From 173c7b08e22f961265377b595c49fa9ca7920c3a Mon Sep 17 00:00:00 2001
From: x0pherl <xopher@interiority.org>
Date: Thu, 30 Oct 2025 21:08:26 -0400
Subject: [PATCH] added support for passing an iterable of radii to
 FilletPolyline.

---
 src/build123d/objects_curve.py | 22 +++++++++++++----
 tests/test_build_line.py       | 43 ++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/src/build123d/objects_curve.py b/src/build123d/objects_curve.py
index 262f9cf..6fbfbf6 100644
--- a/src/build123d/objects_curve.py
+++ b/src/build123d/objects_curve.py
@@ -793,7 +793,7 @@ class FilletPolyline(BaseLineObject):
 
     Args:
         pts (VectorLike | Iterable[VectorLike]): sequence of two or more points
-        radius (float): fillet radius
+        radius (float | Iterable[float]): radius to fillet at each vertex or a single value for all vertices
         close (bool, optional): close end points with extra Edge and corner fillets.
             Defaults to False
         mode (Mode, optional): combination mode. Defaults to Mode.ADD
@@ -808,7 +808,7 @@ class FilletPolyline(BaseLineObject):
     def __init__(
         self,
         *pts: VectorLike | Iterable[VectorLike],
-        radius: float,
+        radius: float | Iterable[float],
         close: bool = False,
         mode: Mode = Mode.ADD,
     ):
@@ -819,7 +819,16 @@ class FilletPolyline(BaseLineObject):
 
         if len(points) < 2:
             raise ValueError("FilletPolyline requires two or more pts")
-        if radius <= 0:
+
+        if isinstance(radius, (int, float)):
+            radius_list = [radius] * len(points)  # Single radius for all points
+        else:
+            radius_list = list(radius)
+            if len(radius_list) != len(points):
+                raise ValueError(
+                    f"radius list length ({len(radius_list)}) must match points ({len(points)})"
+                )
+        if any(r <= 0 for r in radius_list):
             raise ValueError("radius must be positive")
 
         lines_pts = WorkplaneList.localize(*points)
@@ -852,12 +861,14 @@ class FilletPolyline(BaseLineObject):
 
         # For each corner vertex create a new fillet Edge
         fillets = []
-        for vertex, edges in vertex_to_edges.items():
+        for i, (vertex, edges) in enumerate(vertex_to_edges.items()):
             if len(edges) != 2:
                 continue
             other_vertices = {ve for e in edges for ve in e.vertices() if ve != vertex}
             third_edge = Edge.make_line(*[v for v in other_vertices])
-            fillet_face = Face(Wire(edges + [third_edge])).fillet_2d(radius, [vertex])
+            fillet_face = Face(Wire(edges + [third_edge])).fillet_2d(
+                radius_list[i], [vertex]
+            )
             fillets.append(fillet_face.edges().filter_by(GeomType.CIRCLE)[0])
 
         # Create the Edges that join the fillets
@@ -1597,6 +1608,7 @@ class ArcArcTangentLine(BaseEdgeObject):
             Defaults to Keep.INSIDE
         mode (Mode, optional): combination mode. Defaults to Mode.ADD
     """
+
     warnings.warn(
         "The 'ArcArcTangentLine' object is deprecated and will be removed in a future version.",
         DeprecationWarning,
diff --git a/tests/test_build_line.py b/tests/test_build_line.py
index 01c2fbe..7b5858f 100644
--- a/tests/test_build_line.py
+++ b/tests/test_build_line.py
@@ -183,6 +183,49 @@ class BuildLineTests(unittest.TestCase):
         self.assertEqual(len(p.edges().filter_by(GeomType.CIRCLE)), 2)
         self.assertEqual(len(p.edges().filter_by(GeomType.LINE)), 3)
 
+        with self.assertRaises(ValueError):
+            p = FilletPolyline(
+                (0, 0),
+                (10, 0),
+                (10, 10),
+                (0, 10),
+                radius=(1, 2, 3, 0),
+                close=True,
+            )
+
+        with self.assertRaises(ValueError):
+            p = FilletPolyline(
+                (0, 0),
+                (10, 0),
+                (10, 10),
+                (0, 10),
+                radius=-1,
+                close=True,
+            )
+
+        with self.assertRaises(ValueError):
+            p = FilletPolyline(
+                (0, 0),
+                (10, 0),
+                (10, 10),
+                (0, 10),
+                radius=(1, 2),
+                close=True,
+            )
+
+        with BuildLine(Plane.YZ):
+            p = FilletPolyline(
+                (0, 0),
+                (10, 0),
+                (10, 10),
+                (0, 10),
+                radius=(1, 2, 3, 4),
+                close=True,
+            )
+        self.assertEqual(len(p.edges()), 8)
+        self.assertEqual(len(p.edges().filter_by(GeomType.CIRCLE)), 4)
+        self.assertEqual(len(p.edges().filter_by(GeomType.LINE)), 4)
+
         with BuildLine(Plane.YZ):
             p = FilletPolyline(
                 (0, 0, 0), (0, 0, 10), (10, 2, 10), (10, 0, 0), radius=2, close=True