1 files changed, 66 insertions, 0 deletions
diff --git a/lib/patterns.py b/lib/patterns.py
new file mode 100644
index 00000000..8872a8ce
--- /dev/null
+++ b/lib/patterns.py
@@ -0,0 +1,66 @@
+# Authors: see git history
+#
+# Copyright (c) 2010 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
+import inkex
+from shapely import geometry as shgeo
+
+from .svg import apply_transforms
+from .svg.tags import EMBROIDERABLE_TAGS
+from .utils import Point
+
+
+def is_pattern(node):
+    if node.tag not in EMBROIDERABLE_TAGS:
+        return False
+    return "marker-start:url(#inkstitch-pattern-marker)" in node.get('style', '')
+
+
+def apply_patterns(patches, node):
+    patterns = _get_patterns(node)
+    if not patterns:
+        return patches
+
+    patch_points = []
+    for patch in patches:
+        for i, stitch in enumerate(patch.stitches):
+            patch_points.append(stitch)
+            if i == len(patch.stitches) - 1:
+                continue
+            intersection_points = _get_pattern_points(stitch, patch.stitches[i+1], patterns)
+            for point in intersection_points:
+                patch_points.append(point)
+    patch.stitches = patch_points
+
+
+def _get_patterns(node):
+    xpath = "./parent::svg:g/*[contains(@style, 'marker-start:url(#inkstitch-pattern-marker)')]"
+    patterns = node.xpath(xpath, namespaces=inkex.NSS)
+    line_strings = []
+    for pattern in patterns:
+        if pattern.tag not in EMBROIDERABLE_TAGS:
+            continue
+        d = pattern.get_path()
+        path = inkex.paths.Path(d).to_superpath()
+        path = apply_transforms(path, pattern)
+        inkex.bezier.cspsubdiv(path, 0.1)
+        path = [[point for control_before, point, control_after in subpath] for subpath in path]
+        lines = [shgeo.LineString(p) for p in path]
+        for line in lines:
+            line_strings.append(line)
+    return shgeo.MultiLineString(line_strings)
+
+
+def _get_pattern_points(first, second, patterns):
+    points = []
+    for pattern in patterns:
+        intersection = shgeo.LineString([first, second]).intersection(pattern)
+        if isinstance(intersection, shgeo.Point):
+            points.append(Point(intersection.x, intersection.y))
+        if isinstance(intersection, shgeo.MultiPoint):
+            for point in intersection:
+                points.append(Point(point.x, point.y))
+    # sort points after their distance to left
+    points.sort(key=lambda point: point.distance(first))
+    return points