#816 Use more than one cycle of self intersections in IfcArbitraryClosedProfileDef

src/ifcgeom/IfcGeom.h

@@ -289,6 +289,7 @@ public:
 	void set_rotation(const std::array<double, 4>& rotation);
 
 	bool convert_wire_to_face(const TopoDS_Wire& wire, TopoDS_Face& face);
+	bool convert_wire_to_faces(const TopoDS_Wire& wire, TopoDS_Compound& face);
 	bool convert_curve_to_wire(const Handle(Geom_Curve)& curve, TopoDS_Wire& wire);
 	bool convert_shapes(const IfcUtil::IfcBaseClass* L, IfcRepresentationShapeItems& result);
 	IfcGeom::ShapeType shape_type(const IfcUtil::IfcBaseClass* L);

src/ifcgeom/IfcGeomFaces.cpp

@@ -447,8 +447,8 @@ bool IfcGeom::Kernel::convert(const IfcSchema::IfcArbitraryClosedProfileDef* l,
 
 	assert_closed_wire(wire);
 
-	TopoDS_Face f;
-	bool success = convert_wire_to_face(wire, f);
+	TopoDS_Compound f;
+	bool success = convert_wire_to_faces(wire, f);
 	if (success) {
 		face = f;
 	}

src/ifcgeom/IfcGeomFunctions.cpp

@@ -1139,6 +1139,76 @@ bool IfcGeom::Kernel::convert_wire_to_face(const TopoDS_Wire& w, TopoDS_Face& fa
 	return true;
 }
 
+bool IfcGeom::Kernel::convert_wire_to_faces(const TopoDS_Wire& w, TopoDS_Compound& faces) {
+	bool is_2d = true;
+	TopExp_Explorer exp(w, TopAbs_EDGE);
+	for (; exp.More(); exp.Next()) {
+		double a, b;
+		Handle(Geom_Curve) crv = BRep_Tool::Curve(TopoDS::Edge(exp.Current()), a, b);
+		if (crv->DynamicType() != STANDARD_TYPE(Geom_Line)) {
+			is_2d = false;
+			break;
+		}
+		Handle(Geom_Line) line = Handle(Geom_Line)::DownCast(crv);
+		if (line->Lin().Direction().Z() > ALMOST_ZERO) {
+			is_2d = false;
+			break;
+		}
+	}
+
+	TopTools_ListOfShape results;
+	if (wire_intersections(w, results)) {
+		Logger::Warning("Self-intersections with " + boost::lexical_cast<std::string>(results.Extent()) + " cycles detected");
+	} else {
+		results.Clear();
+		results.Append(w);
+	}
+
+	TopoDS_Compound C;
+	BRep_Builder B;
+	B.MakeCompound(faces);
+
+	std::list<std::pair<double, TopoDS_Face>> face_list;
+	double max_area = 0.;
+
+	TopTools_ListIteratorOfListOfShape it(results);
+	for (; it.More(); it.Next()) {
+		const TopoDS_Wire& wire = TopoDS::Wire(it.Value());
+		if (!is_2d) {
+			// For 2d wires (e.g. profiles) a higher tolerance for plane fitting is never required.
+			ShapeFix_ShapeTolerance FTol;
+			FTol.SetTolerance(wire, getValue(GV_PRECISION), TopAbs_WIRE);
+		}
+
+		BRepBuilderAPI_MakeFace mf(wire, false);
+		BRepBuilderAPI_FaceError er = mf.Error();
+
+		if (er != BRepBuilderAPI_FaceDone) {
+			Logger::Error("Failed to create face.");
+			continue;
+		}
+
+		TopoDS_Face face = mf.Face();
+		const double m = face_area(face);
+
+		face_list.push_back({ m, face });
+		if (m > max_area) {
+			max_area = m;
+		}
+	}
+
+	for (auto& p : face_list) {
+		if (p.first >= max_area / 10.) {
+			B.Add(faces, p.second);
+		} else {
+			Logger::Warning("Ignoring self-intersection loop with area " + boost::lexical_cast<std::string>(p.first));
+		}
+	}
+
+	return true;
+}
+
+
 void IfcGeom::Kernel::assert_closed_wire(TopoDS_Wire& wire) {
 	if (wire.Closed() == 0) {
 		TopoDS_Vertex v0, v1;