IfcOpenShell/src/ifcgeom/kernels/cgal/CgalKernel.cpp

/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
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 * IfcOpenShell is free software: you can redistribute it and/or modify         *
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
 * Lesser GNU General Public License for more details.                          *
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#include "CgalKernel.h"

#include "../../../ifcparse/IfcLogger.h"
#include "../../../ifcgeom/kernels/cgal/CgalConversionResult.h"

#include <CGAL/minkowski_sum_3.h>

using namespace ifcopenshell::geometry; 
using namespace ifcopenshell::geometry::kernels;

void CgalKernel::remove_duplicate_points_from_loop(cgal_wire_t& polygon) {
	std::set<cgal_point_t> points;
	for (int i = 0; i < polygon.size(); ++i) {
		if (points.count(polygon[i])) {
			polygon.erase(polygon.begin() + i);
			--i;
		} else points.insert(polygon[i]);
	}
}

CGAL::Polyhedron_3<Kernel_> CgalKernel::create_polyhedron(std::list<cgal_face_t> &face_list) {

	// Naive creation
	CGAL::Polyhedron_3<Kernel_> polyhedron;
	PolyhedronBuilder builder(&face_list);
	polyhedron.delegate(builder);

	// Stitch edges
	//  std::cout << "Before: " << polyhedron.size_of_vertices() << " vertices and " << polyhedron.size_of_facets() << " facets" << std::endl;
	CGAL::Polygon_mesh_processing::stitch_borders(polyhedron);
	if (!polyhedron.is_valid()) {
		Logger::Message(Logger::LOG_ERROR, "create_polyhedron: Polyhedron not valid!");
		//    std::ofstream fresult;
		//    fresult.open("/Users/ken/Desktop/invalid.off");
		//    fresult << polyhedron << std::endl;
		//    fresult.close();
		return CGAL::Polyhedron_3<Kernel_>();
	} if (polyhedron.is_closed()) {
		if (!CGAL::Polygon_mesh_processing::is_outward_oriented(polyhedron)) {
			CGAL::Polygon_mesh_processing::reverse_face_orientations(polyhedron);
		}
	}

	//  std::cout << "After: " << polyhedron.size_of_vertices() << " vertices and " << polyhedron.size_of_facets() << " facets" << std::endl;

	return polyhedron;
}

CGAL::Polyhedron_3<Kernel_> CgalKernel::create_polyhedron(CGAL::Nef_polyhedron_3<Kernel_> &nef_polyhedron) {
	if (nef_polyhedron.is_simple()) {
		try {
			CGAL::Polyhedron_3<Kernel_> polyhedron;
			nef_polyhedron.convert_to_polyhedron(polyhedron);
			return polyhedron;
		} catch (...) {
			Logger::Message(Logger::LOG_ERROR, "Conversion from Nef to polyhedron failed!");
			return CGAL::Polyhedron_3<Kernel_>();
		}
	} else {
		Logger::Message(Logger::LOG_ERROR, "Nef polyhedron not simple: cannot create polyhedron!");
		return CGAL::Polyhedron_3<Kernel_>();
	}
}

CGAL::Nef_polyhedron_3<Kernel_> CgalKernel::create_nef_polyhedron(std::list<cgal_face_t> &face_list) {
	CGAL::Polyhedron_3<Kernel_> polyhedron = create_polyhedron(face_list);
	CGAL::Polygon_mesh_processing::triangulate_faces(polyhedron);
	CGAL::Nef_polyhedron_3<Kernel_> nef_polyhedron;
	try {
		nef_polyhedron = CGAL::Nef_polyhedron_3<Kernel_>(polyhedron);
	} catch (...) {
		Logger::Message(Logger::LOG_ERROR, "Conversion to Nef polyhedron failed!");
		return nef_polyhedron;
	} return nef_polyhedron;
}

