use pyclipper for polygon cutting

masque/shapes/polygon.py

@@ -185,63 +185,37 @@ class Polygon(Shape):
         :param cut_ys: list of y-coordinates to cut along (e.g., [1, 3, 5.4])
         :return: List of Polygon objects
         """
-        import float_raster
-        xy_complex = self.vertices[:, 0] + 1j * self.vertices[:, 1]
-        xy_cleaned = _clean_complex_vertices(xy_complex)
-        xy = numpy.vstack((numpy.real(xy_cleaned)[None, :],
-                           numpy.imag(xy_cleaned)[None, :]))
+        import pyclipper
+        from pyclipper import scale_to_clipper, scale_from_clipper
 
-        if cut_xs is None:
-            cut_xs = tuple()
-        if cut_ys is None:
-            cut_ys = tuple()
+        min_x, min_y = numpy.min(self.vertices, axis=0)
+        max_x, max_y = numpy.max(self.vertices, axis=0)
+        range_x = max_x - min_x
+        range_y = max_y - min_y
 
-        mins, maxs = self.get_bounds()
-        dx, dy = maxs - mins
+        edge_xs = (min_x - range_x - 1,) + tuple(cut_xs) + (max_x + range_x + 1,)
+        edge_ys = (min_y - range_y - 1,) + tuple(cut_ys) + (max_y + range_y + 1,)
 
-        cx = numpy.hstack((min(tuple(cut_xs) + (mins[0],)) - dx, cut_xs, max((maxs[0],) + tuple(cut_xs)) + dx))
-        cy = numpy.hstack((min(tuple(cut_ys) + (mins[1],)) - dy, cut_ys, max((maxs[1],) + tuple(cut_ys)) + dy))
+        clipped_shapes = []
+        for i in range(2):
+            for j in range(2):
+                clipper = pyclipper.Pyclipper()
+                clipper.AddPath(scale_to_clipper(self.vertices), pyclipper.PT_SUBJECT, True)
 
-        all_verts = float_raster.create_vertices(xy, cx, cy)
-
-        polygons = []
-        for cx_min, cx_max in zip(cx, cx[1:]):
-            for cy_min, cy_max in zip(cy, cy[1:]):
-                clipped_verts = (numpy.real(all_verts).clip(cx_min, cx_max) + 1j *
-                                 numpy.imag(all_verts).clip(cy_min, cy_max))
-
-                cleaned_verts = _clean_complex_vertices(clipped_verts)
-                if len(cleaned_verts) == 0:
-                    continue
-
-                final_verts = numpy.hstack((numpy.real(cleaned_verts)[:, None],
-                                            numpy.imag(cleaned_verts)[:, None]))
-                polygons.append(Polygon(
-                    vertices=final_verts,
-                    layer=self.layer,
-                    dose=self.dose))
-        return polygons
-
-
-def _clean_complex_vertices(vertices: numpy.ndarray) -> numpy.ndarray:
-    eps = numpy.finfo(vertices.dtype).eps
-
-    def cleanup(v):
-        # Remove duplicate points
-        dv = v - numpy.roll(v, 1)
-        v = v[numpy.abs(dv) > eps]
-
-        # Remove colinear points
-        dv = v - numpy.roll(v, 1)
-        m = numpy.angle(dv) % pi
-        diff_m = m - numpy.roll(m, -1)
-        return v[numpy.abs(diff_m) > eps]
-
-    n = len(vertices)
-    cleaned = cleanup(vertices)
-    while n != len(cleaned):
-        n = len(cleaned)
-        cleaned = cleanup(cleaned)
-
-    return cleaned
+                for start_x, stop_x in zip(edge_xs[i::2], edge_xs[(i+1)::2]):
+                    for start_y, stop_y in zip(edge_ys[j::2], edge_ys[(j+1)::2]):
+                        clipper.AddPath(scale_to_clipper((
+                            (start_x, start_y),
+                            (start_x, stop_y),
+                            (stop_x, stop_y),
+                            (stop_x, start_y),
+                        )), pyclipper.PT_CLIP, True)
 
+                clipped_parts = scale_from_clipper(clipper.Execute(pyclipper.CT_INTERSECTION,
+                                                                   pyclipper.PFT_EVENODD,
+                                                                   pyclipper.PFT_EVENODD))
+                for part in clipped_parts:
+                    poly = self.copy()
+                    poly.vertices = part
+                    clipped_shapes.append(poly)
+        return clipped_shapes

masque/subpattern.py

@@ -156,4 +156,3 @@ class SubPattern:
         """
         self.scale *= c
         return self
-

setup.py

@@ -16,7 +16,8 @@ setup(name='masque',
           'visualization': ['matplotlib'],
           'gdsii': ['python-gdsii'],
           'svg': ['svgwrite'],
-          'text': ['freetype-py', 'matplotlib']
+          'text': ['freetype-py', 'matplotlib'],
+          'clipping': ['pyclipper'],
       },
       )