Store actual subentities in CgalShape instead of the strange degeneracies convention

src/ifcgeom/kernels/cgal/CgalConversionResult.cpp

@@ -30,6 +30,140 @@ typedef Polyhedron::Facet_const_handle Facet_const_handle;
 typedef Polyhedron::Halfedge_around_facet_const_circulator Halfedge_around_facet_circulator;
 
 namespace {
+	cgal_placement_t make_transform(const ifcopenshell::geometry::taxonomy::matrix4& place) {
+		const auto& m = place.ccomponents();
+		return cgal_placement_t(
+			m(0, 0), m(0, 1), m(0, 2), m(0, 3),
+			m(1, 0), m(1, 1), m(1, 2), m(1, 3),
+			m(2, 0), m(2, 1), m(2, 2), m(2, 3));
+	}
+
+	OpaqueCoordinate<3> opaque_point(const cgal_point_t& p) {
+		return OpaqueCoordinate<3>(
+			new NumberType(p.cartesian(0)),
+			new NumberType(p.cartesian(1)),
+			new NumberType(p.cartesian(2))
+		);
+	}
+
+	typename Kernel_::FT max_abs3(const typename Kernel_::FT& a, const typename Kernel_::FT& b, const typename Kernel_::FT& c) {
+		std::array<typename Kernel_::FT, 3> abc{ a, b, c };
+		auto minel = std::min_element(abc.begin(), abc.end());
+		auto maxel = std::max_element(abc.begin(), abc.end());
+		return ((-*minel) > *maxel) ? (-*minel) : *maxel;
+	}
+
+	OpaqueCoordinate<3> opaque_axis(const cgal_vector_t& v) {
+		auto maxval = max_abs3(v.x(), v.y(), v.z());
+		if (maxval == 0) {
+			throw std::runtime_error("Invalid shape type");
+		}
+		return OpaqueCoordinate<3>(
+			new NumberType(v.x() / maxval),
+			new NumberType(v.y() / maxval),
+			new NumberType(v.z() / maxval)
+		);
+	}
+
+	OpaqueCoordinate<4> opaque_plane(const cgal_plane_t& p) {
+		auto maxval = max_abs3(p.a(), p.b(), p.c());
+		if (maxval == 0) {
+			throw std::runtime_error("Invalid shape type");
+		}
+		return OpaqueCoordinate<4>(
+			new NumberType(p.a() / maxval),
+			new NumberType(p.b() / maxval),
+			new NumberType(p.c() / maxval),
+			new NumberType(p.d() / maxval)
+		);
+	}
+
+	cgal_vector_t wire_normal(const cgal_wire_t& wire) {
+		typename Kernel_::FT a(0), b(0), c(0);
+		if (wire.size() < 3) {
+			return cgal_vector_t(a, b, c);
+		}
+		for (std::size_t i = 0; i < wire.size(); ++i) {
+			const auto& curr = wire[i];
+			const auto& next = wire[(i + 1) % wire.size()];
+			a += (curr.y() - next.y()) * (curr.z() + next.z());
+			b += (curr.z() - next.z()) * (curr.x() + next.x());
+			c += (curr.x() - next.x()) * (curr.y() + next.y());
+		}
+		return cgal_vector_t(a, b, c);
+	}
+
+	cgal_point_t wire_centroid(const cgal_wire_t& wire) {
+		if (wire.empty()) {
+			throw std::runtime_error("Invalid shape type");
+		}
+		std::array<Kernel_::FT, 3> p{ Kernel_::FT(0), Kernel_::FT(0), Kernel_::FT(0) };
+		for (const auto& point : wire) {
+			for (int i = 0; i < 3; ++i) {
+				p[i] += point.cartesian(i);
+			}
+		}
+		Kernel_::FT n(wire.size());
+		return cgal_point_t(p[0] / n, p[1] / n, p[2] / n);
+	}
+
+	Kernel_::FT wire_length(const cgal_wire_t& wire) {
+		Kernel_::FT len(0);
+		if (wire.size() < 2) {
+			return len;
+		}
+		for (std::size_t i = 1; i < wire.size(); ++i) {
+			len += CGAL::approximate_sqrt(CGAL::Segment_3<Kernel_>(wire[i - 1], wire[i]).squared_length());
+		}
+		if (wire.size() > 2) {
+			len += CGAL::approximate_sqrt(CGAL::Segment_3<Kernel_>(wire.back(), wire.front()).squared_length());
+		}
+		return len;
+	}
+
+	Kernel_::FT wire_area(const cgal_wire_t& wire) {
+		Kernel_::FT area(0);
+		if (wire.size() < 3) {
+			return area;
+		}
+		const auto& origin = wire.front();
+		for (std::size_t i = 1; i + 1 < wire.size(); ++i) {
+			auto v1 = wire[i] - origin;
+			auto v2 = wire[i + 1] - origin;
+			area += CGAL::approximate_sqrt(CGAL::cross_product(v1, v2).squared_length()) / Kernel_::FT(2);
+		}
+		return area;
+	}
+
+	cgal_wire_t moved_wire(const cgal_wire_t& wire, const cgal_placement_t& trsf) {
+		cgal_wire_t result;
+		result.reserve(wire.size());
+		for (const auto& point : wire) {
+			result.push_back(point.transform(trsf));
+		}
+		return result;
+	}
+
+	void write_off_point(std::stringstream& sstream, const cgal_point_t& point) {
+		sstream << "OFF\n1 0 0\n";
+		sstream << point.x() << " " << point.y() << " " << point.z() << "\n";
+	}
+
+	void write_off_wire(std::stringstream& sstream, const cgal_wire_t& wire) {
+		const bool face = wire.size() >= 3;
+		sstream << "OFF\n" << wire.size() << " " << (face ? 1 : 0) << " 0\n";
+		for (const auto& point : wire) {
+			sstream << point.x() << " " << point.y() << " " << point.z() << "\n";
+		}
+		if (face) {
+			sstream << wire.size();
+			for (std::size_t i = 0; i < wire.size(); ++i) {
+				sstream << " " << i;
+			}
+			sstream << "\n";
+		}
+	}
+
 	template <typename Facet>
 	CGAL::Direction_3<Kernel_> newell(Facet& face) {
 		typename Kernel_::FT a(0), b(0), c(0);
@@ -102,10 +236,11 @@ namespace {
 ifcopenshell::geometry::CgalShape::CgalShape(const cgal_shape_t& shape, bool convex, Logger& logger) {
 	shape_ = shape;
 	convex_tag_ = convex;
+	auto& poly = std::get<cgal_shape_t>(*shape_);
 
