add bean stitch option

lib/elements/stroke.py

@@ -4,7 +4,7 @@ import shapely.geometry
 from .element import param, EmbroideryElement, Patch
 from ..i18n import _
 from ..utils import cache, Point
-from ..stitches import running_stitch
+from ..stitches import running_stitch, bean_stitch
 from ..svg import parse_length_with_units
 
 warned_about_legacy_running_stitch = False
@@ -27,18 +27,28 @@ class Stroke(EmbroideryElement):
         return self.get_style("stroke-dasharray") is not None
 
     @property
-    @param('running_stitch_length_mm', _('Running stitch length'), unit='mm', type='float', default=1.5)
+    @param('running_stitch_length_mm', _('Running stitch length'), unit='mm', type='float', default=1.5, sort_index=3)
     def running_stitch_length(self):
         return max(self.get_float_param("running_stitch_length_mm", 1.5), 0.01)
 
     @property
-    @param('zigzag_spacing_mm', _('Zig-zag spacing (peak-to-peak)'), unit='mm', type='float', default=0.4)
+    @param('bean_stitch_repeats',
+           _('Bean stitch number of repeats'),
+           tooltip=_('Backtrack each stitch this many times.  A value of 1 would triple each stitch (forward, back, forward).  A value of 2 would quintuple each stitch, etc.  Only applies to running stitch.'),
+           type='int',
+           default=0,
+           sort_index=2)
+    def bean_stitch_repeats(self):
+        return self.get_int_param("bean_stitch_repeats", 0)
+
+    @property
+    @param('zigzag_spacing_mm', _('Zig-zag spacing (peak-to-peak)'), unit='mm', type='float', default=0.4, sort_index=3)
     @cache
     def zigzag_spacing(self):
         return max(self.get_float_param("zigzag_spacing_mm", 0.4), 0.01)
 
     @property
-    @param('repeats', _('Repeats'), type='int', default="1")
+    @param('repeats', _('Repeats'), type='int', default="1", sort_index=1)
     def repeats(self):
         return self.get_int_param("repeats", 1)
 
@@ -58,7 +68,7 @@ class Stroke(EmbroideryElement):
         return shapely.geometry.MultiLineString(line_strings)
 
     @property
-    @param('manual_stitch', _('Manual stitch placement'), tooltip=_("Stitch every node in the path.  Stitch length and zig-zag spacing are ignored."), type='boolean', default=False)
+    @param('manual_stitch', _('Manual stitch placement'), tooltip=_("Stitch every node in the path.  Stitch length and zig-zag spacing are ignored."), type='boolean', default=False, sort_index=0)
     def manual_stitch_mode(self):
         return self.get_boolean_param('manual_stitch')
 
@@ -139,6 +149,7 @@ class Stroke(EmbroideryElement):
             repeated_path.extend(this_path)
 
         stitches = running_stitch(repeated_path, stitch_length)
+        stitches = bean_stitch(stitches, self.bean_stitch_repeats)
 
         return Patch(self.color, stitches)
 

lib/stitches/running_stitch.py

@@ -1,3 +1,6 @@
+from copy import copy
+
+
 """ Utility functions to produce running stitches. """
 
 
@@ -64,3 +67,29 @@ def running_stitch(points, stitch_length):
         output.append(segment_start)
 
     return output
+
+
+def bean_stitch(stitches, repeats):
+    """Generate bean stitch from a set of stitches.
+
+    "Bean" stitch is made by backtracking each stitch to make it heaver.  A
+    simple bean stitch would be two stitches forward, one stitch back, two
+    stitches forward, etc.  This would result in each stitch being tripled.
+
+    We'll say that the above counts as 1 repeat.  Backtracking each stitch
+    repeatedly will result in a heavier bean stitch.  There will always be
+    an odd number of threads piled up for each stitch.
+    """
+
+    if len(stitches) < 2:
+        return stitches
+
+    new_stitches = [stitches[0]]
+
+    for stitch in stitches:
+        new_stitches.append(stitch)
+
+        for i in xrange(repeats):
+            new_stitches.extend(copy(new_stitches[-2:]))
+
+    return new_stitches

messages.po

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PROJECT VERSION\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2018-07-25 21:18-0400\n"
+"POT-Creation-Date: 2018-07-27 20:26-0400\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -100,7 +100,7 @@ msgstr ""
 msgid "Custom satin column"
 msgstr ""
 
-#: lib/elements/satin_column.py:25 lib/elements/stroke.py:35
+#: lib/elements/satin_column.py:25 lib/elements/stroke.py:45
 msgid "Zig-zag spacing (peak-to-peak)"
 msgstr ""
 
@@ -195,21 +195,32 @@ msgstr ""
 msgid "Running stitch length"
 msgstr ""
 
-#: lib/elements/stroke.py:41
+#: lib/elements/stroke.py:36
+msgid "Bean stitch number of repeats"
+msgstr ""
+
+#: lib/elements/stroke.py:37
+msgid ""
+"Backtrack each stitch this many times.  A value of 1 would triple each "
+"stitch (forward, back, forward).  A value of 2 would quintuple each "
+"stitch, etc.  Only applies to running stitch."
+msgstr ""
+
+#: lib/elements/stroke.py:51
 msgid "Repeats"
 msgstr ""
 
-#: lib/elements/stroke.py:61
+#: lib/elements/stroke.py:71
 msgid "Manual stitch placement"
 msgstr ""
 
-#: lib/elements/stroke.py:61
+#: lib/elements/stroke.py:71
 msgid ""
 "Stitch every node in the path.  Stitch length and zig-zag spacing are "
 "ignored."
 msgstr ""
 
-#: lib/elements/stroke.py:92
+#: lib/elements/stroke.py:102
 msgid ""
 "Legacy running stitch setting detected!\n"
 "\n"