Streamline topology exploration

src/build123d/exporters.py

@@ -66,8 +66,10 @@
     Edge,
     Wire,
     Shape,
+    downcast,
 )
 from build123d.build_common import UNITS_PER_METER
+from build123d.topology.shape_core import _topods_entities
 
 PathSegment: TypeAlias = PT.Line | PT.Arc | PT.QuadraticBezier | PT.CubicBezier
 """A type alias for the various path segment types in the svgpathtools library."""
@@ -1150,13 +1152,15 @@ def _add_single_shape(self, shape: Shape, layer: _Layer, reverse_wires: bool):
     def _wire_edges(wire: Wire, reverse: bool) -> list[Edge]:
         # Note that BRepTools_WireExplorer can return edges in a different order
         # than the standard edges() method.
-        edges = []
-        explorer = BRepTools_WireExplorer(wire.wrapped)
-        while explorer.More():
-            topo_edge = explorer.Current()
-            edges.append(Edge(topo_edge))
-            explorer.Next()
-        # edges = wire.edges()
+
+        # edges = []
+        # explorer = BRepTools_WireExplorer(wire.wrapped)
+        # while explorer.More():
+        #     topo_edge = explorer.Current()
+        #     edges.append(Edge(topo_edge))
+        #     explorer.Next()
+
+        edges = [Edge(downcast(i)) for i in _topods_entities(wire.wrapped, "Edge")]
         if reverse:
             edges.reverse()
         return edges

src/build123d/exporters3d.py

@@ -65,6 +65,7 @@
 from build123d.build_enums import PrecisionMode, Unit
 from build123d.geometry import Location
 from build123d.topology import Compound, Curve, Part, Shape, Sketch
+from build123d.topology.shape_core import _topods_entities
 
 
 def _create_xde(to_export: Shape, unit: Unit = Unit.MM) -> TDocStd_Document:
@@ -122,20 +123,22 @@ def _create_xde(to_export: Shape, unit: Unit = Unit.MM) -> TDocStd_Document:
         # object not just the Compound wrapper
         sub_node_labels = []
         if isinstance(node, Compound) and not node.children:
-            sub_nodes = []
+
             if isinstance(node, Part):
-                explorer = TopExp_Explorer(node.wrapped, ta.TopAbs_SOLID)
+                sub_nodes = _topods_entities(node.wrapped, "Solid")
             elif isinstance(node, Sketch):
-                explorer = TopExp_Explorer(node.wrapped, ta.TopAbs_FACE)
+                sub_nodes = _topods_entities(node.wrapped, "Face")
             elif isinstance(node, Curve):
-                explorer = TopExp_Explorer(node.wrapped, ta.TopAbs_EDGE)
+                sub_nodes = _topods_entities(node.wrapped, "Edge")
             else:
                 warnings.warn("Unknown Compound type, color not set", stacklevel=2)
-                explorer = TopExp_Explorer()  # don't know what to look for
+                # TODO: extend Shape._topods_entities to be capable of enumerating all types
 
-            while explorer.More():
-                sub_nodes.append(explorer.Current())
-                explorer.Next()
+                sub_nodes = []
+                explorer = TopExp_Explorer()  # don't know what to look for
+                while explorer.More():
+                    sub_nodes.append(explorer.Current())
+                    explorer.Next()
 
             sub_node_labels = [
                 shape_tool.FindShape(sub_node, findInstance=False)

src/build123d/mesher.py

@@ -106,14 +106,14 @@
 from OCP.gp import gp_Pnt
 from OCP.GProp import GProp_GProps
 from OCP.TopAbs import TopAbs_ShapeEnum
-from OCP.TopExp import TopExp_Explorer
 from OCP.TopLoc import TopLoc_Location
 from OCP.TopoDS import TopoDS_Compound
 from lib3mf import Lib3MF
 
 from build123d.build_enums import MeshType, Unit
 from build123d.geometry import TOLERANCE, Color
 from build123d.topology import Compound, Shape, Shell, Solid, downcast
+from build123d.topology.shape_core import _topods_entities
 
