Add an example for spatial searching with projection

Spatial_searching/doc/Spatial_searching/examples.txt

@@ -6,6 +6,7 @@
 \example Spatial_searching/fuzzy_range_query.cpp
 \example Spatial_searching/general_neighbor_searching.cpp
 \example Spatial_searching/iso_rectangle_2_query.cpp
+\example Spatial_searching/iso_rectangle_2_query_projection.cpp
 \example Spatial_searching/nearest_neighbor_searching.cpp
 \example Spatial_searching/searching_with_circular_query.cpp
 \example Spatial_searching/searching_surface_mesh_vertices.cpp

Spatial_searching/examples/Spatial_searching/CMakeLists.txt

@@ -28,6 +28,8 @@ create_single_source_cgal_program("distance_browsing.cpp")
 
 create_single_source_cgal_program("iso_rectangle_2_query.cpp")
 
+create_single_source_cgal_program("iso_rectangle_2_query_projection.cpp")
+
 create_single_source_cgal_program("nearest_neighbor_searching.cpp")
 
 create_single_source_cgal_program("searching_with_circular_query.cpp")

Spatial_searching/examples/Spatial_searching/iso_rectangle_2_query.cpp

@@ -46,7 +46,7 @@ int main()
   // using value 0.1 for fuzziness paramater
   Fuzzy_iso_box approximate_range(p, q, 0.1);
   tree.search(std::back_inserter( result ), approximate_range);
-  std::cout << "The points in the fuzzy box [[0.1, 0.3], [0.6, 0.9]]^2 are: " << std::endl;
+  std::cout << "The points in the fuzzy box [[0.1, 0.3], [0.6, 0.8]]^2 are: " << std::endl;
   std::copy (result.begin(), result.end(), std::ostream_iterator<Point_d>(std::cout,"\n") );
   std::cout << std::endl;
   return 0;

Spatial_searching/examples/Spatial_searching/iso_rectangle_2_query_projection.cpp

@@ -0,0 +1,72 @@
+#include <CGAL/Simple_cartesian.h>
+#include <CGAL/Kd_tree.h>
+#include <CGAL/point_generators_3.h>
+#include <CGAL/algorithm.h>
+#include <CGAL/Fuzzy_iso_box.h>
+
+#include <CGAL/Search_traits_2.h>
+
+// Point_3 to Point_2 projection on the fly
+template<class K>
+struct Projection_xy_property_map
+{
+  typedef typename K::Point_3 key_type;
+  typedef typename K::Point_2 value_type;
+  typedef value_type reference;
+  typedef boost::readable_property_map_tag category;
+
+  friend value_type get(Projection_xy_property_map<K>, const key_type& k)
+  {
+    return value_type(k.x(), k.y());
+  }
+};
+
+typedef CGAL::Simple_cartesian<double> K;
+typedef K::Point_2 Point_2;
+typedef K::Point_3 Point_3;
+
+typedef CGAL::Random_points_in_cube_3<Point_3> Random_points_iterator;
+typedef CGAL::Counting_iterator<Random_points_iterator> N_Random_points_iterator;
+
+typedef CGAL::Search_traits_2<K>Traits_base;
+typedef CGAL::Search_traits_adapter<Point_3, Projection_xy_property_map<K>, Traits_base> Traits;
+typedef CGAL::Kd_tree<Traits> Tree;
+typedef CGAL::Fuzzy_iso_box<Traits> Fuzzy_iso_box;
+
+int main()
+{
+  const int N = 1000;
+
+  std::list<Point_3> points;
+  points.push_back(Point_3(0, 0, 0));
+
+  Tree tree;
+  Random_points_iterator rpg;
+  for(int i = 0; i < N; i++)
+    tree.insert(*rpg++);
+
+  std::list<Point_3> result;
+
+  // define 2D range query
+  Point_2 p(0.2, 0.2);
+  Point_2 q(0.7, 0.7);
+
+  // Searching an exact range
+  // using default value 0.0 for epsilon fuzziness paramater
+  Fuzzy_iso_box exact_range(p,q);
+  tree.search( std::back_inserter( result ), exact_range);
+  std::cout << "The points in the box [0.2, 0.7]^2 are: " << std::endl;
+  std::copy (result.begin(), result.end(), std::ostream_iterator<Point_3>(std::cout,"\n") );
+  std::cout << std::endl;
+
+  result.clear();
+
+  // Searching a fuzzy range
+  // using value 0.1 for fuzziness paramater
+  Fuzzy_iso_box approximate_range(p, q, 0.1);
+  tree.search(std::back_inserter( result ), approximate_range);
+  std::cout << "The points in the fuzzy box [[0.1, 0.3], [0.6, 0.8]]^2 are: " << std::endl;
+  std::copy (result.begin(), result.end(), std::ostream_iterator<Point_3>(std::cout,"\n") );
+  std::cout << std::endl;
+  return 0;
+}