 	std::set<cgal_shape_t::Facet_handle> faces_to_remove;
 
-	for (const auto& face : CGAL::faces(*shape_)) {
+	for (const auto& face : CGAL::faces(poly)) {
 		auto V = newell(*face).to_vector();
 		CGAL::Plane_3<Kernel_> plane(CGAL::Point_3<Kernel_>(), V);
 		auto b1 = plane.base1();
@@ -127,7 +262,7 @@ ifcopenshell::geometry::CgalShape::CgalShape(const cgal_shape_t& shape, bool con
 
 		std::vector<CGAL::Point_2<Kernel_>> ps;
 			
-		for (auto& he1 : CGAL::halfedges_around_face(face->halfedge(), *shape_)) {
+		for (auto& he1 : CGAL::halfedges_around_face(face->halfedge(), poly)) {
 			const auto& source = he1->vertex()->point();
 			ps.push_back(transform_point(source));
 		}
@@ -140,33 +275,41 @@ ifcopenshell::geometry::CgalShape::CgalShape(const cgal_shape_t& shape, bool con
 
 	{
 		for (auto& face : faces_to_remove) {
-			CGAL::Euler::remove_face(face->halfedge(), *shape_);
+			CGAL::Euler::remove_face(face->halfedge(), poly);
 		}
 	}
+}
 
