dust3d/thirdparty/cgal/CGAL-5.1/include/CGAL/Path_on_surface.h

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C++

// Copyright (c) 2019 CNRS and LIRIS' Establishments (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v5.1/Surface_mesh_topology/include/CGAL/Path_on_surface.h $
// $Id: Path_on_surface.h 52186a0 2020-05-14T11:38:15+02:00 Guillaume Damiand
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s) : Guillaume Damiand <guillaume.damiand@liris.cnrs.fr>
//
#ifndef CGAL_PATH_ON_SURFACE_H
#define CGAL_PATH_ON_SURFACE_H 1
#include <CGAL/license/Surface_mesh_topology.h>
#include <CGAL/Combinatorial_map_operations.h>
#include <CGAL/Combinatorial_map.h>
#include <CGAL/Random.h>
#include <CGAL/Face_graph_wrapper.h>
#include <CGAL/Surface_mesh_topology/internal/Path_on_surface_with_rle.h>
#include <boost/algorithm/searching/knuth_morris_pratt.hpp>
#include <utility>
#include <string>
#include <vector>
#include <iostream>
#include <sstream>
#include <initializer_list>
// A Path_on_surface contains two vectors of equal length n
// The first one is a vector of darts called m_path and the second one a vector
// of booleans called m_flip.
// If n = 0, the path represented by those vectors is the empty path.
// Else, it is the path represented by the n-1 first elements of both vectors,
// at the one we add the m_path[n-1] dart if m_flip[n-1] is false and the
// opposite of this dart if m_flip[n-1] is true i.e. if m_flip[i] is true means
// that the i-th dart m_path[i] has to be flipped.
// We use flips because sometimes opposite darts doesn't exist on surfaces with
// boundaries. But if m_flip[i] is true doesn't necesary mean that
// m_path[i] is 2-free
namespace CGAL {
namespace Surface_mesh_topology {
template<typename Mesh_>
class Path_on_surface
{
public:
typedef Path_on_surface<Mesh_> Self;
typedef Mesh_ Mesh;
typedef typename Get_map<Mesh, Mesh>::type Map; // Mesh seen as a 2-map
typedef typename Map::Dart_const_handle Dart_const_handle;
typedef Dart_const_handle halfedge_descriptor; // To be compatible with BGL
Path_on_surface(const Mesh& amesh) : m_map(amesh), m_is_closed(false)
{}
template<class COST>
Path_on_surface(const internal::Path_on_surface_with_rle<COST>& apath) :
m_map(apath.get_map()),
m_is_closed(apath.is_closed())
{
for (auto it=apath.m_path.begin(), itend=apath.m_path.end(); it!=itend; ++it)
{
push_back(it->begin, false, false);
if (it->length>0)
{ extend_straight_positive(it->length, false); }
else if (it->length<0)
{ extend_straight_negative(-(it->length), false); }
}
update_is_closed();
CGAL_assertion(is_valid(true));
}
Path_on_surface(const Self& apath) : m_map(apath.m_map),
m_path(apath.m_path),
m_is_closed(apath.m_is_closed),
m_flip(apath.m_flip)
{}
void swap(Self& p2)
{
if (this==&p2) { return; }
CGAL_assertion(&get_mesh()==&(p2.get_mesh()));
m_path.swap(p2.m_path);
std::swap(m_is_closed, p2.m_is_closed);
m_flip.swap(p2.m_flip);
}
Self& operator=(const Self& other)
{
CGAL_assertion(&get_mesh()==&(other.get_mesh()));
if (this!=&other)
{
m_path=other.m_path;
m_is_closed=other.m_is_closed;
m_flip=other.m_flip;
}
return *this;
}
/// @return true iff the path is empty
bool is_empty() const
{ return m_path.empty(); }
/// @return the length of the path, i.e. its number of darts.
std::size_t length() const
{ return m_path.size(); }
/// @return true iff the path is closed.
/// (m_is_closed is updated after each path modification).
bool is_closed() const
{ return m_is_closed; }
/// @return the combinatorial map supporting this path.
const Map& get_map() const
{ return m_map; }
/// @return the combinatorial map supporting this path.
const Mesh& get_mesh() const
{ return Get_map<Mesh, Mesh>::get_mesh(m_map); }
const std::vector<bool>& get_flip() const
{ return m_flip; }
/// clear the path.
void clear()
{
m_path.clear();
m_flip.clear();
m_is_closed=false;
}
/// @return true iff the prev index exists
bool prev_index_exists(std::size_t i) const
{ return is_closed() || i>0; }
/// @return true iff the next index exists
bool next_index_exists(std::size_t i) const
{ return is_closed() || i<(m_path.size()-1); }
/// @return the index after index i.
std::size_t next_index(std::size_t i) const
{ return ((is_closed() && i==(m_path.size()-1))?0:(i+1)); }
/// @return the index before index i.
std::size_t prev_index(std::size_t i) const
{ return ((is_closed() && i==0)?(m_path.size()-1):(i-1)); }
/// @return the ith dart of the path.
