solved the triangulation error

Arrangement_on_surface_2/demo/earth/Aos.cpp

@@ -1310,6 +1310,10 @@ Aos::Arr_handle  Aos::construct(Kml::Placemarks& placemarks)
 #include <CGAL/Polygon_2.h>
 //#include <CGAL/Projection_traits_3.h>
 
+#include <iostream>
+#include <unordered_map>
+#include <boost/property_map/property_map.hpp>
+
 std::vector<QVector3D> Aos::get_triangles(Arr_handle arrh)
 {
   typedef CGAL::Exact_predicates_inexact_constructions_kernel       K;
@@ -1356,9 +1360,20 @@ std::vector<QVector3D> Aos::get_triangles(Arr_handle arrh)
   // RESULTING TRIANGLE POINTS (every 3 point => triangle)
   std::vector<QVector3D>  triangles;
 
+  std::cout << "triangulating individual faces\n";
+
   // loop on all approximated faces
   for (auto& face_points : all_faces)
   {
+    std::cout << "num face points = " << face_points.size() << std::endl;
+    // no need to triangulate if the number of points is 3
+    if (face_points.size() == 3)
+    {
+      triangles.insert(triangles.end(), face_points.begin(), face_points.end());
+      continue;
+    }
+
+
     // find the centroid of all face-points
     QVector3D centroid(0, 0, 0);
     for (const auto& fp : face_points)
@@ -1394,9 +1409,20 @@ std::vector<QVector3D> Aos::get_triangles(Arr_handle arrh)
     CDT cdt;
     cdt.insert_constraint(polygon.vertices_begin(), polygon.vertices_end(), true);
 
+    std::unordered_map<Face_handle, bool> in_domain_map;
+    boost::associative_property_map< std::unordered_map<Face_handle, bool> >
+      in_domain(in_domain_map);
+
+    //Mark facets that are inside the domain bounded by the polygon
+    CGAL::mark_domain_in_triangulation(cdt, in_domain);
+
     // loop on all the triangles ("faces" in triangulation doc)
     for (Face_handle f : cdt.finite_face_handles())
     {
+      // if the current triangles is not inside the polygon -> skip it
+      if (false == get(in_domain, f))
+        continue;
+
       for(int i=0; i<3; ++i)
       {
         auto tp = f->vertex(i)->point();

Arrangement_on_surface_2/demo/earth/Main_widget.cpp

@@ -177,8 +177,8 @@ void Main_widget::initializeGL()
   //Shapefile::read(shape_file_name);
 
   //const auto file_name = data_path + "world_countries.kml";
-  //const auto file_name = data_path + "ne_110m_admin_0_countries.kml";
-  const auto file_name = data_path + "ne_110m_admin_0_countries_africa.kml";
+  const auto file_name = data_path + "ne_110m_admin_0_countries.kml";
+  //const auto file_name = data_path + "ne_110m_admin_0_countries_africa.kml";
   m_countries = Kml::read(file_name);
   auto dup_nodes = Kml::get_duplicates(m_countries);
   //auto all_nodes = Kml::generate_ids(m_countries);
@@ -199,8 +199,12 @@ void Main_widget::initializeGL()
 
   // trianglulation
   {
+    qDebug() << "constructiong arr..";
     auto arrh = Aos::construct(m_countries);
+
+    qDebug() << "generating triangles..";
     auto triangle_points = Aos::get_triangles(arrh);
+
     qDebug() << "num triangles = " << triangle_points.size() / 3;
     g_face_triangles = std::make_unique<Triangles>(triangle_points);
   }
@@ -477,22 +481,25 @@ void Main_widget::paintGL()
     auto& sp = m_sp_smooth;
     sp.use();
     sp.set_uniform("u_mvp", mvp);
-    sp.set_uniform("u_color", m_sphere->get_color());
+    QVector4D sphere_color(167. / 255, 205. / 255, 242. / 255, 1);
+    sp.set_uniform("u_color", sphere_color);
+    //sp.set_uniform("u_color", m_sphere->get_color());
 
-    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+    //glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
     m_sphere->draw();
 
     // DRAW SOLID FACES
+    if(1)
     {
       glDisable(GL_DEPTH_TEST);
       QVector4D face_color(1, .5, 0, 1);
       sp.set_uniform("u_color", face_color);
-      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+      //glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
       g_face_triangles->draw();
 
-      sp.set_uniform("u_color", QVector4D(0,0,0,1));
-      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-      g_face_triangles->draw();
+      //sp.set_uniform("u_color", QVector4D(0,0,0,1));
+      //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+      //g_face_triangles->draw();
     }
 
     sp.unuse();
@@ -504,6 +511,7 @@ void Main_widget::paintGL()
     sp.use();
     sp.set_uniform("u_mvp", mvp);
 
+    glEnable(GL_DEPTH_TEST);
     m_world_coord_axes->draw();
 
     sp.unuse();