CGAL::Nef_polyhedron_3<Kernel_> CgalKernel::create_nef_polyhedron(CGAL::Polyhedron_3<Kernel_> &polyhedron) {
	if (polyhedron.is_valid()) {
		CGAL::Polygon_mesh_processing::triangulate_faces(polyhedron);
		CGAL::Nef_polyhedron_3<Kernel_> nef_polyhedron;
		try {
			nef_polyhedron = CGAL::Nef_polyhedron_3<Kernel_>(polyhedron);
		} catch (...) {
			Logger::Message(Logger::LOG_ERROR, "Conversion to Nef polyhedron failed!");
			return nef_polyhedron;
		} return nef_polyhedron;
	} else {
		Logger::Message(Logger::LOG_ERROR, "Polyhedron not valid: cannot create Nef polyhedron!");
		return CGAL::Nef_polyhedron_3<Kernel_>();
	}
}

bool CgalKernel::convert(const taxonomy::shell* l, cgal_shape_t& shape) {
	auto faces = l->children_as<taxonomy::face>();

	std::list<cgal_face_t> face_list;
	for (auto& f : faces) {
		bool success = false;
		cgal_face_t face;

		try {
			success = convert(f, face);
		} catch (...) {}

		if (!success) {
			Logger::Message(Logger::LOG_WARNING, "Failed to convert face:", f->instance);
			continue;
		}

		//    std::cout << "Face in ConnectedFaceSet: " << std::endl;
		//    for (auto &point: face.outer) {
		//      std::cout << "\tPoint(" << point << ")" << std::endl;
		//    }

		face_list.push_back(face);
	}

	shape = create_polyhedron(face_list);
	return true;
}

bool CgalKernel::convert(const taxonomy::face* face, cgal_face_t& result) {
	auto bounds = face->children_as<taxonomy::loop>();

	int num_outer_bounds = 0;

	for (auto& bound : bounds) {
		if (bound->external.get_value_or(false)) num_outer_bounds++;
	}

	if (num_outer_bounds != 1) {
		Logger::Message(Logger::LOG_ERROR, "Invalid configuration of boundaries for:", face->instance);
		return false;
	}

	cgal_face_t mf;

	for (auto& bound : bounds) {

		const bool is_interior = !bound->external.get_value_or(false);

		cgal_wire_t wire;
		if (!convert(bound, wire)) {
			Logger::Message(Logger::LOG_ERROR, "Failed to process face boundary loop", bound->instance);
			return false;
		}

		if (!is_interior) {
			mf.outer = wire;
		} else {
			mf.inner.push_back(wire);
		}
	}

	result = mf;

	//  std::cout << "Face: " << std::endl;
	//  for (auto &point: face.outer) {
	//    std::cout << "\tPoint(" << point << ")" << std::endl;
	//  }

	return true;
}

namespace {
	bool convert_curve(CgalKernel* kernel, const taxonomy::item* curve, cgal_wire_t& builder) {
		if (curve->kind() == taxonomy::EDGE) {
			auto e = (taxonomy::edge*) curve;
			if (true || e->basis == nullptr) {
				if (builder.empty()) {
					const auto& p = boost::get<taxonomy::point3>(e->start);
					cgal_point_t pnt(p.components(0), p.components(1), p.components(2));
					builder.push_back(pnt);
				}
				const auto& p = boost::get<taxonomy::point3>(e->end);
				cgal_point_t pnt(p.components(0), p.components(1), p.components(2));
				builder.push_back(pnt);
			} else if (e->basis->kind() == taxonomy::CIRCLE) {
				// @todo
			} else if (e->basis->kind() == taxonomy::ELLIPSE) {

			} else {
				throw std::runtime_error("Not implemented basis kind");
			}
		} else if (curve->kind() == taxonomy::LOOP) {
			const auto& edges = ((taxonomy::loop*) curve)->children;
			for (auto& c : edges) {
				convert_curve(kernel, c, builder);
			}
		} else {
			throw std::runtime_error("Not implemented curve");
		}
	}
}

bool CgalKernel::convert(const taxonomy::loop* loop, cgal_wire_t& result) {
	// @todo only implement polygonal loops

	auto edges = loop->children_as<taxonomy::edge>();
	std::vector<taxonomy::point3> points;

	for (auto& e : edges) {
		if (e->basis) {
			Logger::Error("Only polyhedra supported :(");
			return false;
		}
		points.push_back(boost::get<taxonomy::point3>(e->start));
	}

	// Parse and store the points in a sequence
	cgal_wire_t polygon = std::vector<Kernel_::Point_3>();
	for (auto& p : points) {
		cgal_point_t pnt(p.components(0), p.components(1), p.components(2));
		polygon.push_back(pnt);
	}

	// A loop should consist of at least three vertices
	std::size_t original_count = polygon.size();
	if (original_count < 3) {
		Logger::Message(Logger::LOG_ERROR, "Not enough edges for:", loop->instance);
		return false;
	}