Dart_const_handle get_ith_dart(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
return m_path[i];
}
/// @return true iff the ith dart is flipped
bool get_ith_flip(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
return m_flip[i];
}
/// @return the ith dart of the path.
Dart_const_handle operator[] (std::size_t i) const
{ return get_ith_dart(i); }
/// @return the dart before the ith dart of the path,
/// Map::null_handle if such a dart does not exist.
Dart_const_handle get_prev_dart(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
if (i==0 && !is_closed()) return Map::null_handle;
return m_path[prev_index(i)];
}
/// @return the dart after the ith dart of the path,
/// Map::null_handle if such a dart does not exist.
Dart_const_handle get_next_dart(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
if (i==m_path.size()-1 && !is_closed()) return Map::null_handle;
return m_path[next_index(i)];
}
/// @return the flip before the ith flip of the path,
/// false if such a flip does not exist.
bool get_prev_flip(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
if (i==0 && !is_closed()) return false;
return m_flip[prev_index(i)];
}
/// @return the flip after the ith flip of the path,
/// false if such a flip does not exist.
bool get_next_flip(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
if (i==m_path.size()-1 && !is_closed()) return false;
return m_flip[next_index(i)];
}
/// @return the first dart of the path.
/// @pre !is_empty()
Dart_const_handle front() const
{
CGAL_assertion(!is_empty());
return m_path.front();
}
/// @return the last dart of the path.
/// @pre !is_empty()
Dart_const_handle back() const
{
CGAL_assertion(!is_empty());
return m_path.back();
}
/// @return the first flip of the path.
/// @pre !is_empty()
bool front_flip() const
{
CGAL_assertion(!is_empty());
return m_flip.front();
}
/// @return the last flip of the path.
/// @pre !is_empty()
bool back_flip() const
{
CGAL_assertion(!is_empty());
return m_flip.back();
}
/// @return the index of the first dart of the path.
/// @pre !is_empty()
std::size_t front_index() const
{ return get_map().darts().index(front()); }
/// @return the index of the last dart of the path.
/// @pre !is_empty()
std::size_t back_index() const
{ return get_map().darts().index(back()); }
/// @return the ith dart of the path taking into account flip.
/// return null_handle if flip and there is no beta2
Dart_const_handle get_ith_real_dart(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
return (get_ith_flip(i)?get_map().opposite2(get_ith_dart(i)):
get_ith_dart(i));
}
/// @return the opposite of the ith dart of the path taking into account flip.
/// return null_handle if !flip and there is no beta2
Dart_const_handle get_opposite_ith_real_dart(std::size_t i) const
{
CGAL_assertion(i<m_path.size());
return (get_ith_flip(i)?get_ith_dart(i):
get_map().opposite2(get_ith_dart(i)));
}
/// @return the first dart of the path, taking into account flip.
/// @pre !is_empty()
Dart_const_handle real_front() const
{
CGAL_assertion(!is_empty());
return get_ith_real_dart(0);
}
/// @return the last dart of the path, taking into account flip.
/// @pre !is_empty()
Dart_const_handle real_back() const
{
CGAL_assertion(!is_empty());
return get_ith_real_dart(length()-1);
}
/// @return true iff df can be added at the end of the path.
bool can_be_pushed(Dart_const_handle dh, bool flip=false) const
{
// This assert is too long CGAL_assertion(m_map.darts().owns(dh));
if (is_empty()) return true;
return m_map.template belong_to_same_cell<0>
(m_flip.back() ? back() : m_map.other_extremity(back()),
flip ? m_map.other_extremity(dh) : dh);
}
/// Add the given dart at the end of this path.
/// @pre can_be_pushed(dh)
void push_back(Dart_const_handle dh, bool flip=false,
bool update_isclosed=true)
{
CGAL_assertion(dh!=Map::null_handle);
/* This assert is too long, it is tested in the is_valid method. */
// CGAL_assertion(can_be_pushed(dh, flip));
m_path.push_back(dh);
m_flip.push_back(flip);
if (update_isclosed) { update_is_closed(); }
}
/// @return true iff the ith dart can be added at the end of the path.
bool can_be_pushed_by_index(typename Map::size_type i, bool flip=false,
bool update_isclosed=true) const
{ return can_be_pushed(get_map().dart_handle(i), flip, update_isclosed); }
/// Add the given ith dart at the end of this path.
