Satin center walk underlay repeats (#1671)

lib/elements/satin_column.py

@@ -165,6 +165,11 @@ class SatinColumn(EmbroideryElement):
     def center_walk_underlay_stitch_length(self):
         return max(self.get_float_param("center_walk_underlay_stitch_length_mm", 1.5), 0.01)
 
+    @property
+    @param('center_walk_underlay_repeats', _('Repeats'), group=_('Center-Walk Underlay'), type='int', default=2, sort_index=2)
+    def center_walk_underlay_repeats(self):
+        return max(self.get_int_param("center_walk_underlay_repeats", 2), 1)
+
     @property
     @param('zigzag_underlay', _('Zig-zag underlay'), type='toggle', group=_('Zig-zag Underlay'))
     def zigzag_underlay(self):
@@ -432,6 +437,9 @@ class SatinColumn(EmbroideryElement):
         if not self.to_stitch_groups():
             yield NotStitchableError(self.shape.centroid)
 
+    def _center_walk_is_odd(self):
+        return self.center_walk_underlay_repeats % 2 == 1
+
     def reverse(self):
         """Return a new SatinColumn like this one but in the opposite direction.
 
@@ -736,24 +744,34 @@ class SatinColumn(EmbroideryElement):
     def do_contour_underlay(self):
         # "contour walk" underlay: do stitches up one side and down the
         # other.
-        forward, back = self.plot_points_on_rails(self.contour_underlay_stitch_length,
-                                                  -self.contour_underlay_inset)
+        forward, back = self.plot_points_on_rails(self.contour_underlay_stitch_length, -self.contour_underlay_inset)
+        stitches = (forward + list(reversed(back)))
+        if self._center_walk_is_odd():
+            stitches = (list(reversed(back)) + forward)
+
         return StitchGroup(
             color=self.color,
             tags=("satin_column", "satin_column_underlay", "satin_contour_underlay"),
-            stitches=(forward + list(reversed(back))))
+            stitches=stitches)
 
     def do_center_walk(self):
         # Center walk underlay is just a running stitch down and back on the
         # center line between the bezier curves.
 
         # Do it like contour underlay, but inset all the way to the center.
-        forward, back = self.plot_points_on_rails(self.center_walk_underlay_stitch_length,
-                                                  -100000)
+        forward, back = self.plot_points_on_rails(self.center_walk_underlay_stitch_length, -100000)
+
+        stitches = []
+        for i in range(self.center_walk_underlay_repeats):
+            if i % 2 == 0:
+                stitches += forward
+            else:
+                stitches += list(reversed(back))
+
         return StitchGroup(
             color=self.color,
             tags=("satin_column", "satin_column_underlay", "satin_center_walk"),
-            stitches=(forward + list(reversed(back))))
+            stitches=stitches)
 
     def do_zigzag_underlay(self):
         # zigzag underlay, usually done at a much lower density than the
@@ -771,6 +789,9 @@ class SatinColumn(EmbroideryElement):
         sides = self.plot_points_on_rails(self.zigzag_underlay_spacing / 2.0,
                                           -self.zigzag_underlay_inset)
 
+        if self._center_walk_is_odd():
+            sides = [list(reversed(sides[0])), list(reversed(sides[1]))]
+
         # This organizes the points in each side in the order that they'll be
         # visited.
         sides = [sides[0][::2] + list(reversed(sides[0][1::2])),
@@ -811,6 +832,9 @@ class SatinColumn(EmbroideryElement):
         for point in chain.from_iterable(zip(*sides)):
             patch.add_stitch(point)
 
+        if self._center_walk_is_odd():
+            patch.stitches = list(reversed(patch.stitches))
+
         patch.add_tags(("satin_column", "satin_column_edge"))
         return patch
 
@@ -833,6 +857,9 @@ class SatinColumn(EmbroideryElement):
             patch.add_stitch(right)
             patch.add_stitch(left)
 
+        if self._center_walk_is_odd():
+            patch.stitches = list(reversed(patch.stitches))
+
         patch.add_tags(("satin_column", "e_stitch"))
         return patch
 
@@ -857,6 +884,8 @@ class SatinColumn(EmbroideryElement):
                 for point in points:
                     patch.add_stitch(point)
                     patch.stitches[-1].add_tags(("satin_column", "satin_split_stitch"))
+        if self._center_walk_is_odd():
+            patch.stitches = list(reversed(patch.stitches))
         return patch
 
     def _get_split_points(self, left, right, max_stitch_length, count=None):

lib/stitches/auto_satin.py

@@ -507,6 +507,7 @@ def name_elements(new_elements, preserve_order):
     for element in new_elements:
         if isinstance(element, SatinColumn):
             element.node.set("id", generate_unique_id(element.node, "autosatin"))
+            _ensure_even_repeats(element)
         else:
             element.node.set("id", generate_unique_id(element.node, "autosatinrun"))
 
@@ -514,6 +515,7 @@ def name_elements(new_elements, preserve_order):
             if isinstance(element, SatinColumn):
                 # L10N Label for a satin column created by Auto-Route Satin Columns and Lettering extensions
                 element.node.set(INKSCAPE_LABEL, _("AutoSatin %d") % index)
+                _ensure_even_repeats(element)
             else:
                 # L10N Label for running stitch (underpathing) created by Auto-Route Satin Columns amd Lettering extensions
                 element.node.set(INKSCAPE_LABEL, _("AutoSatin Running Stitch %d") % index)
@@ -521,6 +523,14 @@ def name_elements(new_elements, preserve_order):
             index += 1
 
 
+def _ensure_even_repeats(element):
+    # center underlay can have an odd number of repeats, this would cause jumps in auto route satin
+    # so let's set it to an even number of repeats, but not lower than 2
+    if int(element.node.get(INKSTITCH_ATTRIBS['center_walk_underlay_repeats'], 2)) % 2 == 1:
+        repeats = max(int(element.node.get(INKSTITCH_ATTRIBS['center_walk_underlay_repeats'])) - 1, 2)
+        element.node.set(INKSTITCH_ATTRIBS['center_walk_underlay_repeats'], repeats)
+
+
 def add_trims(elements, trim_indices):
     """Add trim commands on the specified elements.
 

lib/svg/tags.py

@@ -94,6 +94,7 @@ inkstitch_attribs = [
     'running_stitch_length_mm',
     'center_walk_underlay',
     'center_walk_underlay_stitch_length_mm',
+    'center_walk_underlay_repeats',
     'contour_underlay',
     'contour_underlay_stitch_length_mm',
     'contour_underlay_inset_mm',