feat: 推进一级关系参数化编辑与参数导出

step_editor/polydata.py

@@ -69,6 +69,32 @@ def _polydata_id_key(values: Iterable[int] | None) -> tuple[int, ...] | None:
     return tuple(sorted({int(value) for value in values}))
 
 
+def _display_edge_samples(edge: TopoDS_Shape, deflection: float) -> list[tuple[float, float, float]]:
+    try:
+        curve = BRepAdaptor_Curve(edge)
+        curve_type = curve.GetType()
+        first = float(curve.FirstParameter())
+        last = float(curve.LastParameter())
+    except Exception:
+        return list(discretize_edge(edge, deflection))
+
+    if curve_type in {GeomAbs_Circle, GeomAbs_Ellipse} and math.isfinite(first) and math.isfinite(last):
+        span = abs(last - first)
+        if span > 1e-9:
+            min_segments = 24 if span >= math.tau * 0.75 else 8
+            segments = max(min_segments, int(math.ceil(span / math.radians(7.5))))
+            segments = min(max(segments, 2), 128)
+            samples: list[tuple[float, float, float]] = []
+            for index in range(segments + 1):
+                parameter = first + (last - first) * (index / segments)
+                point = curve.Value(parameter)
+                samples.append((float(point.X()), float(point.Y()), float(point.Z())))
+            if len(samples) >= 2:
+                return samples
+
+    return list(discretize_edge(edge, deflection))
+
+
 class PolydataMixin:
     def build_face_polydata(
         self,
@@ -272,7 +298,7 @@ class PolydataMixin:
                 continue
             if edge_id in hidden_edge_ids:
                 continue
-            samples = discretize_edge(edge, deflection)
+            samples = _display_edge_samples(edge, deflection)
             if len(samples) < 2:
                 continue
             polyline = vtk.vtkPolyLine()