1 files changed, 51 insertions, 0 deletions
diff --git a/lib/stitch_plan/ties.py b/lib/stitch_plan/ties.py
new file mode 100644
index 00000000..1207ea51
--- /dev/null
+++ b/lib/stitch_plan/ties.py
@@ -0,0 +1,51 @@
+from ..utils import cut_path
+from ..stitches import running_stitch
+from .. import Stitch
+from copy import deepcopy
+
+def add_tie(stitches, tie_path):
+    if stitches[-1].no_ties:
+        # It's from a manual stitch block, so don't add tie stitches.  The user
+        # will add them if they want them.
+        return
+
+    tie_path = cut_path(tie_path, 0.6)
+    tie_stitches = running_stitch(tie_path, 0.3)
+    tie_stitches = [Stitch(stitch.x, stitch.y) for stitch in tie_stitches]
+
+    stitches.extend(deepcopy(tie_stitches[1:]))
+    stitches.extend(deepcopy(list(reversed(tie_stitches))[1:]))
+
+
+def add_tie_off(stitches):
+    add_tie(stitches, list(reversed(stitches)))
+
+
+def add_tie_in(stitches, upcoming_stitches):
+    add_tie(stitches, upcoming_stitches)
+
+
+def add_ties(stitch_plan):
+    """Add tie-off before and after trims, jumps, and color changes."""
+
+    for color_block in stitch_plan:
+        need_tie_in = True
+        new_stitches = []
+        for i, stitch in enumerate(color_block.stitches):
+            is_special = stitch.trim or stitch.jump or stitch.stop
+
+            if is_special and not need_tie_in:
+                add_tie_off(new_stitches)
+                new_stitches.append(stitch)
+                need_tie_in = True
+            elif need_tie_in and not is_special:
+                new_stitches.append(stitch)
+                add_tie_in(new_stitches, upcoming_stitches=color_block.stitches[i:])
+                need_tie_in = False
+            else:
+                new_stitches.append(stitch)
+
+        if not need_tie_in:
+            add_tie_off(new_stitches)
+
+        color_block.replace_stitches(new_stitches)