void push_back_by_index(typename Map::size_type i, bool flip=false,
bool update_isclosed=true)
{ push_back(get_map().dart_handle(i), flip, update_isclosed); }
void push_back_by_index(std::initializer_list<typename Map::size_type> l,
bool update_isclosed=true)
{
for (std::size_t i : l)
{ push_back_by_index(i, false, update_isclosed); }
}
/// @return true iff the dart labeled e can be added at the end of the path.
bool can_be_pushed_by_label(const std::string& e, bool flip=false) const
{
Dart_const_handle dh=get_map().get_dart_labeled(e);
if (dh==Map::null_handle) { return false; }
return can_be_pushed(dh, flip);
}
/// Add the dart having the given labels at the end of this path.
/// Each label is a word, possibly starting by -, words are separated by spaces
void push_back_by_label(const std::string& s, bool update_isclosed=true)
{
std::istringstream iss(s);
for (std::string e; std::getline(iss, e, ' '); )
{
Dart_const_handle dh=get_map().get_dart_labeled(e);
if (dh!=Map::null_handle) { push_back(dh, false, update_isclosed); }
}
}
void push_back_by_label(std::initializer_list<const char*> l,
bool update_isclosed=true)
{
for (const char* e : l)
{ push_back_by_label(e, false, update_isclosed); }
}
Self& operator+=(const Self& other)
{
m_path.reserve(m_path.size()+other.m_path.size());
// Be careful to the special case when *this==other
// this is the reason of the iend.
for (std::size_t i=0, iend=other.length(); i<iend; ++i)
{ push_back(other[i], other.m_flip[i], false); }
update_is_closed();
return *this;
}
Self operator+(const Self& other) const
{
Self res=*this;
res+=other;
return res;
}
/// change m_path and m_flip in order to get the lower number of flips possible
void simplify_flips(bool show_flips_left=false)
{
if (show_flips_left)
{ std::cout<<"Flips left (maybe none) : "<<std::flush; }
for(unsigned int i=0; i<length(); ++i)
{
if (m_flip[i] && !get_map().template is_free<2>(m_path[i]))
{
m_path[i]=get_map().opposite2(m_path[i]);
m_flip[i]=!m_flip[i];
}
else if (show_flips_left)
{ std::cout<<i<<" "<<std::flush; }
}
if (show_flips_left)
{ std::cout<<std::endl; }
}
/// @return the number of flips of this path.
unsigned int nb_flips()
{
unsigned int res=0;
for (unsigned int i=0; i<length(); ++i)
{ if (m_flip[i]) ++res; }
return res;
}
/// Cut this path to keep only the n first darts.
void cut(std::size_t n, bool update_isclosed=true)
{
if (n>=length()) return;
m_path.resize(n);
m_flip.resize(n);
if (update_isclosed) { update_is_closed(); }
}
/// copy all darts starting from begin and going to the dart before end
/// from this path to new_path.
void copy_rest_of_path(std::size_t begin, std::size_t end,
Self& new_path)
{
CGAL_assertion(begin<=end);
CGAL_assertion(end<=length());
new_path.m_path.reserve(new_path.m_path.size()+end-begin+1);
while(begin!=end)
{
new_path.push_back(get_ith_dart(begin), get_ith_flip(begin), false);
++begin;
}
update_is_closed();
}
/// Debugging method.
void display_failed_extention(const std::string& /*name_of_function*/)
{
// std::cout<<"Cant extend the path this way ("<<name_of_function<<")"
// <<std::endl;
}
/// Extend the path straight positive.
/// @pre must be non empty.
void extend_straight_positive(std::size_t nb=1, bool update_isclosed=true)
{
if (is_empty() || nb==0)
{ display_failed_extention("extend_straight_positive"); return; }
Dart_const_handle dh=back();
if(back_flip())
{
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_straight_positive"); return; }
else
{ dh=get_map().opposite2(dh); }
}
for (unsigned int i=0; i<nb; ++i)
{
dh=get_map().next(dh);
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_straight_positive"); return; }
dh=get_map().next(get_map().opposite2(dh));
push_back(dh, false, false);
}
if (update_isclosed) { update_is_closed(); }
}
/// Extend the path straight negative.
/// @pre must be non empty.
void extend_straight_negative(std::size_t nb=1, bool update_isclosed=true)
{
if (is_empty() || nb==0)
{ display_failed_extention("extend_straight_negative"); return; }
Dart_const_handle dh=back();
if(!back_flip())
{
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_straight_positive"); return; }
else
{ dh=get_map().opposite2(dh); }
}
for (unsigned int i=0; i<nb; ++i)
{
dh=get_map().previous(dh);
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_straight_negative"); return; }
dh=get_map().previous(get_map().opposite2(dh));
push_back(dh, true, false);
}
if (update_isclosed) { update_is_closed(); }
}
/// Extend the path given a positive turn.