-	if (shape.size_of_facets() != 1) {
-		// the size_of_facets() == 1 check is for handling the specical case of
-		// storing a single point in a polyhedron as a degenerate triangle
-		// 
-		// @todo come up with a proper variant for storing lower dimensional entities
-		
-		// @todo we don't have access to settings here so we don't know whether we should triangulate
-		// remove_degenerate_faces() is also called in the triangulate() call below though...
-		// CGAL::Polygon_mesh_processing::triangulate_faces(*shape_);
-		// CGAL::Polygon_mesh_processing::remove_degenerate_faces(*shape_);
+ifcopenshell::geometry::CgalShape::CgalShape(const cgal_point_t& point, bool convex) {
+	shape_ = point;
+	convex_tag_ = convex;
+}
+
+ifcopenshell::geometry::CgalShape::CgalShape(const cgal_wire_t& wire, bool convex) {
+	shape_ = wire;
+	convex_tag_ = convex;
+}
+
+const cgal_shape_t& ifcopenshell::geometry::CgalShape::poly() const {
+#ifndef IFOPSH_SIMPLE_KERNEL
+	to_poly();
+#endif
+	if (!shape_ || !std::holds_alternative<cgal_shape_t>(*shape_)) {
+		throw std::runtime_error("Invalid shape type");
 	}
+	return std::get<cgal_shape_t>(*shape_);
 }
 
 #ifndef IFOPSH_SIMPLE_KERNEL
 void ifcopenshell::geometry::CgalShape::to_poly() const {
 	if (!shape_) {
-		shape_.emplace();
-
-		convert_to_polyhedron(*nef_, *shape_);
-		if (shape_->size_of_vertices() > 0) {
+		cgal_shape_t poly;
+		convert_to_polyhedron(*nef_, poly);
+		if (poly.size_of_vertices() > 0) {
 			// @todo why is this necessary? we have the mark of the volumes?
-			CGAL::Polygon_mesh_processing::orient_to_bound_a_volume(*shape_);
+			CGAL::Polygon_mesh_processing::orient_to_bound_a_volume(poly);
 		}
+		shape_ = poly;
 		
 		// nef_->convert_to_polyhedron(*shape_);
 	}
@@ -174,18 +317,23 @@ void ifcopenshell::geometry::CgalShape::to_poly() const {
 
 void ifcopenshell::geometry::CgalShape::to_nef() const {
 	if (!nef_) {
+		auto shp = poly();
 		if (!convex_tag_) {
-			if (CGAL::Polygon_mesh_processing::does_self_intersect(*shape_)) {
+			if (CGAL::Polygon_mesh_processing::does_self_intersect(shp)) {
 				throw std::runtime_error("Self-intersections detected, unable to proceed");
 			}
 		}
-		nef_ = utils::create_nef_polyhedron(*shape_);
+		nef_ = utils::create_nef_polyhedron(shp);
 	}
 }
 #endif
 
 void ifcopenshell::geometry::CgalShape::Triangulate(ifcopenshell::geometry::Settings settings, const ifcopenshell::geometry::taxonomy::matrix4& place, IfcGeom::Representation::Triangulation* t, int item_id, int surface_style_id, Logger& logger) const {
-	const bool all_triangles = std::all_of(shape_->facets_begin(), shape_->facets_end(), [](auto f) { return f.is_triangle(); });
+	if (is_point() || is_wire()) {
+		return;
+	}
+	const auto& base_shape = poly();
+	const bool all_triangles = std::all_of(base_shape.facets_begin(), base_shape.facets_end(), [](auto f) { return f.is_triangle(); });
 	const bool has_iden_transform = place.is_identity();
 
 	std::unique_ptr<cgal_shape_t> shape_copy_holder;
@@ -193,10 +341,10 @@ void ifcopenshell::geometry::CgalShape::Triangulate(ifcopenshell::geometry::Sett
 
