Added: check with extended DCEL

Arrangement_on_surface_2/demo/earth/Aos.cpp

@@ -11,6 +11,7 @@
 #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>
@@ -25,6 +26,20 @@ namespace {
   using Topol_traits = CGAL::Arr_spherical_topology_traits_2<Geom_traits>;
   using Arrangement = CGAL::Arrangement_on_surface_2<Geom_traits, Topol_traits>;
 
+  // Extended DCEL & Arrangement
+  struct Flag
+  {
+    bool v;
+    Flag() : v{ false } {}
+    Flag(bool init) : v{ init } {}
+  };
+
+  using Ext_dcel = CGAL::Arr_extended_dcel<Geom_traits, Flag, Flag, Flag>;
+  using Ext_topol_traits = CGAL::Arr_spherical_topology_traits_2<Geom_traits, 
+                                                                      Ext_dcel>;
+  using Ext_aos = CGAL::Arrangement_on_surface_2<Geom_traits, Ext_topol_traits>;
+
+
 
   using Dir3 = Kernel::Direction_3;
   std::ostream& operator << (std::ostream& os, const Dir3& d)
@@ -55,6 +70,7 @@ namespace {
   }
 }
 
+
 void Aos::check(const Kml::Placemarks& placemarks)
 {
   // Construct the arrangement from 12 geodesic arcs.
@@ -79,17 +95,9 @@ void Aos::check(const Kml::Placemarks& placemarks)
       for (const auto& node : lring.nodes)
       {
         num_counted_nodes++;
-
         const auto p = node.get_coords_3d();
-        //const auto phi = qDegreesToRadians(node.lat);
-        //const auto theta = qDegreesToRadians(node.lon);
-        //const auto z = std::sin(phi);
-        //const auto rxy = std::cos(phi);
-        //const auto x = rxy * std::cos(theta);
-        //const auto y = rxy * std::sin(theta);
         Approximate_Vector_3  v(p.x, p.y, p.z);
         sphere_points.push_back(v);
-
         CGAL::insert_point(arr, ctr_p(p.x, p.y, p.z));
       }
 
@@ -126,4 +134,91 @@ void Aos::check(const Kml::Placemarks& placemarks)
   std::cout << "-------------------------------\n";
   std::cout << "num polygons = " << num_counted_polygons << std::endl;
   std::cout << "num arr faces = " << arr.number_of_faces() << std::endl;
-}
+}
+
+void Aos::ext_check(const Kml::Placemarks& placemarks)
+{
+  // Construct the arrangement from 12 geodesic arcs.
+  Geom_traits traits;
+  Ext_aos arr(&traits);
+
+  auto ctr_p = traits.construct_point_2_object();
+  auto ctr_cv = traits.construct_curve_2_object();
+
+  int num_counted_nodes = 0;
+  int num_counted_arcs = 0;
+  int num_counted_polygons = 0;
+  std::vector<Curve>  xcvs;
+  for (const auto& pm : placemarks)
+  {
+    for (const auto& lring : pm.polygons)
+    {
+      num_counted_polygons++;
+
+      // convert the nodes to points on unit-sphere
+      std::vector<Approximate_Vector_3> sphere_points;
+      for (const auto& node : lring.nodes)
+      {
+        num_counted_nodes++;
+        const auto p = node.get_coords_3d();
+        Approximate_Vector_3  v(p.x, p.y, p.z);
+        sphere_points.push_back(v);
+        CGAL::insert_point(arr, ctr_p(p.x, p.y, p.z));
+      }
+
+      // add curves
+      int num_points = sphere_points.size();
+      for (int i = 0; i < sphere_points.size() - 1; i++)
+      {
+        num_counted_arcs++;
+        const auto p1 = sphere_points[i];
+        const auto p2 = sphere_points[i + 1];
+        auto xcv = ctr_cv(ctr_p(p1.x(), p1.y(), p1.z()),
+          ctr_p(p2.x(), p2.y(), p2.z()));
+        xcvs.push_back(xcv);
+      }
+    }
+  }
+
+  // MARK all vertices as true
+  for (auto vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit)
+  {
+    vit->set_data(Flag(true));
+  }
+
+  std::cout << "-------------------------------\n";
+  std::cout << "num arr vertices (before adding arcs) = " <<
+    arr.number_of_vertices() << std::endl;
+
+  // add arcs
+  for (auto xcv : xcvs)
+    CGAL::insert_curve(arr, xcv);
+
+  // extract all vertices that are ADDED when inserting the arcs!
+  int num_created_vertices = 0;
+  for (auto vit = arr.vertices_begin(); vit != arr.vertices_end(); ++vit)
+  {
+    auto& d = vit->data();
+    if (vit->data().v == false)
+    {
+      num_created_vertices++;
+      auto p = vit->point();
+      const auto x = CGAL::to_double(p.dx());
+      const auto y = CGAL::to_double(p.dy());
+      const auto z = CGAL::to_double(p.dz());
+    }
+  }
+  std::cout << "*** num created vertices = " << num_created_vertices << std::endl;
+
+  std::cout << "-------------------------------\n";
+  std::cout << "num nodes = " << num_counted_nodes << std::endl;
+  std::cout << "num arr vertices = " << arr.number_of_vertices() << std::endl;
+
+  std::cout << "-------------------------------\n";
+  std::cout << "num counted arcs = " << num_counted_arcs << std::endl;
+  std::cout << "num arr edges = " << arr.number_of_edges() << std::endl;
+
+  std::cout << "-------------------------------\n";
+  std::cout << "num polygons = " << num_counted_polygons << std::endl;
+  std::cout << "num arr faces = " << arr.number_of_faces() << std::endl;
+}

Arrangement_on_surface_2/demo/earth/Aos.h

@@ -13,6 +13,12 @@ class Aos
 public:
 
   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 void ext_check(const Kml::Placemarks& placemarks);
 };
 
 

Arrangement_on_surface_2/demo/earth/Main_widget.cpp

@@ -108,16 +108,8 @@ void Main_widget::timerEvent(QTimerEvent*)
 }
 
 
-auto func()
-{
-  double x, y, z;
-  return std::make_tuple(x,y,z); 
-}
-
 void Main_widget::initializeGL()
 {
-  auto [x, y, z] = func();
-
   //const auto file_name = "C:/work/gsoc2023/data/world_countries.kml";
   const auto file_name = "C:/work/gsoc2023/data/ne_110m_admin_0_countries.kml";
   auto countries = Kml::read(file_name);
@@ -137,7 +129,7 @@ void Main_widget::initializeGL()
 
   // check the arrangement constructed from the GIS data-set
   {
-    Aos::check(countries);
+    Aos::ext_check(countries);
   }