Moved edge/point ordering to make_constrained_arcs

src/build123d/topology/constrained_lines.py

@@ -264,11 +264,11 @@ def _make_2tan_rad_arcs(
     if isinstance(object_1, tuple):
         object_one, object_one_constraint = object_1
     else:
-        object_one, object_one_constraint = object_1, None
+        object_one, object_one_constraint = object_1, PositionConstraint.UNQUALIFIED
     if isinstance(object_2, tuple):
         object_two, object_two_constraint = object_2
     else:
-        object_two, object_two_constraint = object_2, None
+        object_two, object_two_constraint = object_2, PositionConstraint.UNQUALIFIED
 
     # ---------------------------
     # Build inputs and GCC
@@ -280,10 +280,6 @@ def _make_2tan_rad_arcs(
         object_two, object_two_constraint
     )
 
-    # Put the Edge arg first when exactly one is an Edge (improves robustness)
-    if is_edge1 ^ is_edge2:
-        q_o1, q_o2 = (q_o1, q_o2) if is_edge1 else (q_o2, q_o1)
-
     gcc = Geom2dGcc_Circ2d2TanRad(q_o1, q_o2, radius, TOLERANCE)
     if not gcc.IsDone() or gcc.NbSolutions() == 0:
         raise RuntimeError("Unable to find a tangent arc")
@@ -349,25 +345,18 @@ def _make_2tan_on_arcs(
 
     Notes
     -----
-    - `center_on` is treated as a **center locus** (not a tangency target). For a line
+    - `center_on` is treated as a **center locus** (not a tangency target).
-      locus this uses Geom2dGcc_Circ2d2TanOn; for other 2D curves it uses the *Geo variant*.
-    - A point is NOT a valid center locus for the 2TanOn solver; use the TanCen variant
-      (fixed center) for that case.
     """
 
-    # Unpack optional qualifiers on the two tangency args
-    object_one_constraint = PositionConstraint.UNQUALIFIED
-    object_two_constraint = PositionConstraint.UNQUALIFIED
-
     if isinstance(object_1, tuple):
         object_one, object_one_constraint = object_1
     else:
-        object_one = object_1
+        object_one, object_one_constraint = object_1, PositionConstraint.UNQUALIFIED
 
     if isinstance(object_2, tuple):
         object_two, object_two_constraint = object_2
     else:
-        object_two = object_2
+        object_two, object_two_constraint = object_2, PositionConstraint.UNQUALIFIED
 
     # ---------------------------
     # Build tangency inputs
@@ -379,17 +368,6 @@ def _make_2tan_on_arcs(
         object_two, object_two_constraint
     )
 
-    # Prefer "edge-first" ordering when exactly one arg is an Edge
-    if is_edge1 ^ is_edge2:
-        q_o1, q_o2 = (q_o1, q_o2) if is_edge1 else (q_o2, q_o1)
-        h_e1, h_e2 = (h_e1, h_e2) if is_edge1 else (h_e2, h_e1)
-        e1_first, e1_last, e2_first, e2_last = (
-            (e1_first, e1_last, e2_first, e2_last)
-            if is_edge1
-            else (e2_first, e2_last, e1_first, e1_last)
-        )
-        is_edge1, is_edge2 = (True, False) if is_edge1 else (False, True)
-
     # ---------------------------
     # Build center locus ("On") input
     # ---------------------------
@@ -404,7 +382,10 @@ def _make_2tan_on_arcs(
         guesses.append((e2_last - e2_first) / 2 + e2_first)
     guesses.append((on_last - on_first) / 2 + on_first)
 
-    gcc = Geom2dGcc_Circ2d2TanOn(q_o1, q_o2, adapt_on, TOLERANCE, *guesses)
+    if is_edge1 or is_edge2:
+        gcc = Geom2dGcc_Circ2d2TanOn(q_o1, q_o2, adapt_on, TOLERANCE, *guesses)
+    else:
+        gcc = Geom2dGcc_Circ2d2TanOn(q_o1, q_o2, adapt_on, TOLERANCE)
 
     if not gcc.IsDone() or gcc.NbSolutions() == 0:
         raise RuntimeError("Unable to find a tangent arc with center_on constraint")
@@ -510,10 +491,15 @@ def _make_3tan_arcs(
     q_o2, h_e2, e2_first, e2_last, is_edge2 = _as_gcc_arg(object_two, obj2_qual)
     q_o3, h_e3, e3_first, e3_last, is_edge3 = _as_gcc_arg(object_three, obj3_qual)
 
