1 files changed, 308 insertions, 0 deletions
diff --git a/src/common/include/gudhi/Delaunay_triangulation_off_io.h b/src/common/include/gudhi/Delaunay_triangulation_off_io.h
new file mode 100644
index 00000000..0c5474c9
--- /dev/null
+++ b/src/common/include/gudhi/Delaunay_triangulation_off_io.h
@@ -0,0 +1,308 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       Vincent Rouvreau
+ *
+ *    Copyright (C) 2015  INRIA Saclay (France)
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef SRC_ALPHA_SHAPES_INCLUDE_GUDHI_ALPHA_SHAPES_DELAUNAY_TRIANGULATION_OFF_IO_H_
+#define SRC_ALPHA_SHAPES_INCLUDE_GUDHI_ALPHA_SHAPES_DELAUNAY_TRIANGULATION_OFF_IO_H_
+
+#include <string>
+#include <vector>
+#include <fstream>
+#include <map>
+
+#include "gudhi/Off_reader.h"
+
+namespace Gudhi {
+
+/** \brief OFF file visitor implementation according to Off_reader in order to construct a CGAL Delaunay triangulation.
+ * 
+ * For more informations on CGAL Delaunay triangulation, please refer to the corresponding chapter in page
+ *  http://doc.cgal.org/latest/Triangulation/
+ */
+template<typename Complex>
+class Delaunay_triangulation_off_visitor_reader {
+ private:
+  Complex* complex_;
+  typedef typename Complex::Point Point;
+
+ public:
+
+  // TODO(VR) : Pass a Complex as a parameter is required, even if not used. Otherwise, compilation is KO.
+
+  /** \brief Delaunay_triangulation_off_visitor_reader constructor
+   *
+   * @param[in] complex_ptr_ pointer on a Delaunay triangulation.
+   */
+  Delaunay_triangulation_off_visitor_reader(Complex* complex_ptr_)
+      : complex_(nullptr) { }
+
+  /** \brief Off_reader visitor init implementation. 
+   * 
+   * The init parameters are set from OFF file header.
+   * Dimension value is required in order to construct Delaunay triangulation.
+   *
+   * @param[in] dim space dimension of vertices.
+   * @param[in] num_vertices number of vertices in the OFF file (not used).
+   * @param[in] num_faces number of faces in the OFF file (not used).
+   * @param[in] num_edges number of edges in the OFF file (not used).
+   */
+  void init(int dim, int num_vertices, int num_faces, int num_edges) {
+#ifdef DEBUG_TRACES
+    std::cout << "Delaunay_triangulation_off_visitor_reader::init - dim=" << dim << " - num_vertices=" <<
+        num_vertices << " - num_faces=" << num_faces << " - num_edges=" << num_edges << std::endl;
+#endif  // DEBUG_TRACES
+    if (num_faces > 0) {
+      std::cerr << "Delaunay_triangulation_off_visitor_reader::init faces are not taken into account from OFF " <<
+          "file for Delaunay triangulation - faces are computed." << std::endl;
+    }
+    if (num_edges > 0) {
+      std::cerr << "Delaunay_triangulation_off_visitor_reader::init edges are not taken into account from OFF " <<
+          "file for Delaunay triangulation - edges are computed." << std::endl;
+    }
+    // Complex construction with dimension from file
+    complex_ = new Complex(dim);
+  }
+
+  /** \brief Off_reader visitor point implementation. 
+   * 
+   * The point function is called on each vertex line from OFF file.
+   * This function inserts the vertex in the Delaunay triangulation.
+   *
+   * @param[in] point vector of vertex coordinates.