 
 class Mesher:
@@ -312,42 +312,43 @@ def _create_3mf_mesh(
         # Round off the vertices to avoid vertices within tolerance being
         # considered as different vertices
         digits = -int(round(math.log(TOLERANCE, 10), 1))
-        
+
         # Create vertex to index mapping directly
         vertex_to_idx = {}
         next_idx = 0
         vert_table = {}
-        
+
         # First pass - create mapping
         for i, (x, y, z) in enumerate(ocp_mesh_vertices):
             key = (round(x, digits), round(y, digits), round(z, digits))
             if key not in vertex_to_idx:
                 vertex_to_idx[key] = next_idx
                 next_idx += 1
             vert_table[i] = vertex_to_idx[key]
-        
+
         # Create vertices array in one shot
         vertices_3mf = [
-            Lib3MF.Position((ctypes.c_float * 3)(*v))
-            for v in vertex_to_idx.keys()
+            Lib3MF.Position((ctypes.c_float * 3)(*v)) for v in vertex_to_idx.keys()
         ]
-        
+
         # Pre-allocate triangles array and process in bulk
         c_uint3 = ctypes.c_uint * 3
         triangles_3mf = []
-        
+
         # Process triangles in bulk
         for tri in triangles:
             # Map indices directly without list comprehension
             a, b, c = tri[0], tri[1], tri[2]
             mapped_a = vert_table[a]
             mapped_b = vert_table[b]
             mapped_c = vert_table[c]
-            
+
             # Quick degenerate check without set creation
             if mapped_a != mapped_b and mapped_b != mapped_c and mapped_c != mapped_a:
-                triangles_3mf.append(Lib3MF.Triangle(c_uint3(mapped_a, mapped_b, mapped_c)))
-
+                triangles_3mf.append(
+                    Lib3MF.Triangle(c_uint3(mapped_a, mapped_b, mapped_c))
+                )
+
         return (vertices_3mf, triangles_3mf)
 
     def _add_color(self, b3d_shape: Shape, mesh_3mf: Lib3MF.MeshObject):
@@ -477,11 +478,9 @@ def _get_shape(self, mesh_3mf: Lib3MF.MeshObject) -> Shape:
         occ_sewed_shape = downcast(shell_builder.SewedShape())
 
         if isinstance(occ_sewed_shape, TopoDS_Compound):
-            occ_shells = []
-            explorer = TopExp_Explorer(occ_sewed_shape, TopAbs_ShapeEnum.TopAbs_SHELL)
-            while explorer.More():
-                occ_shells.append(downcast(explorer.Current()))
-                explorer.Next()
+            occ_shells = [
+                downcast(i) for i in _topods_entities(occ_sewed_shape, "Shell")
+            ]
         else:
             occ_shells = [occ_sewed_shape]
 

src/build123d/topology/one_d.py

@@ -199,6 +199,8 @@
     shapetype,
     topods_dim,
     unwrap_topods_compound,
+    _topods_entities,
+    _topods_entities_nodict_downcast,
 )
 from .utils import (
     _extrude_topods_shape,
@@ -936,19 +938,8 @@ def project_to_viewport(
             tuple[ShapeList[Edge],ShapeList[Edge]]: visible & hidden Edges
         """
 
-        def extract_edges(compound):
-            edges = []  # List to store the extracted edges
-
-            # Create a TopExp_Explorer to traverse the sub-shapes of the compound
-            explorer = TopExp_Explorer(compound, TopAbs_ShapeEnum.TopAbs_EDGE)
-
-            # Loop through the sub-shapes and extract edges
-            while explorer.More():
-                edge = downcast(explorer.Current())
-                edges.append(edge)
-                explorer.Next()
-
-            return edges
+        def extract_edges(compound) -> list[TopoDS_Edge]:
+            return [downcast(i) for i in _topods_entities(compound, "Edge")]
 
         # Setup the projector
         hidden_line_removal = HLRBRep_Algo()
@@ -3257,6 +3248,7 @@ def topo_explore_connected_edges(
         common_topods_vertex: Vertex | None = topo_explore_common_vertex(
             given_topods_edge, topods_edge
         )
+
         if common_topods_vertex is not None:
             # shared_vertex is the TopoDS_Vertex common to edge1 and edge2
             u1 = BRep_Tool.Parameter_s(common_topods_vertex.wrapped, given_topods_edge)

src/build123d/topology/shape_core.py

@@ -114,6 +114,12 @@
 from OCP.TopAbs import TopAbs_Orientation, TopAbs_ShapeEnum
 from OCP.TopExp import TopExp, TopExp_Explorer
 from OCP.TopLoc import TopLoc_Location
+from OCP.TopTools import (
+    TopTools_IndexedDataMapOfShapeListOfShape,
+    TopTools_IndexedMapOfShape,
+    TopTools_ListOfShape,
+    TopTools_SequenceOfShape,
+)
 from OCP.TopoDS import (
     TopoDS,
     TopoDS_Compound,
@@ -126,11 +132,6 @@
     TopoDS_Vertex,
     TopoDS_Wire,
 )
-from OCP.TopTools import (
-    TopTools_IndexedDataMapOfShapeListOfShape,
-    TopTools_ListOfShape,
-    TopTools_SequenceOfShape,
-)
 from typing_extensions import Self
 