/// @pre must be non empty.
void extend_positive_turn(std::size_t nb=1, bool update_isclosed=true)
{
if (is_empty())
{ display_failed_extention("extend_positive_turn"); return; }
if (nb==0)
{
push_back(back(), !back_flip(), update_isclosed);
return;
}
Dart_const_handle dh=back();
if(back_flip())
{
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_positive_turn"); return; }
else
{ dh=get_map().opposite2(dh); }
}
dh=get_map().next(dh);
for (unsigned int i=1; i<nb; ++i)
{
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_positive_turn"); return; }
dh=get_map().next(get_map().opposite2(dh));
}
push_back(dh, false, update_isclosed);
}
/// Extend the path given a negative turn.
/// @pre must be non empty.
void extend_negative_turn(std::size_t nb=1, bool update_isclosed=true)
{
if (is_empty()) { display_failed_extention("extend_negative_turn"); return; }
if (nb==0)
{
push_back(back(), !back_flip(), update_isclosed);
return;
}
Dart_const_handle dh=back();
if(!back_flip())
{
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_negative_turn"); return; }
else
{ dh=get_map().opposite2(dh); }
}
dh=get_map().previous(dh);
for (unsigned int i=1; i<nb; ++i)
{
if (get_map().template is_free<2>(dh))
{ display_failed_extention("extend_negative_turn"); return; }
dh=get_map().previous(get_map().opposite2(dh));
}
push_back(dh, true, update_isclosed);
}
/// Initializes this path to a random starting path.
/// @pre must be empty.
bool initialize_random_starting_dart(CGAL::Random& random,
bool update_isclosed=true)
{
if (!is_empty() || get_map().is_empty()) { return false; }
// first select a random edge by taking the lower index of
// the two darts when it is not a boundary
typename Map::size_type index=static_cast<typename Map::size_type>
(random.get_int(0, static_cast<int>(get_map().darts().capacity())));
while (!get_map().darts().is_used(index) ||
(!get_map().template is_free<2>(get_map().dart_handle(index)) &&
get_map().dart_handle(index)>get_map().
opposite2(get_map().dart_handle(index))))
{
++index;
if (index==get_map().darts().capacity()) index=0;
}
// second we take randomly one of the two darts of this edge
// (potentially with the help of a flip)
bool heads_or_tails=random.get_bool();
if (get_map().template is_free<2>(get_map().dart_handle(index)))
{
push_back(get_map().dart_handle(index), heads_or_tails, update_isclosed);
}
else
{
if (heads_or_tails)
{ push_back(get_map().dart_handle(index), false, update_isclosed); }
else
{ push_back(get_map().opposite2(get_map().dart_handle(index)),
false, update_isclosed); }
}
return true;
}
/// Initializes this path to a random starting path.
/// @pre must be empty.
bool initialize_random_starting_dart(bool update_isclosed=true)
{
CGAL::Random& random=get_default_random();
return initialize_random_starting_dart(random, update_isclosed);
}
/// Extends this path with a random dart.
/// @pre must be non empty.
bool extend_path_randomly(CGAL::Random& random,
bool allow_half_turn=true,
bool update_isclosed=true)
{
if (is_empty())
{ return initialize_random_starting_dart(random, update_isclosed); }
if(get_map().template is_free<1>(back()))
{ return false; }
Dart_const_handle next_vertex;
if (back_flip())
{ next_vertex=back(); }
else if (get_map().template is_free<2>(back()))
{ next_vertex=get_map().next(back()); }
else
{ next_vertex=get_map().opposite2(back()); }
std::vector<std::pair<Dart_const_handle, bool> > candidats;
for (auto it=get_map().template darts_of_cell<0>(next_vertex).begin(),
itend=get_map().template darts_of_cell<0>(next_vertex).end();
it!=itend; ++it )
{
if (back_flip() || !get_map().template is_free<2>(back()))
{
candidats.push_back(std::make_pair(it, false));
if (get_map().template is_free<2>(get_map().previous(it)))
{ candidats.push_back
(std::make_pair(get_map().previous(it), true)); }
}
else
{
if (get_map().template is_free<2>(get_map().previous(it)))
{ candidats.push_back
(std::make_pair(get_map().previous(it), true)); }
candidats.push_back(std::make_pair(it, false));
}
}
//candidats is now the list of all the darts that can be pushed back to
// the path (maybe with a flip) the first of them in the list is the
// opposite of back(), or back() itself if it is 2-free
std::size_t i=static_cast<std::size_t>
(random.get_int(allow_half_turn?0:1,static_cast<int>(candidats.size())));
auto it=candidats.begin();
for (std::size_t nb=0; nb<i; ++nb, ++it) {}
push_back(it->first, it->second, update_isclosed);
return true;
}
/// Extends this path with a random dart.