+   */
+  void point(const std::vector<double>& point) {
+#ifdef DEBUG_TRACES
+    std::cout << "Delaunay_triangulation_off_visitor_reader::point ";
+    for (auto coordinate : point) {
+      std::cout << coordinate << " | ";
+    }
+    std::cout << std::endl;
+#endif  // DEBUG_TRACES
+    complex_->insert(Point(point.size(), point.begin(), point.end()));
+  }
+
+  // Off_reader visitor maximal_face implementation - not used
+  void maximal_face(const std::vector<int>& face) {
+    // For Delaunay Triangulation, only points are read
+  }
+
+  // Off_reader visitor done implementation - not used
+  void done() {
+    // Nothing to be done on end of OFF file read
+  }
+
+  /** \brief Returns the constructed Delaunay triangulation.
+   *
+   * @return A pointer on the Delaunay triangulation.
+   * 
+   * @warning The returned pointer can be nullptr.
+   */
+  Complex* get_complex() const {
+    return complex_;
+  }
+};
+
+/** \brief OFF file reader implementation in order to construct a Delaunay triangulation.
+ * 
+ * This class is using the Delaunay_triangulation_off_visitor_reader to visit the OFF file according to Off_reader.
+ * 
+ * For more informations on CGAL Delaunay triangulation, please refer to the corresponding chapter in page
+ *  http://doc.cgal.org/latest/Triangulation/
+ * 
+ * \section Example
+ *
+ * This example loads points from an OFF file and builds the Delaunay triangulation.
+ * Then, it is asked to display the number of vertices and finites full cells from the Delaunay triangulation.
+ * 
+ * \include Delaunay_triangulation_off_rw.cpp
+ * 
+ * When launching:
+ * 
+ * \code $> ./dtoffrw ../../data/points/alphashapedoc.off triangulated.off
+ * \endcode
+ *
+ * the program output is:
+ * 
+ * \include dtoffrw_alphashapedoc_result.txt
+ */
+template<typename Complex>
+class Delaunay_triangulation_off_reader {
+ public:
+
+  /** \brief Reads the OFF file and constructs the Delaunay triangulation from the points
+   * that are in the OFF file.
+   *
+   * @param[in] name_file OFF file to read.
+   *
+   * @warning Check with is_valid() function to see if read operation was successful.
+   */
+  Delaunay_triangulation_off_reader(const std::string & name_file)
+  : valid_(false) {
+    std::ifstream stream(name_file);
+    if (stream.is_open()) {
+      Delaunay_triangulation_off_visitor_reader<Complex> off_visitor(complex_);
+      Off_reader off_reader(stream);
+      valid_ = off_reader.read(off_visitor);
+      if (valid_) {
+        complex_ = off_visitor.get_complex();
+        if (complex_ == nullptr) {
+          std::cerr << "Delaunay_triangulation_off_reader::Delaunay_triangulation_off_reader off_visitor returns an empty pointer" << std::endl;
+          valid_ = false;
+        }
+      }
+    } else {
+      std::cerr << "Delaunay_triangulation_off_reader::Delaunay_triangulation_off_reader could not open file " <<
+          name_file << std::endl;
+    }
+
+  }
+
+  /** \brief Returns if the OFF file read operation was successful or not.
+   *
+   * @return OFF file read status.
+   */
+  bool is_valid() const {
+    return valid_;
+  }
+
+  /** \brief Returns the constructed Delaunay triangulation.
+   *
+   * @return A pointer on the Delaunay triangulation.
+   * 
+   * @warning The returned pointer can be nullptr.
+   */
+  Complex* get_complex() const {
+    if (valid_)
+      return complex_;
+    return nullptr;
+
+  }
+
+ private:
+  /** \brief OFF file read status.*/
+  bool valid_;
+  /** \brief A pointer on the Delaunay triangulation.*/
+  Complex* complex_;
+};
+
+/** \brief OFF file writer from a Delaunay triangulation.
+ * 
+ * This class constructs the OFF file header according to http://www.geomview.org/docs/html/OFF.html
+ * 
+ * The header is followed by the list of points coordinates (Delaunay triangulation vertices)
+ * 
+ * And finally is followed by the list of faces (Delaunay triangulation finite full cells)
+ * 
+ * For more informations on CGAL Delaunay triangulation, please refer to the corresponding chapter in page
+ * http://doc.cgal.org/latest/Triangulation/
+ * 
+ * \section Example
+ *
+ * This example loads points from an OFF file and builds the Delaunay triangulation.
