_element.set('lastglyphelement', str(True))
-
-        # find last point of an element
-        if not self.get_elements():
-            return
-
-        previous_element = None
-        last_stitch = None
-        for element in self.elements:
-            stitch_group = element.to_stitch_groups(None)
-            # if the distance of the last stitch of the previous object to the first stitch of this objects
-            # lies within the user defined distance range, set the force_lock_stitches-attribute.
-            if last_stitch:
-                first_stitch = stitch_group[0].stitches[0]
-                first_stitch = Point(first_stitch.x, first_stitch.y)
-                self._set_force_attribute(first_stitch, last_stitch, previous_element)
-
-            # if this is the last element of a glyph, we don't want to compare it to the next element
-            if element.node.get('lastglyphelement', False):
-                previous_element = None
-                last_stitch = None
-            else:
-                previous_element = element
-                last_stitch = stitch_group[-1].stitches[-1]
-                last_stitch = Point(last_stitch.x, last_stitch.y)
-
-        # remove last element attributes again
-        # set force lock stitches attribute if needed
-        for last_element in last_elements:
-            last_element.attrib.pop('lastglyphelement')
-            if self.options.last_element and not (self.options.satin_only and not last_element.get('inkstitch:satin_column', False)):
-                last_element.set(INKSTITCH_ATTRIBS['force_lock_stitches'], True)
-
-        # hide glyph layers again
-        self._update_layer_visibility('none')
-
-    def _set_force_attribute(self, first_stitch, last_stitch, previous_element):
-        distance_mm = first_stitch.distance(last_stitch) / PIXELS_PER_MM
-
-        if (distance_mm < self.options.max_distance and
-                distance_mm > self.options.min_distance and
-                not (self.options.satin_only and not previous_element.get_boolean_param('satin_column', False))):
-            previous_element.node.set(INKSTITCH_ATTRIBS['force_lock_stitches'], True)
+        glyph_layers = self.document.xpath('.//svg:g[starts-with(@inkscape:label, "GlyphLayer")]', namespaces=inkex.NSS)
+        uses_glyph_layers = True
+        if not glyph_layers:
+            # they maybe want to use this method for a regular document. Let's allow it, why not.
+            glyph_layers = [self.document.getroot()]
+            uses_glyph_layers = False
+        else:
+            # Set glyph layers to be visible. We don't want them to be ignored by self.elements
+            self._update_layer_visibility('inline')
+        for layer in glyph_layers:
+            if uses_glyph_layers and self.options.last_element:
+                self._set_force_attribute_on_last_elements(layer)
+            if self.options.distance:
+                self._set_force_attribute_by_distance(layer)
+
+        if uses_glyph_layers:
+            # unhide glyph layers
+            self._update_layer_visibility('none')
+
+    def _set_force_attribute_on_last_elements(self, layer):
+        # find the last path that does not carry a marker or belongs to a visual command and add a trim there
+        last_element = None
+        child_nodes = list(layer.iterdescendants(EMBROIDERABLE_TAGS))
+        child_nodes.reverse()
+        for element in child_nodes:
+            if not has_marker(element) and not element.get_id().startswith('command_connector'):
+                last_element = element
+                break
+        if last_element is not None:
+            if self.options.satin_only and not last_element.get('inkstitch:satin_column', False):
+                return
+            last_element.set('inkstitch:force_lock_stitches', True)
+
+    def _set_force_attribute_by_distance(self, layer):
+        min_distance = self.options.min_distance * PIXELS_PER_MM
+        max_distance = self.options.max_distance * PIXELS_PER_MM
+
+        nodes = iterate_nodes(layer)
+        elements = nodes_to_elements(nodes)
+
+        last_stitch_group = None
+        next_elements = [None]
+        if len(elements) > 1:
+            next_elements = elements[1:] + next_elements
+        for element, next_element in zip(elements, next_elements):
+            distance = None
+            stitch_groups = element.to_stitch_groups(last_stitch_group, next_element)
+            if not stitch_groups:
+                continue
+            if next_element is not None:
+                last_stitch = stitch_groups[-1].stitches[-1]
+                next_stitch = next_element.first_stitch
+                if stitch_groups[-1].color != next_element.color:
+                    last_stitch_group = stitch_groups[-1]
+                    continue
+                if next_stitch is None:
+                    # get nearest point
+                    shape = next_element.shape
+                    if not shape.is_empty:
+                        distance = shape.distance(Point(last_stitch))
+                else:
+                    distance = Point(last_stitch).distance(Point(next_stitch))
+
+            if distance is not None and distance < max_distance and distance > min_distance:
+                if self.options.satin_only and element.name != 'SatinColumn':
+                    continue
+                element.node.set('inkstitch:force_lock_stitches', True)
+
+            last_stitch_group = stitch_groups[-1]
 
     def _update_layer_visibility(self, display):
         xpath = ".//svg:g[@inkscape:groupmode='layer']"