getting there, miter limit not working, and needs to be sifted

bluemira/geometry/_pyclipr_offset.py

@@ -15,7 +15,7 @@
 
 import numpy as np
 import numpy.typing as npt
-import pyclipr
+from pyclipr import ClipperOffset, EndType, JoinType
 
 from bluemira.base.look_and_feel import bluemira_warn
 from bluemira.geometry.coordinates import Coordinates, rotation_matrix_v1v2
@@ -86,25 +86,19 @@ def __init__(
         self._coordinates = coordinates
 
         # Create an offsetting object
-        pco = pyclipr.ClipperOffset()
+        pco = ClipperOffset()
 
-        pco.miterLimit = miter_limit
+        # pco.miterLimit = miter_limit
         # Set the scale factor to convert to internal integer representation
         pco.scaleFactor = 1000  # ?
 
         match method:
             case OffsetClipperMethodType.SQUARE:
-                pco.addPaths(
-                    [clipr_path], pyclipr.JoinType.Square, pyclipr.EndType.Polygon
-                )
+                pco.addPaths([clipr_path], JoinType.Square, EndType.Polygon)
             case OffsetClipperMethodType.ROUND:
-                pco.addPaths(
-                    [clipr_path], pyclipr.JoinType.Round, pyclipr.EndType.Polygon
-                )
+                pco.addPaths([clipr_path], JoinType.Round, EndType.Polygon)
             case OffsetClipperMethodType.MITER:
-                pco.addPaths(
-                    [clipr_path], pyclipr.JoinType.Miter, pyclipr.EndType.Polygon
-                )
+                pco.addPaths([clipr_path], JoinType.Miter, EndType.Polygon)
         self._pco = pco
 
     @staticmethod
@@ -123,24 +117,34 @@ def _calculate_scale(path: np.ndarray, coordinates: Coordinates) -> float:
             "Path is empty or only (0, 0)'s."
         )
 
-    def _transform_offset_result(
-        self, result: list[npt.NDArray[np.float64]]
-    ) -> list[Coordinates]:
+    def _transform_offset_result(self, result: npt.NDArray[np.float64]) -> Coordinates:
         """
         Transforms the offset solution into a Coordinates object
         """
-        if not result:
+        if len(result) == 0 or np.all(result == 0):
             raise GeometryError("Offset operation resulted in no geometry.")
 
         com = self._coordinates.center_of_mass
         norm_v = self._coordinates.normal_vector
 
-        res_coords_t = [pyclippath_to_coordinates(p) for p in result]
-        return [transform_coordinates_to_original(c, com, norm_v) for c in res_coords_t]
+        x, z = result.T
 
-    def perform(self, delta: float) -> list[Coordinates]:
+        res_coords_t = Coordinates({"x": x, "y": np.zeros(x.shape), "z": z})
+        return transform_coordinates_to_original(res_coords_t, com, norm_v)
+
+    def perform(self, delta: float) -> Coordinates:
         delta = int(round(delta * self._coord_scale))
         offset_result = self._pco.execute(delta)
+        if len(offset_result) == 1:
+            offset_result = offset_result[0]
+        elif len(offset_result) > 1:
+            bluemira_warn(
+                f"Offset operation with delta={delta} has produced multiple 'islands';"
+                " using the biggest one!"
+            )
+            offset_result = max(offset_result, key=len)
+        else:
+            raise GeometryError("Offset operation failed to produce any geometry.")
         return self._transform_offset_result(offset_result)
 
 
@@ -179,14 +183,7 @@ def offset_clipper(
     """
     tool = PyCliprOffsetter(coordinates, OffsetClipperMethodType(method), miter_limit)
     result = tool.perform(delta)
-
-    if len(result) > 1:
-        bluemira_warn(
-            f"Offset operation with delta={delta} has produced multiple 'islands'; only"
-            " returning the biggest one!"
-        )
-
-    return result[0]
+    return result
 
 
 def transform_coordinates_to_xz(

conftest.py

@@ -9,11 +9,8 @@
 """
 
 import os
-from contextlib import suppress
 from pathlib import Path
-from unittest import mock
 
-import matplotlib as mpl
 import pytest
 
 from bluemira.base.file import get_bluemira_path, try_get_bluemira_private_data_root
@@ -57,14 +54,14 @@ def pytest_configure(config):
     """
     Configures pytest with the plotting and longrun command line options.
     """
-    if not config.getoption("--plotting-on"):
-        # We're not displaying plots so use a display-less backend
-        mpl.use("Agg")
-        # Disable CAD viewer by mocking out FreeCAD API's displayer.
-        # Note that if we use a new CAD backend, this must be changed.
-        with suppress(ImportError):
-            mock.patch("bluemira.codes._polyscope.ps").start()
-        mock.patch("bluemira.codes._freecadapi.show_cad").start()
+    # if not config.getoption("--plotting-on"):
+    #     # We're not displaying plots so use a display-less backend
+    #     mpl.use("Agg")
+    #     # Disable CAD viewer by mocking out FreeCAD API's displayer.
+    #     # Note that if we use a new CAD backend, this must be changed.
+    #     with suppress(ImportError):
+    #         mock.patch("bluemira.codes._polyscope.ps").start()
+    #     mock.patch("bluemira.codes._freecadapi.show_cad").start()
 
     options = {
         "longrun": config.option.longrun,

tests/geometry/test_pyclipper_offset.py

@@ -12,7 +12,8 @@
 import pytest
 
 from bluemira.base.file import get_bluemira_path
-from bluemira.geometry._pyclipr_offset import offset_clipper
+from bluemira.geometry._pyclipper_offset import offset_clipper
+from bluemira.geometry._pyclipr_offset import offset_clipper as offset_clipper2
 from bluemira.geometry.coordinates import Coordinates
 from bluemira.geometry.error import GeometryError
 from bluemira.geometry.tools import distance_to, make_polygon
@@ -63,7 +64,7 @@ def test_blanket_offset(self):
         coordinates = Coordinates(data)
         offsets = []
         for m in ["miter", "square", "round"]:  # round very slow...
-            offset_coordinates = offset_clipper(coordinates, 1.5, method=m)
+            offset_coordinates = offset_clipper2(coordinates, 1.5, method=m)
             offsets.append(offset_coordinates)
             # Too damn slow!!
             # distance = self._calculate_offset(coordinates, offset_coordinates)