	// Remove points that are too close to one another
	remove_duplicate_points_from_loop(polygon);

	std::size_t count = polygon.size();
	if (original_count - count != 0) {
		std::stringstream ss; ss << (original_count - count) << " edges removed for:";
		Logger::Message(Logger::LOG_WARNING, ss.str(), loop->instance);
	}

	if (count < 3) {
		Logger::Message(Logger::LOG_ERROR, "Not enough edges for:", loop->instance);
		return false;
	}

	result = polygon;

	//  std::cout << "PolyLoop: " << std::endl;
	//  for (auto &point: polygon) {
	//    std::cout << "\tPoint(" << point << ")" << std::endl;
	//  }

	return true;
}


bool CgalKernel::convert_impl(const taxonomy::shell *shell, ifcopenshell::geometry::ConversionResults& results) {
	cgal_shape_t shape;
	if (!convert(shell, shape)) {
		return false;
	}
	results.emplace_back(ConversionResult(
		shell->instance->data().id(),
		shell->matrix,
		new CgalShape(shape),
		shell->surface_style
	));
	return true;
}

bool CgalKernel::convert_impl(const taxonomy::extrusion* extrusion, ifcopenshell::geometry::ConversionResults& results) {
	cgal_shape_t shape;
	if (!convert(extrusion, shape)) {
		return false;
	}
	results.emplace_back(ConversionResult(
		extrusion->instance->data().id(),
		extrusion->matrix,
		new CgalShape(shape),
		extrusion->surface_style
	));
	return true;
}

bool CgalKernel::convert(const taxonomy::extrusion* extrusion, cgal_shape_t &shape) {
	const double& height = extrusion->depth;
	if (height < precision_) {
		Logger::Message(Logger::LOG_ERROR, "Non-positive extrusion height encountered for:", extrusion->instance);
		return false;
	}

	// Outer
	cgal_face_t bottom_face;
	if (!convert(&extrusion->basis, bottom_face)) {
		return false;
	}
	//  std::cout << "Face vertices: " << face.outer.size() << std::endl;

	auto fs = extrusion->direction.components;
	cgal_direction_t dir(fs(0), fs(1), fs(2));
	//  std::cout << "Direction: " << dir << std::endl;

	std::list<cgal_face_t> face_list;
	face_list.push_back(bottom_face);

	for (std::vector<Kernel_::Point_3>::const_iterator current_vertex = bottom_face.outer.begin();
		current_vertex != bottom_face.outer.end();
		++current_vertex) {
		std::vector<Kernel_::Point_3>::const_iterator next_vertex = current_vertex;
		++next_vertex;
		if (next_vertex == bottom_face.outer.end()) {
			next_vertex = bottom_face.outer.begin();
		} cgal_face_t side_face;
		side_face.outer.push_back(*next_vertex);
		side_face.outer.push_back(*current_vertex);
		side_face.outer.push_back(*current_vertex + height * dir);
		side_face.outer.push_back(*next_vertex + height * dir);
		face_list.push_back(side_face);
	}

	cgal_face_t top_face;
	for (std::vector<Kernel_::Point_3>::const_reverse_iterator vertex = bottom_face.outer.rbegin();
		vertex != bottom_face.outer.rend();
		++vertex) {
		top_face.outer.push_back(*vertex + height * dir);
	} face_list.push_back(top_face);

	if (bottom_face.inner.empty()) {
		shape = create_polyhedron(face_list);
		// if (has_position) for (auto &vertex : vertices(shape)) vertex->point() = vertex->point().transform(trsf);
		return true;
	}

	CGAL::Nef_polyhedron_3<Kernel_> nef_shape = create_nef_polyhedron(face_list);

	// Inner
	// TODO: Would be faster to triangulate top/bottom face template rather than use Nef polyhedra for subtraction
	for (auto &inner : bottom_face.inner) {
		//    std::cout << "Inner wire" << std::endl;
		face_list.clear();

		cgal_face_t hole_bottom_face;
		hole_bottom_face.outer = inner;
		remove_duplicate_points_from_loop(hole_bottom_face.outer);
		face_list.push_back(hole_bottom_face);