/// @pre must be non empty.
bool extend_path_randomly(bool allow_half_turn=false,
bool update_isclosed=true)
{
CGAL::Random& random=get_default_random();
return extend_path_randomly(random, allow_half_turn, update_isclosed);
}
/// Generates a random path, with a number of darts >= length.
void generate_random_path(std::size_t length,
CGAL::Random& random=get_default_random(),
bool allow_half_turns=true,
bool update_isclosed=true)
{
m_path.reserve(m_path.size()+length);
for (std::size_t i=0; i<length; ++i)
{ extend_path_randomly(random, allow_half_turns, true); }
if (update_isclosed) { update_is_closed(); }
}
/// Generates a random path.
template<typename Path>
void generate_random_path(CGAL::Random& random,
bool update_isclosed=true)
{ generate_random_path(random.get_int(1, 10000),
random, true, update_isclosed); }
/// Generates a random path.
template<typename Path>
void generate_random_path(std::size_t length,
bool update_isclosed=true)
{
CGAL::Random& random=get_default_random();
generate_random_path(length, random, true, update_isclosed);
}
/// Generates a random path.
template<typename Path>
void generate_random_path(bool update_isclosed=true)
{
CGAL::Random& random=get_default_random();
generate_random_path(random, update_isclosed);
}
/// Generates a random closed path.
void generate_random_closed_path(std::size_t length, CGAL::Random& random)
{
m_path.reserve(m_path.size()+length);
std::size_t i=0;
while(i<length || !is_closed())
{
extend_path_randomly(random, true, true);
++i;
}
}
/// Generates a random closed path.
void generate_random_closed_path(std::size_t length)
{
CGAL::Random& random=get_default_random();
generate_random_closed_path(length, random);
}
/// Generates a random closed path.
void generate_random_closed_path(CGAL::Random& random)
{ generate_random_closed_path(random.get_int(1, 10000), random); }
/// Generates a random closed path.
void generate_random_closed_path()
{
CGAL::Random& random=get_default_random();
generate_random_closed_path(random.get_int(1, 10000), random);
}
/// Replace edge [i] by the path of darts along the face.
/// If this face does not exist (if it is a boundary) then replace the edge
/// by the face on the other side. Problem of complexity when used many times
/// (like in update_path_randomly).
bool push_around_face(std::size_t i, bool update_isclosed=true)
{
CGAL_assertion(i<length());
// It is not possible to push around a perforated face since it changes
// the homotopy of the path.
if (get_map().is_perforated(get_ith_dart(i))) { return false; }
Self p2(get_mesh());
// 1) We add in p2 the part of the path which is pushed.
if (get_ith_flip(i))
{
Dart_const_handle dh=get_map().next(get_ith_dart(i));
do
{
p2.push_back(dh, false, false);
dh=get_map().next(dh);
}
while(dh!=get_ith_dart(i));
}
else
{
Dart_const_handle dh=get_map().previous(get_ith_dart(i));
do
{
p2.push_back(dh, true, false);
dh=get_map().previous(dh);
}
while(dh!=get_ith_dart(i));
}
// 2) We copy the end of the path.
p2.m_path.reserve(p2.length()+length()-i);
for (std::size_t j=i+1; j<length(); ++j)
{ p2.push_back(get_ith_dart(j), get_ith_flip(j), false); }
// 3) We cut this path to keep the first i darts.
cut(i, false);
m_path.reserve(length()+p2.length());
for (std::size_t j=0; j<p2.length(); ++j)
{ push_back(p2[j], p2.get_ith_flip(j), false); }
if (update_isclosed) { update_is_closed(); }
return true;
//CGAL_assertion(is_valid());
}
/// Transform the current path by pushing some dart around faces.
/// At the end, the new path is homotopic to the original one.
void update_path_randomly(std::size_t nb, CGAL::Random& random,
bool update_isclosed=true)
{
if (is_empty()) return;
for (unsigned int i=0; i<nb; ++i)
{
std::size_t dartn=static_cast<std::size_t>
(random.get_int(0, static_cast<int>(length())));
std::size_t j=dartn;
while(!push_around_face(dartn, false) && dartn!=j)
{ ++dartn; }
}
if (update_isclosed) { update_is_closed(); }
}
void update_path_randomly(CGAL::Random& random,
bool update_isclosed=true)
{ update_path_randomly(random.get_int(0, 10000), update_isclosed); }
void update_path_randomly(std::size_t nb, bool update_isclosed=true)
{
CGAL::Random random;
update_path_randomly(nb, random, update_isclosed);
}
void update_path_randomly(bool update_isclosed=true)
{
CGAL::Random& random=get_default_random();
update_path_randomly(random, update_isclosed);
}
/// @return true iff the i-th dart of the path and the j-th dart of the other
/// are the same (taking into account the flips !)