-    guesses = [
+    # Provide initial guess parameters for all of the lines
-        (l - f) / 2 + f
+    guesses = []
-        for f, l in [(e1_first, e1_last), (e2_first, e2_last), (e3_first, e3_last)]
+    if is_edge1:
-    ]
+        guesses.append((e1_last - e1_first) / 2 + e1_first)
+    if is_edge2:
+        guesses.append((e2_last - e2_first) / 2 + e2_first)
+    if is_edge3:
+        guesses.append((e3_last - e3_first) / 2 + e3_first)
+
     # For 3Tan we keep the user-given order so the arc endpoints remain (arg1,arg2)
     gcc = Geom2dGcc_Circ2d3Tan(q_o1, q_o2, q_o3, TOLERANCE, *guesses)
     if not gcc.IsDone() or gcc.NbSolutions() == 0:

src/build123d/topology/one_d.py

@@ -1588,8 +1588,8 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
     @classmethod
     def make_constrained_arcs(
         cls,
-        tangency_one: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_one: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
-        tangency_two: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_two: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
         *,
         radius: float,
         sagitta_constraint: LengthConstraint = LengthConstraint.SHORT,
@@ -1598,8 +1598,8 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
         Create all planar circular arcs of a given radius that are tangent/contacting
         the two provided objects on the XY plane.
         Args:
-            tangency_one (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_one (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
-            tangency_two (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_two (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
                 Geometric entities to be contacted/touched by the circle(s)
             radius (float): arc radius
             sagitta_constraint (LengthConstraint, optional): returned arc selector
@@ -1614,8 +1614,8 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
     @classmethod
     def make_constrained_arcs(
         cls,
-        tangency_one: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_one: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
-        tangency_two: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_two: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
         *,
         center_on: Edge,
         sagitta_constraint: LengthConstraint = LengthConstraint.SHORT,
@@ -1625,8 +1625,8 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
         CENTER lies on a given locus (line/circle/curve) on the XY plane.
 
         Args:
-            tangency_one (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_one (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
-            tangency_two (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_two (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
                 Geometric entities to be contacted/touched by the circle(s)
             center_on (Edge): center must lie on this edge
             sagitta_constraint (LengthConstraint, optional): returned arc selector
@@ -1641,9 +1641,9 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
     @classmethod
     def make_constrained_arcs(
         cls,
-        tangency_one: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_one: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
-        tangency_two: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_two: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
-        tangency_three: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_three: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
         *,
         sagitta_constraint: LengthConstraint = LengthConstraint.SHORT,
     ) -> ShapeList[Edge]:
@@ -1651,9 +1651,9 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
         Create planar circular arc(s) on XY tangent to three provided objects.
 
         Args:
-            tangency_one (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_one (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
-            tangency_two (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_two (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
-            tangency_three (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_three (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
                 Geometric entities to be contacted/touched by the circle(s)
             sagitta_constraint (LengthConstraint, optional): returned arc selector
                 (i.e. either the short, long or both arcs). Defaults to
@@ -1667,7 +1667,7 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
     @classmethod
     def make_constrained_arcs(
         cls,
-        tangency_one: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_one: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
         *,
         center: VectorLike,
     ) -> ShapeList[Edge]:
@@ -1677,7 +1677,7 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
         a single object.
 
         Args:
-            tangency_one (tuple[Edge, PositionConstraint] | Vertex | VectorLike):
+            tangency_one (tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike):
                 Geometric entity to be contacted/touched by the circle(s)
             center (VectorLike): center position
 
@@ -1689,7 +1689,7 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
     @classmethod
     def make_constrained_arcs(
         cls,
-        tangency_one: tuple[Edge, PositionConstraint] | Vertex | VectorLike,
+        tangency_one: tuple[Edge, PositionConstraint] | Edge | Vertex | VectorLike,
         *,
         radius: float,
         center_on: Edge,
@@ -1742,6 +1742,14 @@ class Edge(Mixin1D, Shape[TopoDS_Edge]):
         tangencies = [
             t for t in (tangency_one, tangency_two, tangency_three) if t is not None
         ]
+
+        # Sort the tangency inputs so points are always last
+        tangent_tuples = [t if isinstance(t, tuple) else (t, None) for t in tangencies]
+        tangent_tuples = sorted(
+            tangent_tuples, key=lambda t: not issubclass(type(t[0]), Edge)
+        )
+        tangencies = [t[0] if t[1] is None else t for t in tangent_tuples]
+
         tan_count = len(tangencies)
         if not (1 <= tan_count <= 3):
             raise TypeError("Provide 1 to 3 tangency targets.")