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

#include "CgalConversionResult.h"
#include "CgalKernel.h"

#include <CGAL/Polygon_mesh_processing/repair.h>

#include "../../../ifcparse/IfcLogger.h"
#include "../../../ifcgeom/IfcGeomRepresentation.h"

void ifcopenshell::geometry::CgalShape::Triangulate(const IfcGeom::IteratorSettings& settings, const ifcopenshell::geometry::taxonomy::matrix4& place, IfcGeom::Representation::Triangulation* t, int surface_style_id) const {
	// Copy is made because triangulate_faces() obviously does not accept a const argument
	// ... also becuase of transforming the vertex positions, right?
	cgal_shape_t s = shape_;

	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 : vertices(s)) {
			vertex->point() = vertex->point().transform(trsf);
		}
	}

	if (!std::all_of(s.facets_begin(), s.facets_end(), [](auto f) { return f.is_triangle(); })) {

		if (!s.is_valid()) {
			Logger::Message(Logger::LOG_ERROR, "Invalid Polyhedron_3 in object (before triangulation)");
			return;
		}

		CGAL::Polygon_mesh_processing::remove_degenerate_faces(s);

		bool success = false;
		try {
			success = CGAL::Polygon_mesh_processing::triangulate_faces(s);
		} catch (...) {
			Logger::Message(Logger::LOG_ERROR, "Triangulation crashed");
			return;
		}

		if (!success) {
			Logger::Message(Logger::LOG_ERROR, "Triangulation failed");
			return;
		}
		//    std::cout << "Triangulated model: " << s.size_of_facets() << " facets and " << s.size_of_vertices() << " vertices" << std::endl;

		if (!s.is_valid()) {
			Logger::Message(Logger::LOG_ERROR, "Invalid Polyhedron_3 in object (after triangulation)");
			return;
		}

	}

	// std::map<cgal_vertex_descriptor_t, Kernel_::Vector_3> vertex_normals;
	// boost::associative_property_map<std::map<cgal_vertex_descriptor_t, Kernel_::Vector_3>> vertex_normals_map(vertex_normals);
	
	// Triangulate the shape and compute the normals
	std::map<cgal_face_descriptor_t, Kernel_::Vector_3> face_normals;
	boost::associative_property_map<std::map<cgal_face_descriptor_t, Kernel_::Vector_3>> face_normals_map(face_normals);

	//  CGAL::Polygon_mesh_processing::compute_normals(s, vertex_normals_map, face_normals_map);
	try {
		CGAL::Polygon_mesh_processing::compute_face_normals(s, face_normals_map);
	} catch (...) {
		Logger::Message(Logger::LOG_ERROR, "Face normal calculation failed");
		return;
	}

	int num_faces = 0, num_vertices = 0;
	for (auto &face : faces(s)) {
		if (!face->is_triangle()) {
			std::cout << "Warning: non-triangular face!" << std::endl;
			continue;
		}
		CGAL::Polyhedron_3<Kernel_>::Halfedge_around_facet_const_circulator current_halfedge = face->facet_begin();
		int vertexidx[3];
		int i = 0;
		do {
			vertexidx[i++] = t->addVertex(surface_style_id,
				CGAL::to_double(current_halfedge->vertex()->point().cartesian(0)),
				CGAL::to_double(current_halfedge->vertex()->point().cartesian(1)),
				CGAL::to_double(current_halfedge->vertex()->point().cartesian(2)));

			double nx = 0.;
			double ny = 0.;
			double nz = 1.;

			nx = CGAL::to_double(face_normals_map[face].cartesian(0));
			ny = CGAL::to_double(face_normals_map[face].cartesian(1));
			nz = CGAL::to_double(face_normals_map[face].cartesian(2));
		
			t->addNormal(nx, ny, nz);

			++num_vertices;
			++current_halfedge;
		} while (current_halfedge != face->facet_begin());

		t->addFace(surface_style_id, vertexidx[0], vertexidx[1], vertexidx[2]);

		++num_faces;
	}

}

void ifcopenshell::geometry::CgalShape::Serialize(const ifcopenshell::geometry::taxonomy::matrix4& place, std::string& r) const {
	cgal_shape_t s = shape_;

	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 : vertices(s)) {
			vertex->point() = vertex->point().transform(trsf);
		}
	}

	std::stringstream sstream;
	sstream << s;
	r = sstream.str();
}

#include <CGAL/Polygon_mesh_processing/bbox.h>

double ifcopenshell::geometry::CgalShape::bounding_box(void *& b) const {
	if (b == nullptr) {
		b = new CGAL::Bbox_3;
	}
	auto& bb = (*((CGAL::Bbox_3*)b));
	bb += CGAL::Polygon_mesh_processing::bbox(shape_);
	return (bb.xmax() - bb.xmin()) * (bb.ymax() - bb.ymin()) * (bb.zmax() - bb.zmin());
}

int ifcopenshell::geometry::CgalShape::num_vertices() const {
	return shape_.size_of_vertices();
}

void ifcopenshell::geometry::CgalShape::set_box(void * b) {
	auto& bb = (*((CGAL::Bbox_3*)b));
	Kernel_::Point_3 lower(bb.xmin(), bb.ymin(), bb.zmin());
	Kernel_::Point_3 upper(bb.xmax(), bb.ymax(), bb.zmax());
	shape_ = ifcopenshell::geometry::utils::create_cube(lower, upper);
}

int ifcopenshell::geometry::CgalShape::surface_genus() const {
	throw std::runtime_error("Not implemented");
}