bool are_same_step(std::size_t i, const Self& other, std::size_t j) const
{
if (get_ith_flip(i)==other.get_ith_flip(j))
{ return get_ith_dart(i)==other[j]; }
if (get_map().template is_free<2>(get_ith_dart(i)) ||
get_map().template is_free<2>(other[j]))
{ return false; }
return get_ith_dart(i)==get_map().opposite2(other[j]);
}
/// @return true if this path is equal to other path, identifying dart 0 of
/// this path with dart start in other path.
bool are_same_paths_from(const Self& other, std::size_t start) const
{
CGAL_assertion(start==0 || start<length());
CGAL_assertion(is_closed() || start==0);
CGAL_assertion(length()==other.length() && is_closed()==other.is_closed());
for(std::size_t i=0; i<length(); ++i)
{
if (!are_same_step(i, other, start))
{ return false; }
start=next_index(start);
}
return true;
}
/// @return true if this path is equal to other path. For closed paths, test
/// all possible starting darts. Old quadratic version, new version
/// (operator==) use linear version based on Knuth, Morris, Pratt
bool are_paths_equals(const Self& other) const
{
if (length()!=other.length() || is_closed()!=other.is_closed())
{ return false; }
if (!is_closed())
{ return are_same_paths_from(other, 0); }
for(std::size_t start=0; start<length(); ++start)
{
if (are_same_paths_from(other, start))
{ return true; }
}
return false;
}
/// @return true if this path is equal to other path. For closed paths,
/// equality is achieved whatever the first dart.
bool operator==(const Self& other) const
{
if (length()!=other.length() || is_closed()!=other.is_closed())
{ return false; }
if (!is_closed())
{ return are_same_paths_from(other, 0); }
Self pp1=*this;
pp1.simplify_flips();
Self pp2=other;
pp2.simplify_flips();
pp2+=pp2;
// Now we search if pp1 is a sub-motif of pp2 <=> *this==other
return boost::algorithm::knuth_morris_pratt_search(pp2.m_path.begin(),
pp2.m_path.end(),
pp1.m_path.begin(),
pp1.m_path.end())
#if BOOST_VERSION>=106200
.first
#endif
!=pp2.m_path.end();
}
bool operator!=(const Self& other) const
{ return !(operator==(other)); }
/// @Return true if this path is equal to other path, identifying dart 0 of
/// this path with dart start in other path. other path is given
/// by index of its darts, in text format.
bool are_same_paths_from(const char* other, std::size_t start) const
{
CGAL_assertion(start==0 || start<length());
CGAL_assertion(is_closed() || start==0);
std::string sother(other);
std::istringstream iss(sother);
uint64_t nb;
for(std::size_t i=0; i<length(); ++i)
{
if (!iss.good())
{ return false; }
iss>>nb;
if (nb!=m_map.darts().index(get_ith_dart(start)))
{ return false; }
start=next_index(start);
}
iss>>nb;
if (iss.good())
{ return false; } // There are more elements in other than in this path
return true;
}
/// @return true if this path is equal to other path. For closed paths, test
/// all possible starting darts. other path is given by index of its
/// darts, in text format.
bool operator==(const char* other) const
{
if (!is_closed())
{ return are_same_paths_from(other, 0); }
for(std::size_t start=0; start<length(); ++start)
{
if (are_same_paths_from(other, start))
{ return true; }
}
return false;
}
bool operator!=(const char* other) const
{ return !(operator==(other)); }
/// @return true iff the path is valid; i.e. a sequence of edges two by
/// two adjacent.