 from build123d.build_enums import CenterOf, GeomType, Keep, SortBy, Transition
@@ -208,7 +209,7 @@ class Shape(NodeMixin, Generic[TOPODS]):
 
     inverse_shape_LUT = {v: k for k, v in shape_LUT.items()}
 
-    downcast_LUT = {
+    downcast_LUT: [ta.TopAbs_SHAPE, TopoDS_Shape] = {
         ta.TopAbs_VERTEX: TopoDS.Vertex_s,
         ta.TopAbs_EDGE: TopoDS.Edge_s,
         ta.TopAbs_WIRE: TopoDS.Wire_s,
@@ -797,7 +798,12 @@ def get_shape_list(
         if shape.wrapped is None:
             return ShapeList()
         shape_list = ShapeList(
-            [shape.__class__.cast(i) for i in shape.entities(entity_type)]
+            [
+                shape.__class__.cast(i)
+                for i in _topods_entities_nodict_downcast(
+                    shape.wrapped, Shape.inverse_shape_LUT[entity_type]
+                )
+            ]
         )
         for item in shape_list:
             item.topo_parent = shape if shape.topo_parent is None else shape.topo_parent
@@ -2195,17 +2201,14 @@ def _ocp_section(
         # Get the resulting shapes from the intersection
         intersection_shape: TopoDS_Shape = section.Shape()
 
-        vertices: list[Vertex] = []
-        # Iterate through the intersection shape to find intersection points/edges
-        explorer = TopExp_Explorer(intersection_shape, TopAbs_ShapeEnum.TopAbs_VERTEX)
-        while explorer.More():
-            vertices.append(self.__class__.cast(downcast(explorer.Current())))
-            explorer.Next()
-        edges: ShapeList[Edge] = ShapeList()
-        explorer = TopExp_Explorer(intersection_shape, TopAbs_ShapeEnum.TopAbs_EDGE)
-        while explorer.More():
-            edges.append(self.__class__.cast(downcast(explorer.Current())))
-            explorer.Next()
+        vertices = [
+            self.__class__.cast(downcast(i))
+            for i in _topods_entities(intersection_shape, "Vertex")
+        ]
+        edges = [
+            self.__class__.cast(downcast(i))
+            for i in _topods_entities(intersection_shape, "Edge")
+        ]
 
         return (ShapeList(set(vertices)), edges)
 
@@ -2970,18 +2973,53 @@ def _sew_topods_faces(faces: Iterable[TopoDS_Face]) -> TopoDS_Shape:
     return downcast(shell_builder.SewedShape())
 
 
+def _topods_entities_nodict(shape: TopoDS_Shape, topo_type: ta) -> list[TopoDS_Shape]:
+    """Return the TopoDS_Shapes of topo_type from this TopoDS_Shape"""
+    shape_set = TopTools_IndexedMapOfShape()
+    TopExp.MapShapes_s(shape, topo_type, shape_set)
+    return [shape_set.FindKey(i) for i in range(1, shape_set.Size() + 1)]
+
+
+def _topods_entities_nodict_downcast(
+    shape: TopoDS_Shape, topo_type: ta
+) -> ShapeList[TopoDS_Shape]:
+    """Return the TopoDS_Shapes of topo_type from this TopoDS_Shape"""
+    shape_set = TopTools_IndexedMapOfShape()
+    TopExp.MapShapes_s(shape, topo_type, shape_set)
+    return [downcast(shape_set.FindKey(i)) for i in range(1, shape_set.Size() + 1)]
+
+
 def _topods_entities(shape: TopoDS_Shape, topo_type: Shapes) -> list[TopoDS_Shape]:
     """Return the TopoDS_Shapes of topo_type from this TopoDS_Shape"""
-    out = {}  # using dict to prevent duplicates
+    shape_set = TopTools_IndexedMapOfShape()
+    TopExp.MapShapes_s(shape, Shape.inverse_shape_LUT[topo_type], shape_set)
+    return [shape_set.FindKey(i) for i in range(1, shape_set.Size() + 1)]
+
+
+def _topods_entities_downcast(
+    shape: TopoDS_Shape, topo_type: Shapes
+) -> list[TopoDS_Shape]:
+    """Return the specialized type TopoDS_Shapes of topo_type from this TopoDS_Shape"""
+    shape_set = TopTools_IndexedMapOfShape()
+    TopExp.MapShapes_s(shape, Shape.inverse_shape_LUT[topo_type], shape_set)
+    return [downcast(shape_set.FindKey(i)) for i in range(1, shape_set.Size() + 1)]
+
 
