apply clip to stroke (#2283)

lib/elements/fill_stitch.py

@@ -23,6 +23,7 @@ from ..stitches import (auto_fill, circular_fill, contour_fill, guided_fill,
                         legacy_fill)
 from ..stitches.meander_fill import meander_fill
 from ..svg import PIXELS_PER_MM, get_node_transform
+from ..svg.clip import get_clip_path
 from ..svg.tags import INKSCAPE_LABEL
 from ..utils import cache, version
 from ..utils.param import ParamOption
@@ -571,12 +572,9 @@ class FillStitch(EmbroideryElement):
         if self.node.clip is None:
             return self.original_shape
 
-        from .element import EmbroideryElement
-        clip_element = EmbroideryElement(self.node.clip)
-        clip_element.paths.sort(key=lambda point_list: shgeo.Polygon(point_list).area, reverse=True)
-        polygon = shgeo.MultiPolygon([(clip_element.paths[0], clip_element.paths[1:])])
+        clip_path = get_clip_path(self.node)
         try:
-            intersection = polygon.intersection(self.original_shape)
+            intersection = clip_path.intersection(self.original_shape)
         except TopologicalError:
             return self.original_shape
 

lib/elements/stroke.py

@@ -5,7 +5,7 @@
 
 from math import ceil
 
-import shapely.geometry
+import shapely.geometry as shgeo
 from inkex import Transform
 
 from ..i18n import _
@@ -18,7 +18,9 @@ from ..threads import ThreadColor
 from ..utils import Point, cache
 from ..utils.param import ParamOption
 from .element import EmbroideryElement, param
+from ..svg.clip import get_clip_path
 from .validation import ValidationWarning
+from shapely.errors import TopologicalError
 
 
 class MultipleGuideLineWarning(ValidationWarning):
@@ -349,6 +351,7 @@ class Stroke(EmbroideryElement):
     def paths(self):
         path = self.parse_path()
         flattened = self.flatten(path)
+        flattened = self._get_clipped_path(flattened)
 
         # manipulate invalid path
         if len(flattened[0]) == 1:
@@ -366,8 +369,32 @@ class Stroke(EmbroideryElement):
 
     @cache
     def as_multi_line_string(self):
-        line_strings = [shapely.geometry.LineString(path) for path in self.paths]
-        return shapely.geometry.MultiLineString(line_strings)
+        line_strings = [shgeo.LineString(path) for path in self.paths]
+        return shgeo.MultiLineString(line_strings)
+
+    def _get_clipped_path(self, paths):
+        if self.node.clip is None:
+            return paths
+
+        clip_path = get_clip_path(self.node)
+        # path to linestrings
+        line_strings = [shgeo.LineString(path) for path in paths]
+        try:
+            intersection = clip_path.intersection(shgeo.MultiLineString(line_strings))
+        except TopologicalError:
+            return paths
+
+        coords = []
+        if intersection.is_empty:
+            return paths
+        elif isinstance(intersection, shgeo.MultiLineString):
+            for c in [intersection for intersection in intersection.geoms if isinstance(intersection, shgeo.LineString)]:
+                coords.append(c.coords)
+        elif isinstance(intersection, shgeo.LineString):
+            coords.append(intersection.coords)
+        else:
+            return paths
+        return coords
 
     def get_ripple_target(self):
         command = self.get_command('ripple_target')
@@ -431,7 +458,7 @@ class Stroke(EmbroideryElement):
         # apply max distances
         max_len_path = [path[0]]
         for points in zip(path[:-1], path[1:]):
-            line = shapely.geometry.LineString(points)
+            line = shgeo.LineString(points)
             dist = line.length
             if dist > self.max_stitch_length:
                 num_subsections = ceil(dist / self.max_stitch_length)

lib/svg/clip.py

@@ -0,0 +1,18 @@
+# Authors: see git history
+#
+# Copyright (c) 2023 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
+from shapely.geometry import MultiPolygon, Polygon
+
+from ..elements import EmbroideryElement
+
+
+def get_clip_path(node):
+    # get clip and apply node transform
+    clip = node.clip
+    transform = node.composed_transform()
+    clip.transform = transform
+    clip_element = EmbroideryElement(clip)
+    clip_element.paths.sort(key=lambda point_list: Polygon(point_list).area, reverse=True)
+    return MultiPolygon([(clip_element.paths[0], clip_element.paths[1:])])