 	if (!all_triangles || !has_iden_transform) {
 		// A copy is made when triangulate_faces() is required or when vertex positions need be transformed
-		shape_copy_holder.reset(new cgal_shape_t(*this));
+		shape_copy_holder.reset(new cgal_shape_t(base_shape));
 		shape_to_use = shape_copy_holder.get();
 	} else {
-		shape_to_use = &*shape_;
+		shape_to_use = const_cast<cgal_shape_t*>(&base_shape);
 	}
 
 	const bool setting_use_original_edges = settings.get<ifcopenshell::geometry::settings::CgalEmitOriginalEdges>().get();
@@ -403,25 +551,33 @@ void ifcopenshell::geometry::CgalShape::Triangulate(ifcopenshell::geometry::Sett
 }
 
 void ifcopenshell::geometry::CgalShape::Serialize(const ifcopenshell::geometry::taxonomy::matrix4& place, std::string& r) const {
-	cgal_shape_t s = *this;
-
-	if (!place.is_identity()) {
-		const auto& m = place.ccomponents();
-
-		// @todo check
-		const cgal_placement_t trsf(
-			m(0, 0), m(0, 1), m(0, 2), m(0, 3),
-			m(1, 0), m(1, 1), m(1, 2), m(1, 3),
-			m(2, 0), m(2, 1), m(2, 2), m(2, 3));
-
-		// Apply transformation
-		for (auto &vertex : s.vertex_handles()) {
-			vertex->point() = vertex->point().transform(trsf);
-		}
-	}
-
 	std::stringstream sstream;
-	sstream << s;
+	if (is_point()) {
+		auto p = point();
+		if (!place.is_identity()) {
+			p = p.transform(make_transform(place));
+		}
+		write_off_point(sstream, p);
+	} else if (is_wire()) {
+		auto w = wire();
+		if (!place.is_identity()) {
+			w = moved_wire(w, make_transform(place));
+		}
+		write_off_wire(sstream, w);
+	} else {
+		cgal_shape_t s = poly();
+
+		if (!place.is_identity()) {
+			const auto trsf = make_transform(place);
+
+			// Apply transformation
+			for (auto &vertex : s.vertex_handles()) {
+				vertex->point() = vertex->point().transform(trsf);
+			}
+		}
+
+		sstream << s;
+	}
 	r = sstream.str();
 }
 
@@ -432,12 +588,26 @@ double ifcopenshell::geometry::CgalShape::bounding_box(void *& b) const {
 		b = new CGAL::Bbox_3;
 	}
 	auto& bb = (*((CGAL::Bbox_3*)b));
-	bb += CGAL::Polygon_mesh_processing::bbox(static_cast<cgal_shape_t>(*this));
+	if (is_point()) {
+		bb += point().bbox();
+	} else if (is_wire()) {
+		for (const auto& point : wire()) {
+			bb += point.bbox();
+		}
+	} else {
+		bb += CGAL::Polygon_mesh_processing::bbox(poly());
+	}
 	return (bb.xmax() - bb.xmin()) * (bb.ymax() - bb.ymin()) * (bb.zmax() - bb.zmin());
 }
 
 int ifcopenshell::geometry::CgalShape::num_vertices() const {
-	return (int) static_cast<cgal_shape_t>(*this).size_of_vertices();
+	if (is_point()) {
+		return 1;
+	}
+	if (is_wire()) {
+		return (int) wire().size();
+	}
+	return (int) poly().size_of_vertices();
 }
 
 void ifcopenshell::geometry::CgalShape::set_box(void * b) {
@@ -448,10 +618,13 @@ void ifcopenshell::geometry::CgalShape::set_box(void * b) {
 }
 
 int ifcopenshell::geometry::CgalShape::surface_genus() const {
-	to_poly();
-	auto nv = shape_->size_of_vertices();
-	auto ne = shape_->size_of_halfedges() / 2;
-	auto nf = shape_->size_of_facets();
+	if (is_point() || is_wire()) {
+		return 0;
+	}
+	const auto& shp = poly();
+	auto nv = shp.size_of_vertices();
+	auto ne = shp.size_of_halfedges() / 2;
+	auto nf = shp.size_of_facets();
 
