IfcOpenShell/src/ifcgeom/kernels/opencascade/loft.cpp

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 * This file is part of IfcOpenShell.                                           *
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#include "OpenCascadeKernel.h"
#include "base_utils.h"

#include <TopExp.hxx>
#include <BRepFill_Filling.hxx>
#include <BRepTools_WireExplorer.hxx>
#include <BRepBuilderAPI_MakeEdge.hxx>
#include <BRepBuilderAPI_MakePolygon.hxx>
#include <BRepBuilderAPI_MakeFace.hxx>

using namespace ifcopenshell::geometry;
using namespace ifcopenshell::geometry::kernels;
using namespace IfcGeom;
using namespace IfcGeom::util;

bool OpenCascadeKernel::convert(const taxonomy::loft::ptr loft, TopoDS_Shape& result) {
	// @todo this approach based on BRepFill_Filling is both slow, as well as
	// potentially incorrect as there is no guarantee that the wires for
	// subsequently placed profiles are traversed from an equivalent start vertex.
	
	if (loft->children.size() < 2) {
		return false;
	}
	
	TopTools_ListOfShape faces;
	TopoDS_Compound comp;
	BRep_Builder BB;
	BB.MakeCompound(comp);

	for (auto it = loft->children.begin(); it < loft->children.end() - 1; ++it) {
		auto jt = it + 1;
		std::array<taxonomy::item::ptr, 2> fa = { *it, *jt };
		std::array<TopoDS_Shape, 2> shps;
		std::array<TopoDS_Wire, 2> ws;
		for (int i = 0; i < 2; ++i) {
			if (fa[i]->kind() == taxonomy::FACE) {
				if (!convert(std::static_pointer_cast<taxonomy::face>(fa[i]), shps[i])) {
					return false;
				}
			}
			if (fa[i]->kind() == taxonomy::LOOP) {
				TopoDS_Wire w;
				if (!convert(std::static_pointer_cast<taxonomy::loop>(fa[i]), w)) {
					return false;
				}
				shps[i] = w;
			}
			if (shps[i].ShapeType() != TopAbs_FACE && shps[i].ShapeType() != TopAbs_WIRE) {
				return false;
			}
			// @todo this is only outer wire
			if (shps[i].ShapeType() == TopAbs_FACE) {
				ws[i] = BRepTools::OuterWire(TopoDS::Face(shps[i]));
			} else {
				ws[i] = TopoDS::Wire(shps[i]);
			}
		}
		if (shps[0].ShapeType() == TopAbs_FACE) {
			// When processing a sectioned *surface* there are no
			// begin and end caps that need to be added.
			if (it == loft->children.begin()) {
				// faces.Append(shps[0]);
				BB.Add(comp, shps[0]);
			}
			if (jt == loft->children.end() - 1) {
				// faces.Append(shps[1]);
				BB.Add(comp, shps[1]);
			}
		}
		BRepTools_WireExplorer a(ws[0]);
		BRepTools_WireExplorer b(ws[1]);
		for (; a.More() && b.More(); a.Next(), b.Next()) {
			auto& e1 = a.Current();
			// auto e3 = TopoDS::Edge(b.Current().Reversed());
			auto& e3 = b.Current();

			// Documentation says unconnected edges are automatically connected, but this is not the case
			TopoDS_Vertex e1a, e1b, e3a, e3b;
			TopExp::Vertices(e1, e1a, e1b, true);
			TopExp::Vertices(e3, e3a, e3b, true);
			auto e2 = BRepBuilderAPI_MakeEdge(e1b, e3a).Edge();
			auto e4 = BRepBuilderAPI_MakeEdge(e3b, e1a).Edge();
			
			/*
			BRepFill_Filling fill;
			fill.Add(e1, GeomAbs_C0);
			fill.Add(e2, GeomAbs_C0);
			fill.Add(e3, GeomAbs_C0);
			fill.Add(e4, GeomAbs_C0);
			fill.Build();
			// faces.Append(fill.Face());
			BB.Add(comp, fill.Face());
			*/

			auto f = BRepBuilderAPI_MakeFace(BRepBuilderAPI_MakePolygon(e1a, e1b, e3b, true).Wire()).Face();
			BB.Add(comp, f);
			auto g = BRepBuilderAPI_MakeFace(BRepBuilderAPI_MakePolygon(e3b, e3a, e1a, true).Wire()).Face();
			BB.Add(comp, g);
		}
	}

	// create_solid_from_faces(faces, result, settings_.get<settings::Precision>().get());
	result = comp;

	return true;
}

bool OpenCascadeKernel::convert_impl(const taxonomy::loft::ptr loft, IfcGeom::ConversionResults& results) {
	TopoDS_Shape shape;
	if (!convert(loft, shape)) {
		return false;
	}
	results.emplace_back(ConversionResult(
		loft->instance->as<IfcUtil::IfcBaseEntity>()->id(),
		loft->matrix,
		new OpenCascadeShape(shape),
		loft->surface_style
	));
	return true;
}