-    explorer = TopExp_Explorer(shape, Shape.inverse_shape_LUT[topo_type])
+def _topods_entities_downcast_generator(
+    shape: TopoDS_Shape, topo_type: Shapes
+) -> list[Shape]:
+    """Return the TopoDS_Shapes of topo_type from this TopoDS_Shape"""
+    shape_set = TopTools_IndexedMapOfShape()
+    TopExp.MapShapes_s(shape, Shape.inverse_shape_LUT[topo_type], shape_set)
+    yield from (downcast(shape_set.FindKey(i)) for i in range(1, shape_set.Size() + 1))
 
-    while explorer.More():
-        item = explorer.Current()
-        out[hash(item)] = item  # needed to avoid pseudo-duplicate entities
-        explorer.Next()
+    # for i in range(1, shape_set.Size() + 1):
+    # yield downcast(shape_set.FindKey(i))
 
-    return list(out.values())
+    # return [
+    #     Shape.__class__.cast(downcast(shape_set.FindKey(i)))
+    #     for i in range(1, shape_set.Size() + 1)
+    # ]
 
 
 def _topods_face_normal_at(face: TopoDS_Face, surface_point: gp_Pnt) -> Vector:
@@ -3009,7 +3047,7 @@ def downcast(obj: TopoDS_Shape) -> TopoDS_Shape:
 
     """
 
-    f_downcast: Any = Shape.downcast_LUT[shapetype(obj)]
+    f_downcast: TopoDS_Shape = Shape.downcast_LUT[shapetype(obj)]
     return_value = f_downcast(obj)
 
     return return_value

src/build123d/topology/utils.py

@@ -70,7 +70,6 @@
 from OCP.BRepPrimAPI import BRepPrimAPI_MakePrism
 from OCP.ShapeFix import ShapeFix_Face, ShapeFix_Shape
 from OCP.TopAbs import TopAbs_ShapeEnum
-from OCP.TopExp import TopExp_Explorer
 from OCP.TopTools import TopTools_ListOfShape
 from OCP.TopoDS import (
     TopoDS,
@@ -85,7 +84,14 @@
 )
 from build123d.geometry import TOLERANCE, BoundBox, Vector, VectorLike
 
-from .shape_core import Shape, ShapeList, downcast, shapetype, unwrap_topods_compound
+from .shape_core import (
+    Shape,
+    ShapeList,
+    downcast,
+    shapetype,
+    unwrap_topods_compound,
+    _topods_entities,
+)
 
 
 if TYPE_CHECKING:  # pragma: no cover
@@ -125,11 +131,7 @@ def _extrude_topods_shape(obj: TopoDS_Shape, direction: VectorLike) -> TopoDS_Sh
     extrusion = downcast(prism_builder.Shape())
     shape_type = extrusion.ShapeType()
     if shape_type == TopAbs_ShapeEnum.TopAbs_COMPSOLID:
-        solids = []
-        explorer = TopExp_Explorer(extrusion, TopAbs_ShapeEnum.TopAbs_SOLID)
-        while explorer.More():
-            solids.append(downcast(explorer.Current()))
-            explorer.Next()
+        solids = [downcast(i) for i in _topods_entities(extrusion, "Solid")]
         extrusion = _make_topods_compound_from_shapes(solids)
     return extrusion
 
@@ -390,13 +392,12 @@ def new_edges(*objects: Shape, combined: Shape) -> ShapeList[Edge]:
     operation.SetRunParallel(True)
     operation.Build()
 
-    edges = []
-    explorer = TopExp_Explorer(operation.Shape(), TopAbs_ShapeEnum.TopAbs_EDGE)
-    while explorer.More():
-        found_edge = combined.__class__.cast(downcast(explorer.Current()))
-        found_edge.topo_parent = combined
-        edges.append(found_edge)
-        explorer.Next()
+    edges = [
+        combined.__class__.cast(downcast(i))
+        for i in _topods_entities(operation.Shape(), "Edge")
+    ]
+    for edge in edges:
+        edge.topo_parent = combined
 
     return ShapeList(edges)