 	auto euler = nv - ne + nf;
 	auto genus = (2 - euler) / 2;
@@ -461,14 +634,22 @@ int ifcopenshell::geometry::CgalShape::surface_genus() const {
 
 bool ifcopenshell::geometry::CgalShape::is_manifold() const {
 	// @todo ?
-	to_poly();
-	return shape_->is_valid();
+	return (is_point() || is_wire()) ? true : poly().is_valid();
 }
 
 int ifcopenshell::geometry::CgalShape::num_edges() const
 {
-	to_poly();
-	return (int) shape_->size_of_halfedges() / 2;
+	if (is_point()) {
+		return 0;
+	}
+	if (is_wire()) {
+		const auto n = wire().size();
+		if (n < 2) {
+			return 0;
+		}
+		return (int)(n == 2 ? 1 : n);
+	}
+	return (int) poly().size_of_halfedges() / 2;
 }
 
 int ifcopenshell::geometry::CgalShape::num_faces() const
@@ -479,7 +660,13 @@ int ifcopenshell::geometry::CgalShape::num_faces() const
 	} else
 #endif
 	if (shape_) {
-		return (int) shape_->size_of_facets();
+		if (is_poly()) {
+			return (int) poly().size_of_facets();
+		}
+		if (is_wire() && wire().size() >= 3) {
+			return 1;
+		}
+		return 0;
 	} else {
 		return 0;
 	}
@@ -487,46 +674,63 @@ int ifcopenshell::geometry::CgalShape::num_faces() const
 
 OpaqueNumber* ifcopenshell::geometry::CgalShape::CgalShape::length()
 {
-	to_poly();
 	Kernel_::FT len = 0;
-	for (auto it = shape_->edges_begin(); it != shape_->edges_end(); ++it) {
-		len += CGAL::approximate_sqrt(CGAL::Segment_3<Kernel_>(
-			it->vertex()->point(),
-			it->next()->vertex()->point()
-		).squared_length());
+	if (is_wire()) {
+		len = wire_length(wire());
+	} else if (!is_point()) {
+		const auto& shp = poly();
+		for (auto it = shp.edges_begin(); it != shp.edges_end(); ++it) {
+			len += CGAL::approximate_sqrt(CGAL::Segment_3<Kernel_>(
+				it->vertex()->point(),
+				it->opposite()->vertex()->point()
+			).squared_length());
+		}
 	}
 	return new NumberType(len);
 }
 
 OpaqueNumber* ifcopenshell::geometry::CgalShape::area()
 {
-	to_poly();
-	auto s = *shape_;
+	if (is_wire()) {
+		return new NumberType(wire_area(wire()));
+	}
+	if (is_point()) {
+		return new NumberType(Kernel_::FT(0));
+	}
+	auto s = poly();
 	CGAL::Polygon_mesh_processing::triangulate_faces(s);
 	return new NumberType(CGAL::Polygon_mesh_processing::area(s));
 }
 
 OpaqueNumber* ifcopenshell::geometry::CgalShape::volume()
 {
-	to_poly();
-	auto s = *shape_;
+	if (is_point() || is_wire()) {
+		return new NumberType(Kernel_::FT(0));
+	}
+	auto s = poly();
 	CGAL::Polygon_mesh_processing::triangulate_faces(s);
 	return new NumberType(CGAL::Polygon_mesh_processing::volume(s));
 }
 
