增加了thread几何基础操作

backend/engine/cdsl_engine/build123d_adapter.py

@@ -7,7 +7,8 @@ from typing import Any, Iterable
 
 from build123d import Axis, Compound, Edge, Face, Helix, Location, Plane, ShapeList, Solid, Vector, Wire, export_step
 
-from .runtime_types import AxisSpec, HoleSpec, PlaneSpec, TopologyRecord, Vector3, canonical_plane_signature
+from .parametric_thread import build_thread_solid
+from .runtime_types import AxisSpec, HoleSpec, PlaneSpec, ThreadSpec, TopologyRecord, Vector3, canonical_plane_signature
 
 
 def _vector(value: list[float] | tuple[float, float, float]) -> Vector:
@@ -354,6 +355,26 @@ class Build123dGeometryAdapter:
             raise ValueError("hole has no positions")
         return result
 
+    @staticmethod
+    def thread_solid(spec: ThreadSpec) -> Any:
+        """Build a threaded solid segment anchored on ``spec.axis``.
+
+        The parametric generator constructs the thread in a local +Z frame
+        spanning ``[0, length_mm]``.  This gate rotates that frame so the
+        thread axis lands on ``spec.axis.direction`` with
+        ``spec.axis.origin_mm`` at the leading end face, keeping placement in
+        the adapter and geometry construction in ``parametric_thread.py``.
+        """
+        solid = build_thread_solid(spec)
+        direction = _vector(spec.axis.direction)
+        if abs(direction.X) <= 1e-9 and abs(direction.Y) <= 1e-9:
+            # 轴沿 ±Z：X 方向任意即可，螺纹起始相位绕轴无意义。
+            frame_x = Vector(1.0, 0.0, 0.0)
+        else:
+            frame_x = Vector(0.0, 0.0, 1.0).cross(direction).normalized()
+        plane = Plane(origin=_vector(spec.axis.origin_mm), x_dir=frame_x, z_dir=direction)
+        return solid.moved(Location(plane))
+
     @staticmethod
     def fillet(body: Any, radius_mm: float, edges: Iterable[Edge]) -> Any:
         # 对指定边以给定半径做圆角。