bool is_valid(bool display_error=false) const
{
if (is_empty()) { return !is_closed(); } // an empty past is not closed
Dart_const_handle last_vertex;
for (unsigned int i=1; i<m_path.size(); ++i)
{
/* This assert is long if (!m_map.darts().owns(m_path[i]))
{ return false; } */
if (m_path[i]==Map::null_handle || m_path[i]==m_map.null_dart_handle)
{ return false; }
last_vertex=m_flip[i-1]?m_path[i-1]:get_map().next(m_path[i-1]);
if (last_vertex==Map::null_handle)
{
if (display_error)
{ std::cout<<"Invalid path: one of the vertices doesn't exist"
<<std::endl; }
return false;
}
if (!m_map.template belong_to_same_cell<0>
(m_flip[i]?get_map().next(m_path[i]):m_path[i], last_vertex))
{
if (display_error)
{ std::cout<<"Invalid path: dart "<<i-1<<" and dart "<<i
<<" are not adjacents"<<std::endl; }
return false;
}
}
last_vertex=back_flip()?back():get_map().next(back());
if (is_closed())
{
if (last_vertex==Map::null_handle)
{
if (display_error)
{ std::cout<<"Invalid path: one of the vertices doesn't exist"
<<std::endl; }
return false;
}
if (!m_map.template belong_to_same_cell<0>
(front_flip()?get_map().next(front()):front(), last_vertex))
{
if (display_error)
{ std::cout<<"Invalid path: m_is_closed is true but the path is "
<<"not closed"<<std::endl; }
return false;
}
}
else
{
if (last_vertex==Map::null_handle)
{
if (display_error)
{ std::cout<<"Invalid path: one of the vertices doesn't exist"
<<std::endl; }
return false;
}
if (m_map.template belong_to_same_cell<0>
(front_flip()?get_map().next(front()):front(), last_vertex))
{
if (display_error)
{ std::cout<<"Invalid path: m_is_closed is false but the path "
<<"is closed"<<std::endl; }
return false;
}
}
return true;
}
/// Update m_is_closed to true iff the path is closed (i.e. the second
/// extremity of the last dart of the path is the same vertex than the one
/// of the first dart of the path).
void update_is_closed()
{
// CGAL_assertion(is_valid());
if (is_empty()) { m_is_closed=false; }
else
{
Dart_const_handle
pend=m_flip.back()?back():m_map.other_extremity(back());
if (pend==Map::null_handle) { m_is_closed=false; }
else
{
Dart_const_handle
pbegin=m_flip[0]?m_map.other_extremity(m_path[0]):m_path[0];
m_is_closed=m_map.template belong_to_same_cell<0>(pbegin, pend);
}
}
}
/// @return true iff the path does not pass twice through a same edge
/// or a same vertex.
bool is_simple() const
{
typename Map::size_type markvertex=m_map.get_new_mark();
typename Map::size_type markedge=m_map.get_new_mark();
bool res=true;
Dart_const_handle dh_vertex;
unsigned int i=0;
for (i=0; res && i<m_path.size(); ++i)
{
dh_vertex=m_flip[i]?get_map().next(m_path[i]):m_path[i];
if (m_map.is_marked(dh_vertex, markvertex)) { res=false; }
else { CGAL::mark_cell<Map, 0>(m_map, dh_vertex, markvertex); }
if (m_map.is_marked(m_path[i], markedge)) { res=false; }
else { CGAL::mark_cell<Map, 1>(m_map, m_path[i], markedge); }
}
i=0;
while(m_map.number_of_marked_darts(markedge)>0 ||
m_map.number_of_marked_darts(markvertex)>0)
{
CGAL_assertion(i<m_path.size());
dh_vertex=m_flip[i]?get_map().next(m_path[i]):m_path[i];
if (m_map.is_marked(dh_vertex, markvertex))
{ CGAL::unmark_cell<Map, 0>(m_map, dh_vertex, markvertex); }
if (m_map.is_marked(m_path[i], markedge))
{ CGAL::unmark_cell<Map, 1>(m_map, m_path[i], markedge); }
++i;
}
m_map.free_mark(markvertex);
m_map.free_mark(markedge);
return res;
}
/// Reverse the path (i.e. negate its orientation).
void reverse()
{
bool tmpbool;
for (unsigned int i=0; i<length()/2; ++i)
{
std::swap(m_path[i], m_path[length()-1-i]);
tmpbool=m_flip[i]; // Cannot swap in vector bool
m_flip[i]=m_flip[length()-1-i];
m_flip[length()-1-i]=tmpbool;
}
for (unsigned int i=0; i<length(); ++i)
{ m_flip[i]=!m_flip[i]; }
}
/// If the given path is opened, close it by doing the same path that the
/// first one in reverse direction.
void close()
{ // TODO follow shortest path ?
if (!is_closed())
{
for (int i=m_path.size()-1; i>=0; --i)
{ m_path.push_back(m_path[i], !m_flip[i], false); }
m_is_closed=true;
}
}
/// @return the turn between dart number i and dart number i+1.