 OpaqueCoordinate<3> ifcopenshell::geometry::CgalShape::position()
 {
-	to_poly();
-	if (shape_->size_of_facets() == 1) {
+	if (is_point()) {
+		return opaque_point(point());
+	}
+	if (is_wire()) {
+		return opaque_point(wire_centroid(wire()));
+	}
+	const auto& shp = poly();
+	if (shp.size_of_facets() == 1) {
 		// return centroid;
 		// CGAL::Vector_3<Kernel_> p;
-		std::array<Kernel_::FT, 3> p;
-		for (auto it = shape_->points_begin(); it != shape_->points_end(); ++it) {
+		std::array<Kernel_::FT, 3> p{ Kernel_::FT(0), Kernel_::FT(0), Kernel_::FT(0) };
+		for (auto it = shp.points_begin(); it != shp.points_end(); ++it) {
 			for (int i = 0; i < 3; ++i) {
 				p[i] += it->cartesian(i);
 			}			
 		}
-		Kernel_::FT N(std::distance(shape_->points_begin(), shape_->points_end()));
+		Kernel_::FT N(std::distance(shp.points_begin(), shp.points_end()));
 		for (int i = 0; i < 3; ++i) {
 			p[i] /= N;
 		}
@@ -542,19 +746,19 @@ OpaqueCoordinate<3> ifcopenshell::geometry::CgalShape::position()
 
 OpaqueCoordinate<3> ifcopenshell::geometry::CgalShape::axis()
 {
-	to_poly();
-	if (shape_->size_of_facets() == 1) {
-		auto pl = Plane_equation()(*shape_->facets_begin());
-		std::array<typename Kernel_::FT, 3> abc{ pl.a(), pl.b(), pl.c() };
-		auto minel = std::min_element(abc.begin(), abc.end());
-		auto maxel = std::max_element(abc.begin(), abc.end());
-		auto maxval = ((-*minel) > *maxel) ? (-*minel) : *maxel;
-
-		return OpaqueCoordinate<3>(
-			new NumberType(pl.a() / maxval),
-			new NumberType(pl.b() / maxval),
-			new NumberType(pl.c() / maxval)
-		);
+	if (is_wire()) {
+		if (wire().size() == 2) {
+			return opaque_axis(wire()[1] - wire()[0]);
+		}
+		if (wire().size() >= 3) {
+			return opaque_axis(wire_normal(wire()));
+		}
+		throw std::runtime_error("Invalid shape type");
+	}
+	auto shp = poly();
+	if (shp.size_of_facets() == 1) {
+		auto pl = Plane_equation()(*shp.facets_begin());
+		return opaque_axis(cgal_vector_t(pl.a(), pl.b(), pl.c()));
 	} else {
 		throw std::runtime_error("Invalid shape type");
 	}
@@ -562,6 +766,14 @@ OpaqueCoordinate<3> ifcopenshell::geometry::CgalShape::axis()
 
 OpaqueCoordinate<4> ifcopenshell::geometry::CgalShape::plane_equation()
 {
+	if (is_wire() && wire().size() >= 3) {
+		auto normal = wire_normal(wire());
+		return opaque_plane(cgal_plane_t(wire().front(), CGAL::Direction_3<Kernel_>(normal)));
+	}
+	auto shp = poly();
+	if (shp.size_of_facets() == 1) {
+		return opaque_plane(Plane_equation()(*shp.facets_begin()));
+	}
 	throw std::runtime_error("Invalid shape type");
 }
 
@@ -612,75 +824,71 @@ ConversionResultShape * ifcopenshell::geometry::CgalShape::box()
 
 ConversionResultShape* ifcopenshell::geometry::CgalShape::wrap_in_compound()
 {
-	return new CgalShape(poly(), convex_tag_);
+	return clone();
 }
 
 std::vector<ConversionResultShape*> ifcopenshell::geometry::CgalShape::vertices()
 {
-	// @todo this is ridiculous
-	to_poly();
 	std::vector<ConversionResultShape*> result;
-	for (auto& p : shape_->points()) {
-		std::vector<cgal_point_t> ps = {
-			p, p, p
-		};
-
-		std::vector<std::vector<size_t>> ids(1);
-		ids.front().push_back(0);
-		ids.front().push_back(1);
-		ids.front().push_back(2);
-
-		cgal_shape_t poly;
-		CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh(ps, ids, poly);
-
-		result.push_back(new CgalShape(poly));
+	if (is_point()) {
+		result.push_back(new CgalShape(point()));
+		return result;
+	}
+	if (is_wire()) {
+		for (const auto& p : wire()) {
+			result.push_back(new CgalShape(p));
+		}
+		return result;
+	}
+	for (const auto& p : poly().points()) {
+		result.push_back(new CgalShape(p));
 	}
 	return result;
 }
 
