From ab483fc9d46eee2a5f4f10be91fd6190b0353a2b Mon Sep 17 00:00:00 2001
From: Jan Petykiewicz <anewusername@gmail.com>
Date: Tue, 13 Nov 2018 23:32:26 -0800
Subject: [PATCH] Remove pyclipper dependency; remove shape.cut()

---
 README.md                |  1 -
 masque/__init__.py       |  1 -
 masque/shapes/polygon.py | 39 ++++++++++++++++++++++++++------
 masque/shapes/shape.py   | 49 ----------------------------------------
 setup.py                 |  1 -
 5 files changed, 32 insertions(+), 59 deletions(-)

diff --git a/README.md b/README.md
index d2b7e35..6851d70 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,6 @@ E-beam doses, and the ability to output to multiple formats.
 Requirements:
 * python >= 3.5 (written and tested with 3.6)
 * numpy
-* pyclipper
 * matplotlib (optional, used for visualization functions and text)
 * python-gdsii (optional, used for gdsii i/o)
 * svgwrite (optional, used for svg output)
diff --git a/masque/__init__.py b/masque/__init__.py
index e77b1e7..a2a744c 100644
--- a/masque/__init__.py
+++ b/masque/__init__.py
@@ -18,7 +18,6 @@
 
  Dependencies:
     - numpy
-    - pyclipper
     - matplotlib    [Pattern.visualize(...)]
     - python-gdsii  [masque.file.gdsii]
     - svgwrite      [masque.file.svgwrite]
diff --git a/masque/shapes/polygon.py b/masque/shapes/polygon.py
index 85282a4..9fd10be 100644
--- a/masque/shapes/polygon.py
+++ b/masque/shapes/polygon.py
@@ -2,8 +2,6 @@ from typing import List
 import copy
 import numpy
 from numpy import pi
-import pyclipper
-from pyclipper import scale_to_clipper, scale_from_clipper
 
 from . import Shape, normalized_shape_tuple
 from .. import PatternError
@@ -185,11 +183,38 @@ class Polygon(Shape):
 
         :returns: self
         """
-        self.vertices = scale_from_clipper(
-                            pyclipper.CleanPolygon(
-                                scale_to_clipper(
-                                    self.vertices
-                                )))
+        self.remove_colinear_vertices()
         return self
 
+    def remove_duplicate_vertices(self) -> 'Polygon'
+        '''
+        Removes all consecutive duplicate (repeated) vertices.
+
+        :returns: self
+        '''
+        duplicates = (self.vertices == numpy.roll(self.vertices, 1, axis=0)).all(axis=1)
+        self.vertices = self.vertices[~duplicates]
+        return self
+
+    def remove_colinear_vertices(self) -> 'Polygon'
+        '''
+        Removes consecutive co-linear vertices.
+
+        :returns: self
+        '''
+        dv0 = numpy.roll(self.vertices, 1, axis=0) - self.vertices
+        dv1 = numpy.roll(dv0, -1, axis=0)
+
+        # find cases where at least one coordinate is 0 in successive dv's
+        eq = dv1 == dv0
+        aa_colinear = numpy.logical_and(eq, dv0 == 0).any(axis=1)
+
+        # find cases where slope is equal
+        with numpy.errstate(divide='ignore', invalid='ignore'):   # don't care about zeroes
+            slope_quotient = (dv0[:, 0] * dv1[:, 1]) / (dv1[:, 0] * dv0[:, 1])
+        slopes_equal = numpy.abs(slope_quotient - 1) < 1e-14
+
+        colinear = numpy.logical_or(aa_colinear, slopes_equal)
+        self.vertices = self.vertices[~colinear]
+        return self
 
diff --git a/masque/shapes/shape.py b/masque/shapes/shape.py
index 3384353..13ffa28 100644
--- a/masque/shapes/shape.py
+++ b/masque/shapes/shape.py
@@ -3,9 +3,6 @@ from abc import ABCMeta, abstractmethod
 import copy
 import numpy
 
-import pyclipper
-from pyclipper import scale_to_clipper, scale_from_clipper
-
 from .. import PatternError
 from ..utils import is_scalar, rotation_matrix_2d, vector2
 
@@ -369,49 +366,3 @@ class Shape(metaclass=ABCMeta):
 
         return manhattan_polygons
 
-    def cut(self,
-            cut_xs: numpy.ndarray = None,
-            cut_ys: numpy.ndarray = None
-            ) -> List['Polygon']:
-        """
-        Decomposes the shape into a list of constituent polygons by polygonizing and
-         then cutting along the specified x and/or y coordinates.
-
-        :param cut_xs: list of x-coordinates to cut along (e.g., [1, 1.4, 6])
-        :param cut_ys: list of y-coordinates to cut along (e.g., [1, 3, 5.4])
-        :return: List of Polygon objects
-        """
-        from . import Polygon
-
-        clipped_shapes = []
-        for polygon in self.to_polygons():
-            min_x, min_y = numpy.min(polygon.vertices, axis=0)
-            max_x, max_y = numpy.max(polygon.vertices, axis=0)
-            range_x = max_x - min_x
-            range_y = max_y - min_y
-
-            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,)
-
-            for i in range(2):
-                for j in range(2):
-                    clipper = pyclipper.Pyclipper()
-                    clipper.AddPath(scale_to_clipper(polygon.vertices), pyclipper.PT_SUBJECT, True)
-
-                    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 = polygon.copy()
-                        poly.vertices = part
-                        clipped_shapes.append(poly)
-        return clipped_shapes
diff --git a/setup.py b/setup.py
index b12a255..e3af502 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,6 @@ setup(name='masque',
       packages=find_packages(),
       install_requires=[
             'numpy',
-            'pyclipper',
       ],
       extras_require={
           'visualization': ['matplotlib'],