From ae7ed73a55fd96f21622380c8fa0998ffb8d0dba Mon Sep 17 00:00:00 2001
From: Simon Giraudot <simon.giraudot@geometryfactory.com>
Date: Wed, 2 Dec 2015 15:28:24 +0100
Subject: [PATCH] New example for advancing front taking advantage of point set
 structuring

---
 .../reconstruction_structured.cpp             | 144 ++++++++++++++++++
 1 file changed, 144 insertions(+)
 create mode 100644 Advancing_front_surface_reconstruction/examples/Advancing_front_surface_reconstruction/reconstruction_structured.cpp

diff --git a/Advancing_front_surface_reconstruction/examples/Advancing_front_surface_reconstruction/reconstruction_structured.cpp b/Advancing_front_surface_reconstruction/examples/Advancing_front_surface_reconstruction/reconstruction_structured.cpp
new file mode 100644
index 00000000000..25b4522c6b4
--- /dev/null
+++ b/Advancing_front_surface_reconstruction/examples/Advancing_front_surface_reconstruction/reconstruction_structured.cpp
@@ -0,0 +1,144 @@
+#include <iostream>
+#include <fstream>
+#include <algorithm>
+
+#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
+#include <CGAL/Point_with_normal_3.h>
+#include <CGAL/Shape_detection_3.h>
+#include <CGAL/structure_point_set.h>
+#include <CGAL/Delaunay_triangulation_3.h>
+#include <CGAL/Triangulation_vertex_base_with_info_3.h>
+#include <CGAL/Advancing_front_surface_reconstruction.h>
+#include <CGAL/IO/read_xyz_points.h>
+
+#include <boost/lexical_cast.hpp>
+
+typedef CGAL::Exact_predicates_inexact_constructions_kernel  Kernel;
+typedef Kernel::Point_3  Point;
+typedef std::pair<Kernel::Point_3, Kernel::Vector_3>         Point_with_normal;
+typedef std::vector<Point_with_normal>                       Pwn_vector;
+typedef CGAL::First_of_pair_property_map<Point_with_normal>  Point_map;
+typedef CGAL::Second_of_pair_property_map<Point_with_normal> Normal_map;
+
+// Efficient RANSAC types
+typedef CGAL::Shape_detection_3::Efficient_RANSAC_traits
+  <Kernel, Pwn_vector, Point_map, Normal_map>                Traits;
+typedef CGAL::Shape_detection_3::Efficient_RANSAC<Traits>    Efficient_ransac;
+typedef CGAL::Shape_detection_3::Plane<Traits>               Plane;
+
+typedef CGAL::internal::Point_set_structuring<Traits>        Structuring;
+
+typedef CGAL::Advancing_front_surface_reconstruction_vertex_base_3<Kernel> LVb;
+typedef CGAL::Advancing_front_surface_reconstruction_cell_base_3<Kernel> LCb;
+
+typedef CGAL::Triangulation_data_structure_3<LVb,LCb> Tds;
+typedef CGAL::Delaunay_triangulation_3<Kernel,Tds> Triangulation_3;
+typedef typename Triangulation_3::Vertex_handle Vertex_handle;
+
+typedef CGAL::cpp11::array<std::size_t,3> Facet;
+
+
+struct On_the_fly_pair{
+  const Pwn_vector& points;
+  typedef std::pair<Point, std::size_t> result_type;
+
+  On_the_fly_pair(const Pwn_vector& points) : points(points) {}
+  
+  result_type
+  operator()(std::size_t i) const
+  {
+    return result_type(points[i].first,i);
+  }
+};
+
+
+template <typename Structuring>
+struct Structure_coherence {
+
+  Structuring& structuring;
+
+  Structure_coherence(Structuring& structuring)
+    : structuring (structuring)
+  {}
+
+  template <typename Vertex_handle>
+  bool operator()(const Vertex_handle& p, const Vertex_handle& q, const Vertex_handle& r) const
+  {
+    Facet f = {{ p->info(), q->info(), r->info() }};
+    return (structuring.facet_coherence (f) == 0);
+  }
+};
+
+typedef CGAL::Advancing_front_surface_reconstruction<Triangulation_3,
+                                                     Structure_coherence<Structuring> > Reconstruction;
+
+
+
+int main (int argc, char* argv[])
+{
+  // Points with normals.
+  Pwn_vector points;
+
+  // Loading point set from a file. 
+  std::ifstream stream(argc>1 ? argv[1] : "data/cube.pwn");
+
+  if (!stream || 
+    !CGAL::read_xyz_points_and_normals(stream,
+      std::back_inserter(points),
+      Point_map(),
+      Normal_map()))
+  {
+      std::cerr << "Error: cannot read file" << std::endl;
+      return EXIT_FAILURE;
+  }
+
+  std::cerr << "Shape detection... ";
+  // Shape detection
+  Efficient_ransac ransac;
+  ransac.set_input(points);
+  ransac.add_shape_factory<Plane>();
+
+  Efficient_ransac::Parameters op;
+  op.probability = 0.05;
+  op.min_points = 100;
+  op.epsilon = (argc>2 ? boost::lexical_cast<double>(argv[2]) : 0.002);
+  op.cluster_epsilon = (argc>3 ? boost::lexical_cast<double>(argv[3]) : 0.02);
+  op.normal_threshold = 0.7;
+
+  ransac.detect(op);
+  std::cerr << "done\nPoint set structuring... ";
+  Pwn_vector structured_pts;
+  
+  Structuring pss (points.begin (), points.end (), ransac);
+
+  pss.run (op.cluster_epsilon);
+
+  pss.get_output (std::back_inserter (structured_pts));
+  std::cerr << "done\nAdvancing front... ";
+  std::vector<std::size_t> point_indices(boost::counting_iterator<std::size_t>(0),
+                                         boost::counting_iterator<std::size_t>(structured_pts.size()));
+
+  Triangulation_3 dt (boost::make_transform_iterator(point_indices.begin(), On_the_fly_pair(structured_pts)),
+                      boost::make_transform_iterator(point_indices.end(), On_the_fly_pair(structured_pts)));
+
+  Structure_coherence<Structuring> filter (pss);
+  
+  Reconstruction R(dt, filter);
+  R.run (5., 0.52);
+  std::cerr << "done\nWriting result... ";
+  std::vector<Facet> output;
+  CGAL::write_triple_indices (std::back_inserter (output), R);
+
+  std::ofstream f ("out.off");
+  f << "OFF\n" << structured_pts.size () << " " << output.size() << " 0\n";
+  for (std::size_t i = 0; i < structured_pts.size (); ++ i)
+    f << structured_pts[i].first << std::endl;
+  for (std::size_t i = 0; i < output.size (); ++ i)
+    f << "3 "
+      << output[i][0] << " "
+      << output[i][1] << " "
+      << output[i][2] << std::endl;
+  std::cerr << "all done\n" << std::endl;
+  
+  return 0;
+}