Off_reader.h

/*
 * Off_reader.h
 *  Created on: Nov 28, 2014
 * 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):       David Salinas
 *
 *    Copyright (C) 2014  INRIA Sophia Antipolis-Méditerranée (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 GUDHI_OFF_READER_H_
#define GUDHI_OFF_READER_H_


#include <sstream>
#include <iostream>
#include <iterator>


namespace Gudhi {

class Off_reader{
public:
    Off_reader(std::ifstream& stream):stream_(stream){
    }
//  Off_reader(const std::string& name):stream_(name){
//      if(!stream_.is_open())
//          std::cerr <<"could not open file \n";
//  }

    ~Off_reader(){
        stream_.close();
    }

    template<typename OffVisitor>
    bool read(OffVisitor& off_visitor){
        bool success_read_off_preambule = read_off_preambule(off_visitor);
        if(!success_read_off_preambule) {
            std::cerr <<"could not read off preambule\n";
            return false;
        }

        bool success_read_off_points = read_off_points(off_visitor);
        if(!success_read_off_points) {
            std::cerr <<"could not read off points\n";
            return false;
        }

        bool success_read_off_faces = read_off_faces(off_visitor);
        if(!success_read_off_faces) {
            std::cerr <<"could not read off faces\n";
            return false;
        }

        off_visitor.done();
        return success_read_off_preambule && success_read_off_points && success_read_off_faces;
    }

private:
    std::ifstream& stream_;

    struct Off_info{
        int dim;
        int num_vertices;
        int num_edges;
        int num_faces;
    };

    Off_info off_info_;

    template<typename OffVisitor>
    bool read_off_preambule(OffVisitor& off_visitor){
        std::string line;
        if(!goto_next_uncomment_line(line)) return false;

        bool is_off_file = (line.find("OFF") != std::string::npos);
        bool is_noff_file = (line.find("nOFF") != std::string::npos);

        if(!is_off_file && !is_noff_file) {
            std::cerr << line<<std::endl;
            std::cerr << "missing off header\n";
            return false;
        }

        if(!goto_next_uncomment_line(line)) return false;
        std::istringstream iss(line);
        if(is_off_file){
            off_info_.dim = 3;
            if(!(iss >> off_info_.num_vertices >> off_info_.num_faces >> off_info_.num_edges)){
                std::cerr << "incorrect number of vertices/faces/edges\n";
                return false;
            }
        }
        else
            if(!(iss >> off_info_.dim >> off_info_.num_vertices >> off_info_.num_faces >> off_info_.num_edges)){
                std::cerr << "incorrect number of vertices/faces/edges\n";
                return false;
            }
        off_visitor.init(off_info_.dim,off_info_.num_vertices,off_info_.num_faces,off_info_.num_edges);

        return true;
    }

    bool goto_next_uncomment_line(std::string& uncomment_line){
        uncomment_line.clear();
        do
            std::getline(stream_, uncomment_line);
        while(uncomment_line[0] == '%');// || uncomment_line.empty());
        return (uncomment_line.size()>0 && uncomment_line[0] != '%');
    }


    template<typename OffVisitor>
    bool read_off_points(OffVisitor& visitor){
        int num_vertices_to_read = off_info_.num_vertices;
        while(num_vertices_to_read--){
            std::string line;
            if(!goto_next_uncomment_line(line)) return false;
            std::vector<double> point;
            std::istringstream iss(line);
            point.assign(std::istream_iterator<double>(iss),std::istream_iterator<double>());
//          if(point.size() != off_info_.dim) return false;
            visitor.point(point);
        }
        return true;
    }

    template<typename OffVisitor>
    bool read_off_faces(OffVisitor& visitor){
        std::string line;
        while(goto_next_uncomment_line(line)){
            std::istringstream iss(line);
            int num_face_vertices;
            iss >> num_face_vertices;
            std::vector<int> face;
            face.assign(std::istream_iterator<int>(iss),std::istream_iterator<int>());
            if(!face.size() == off_info_.num_vertices) return false;
            visitor.maximal_face(face);
        }
        return true;
    }
};


template<typename OFFVisitor>
void read_off(const std::string& name_file_off,OFFVisitor& vis){
    std::ifstream stream(name_file_off);
    if(!stream.is_open())
        std::cerr <<"could not open file \n";
    else{
        Off_reader off_reader(stream);
        off_reader.read(vis);
    }
}



}  // namespace Gudhi


#endif /* GUDHI_OFF_READER_H_ */