 std::vector<ConversionResultShape*> ifcopenshell::geometry::CgalShape::edges()
 {
-	// @todo this is ridiculous
-	to_poly();
 	std::vector<ConversionResultShape*> result;
-	for (auto& ed : shape_->edges()) {
-		std::vector<cgal_point_t> ps = {
-			ed.vertex()->point(),
-			ed.vertex()->point(),
-			ed.next()->vertex()->point()
-		};
-
-		std::vector<std::vector<size_t>> ids(1);
-		ids.front().push_back(0);
-		ids.front().push_back(1);
-		ids.front().push_back(2);
-
-		cgal_shape_t poly;
-		CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh(ps, ids, poly);
-
-		result.push_back(new CgalShape(poly));
+	if (is_point()) {
+		return result;
+	}
+	if (is_wire()) {
+		const auto& w = wire();
+		for (std::size_t i = 1; i < w.size(); ++i) {
+			result.push_back(new CgalShape(cgal_wire_t{ w[i - 1], w[i] }));
+		}
+		if (w.size() > 2) {
+			result.push_back(new CgalShape(cgal_wire_t{ w.back(), w.front() }));
+		}
+		return result;
+	}
+	for (auto ed : poly().edges()) {
+		result.push_back(new CgalShape(cgal_wire_t{ ed.vertex()->point(), ed.opposite()->vertex()->point() }));
 	}
 	return result;
 }
 
 std::vector<ConversionResultShape*> ifcopenshell::geometry::CgalShape::facets()
 {
-	to_poly();
 	std::vector<ConversionResultShape*> result;
-	for (auto &face : faces(*shape_)) {
+	if (is_point()) {
+		return result;
+	}
+	if (is_wire()) {
+		if (wire().size() >= 3) {
+			result.push_back(new CgalShape(wire()));
+		}
+		return result;
+	}
+	for (auto face : faces(poly())) {
 		std::vector<cgal_point_t> ps;
-		std::vector<std::vector<size_t>> ids(1);
 
 		auto it = face->facet_begin();
 		do {
 			ps.push_back(it->vertex()->point());
-			ids.front().push_back(ids.front().size());
 		} while (++it != face->facet_begin());
 
-		cgal_shape_t poly;
-		CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh(ps, ids, poly);
-
-		result.push_back(new CgalShape(poly));
+		result.push_back(new CgalShape(ps));
 	}
 	return result;
 }
@@ -756,21 +964,21 @@ std::pair<OpaqueCoordinate<3>, OpaqueCoordinate<3>> ifcopenshell::geometry::Cgal
 
 ConversionResultShape* ifcopenshell::geometry::CgalShape::moved(ifcopenshell::geometry::taxonomy::matrix4::ptr place) const
 {
-	cgal_shape_t s = *this;
+	if (place->is_identity()) {
+		return clone();
+	}
 
-	if (!place->is_identity()) {
-		const auto& m = place->ccomponents();
+	const auto trsf = make_transform(*place);
+	if (is_point()) {
+		return new CgalShape(point().transform(trsf), convex_tag_);
+	}
+	if (is_wire()) {
+		return new CgalShape(moved_wire(wire(), trsf), convex_tag_);
+	}
 
