Gsoc2023, stand-alone interactive program that demonstrates 2D arrangements embedded on the sphere

Arrangement_on_surface_2/demo/earth/Aos.h

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+// Copyright(c) 2023, 2024 Tel-Aviv University (Israel).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org).
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
+//
+// Author(s): Engin Deniz Diktas <[email protected]>
+
+#ifndef AOS_H
+#define AOS_H
+
+#include <map>
+#include <memory>
+#include <vector>
+#include <qvector3d.h>
+
+#include "Kml_reader.h"
+
+class Aos {
+public:
+  using Approx_arc = std::vector<QVector3D>;
+  using Approx_arcs = std::vector<Approx_arc>;
+  //using Arr_handle = void*;
+  using Arr_handle = std::shared_ptr<void>;
+
+  static Approx_arc get_approx_identification_curve(double error);
+
+  // this constructs some sample arcs manually (used to check the visual output)
+  static Approx_arcs get_approx_arcs(double error);
+
+  // this is used to construct approximate arcs from KML-Placemark data
+  static Approx_arcs get_approx_arcs(const Kml::Placemark& placemark,
+                                     double error);
+
+  static void get_curves();
+
+  static void check(const Kml::Placemarks& placemarks);
+
+  // Extended check: here we use the extended version of the DCEL to understand
+  // what is going on with the additional vertices and faces.
+  // INPUT: GIS data
+  // OUTPUT: vertices created during arrangement construction
+  static std::vector<QVector3D> ext_check(const Kml::Placemarks& placemarks);
+
+  // Same as above function but works by identifying the duplicate nodes
+  static std::vector<QVector3D> ext_check_id_based(Kml::Placemarks& placemarks);
+
+  // This function is used to find the newly-created faces during arrangement
+  // construction. It uses the extended DCEL structure (see: above 2 functions).
+  // NOTE: The need for this function arises due to the following observation:
+  // when constructing the arrangement from our data-set I observed a newly
+  // created face which is not defined explicitly in the data-set. My intiution
+  // tells me that this is the Caspian sea, because it is the only land-locked
+  // polygon whose boundaries are not defined in the data-set and its boundaries
+  // are defined indirecly by its surrounding countries.
+  static Approx_arcs find_new_faces(Kml::Placemarks& placemarks);
+
+  // save the arrangement created with EPEC
+  static void save_arr(Kml::Placemarks& placemarks,
+                       const std::string& file_name);
+
+  // loads the arrangement created by the save_arr function
+  // NOTE: This one loads the arrangement as "Country_arr" type
+  static Arr_handle load_arr(const std::string& file_name);
+
+  static Arr_handle construct(Kml::Placemarks& placemarks);
+  //static std::vector<QVector3D> get_triangles(Arr_handle arrh);
+
+  //using Country_triangles_map = std::map<std::string, std::vector<QVector3D>>;
+  //static Country_triangles_map get_triangles_by_country(Arr_handle arrh);
+
+  using Country_color_map = std::map<std::string, int>;
+  static Country_color_map get_color_mapping(Arr_handle arrh);
+
+  static std::string locate_country(Arr_handle arrh, const QVector3D& point);
+
+  // this will get the approximate arcs of face-edges from the arrangement
+  // NOTE: this is similar to "get_approx_arcs(KML::Placemarks&, float)" above!
+  static Approx_arcs get_approx_arcs_from_faces_edges(Arr_handle arrh,
+                                                      float error);
+};
+
+#endif

Arrangement_on_surface_2/demo/earth/Aos_defs.h

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+// Copyright(c) 2023, 2024 Tel-Aviv University (Israel).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org).
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
+//
+// Author(s): Engin Deniz Diktas <[email protected]>
+
+#ifndef AOS_DEFS_H
+#define AOS_DEFS_H
+
+#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
+#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
+#include <CGAL/Arrangement_on_surface_2.h>
+#include <CGAL/Arr_extended_dcel.h>
+#include <CGAL/Arr_geodesic_arc_on_sphere_traits_2.h>
+#include <CGAL/Arr_spherical_topology_traits_2.h>
+#include <CGAL/Vector_3.h>
+
+//#define USE_EPIC
+
+#ifdef USE_EPIC
+using Kernel = CGAL::Exact_predicates_inexact_constructions_kernel;
+#else
+using Kernel = CGAL::Exact_predicates_exact_constructions_kernel;
+#endif
+
+using Geom_traits = CGAL::Arr_geodesic_arc_on_sphere_traits_2<Kernel>;
+using Point = Geom_traits::Point_2;
+using Curve = Geom_traits::Curve_2;
+using Topol_traits = CGAL::Arr_spherical_topology_traits_2<Geom_traits>;
+using Arrangement = CGAL::Arrangement_on_surface_2<Geom_traits, Topol_traits>;
+
+// the following is from "arr_inexact_construction_segments.h":
+using Segment = Geom_traits::X_monotone_curve_2;
+using Vertex_handle = Arrangement::Vertex_handle;
+
+// COUNTRIES AOS for grouping the faces by the country name
+using Countries_dcel = CGAL::Arr_face_extended_dcel<Geom_traits, std::string>;
+using Countries_topol_traits =
+  CGAL::Arr_spherical_topology_traits_2<Geom_traits, Countries_dcel>;
+using Countries_arr =
+  CGAL::Arrangement_on_surface_2<Geom_traits, Countries_topol_traits>;
+
+
+#endif