		for (std::vector<Kernel_::Point_3>::const_iterator current_vertex = inner.begin();
			current_vertex != inner.end();
			++current_vertex) {
			std::vector<Kernel_::Point_3>::const_iterator next_vertex = current_vertex;
			++next_vertex;
			if (next_vertex == inner.end()) {
				next_vertex = inner.begin();
			} cgal_face_t hole_side_face;
			hole_side_face.outer.push_back(*next_vertex);
			hole_side_face.outer.push_back(*current_vertex);
			hole_side_face.outer.push_back(*current_vertex + height * dir);
			hole_side_face.outer.push_back(*next_vertex + height * dir);
			face_list.push_back(hole_side_face);
		}

		cgal_face_t hole_top_face;
		for (std::vector<Kernel_::Point_3>::const_reverse_iterator vertex = inner.rbegin();
			vertex != inner.rend();
			++vertex) {
			hole_top_face.outer.push_back(*vertex + height * dir);
		} face_list.push_back(hole_top_face);

		try {
			nef_shape -= create_nef_polyhedron(face_list);
		} catch (...) {
			Logger::Message(Logger::LOG_ERROR, "IfcExtrudedAreaSolid: cannot subtract opening for:", extrusion->instance);
			return false;
		}
	}

	/*if (has_position) {
		// IfcSweptAreaSolid.Position (trsf) is an IfcAxis2Placement3D
		// and therefore has a unit scale factor
		nef_shape.transform(trsf);
	}*/

	try {
		nef_shape.convert_to_polyhedron(shape);
		return true;
	} catch (...) {
		Logger::Message(Logger::LOG_ERROR, "IfcExtrudedAreaSolid: cannot convert Nef to polyhedron for:", extrusion->instance);
		return false;
	}

}

CGAL::Polyhedron_3<Kernel_> CgalKernel::create_cube(double d) {
	cgal_face_t bottom_face;
	bottom_face.outer.push_back(Kernel_::Point_3(-d, -d, -d));
	bottom_face.outer.push_back(Kernel_::Point_3(+d, -d, -d));
	bottom_face.outer.push_back(Kernel_::Point_3(+d, +d, -d));
	bottom_face.outer.push_back(Kernel_::Point_3(-d, +d, -d));

	cgal_direction_t dir(0, 0, 2 * d);

	std::list<cgal_face_t> face_list = { bottom_face };
		
	for (std::vector<Kernel_::Point_3>::const_iterator current_vertex = bottom_face.outer.begin();
		current_vertex != bottom_face.outer.end();
		++current_vertex)
	{
		std::vector<Kernel_::Point_3>::const_iterator next_vertex = current_vertex;
		++next_vertex;

		if (next_vertex == bottom_face.outer.end()) {
			next_vertex = bottom_face.outer.begin();
		}
			
		cgal_face_t side_face;
			
		side_face.outer.push_back(*next_vertex);
		side_face.outer.push_back(*current_vertex);
		side_face.outer.push_back(*current_vertex + dir);
		side_face.outer.push_back(*next_vertex + dir);

		face_list.push_back(side_face);
	}

	cgal_face_t top_face;

	for (std::vector<Kernel_::Point_3>::const_reverse_iterator vertex = bottom_face.outer.rbegin();
		vertex != bottom_face.outer.rend();
		++vertex)
	{
		top_face.outer.push_back(*vertex + dir);
	}
		
	face_list.push_back(top_face);

	return create_polyhedron(face_list);
}

bool CgalKernel::preprocess_boolean_operand(const IfcUtil::IfcBaseClass* log_reference, const cgal_shape_t& shape_const, CGAL::Nef_polyhedron_3<Kernel_>& result, bool dilate) {
	cgal_shape_t shape = shape_const;

	if (!shape.is_valid()) {
		Logger::Message(Logger::LOG_ERROR, "Conversion to Nef will fail. Invalid geometry:", log_reference);
		return false;
	}

	if (!shape.is_closed()) {
		// TODO: There can be substractions to remove parts of non-volumetric objects. Maybe iterate over all faces of an entity and put them in a Nef_polyhedron_3 through Boolean union? Highly inefficient but maybe desirable...
		Logger::Message(Logger::LOG_ERROR, "Subtraction of openings not supported for non-closed geometry:", log_reference);
		return false;
	}

	bool success = false;

	try {
		success = CGAL::Polygon_mesh_processing::triangulate_faces(shape);
	} catch (...) {
		Logger::Message(Logger::LOG_ERROR, "Triangulation of geometry crashed:", log_reference);
		return false;
	}

	if (!success) {
		Logger::Message(Logger::LOG_ERROR, "Triangulation of geometry failed:", log_reference);
		return false;
	}