+ * Then, the Delaunay triangulation is saved in a new file including the triangulation as a list of faces.
+ * 
+ * \include Delaunay_triangulation_off_rw.cpp
+ * 
+ * When launching:
+ * 
+ * \code $> ./dtoffrw ../../data/points/alphashapedoc.off triangulated.off
+ * \endcode
+ *
+ * The result will be an OFF file of dimension 2 with the 7 points from alphashapedoc.off followed by the 6
+ * triangulations of dimension 3 (the first value on each faces):
+ * \include dtoffrw_alphashapedoc_result.off
+ */
+template<typename Complex>
+class Delaunay_triangulation_off_writer {
+ public:
+  typedef typename Complex::Point Point;
+
+  /** \brief Writes the OFF file from the Delaunay triangulation
+   *
+   * @param[in] name_file OFF file to write.
+   * @param[in] complex_ptr pointer on a Delaunay triangulation.
+   *
+   * @warning Check with is_valid() function to see if write operation was successful.
+   */
+  Delaunay_triangulation_off_writer(const std::string & name_file, Complex* complex_ptr)
+      : valid_(false) {
+    std::ofstream stream(name_file);
+    if (stream.is_open()) {
+      if (complex_ptr->current_dimension() == 3) {
+        // OFF header
+        stream << "OFF" << std::endl;
+        // no endl on next line - don't know why...
+        stream << complex_ptr->number_of_vertices() << " " << complex_ptr->number_of_finite_full_cells() << " 0";
+      } else {
+        // nOFF header
+        stream << "nOFF" << std::endl;
+        // no endl on next line - don't know why...
+        stream << complex_ptr->current_dimension() << " " << complex_ptr->number_of_vertices() << " " <<
+            complex_ptr->number_of_finite_full_cells() << " 0";
+
+      }
+
+      // bimap to retrieve vertex handles from points and vice versa
+      std::map< Point, int > points_to_vh;
+      // Start to insert at default handle value
+      int vertex_handle = int();
+
+      // Points list
+      for (auto vit = complex_ptr->vertices_begin(); vit != complex_ptr->vertices_end(); ++vit) {
+        for (auto Coord = vit->point().cartesian_begin(); Coord != vit->point().cartesian_end(); ++Coord) {
+          stream << *Coord << " ";
+        }
+        stream << std::endl;
+        points_to_vh[vit->point()] = vertex_handle;
+        vertex_handle++;
+      }
+
+      for (auto cit = complex_ptr->finite_full_cells_begin(); cit != complex_ptr->finite_full_cells_end(); ++cit) {
+        std::vector<int> vertexVector;
+        stream << std::distance(cit->vertices_begin(), cit->vertices_end()) << " ";
+        for (auto vit = cit->vertices_begin(); vit != cit->vertices_end(); ++vit) {
+          stream << points_to_vh[(*vit)->point()] << " ";
+        }
+        stream << std::endl;
+      }
+      stream.close();
+      valid_ = true;
+    } else {
+      std::cerr << "Delaunay_triangulation_off_writer::Delaunay_triangulation_off_writer could not open file " <<
+          name_file << std::endl;
+    }
+  }
+  
+  /** \brief Returns if the OFF write operation was successful or not.
+   *
+   * @return OFF file write status.
+   */
+  bool is_valid() const {
+    return valid_;
+  }
+
+ private:
+  /* \brief OFF file write status. */
+  bool valid_;
+};
+
+} // namespace Gudhi
+
+#endif  // SRC_ALPHA_SHAPES_INCLUDE_GUDHI_ALPHA_SHAPES_DELAUNAY_TRIANGULATION_OFF_IO_H_