-		// @todo check
-		const cgal_placement_t trsf(
-			m(0, 0), m(0, 1), m(0, 2), m(0, 3),
-			m(1, 0), m(1, 1), m(1, 2), m(1, 3),
-			m(2, 0), m(2, 1), m(2, 2), m(2, 3));
-
-		// Apply transformation
-		for (auto &vertex : s.vertex_handles()) {
-			vertex->point() = vertex->point().transform(trsf);
-		}
+	cgal_shape_t s = poly();
+	for (auto &vertex : s.vertex_handles()) {
+		vertex->point() = vertex->point().transform(trsf);
 	}
 
 	return new CgalShape(s, convex_tag_);
@@ -1012,4 +1220,4 @@ ConversionResultShape* ifcopenshell::geometry::CgalShapeHalfSpaceDecomposition::
 	throw std::runtime_error("Not implemented");
 }
 
-#endif
+#endif

src/ifcgeom/kernels/cgal/CgalConversionResult.h

@@ -39,6 +39,8 @@
 #include <CGAL/Polygon_mesh_processing/compute_normal.h>
 #include <CGAL/Polygon_mesh_processing/self_intersections.h>
 
+#include <variant>
+
 #ifdef IFOPSH_SIMPLE_KERNEL
 
 #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
@@ -179,13 +181,17 @@ namespace ifcopenshell { namespace geometry {
 
 	class IFC_GEOMLIBRARY_API CgalShape : public IfcGeom::ConversionResultShape {
 	private:
+		typedef std::variant<cgal_shape_t, cgal_point_t, cgal_wire_t> cgal_shape_storage_t;
+
 		bool convex_tag_ = false;
-		mutable boost::optional<cgal_shape_t> shape_;
+		mutable boost::optional<cgal_shape_storage_t> shape_;
 #ifndef IFOPSH_SIMPLE_KERNEL
 		mutable boost::optional<CGAL::Nef_polyhedron_3<Kernel_>> nef_;
 #endif
     public:
 		CgalShape(const cgal_shape_t& shape, bool convex = false, Logger& logger = Logger::Root());
+		CgalShape(const cgal_point_t& point, bool convex = false);
+		CgalShape(const cgal_wire_t& wire, bool convex = false);
 
 #ifndef IFOPSH_SIMPLE_KERNEL
 		CgalShape(const CGAL::Nef_polyhedron_3<Kernel_>& shape, bool convex = false) {
@@ -206,14 +212,29 @@ namespace ifcopenshell { namespace geometry {
 		void to_poly() const {}
 #endif
 
-		operator const cgal_shape_t& () const { to_poly();  return *shape_; }
-		const cgal_shape_t& poly() const { to_poly(); return *shape_; }
+		operator const cgal_shape_t& () const { return poly(); }
+		const cgal_shape_t& poly() const;
+		bool is_poly() const { return shape_ && std::holds_alternative<cgal_shape_t>(*shape_); }
+		bool is_point() const { return shape_ && std::holds_alternative<cgal_point_t>(*shape_); }
+		bool is_wire() const { return shape_ && std::holds_alternative<cgal_wire_t>(*shape_); }
+		const cgal_point_t& point() const { return std::get<cgal_point_t>(*shape_); }
+		const cgal_wire_t& wire() const { return std::get<cgal_wire_t>(*shape_); }
 
 		virtual void Triangulate(ifcopenshell::geometry::Settings settings, const ifcopenshell::geometry::taxonomy::matrix4& place, IfcGeom::Representation::Triangulation* t, int item_id, int surface_style_id, Logger& logger = Logger::Root()) const;
 		virtual void Serialize(const ifcopenshell::geometry::taxonomy::matrix4& place, std::string&) const;
 
 		virtual IfcGeom::ConversionResultShape* clone() const {
-			return new CgalShape(*shape_);
+			if (shape_) {
+				return std::visit([this](const auto& value) -> IfcGeom::ConversionResultShape* {
+					return new CgalShape(value, convex_tag_);
+				}, *shape_);
+			}
+#ifndef IFOPSH_SIMPLE_KERNEL
+			if (nef_) {
+				return new CgalShape(*nef_, convex_tag_);
+			}
+#endif
+			return nullptr;
 		}
 
 		virtual bool is_manifold() const;