Expose the option to sew shells from connected face sets

src/ifcgeom/IfcGeom.h

@@ -81,6 +81,7 @@ namespace IfcGeom {
 
 	const int DISABLE_OPENING_SUBTRACTIONS = 1 << 0;
 	const int DISABLE_OBJECT_PLACEMENT     = 1 << 1;
+	const int SEW_SHELLS                   = 1 << 2;
 	
 	bool convert_wire_to_face(const TopoDS_Wire& wire, TopoDS_Face& face);
 	bool convert_curve_to_wire(const Handle(Geom_Curve)& curve, TopoDS_Wire& wire);

src/ifcgeom/IfcGeomFunctions.cpp

@@ -692,8 +692,15 @@ bool IfcGeom::fill_nonmanifold_wires_with_planar_faces(TopoDS_Shape& shape) {
 std::string IfcGeom::create_brep_data(Ifc2x3::IfcProduct* ifc_product, unsigned int settings) {
 	const bool no_openings = !!(settings & DISABLE_OPENING_SUBTRACTIONS);
 	const bool no_placement = !!(settings & DISABLE_OBJECT_PLACEMENT);
+	const bool sew_shells = !!(settings & SEW_SHELLS);
 
-	if (!ifc_product->hasRepresentation()) return "";
+	const double old_max_faces_to_sew = GetValue(GV_MAX_FACES_TO_SEW);
+	const double inf = std::numeric_limits<double>::infinity();
+	SetValue(GV_MAX_FACES_TO_SEW, sew_shells ? inf : -inf);
+
+	std::string brep_data = "";
+
+	if (ifc_product->hasRepresentation()) {
 
 		Ifc2x3::IfcProductRepresentation* prod_rep = ifc_product->Representation();
 		Ifc2x3::IfcRepresentation::list li = prod_rep->Representations();
@@ -706,12 +713,10 @@ std::string IfcGeom::create_brep_data(Ifc2x3::IfcProduct* ifc_product, unsigned
 			}
 		}
 
-	if (!shape_rep) return "";
+		if (!!shape_rep) {
 
 			IfcGeom::IfcRepresentationShapeItems shapes;
-	if (!IfcGeom::convert_shapes(shape_rep,shapes)) {
+			if (IfcGeom::convert_shapes(shape_rep,shapes)) {
-		return "";
-	}
 		
 				gp_Trsf trsf;
 				try {
@@ -777,5 +782,12 @@ std::string IfcGeom::create_brep_data(Ifc2x3::IfcProduct* ifc_product, unsigned
 				}
 				std::stringstream sstream;
 				BRepTools::Write(compound,sstream);
-	return sstream.str();
+				brep_data = sstream.str();
+			}
+		}
+	}
+	
+	SetValue(GV_MAX_FACES_TO_SEW, old_max_faces_to_sew);
+	
+	return brep_data;
 }

src/ifcwrap/Interface.h

@@ -105,6 +105,7 @@ namespace IfcParse {
 
 	const int DISABLE_OPENING_SUBTRACTIONS = 1 << 0;
 	const int DISABLE_OBJECT_PLACEMENT     = 1 << 1;
+	const int SEW_SHELLS                   = 1 << 2;
 }
 
 std::ostream& operator<< (std::ostream& os, const IfcParse::IfcFile& f);