Added new Edge.trim_to_length feature

src/build123d/topology.py

@@ -161,6 +161,7 @@
     Geom_TrimmedCurve,
     Geom_Line,
 )
+from OCP.GeomAdaptor import GeomAdaptor_Curve
 from OCP.Geom2d import Geom2d_Curve, Geom2d_Line, Geom2d_TrimmedCurve
 from OCP.Geom2dAPI import Geom2dAPI_InterCurveCurve
 from OCP.GeomAbs import GeomAbs_C0, GeomAbs_Intersection, GeomAbs_JoinType
@@ -558,7 +559,8 @@ def common_plane(self, *lines: Union[Edge, Wire]) -> Union[None, Plane]:
             Union[None, Plane]: Either the common plane or None
         """
         # pylint: disable=too-many-locals
-        # BRepLib_FindSurface could help here
+        # Note: BRepLib_FindSurface is not helpful as it requires the
+        # Edges to form a surface perimeter.
         points: list[Vector] = []
         all_lines: list[Edge, Wire] = [
             line for line in [self, *lines] if line is not None
@@ -4621,6 +4623,39 @@ def trim(self, start: float, end: float) -> Edge:
         new_edge = BRepBuilderAPI_MakeEdge(trimmed_curve).Edge()
         return Edge(new_edge)
 
+    def trim_to_length(self, start: float, length: float) -> Edge:
+        """trim_to_length
+
+        Create a new edge starting at the given normalized parameter of a
+        given length.
+
+        Args:
+            start (float): 0.0 <= start < 1.0
+            length (float): target length
+
+        Returns:
+            Edge: trimmed edge
+        """
+        new_curve = BRep_Tool.Curve_s(
+            copy.deepcopy(self).wrapped, self.param_at(0), self.param_at(1)
+        )
+
+        # Create an adaptor for the curve
+        adaptor_curve = GeomAdaptor_Curve(new_curve)
+
+        # Find the parameter corresponding to the desired length
+        parm_start = self.param_at(start)
+        abscissa_point = GCPnts_AbscissaPoint(adaptor_curve, length, parm_start)
+
+        # Get the parameter at the desired length
+        parm_end = abscissa_point.Parameter()
+
+        # Trim the curve to the desired length
+        trimmed_curve = Geom_TrimmedCurve(new_curve, parm_start, parm_end)
+
+        new_edge = BRepBuilderAPI_MakeEdge(trimmed_curve).Edge()
+        return Edge(new_edge)
+
     def param_at_point(self, point: VectorLike) -> float:
         """Parameter at point of Edge"""
 

tests/test_direct_api.py

@@ -944,6 +944,29 @@ def test_trim(self):
         with self.assertRaises(ValueError):
             line.trim(0.75, 0.25)
 
+    def test_trim_to_length(self):
+
+        e1 = Edge.make_line((0, 0), (10, 10))
+        e1_trim = e1.trim_to_length(0.0, 10)
+        self.assertAlmostEqual(e1_trim.length, 10, 5)
+
+        e2 = Edge.make_circle(10, start_angle=0, end_angle=90)
+        e2_trim = e2.trim_to_length(0.5, 1)
+        self.assertAlmostEqual(e2_trim.length, 1, 5)
+        self.assertVectorAlmostEquals(
+            e2_trim.position_at(0), Vector(10, 0, 0).rotate(Axis.Z, 45), 5
+        )
+
+        e3 = Edge.make_spline(
+            [(0, 10, 0), (-4, 5, 2), (0, 0, 0)], tangents=[(-1, 0), (1, 0)]
+        )
+        e3_trim = e3.trim_to_length(0, 7)
+        self.assertAlmostEqual(e3_trim.length, 7, 5)
+
+        a4 = Axis((0, 0, 0), (1, 1, 1))
+        e4_trim = a4.as_infinite_edge().trim_to_length(0.5, 2)
+        self.assertAlmostEqual(e4_trim.length, 2, 5)
+
     def test_bezier(self):
         with self.assertRaises(ValueError):
             Edge.make_bezier((1, 1))