	if (CGAL::Polygon_mesh_processing::does_self_intersect(shape)) {
		Logger::Message(Logger::LOG_ERROR, "Conversion to Nef will fail. Self-intersecting geometry:", log_reference);
		return false;
	}

	try {
		result = CGAL::Nef_polyhedron_3<Kernel_>(shape);
	} catch (...) {
		Logger::Message(Logger::LOG_ERROR, "Could not convert geometry to Nef:", log_reference);
		return false;
	}

	if (false && dilate) {
		try {
			// @todo don't dilate in 3 dimensions but only in the XY plane, orthogonal to wall axis.
			result = CGAL::minkowski_sum_3(result, precision_cube_);
		} catch (...) {
			Logger::Message(Logger::LOG_ERROR, "Could not dilate boolean operand", log_reference);
			return false;
		}
	}		

	try {
		cgal_shape_t convert_back;
		result.convert_to_polyhedron(convert_back);
	} catch (...) {
		Logger::Message(Logger::LOG_WARNING, "Final conversion will likely fail. Could not convert geometry from Nef:", log_reference);
	}

	return true;
}

namespace {
	bool convert_placement(const ifcopenshell::geometry::taxonomy::matrix4& place, cgal_placement_t& trsf) {
		const auto& m = place.components;

		// @todo check
		trsf = 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));

		return true;
	}
}



bool CgalKernel::convert_impl(const taxonomy::boolean_result* br, ifcopenshell::geometry::ConversionResults& results) {
	bool first = true;

	CGAL::Nef_polyhedron_3<Kernel_> a;

	taxonomy::style first_item_style;

	for (auto& c : br->children) {
		// AbstractKernel::convert(c, results);
		// continue;

		ifcopenshell::geometry::ConversionResults cr;
		// @todo half-space detection
		AbstractKernel::convert(c, cr);

		if (first && br->operation == taxonomy::boolean_result::SUBTRACTION) {
			first_item_style = ((taxonomy::geom_item*)c)->surface_style;
			if (!first_item_style.diffuse && c->kind() == taxonomy::COLLECTION) {
				first_item_style = ((taxonomy::geom_item*) ((taxonomy::collection*)c)->children[0])->surface_style;
			}
		}

		for (auto it = cr.begin(); it != cr.end(); ++it) {
			const cgal_shape_t& entity_shape_unlocated(((CgalShape*)it->Shape())->shape());
			cgal_shape_t entity_shape(entity_shape_unlocated);
			if (!it->Placement().components.isIdentity()) {
				cgal_placement_t trsf;
				convert_placement(it->Placement(), trsf);
				for (auto &vertex : vertices(entity_shape)) {
					if (false) {
						auto x = CGAL::to_double(vertex->point().x());
						auto y = CGAL::to_double(vertex->point().y());
						auto z = CGAL::to_double(vertex->point().z());
						std::wcout << x << " " << y << " " << z << std::endl;
					}
					vertex->point() = vertex->point().transform(trsf);
					if (false) {
						auto x = CGAL::to_double(vertex->point().x());
						auto y = CGAL::to_double(vertex->point().y());
						auto z = CGAL::to_double(vertex->point().z());
						std::wcout << x << " " << y << " " << z << std::endl;
					}
				}
			}

			CGAL::Nef_polyhedron_3<Kernel_> nef;
			preprocess_boolean_operand(c->instance, entity_shape, nef,
				// Dilate boolean subtraction operands
				(!first && br->operation == taxonomy::boolean_result::SUBTRACTION) ? precision_ : 0.);

			if (first) {
				a = nef;
			} else {
				if (br->operation == taxonomy::boolean_result::SUBTRACTION) {
					a -= nef;
				} else if (br->operation == taxonomy::boolean_result::INTERSECTION) {
					a *= nef;
				} else if (br->operation == taxonomy::boolean_result::UNION) {
					a += nef;
				}
			}
		}

		first = false;
	}

	cgal_shape_t a_poly;

	try {
		a.convert_to_polyhedron(a_poly);
	} catch (...) {
		Logger::Message(Logger::LOG_ERROR, "Could not convert geometry with openings from Nef:", br->instance);
		return false;
	}

	results.emplace_back(ConversionResult(
		br->instance->data().id(),
		br->matrix,
		new CgalShape(a_poly),
		br->surface_style.diffuse ? br->surface_style : first_item_style
	));
	return true;
}