/// (turn is position of the second edge in the cyclic ordering of
/// edges starting from the first edge around the second extremity
/// of the first dart)
std::size_t next_positive_turn(std::size_t i) const
{
// CGAL_assertion(is_valid());
CGAL_assertion(i<m_path.size());
CGAL_assertion (is_closed() || i<length()-1);
if ((get_ith_flip(i) && get_map().template is_free<2>(get_ith_dart(i))) ||
(get_next_flip(i) && get_map().template is_free<2>(get_next_dart(i))))
{ return (std::numeric_limits<std::size_t>::max)(); }
return m_map.positive_turn(get_ith_real_dart(i),
get_ith_real_dart(next_index(i)));
}
/// Same than next_positive_turn but turning in reverse orientation
/// around vertex.
std::size_t next_negative_turn(std::size_t i) const
{
// CGAL_assertion(is_valid());
CGAL_assertion(i<m_path.size());
CGAL_assertion (is_closed() || i<length()-1);
if ((!get_ith_flip(i) && get_map().template is_free<2>(get_ith_dart(i))) ||
(!get_next_flip(i) && get_map().template is_free<2>(get_next_dart(i))))
{ return (std::numeric_limits<std::size_t>::max)(); }
return m_map.positive_turn(get_opposite_ith_real_dart(next_index(i)),
get_opposite_ith_real_dart(i));
}
/// Computes all positive turns of this path.
std::vector<std::size_t> compute_positive_turns() const
{
std::vector<std::size_t> res;
if (is_empty()) return res;
std::size_t i;
for (i=0; i<m_path.size()-1; ++i)
{ res.push_back(next_positive_turn(i)); }
if (is_closed())
{ res.push_back(next_positive_turn(i)); }
return res;
}
/// Computes all negative turns of this path.
std::vector<std::size_t> compute_negative_turns() const
{
std::vector<std::size_t> res;
if (is_empty()) return res;
std::size_t i;
for (i=0; i<m_path.size()-1; ++i)
{ res.push_back(next_negative_turn(i)); }
if (is_closed())
{ res.push_back(next_negative_turn(i)); }
return res;
}
/// Computes all positive or negative turns of this path, depending on p.
std::vector<std::size_t> compute_turns(bool p) const
{ return (p?compute_positive_turns():compute_negative_turns()); }
bool same_turns_from(const char* turns,
const std::vector<std::size_t>& resplus,
const std::vector<std::size_t>& resmoins,
std::size_t start) const
{
CGAL_assertion(start==0 || start<resplus.size());
CGAL_assertion(resplus.size()==resmoins.size());
std::string sturns(turns);
std::istringstream iss(sturns);
int64_t nb;
for(std::size_t i=0; i<resplus.size(); ++i)
{
if (!iss.good())
{ return false; }
iss>>nb;
if ((nb>=0 && resplus[start]!=static_cast<std::size_t>(nb)) ||
(nb<0 && resmoins[start]!=static_cast<std::size_t>(-nb)))
{ return false; }
start=next_index(start);
}
iss>>nb;
if (iss.good())
{ return false; } // There are more elements in turns than in res
return true;
}
bool same_turns(const char* turns) const
{
std::vector<std::size_t> resplus=compute_positive_turns();
std::vector<std::size_t> resmoins=compute_negative_turns();
if (!is_closed())
{ return same_turns_from(turns, resplus, resmoins, 0); }
for (std::size_t start=0; start<length(); ++start)
{
if (same_turns_from(turns, resplus, resmoins, start))
{ return true; }
}
return false;
}
void display_positive_turns() const
{
std::cout<<"+(";
std::vector<std::size_t> res=compute_positive_turns();
for (std::size_t i=0; i<res.size(); ++i)
{ std::cout<<res[i]<<(i<res.size()-1?" ":""); }
std::cout<<")";
}
void display_negative_turns() const
{
std::cout<<"-(";
std::vector<std::size_t> res=compute_negative_turns();
for (std::size_t i=0; i<res.size(); ++i)
{ std::cout<<res[i]<<(i<res.size()-1?" ":""); }
std::cout<<")";
}
void display_pos_and_neg_turns() const
{
display_positive_turns();
std::cout<<" ";
display_negative_turns();
}
void display() const
{
for (std::size_t i=0; i<length(); ++i)
{
std::cout<<m_map.darts().index(get_ith_dart(i));
if (m_flip[i])
{ std::cout<<"f"; }
if (i<length()-1) { std::cout<<" "; }
}
if (is_closed())
{ std::cout<<" c "; } //<<m_map.darts().index(get_ith_dart(0)); }
}
friend std::ostream& operator<<(std::ostream& os, const Self& p)
{
p.display();
return os;
}
protected:
const typename Get_map<Mesh, Mesh>::storage_type m_map; // The underlying map
std::vector<Dart_const_handle> m_path; /// The sequence of darts
bool m_is_closed; /// True iff the path is a cycle
std::vector<bool> m_flip; /// The sequence of flips
};
} // namespace Surface_mesh_topology
} // namespace CGAL
#endif // CGAL_PATH_ON_SURFACE_H //
// EOF //