Subject: CGAL users discussion list
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- From: Abdelkrim Mebarki <>
- To:
- Subject: Re: [cgal-discuss] A question about streamline demo of CGAL 3.3
- Date: Thu, 15 Nov 2007 17:25:11 +0100
|
Hi, The right result is shown in the first figure (The result that the package should produce using the default parameters). The web demo uses an old and modified version of the package, but produces the correct results. In fact, there is a bug in the current version about the creterion used to stop the integration of the streamlines, precisely when the length of new introduced segment is checked (the threshold is very large, and must be reduced) ; This causes the premature end of the streamlines. This problem doesn't occur in the web demo because the short streamlines are deleted. Attached is the fixed version, it will be in the next release. dmyan wrote:
--
Abdelkrim Mebarki. |
// Copyright (c) 2005 INRIA Sophia-Antipolis (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh:///svn/cgal/trunk/Stream_lines_2/include/CGAL/Stream_lines_2.h $
// $Id: Stream_lines_2.h 40822 2007-11-07 16:51:18Z ameyer $
//
//
// Author(s) : Abdelkrim Mebarki <>
#ifndef CGAL_STREAM_LINES_2_H_
#define CGAL_STREAM_LINES_2_H_
#include <CGAL/basic.h>
#include <CGAL/Cartesian.h>
#include <CGAL/Filtered_kernel.h>
#include <CGAL/Delaunay_triangulation_2.h>
#include <queue>
#include <math.h>
#include <fstream>
#include <iostream>
#include <CGAL/squared_distance_2.h>
#include <CGAL/streamlines_assertions.h>
CGAL_BEGIN_NAMESPACE
template <class VectorField_2, class Integrator_2>
class Stream_lines_2
{
public:
typedef typename VectorField_2::Vector_field_2 Vector_field_2;
typedef typename VectorField_2::Geom_traits Geom_traits;
typedef typename VectorField_2::FT FT;
typedef typename VectorField_2::Point_2 Point_2;
typedef typename VectorField_2::Vector_2 Vector_2;
protected:
typedef Geom_traits Kernel;
typedef CGAL::Triangulation_vertex_base_2<Kernel> Vb;
typedef CGAL::Triangulation_face_base_2<Kernel> Fb;
typedef CGAL::Triangulation_data_structure_2<Vb,Fb> TDS;
typedef CGAL::Delaunay_triangulation_2<Kernel,TDS> DT;
typedef typename DT::Vertex_handle Vertex_handle;
typedef typename DT::Face_handle Face_handle;
typedef typename DT::Face_circulator Face_circulator;
typedef typename DT::Edge_iterator Edge_iterator;
typedef std::pair<Point_2,FT> Circle;
typedef
CGAL::Quadruple<Vertex_handle,Vertex_handle,Vertex_handle,Circle> Pq_element;
Pq_element Biggest_circle;
FT distance(const Point_2 & p, const Point_2 & q)
{
return sqrt(squared_distance(p, q));
}
int ir;
int il;
Pq_element Pq_element_max_r;
Pq_element Pq_previous_r,Pq_current_r,Pq_next_r;
Pq_element Pq_element_max_l;
Pq_element Pq_previous_l,Pq_current_l,Pq_next_l;
public:
DT m_DT;
typedef std::list<Point_2> Point_container_2;
typedef typename Point_container_2::iterator Point_iterator_2;
typedef std::list<std::pair<Point_iterator_2, Point_iterator_2> > Iterator_container_2;
Iterator_container_2 iterator_container;
typedef std::list<Vertex_handle> Vertex_container_2;
typedef typename Iterator_container_2::iterator Stream_line_iterator_2;
typedef std::list<Point_container_2> Stream_line_container_2;
protected:
Stream_line_container_2 stl_container;
class C
{
public:
bool operator()(const Pq_element &a1, const Pq_element
&a2)
{
return a1.fourth.second < a2.fourth.second ;
}
};
std::priority_queue<Pq_element, std::vector<Pq_element>, C> pq;
int iOrder_insertion;
FT fSepStl_seed;
FT separating_distance;
FT saturation_ratio;
Point_2 seed_point;
int samp_step;
unsigned int _number_of_lines;
Vector_field_2 * vf_2;
Integrator_2 * int_2;
public:
void set_separating_distance(FT new_value){separating_distance = new_value;}
void set_saturation_ratio(FT new_value){ saturation_ratio = new_value;}
void update()
{
ir = il = 0; // initialization
fSepStl_seed = separating_distance*saturation_ratio;
m_DT.clear();
Point_2 pPoint;
pPoint = Point_2(min_x-separating_distance,min_y-separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(min_x-separating_distance,max_y+separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(max_x+separating_distance,min_y-separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(max_x+separating_distance,max_y+separating_distance);
m_DT.insert(pPoint);
for (int i=(int) (min_x-separating_distance);i<max_x+(int)
separating_distance;i=i+(int) (fSepStl_seed))
{
pPoint = Point_2((FT)i,(FT)max_y+separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2((FT)max_x+separating_distance,(FT)i);
m_DT.insert(pPoint);
pPoint = Point_2((FT)i,min_y-separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(min_x-separating_distance,(FT)i);
m_DT.insert(pPoint);
}
_number_of_lines = 0;
place_stream_lines(*vf_2, *int_2,
samp_step);
}
protected:
void place_stream_lines(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator,
const int & sampling_step, const bool & step_by_step = false);
bool get_next_seed_point(FT & distanceg, Point_2 & seed_point_);
FT find_smallest_circle(const Vertex_handle & pVertex_handle);
Vertex_handle insert_point(const Point_2 & pPoint, FT& fDist,bool bDistanceCalculation);
Vertex_handle insert_point(const Point_2 & pPoint, const Face_handle & m_Face_handle, FT& fDist,
bool bDistanceCalculation);
void integrate_streamline(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator,
Point_container_2& stl, Point_2& seed_point_, Vertex_container_2& stl_vertices, const int & sampling_step);
void integrate_forward(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator,
Point_container_2& stl,Point_2& seed_point,
Vertex_container_2& stl_vertices, const int & sampling_step);
void integrate_backward(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, Point_container_2&
stl, Vertex_container_2& stl_vertices, const int & sampling_step);
void insert_streamline(const Vector_field_2 & vector_field_2, Point_container_2 stl,
Vertex_container_2 stl_vertices);
void pq_elements(const Vector_field_2 & vector_field_2, Vertex_container_2 stl_vertices, int i,
const Vertex_handle & m_Vertex_handle, int before_end);
void make_iterator();
public:
Stream_lines_2(const Vector_field_2 & m_vector_field_2, const Integrator_2 & m_integrator, const FT
& m_separating_distance, const FT & m_saturation_ratio, const int & sampling_insertion = 0, const bool &
step_by_step = false);
bool continue_next(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, const int & sampling_step);
Stream_line_iterator_2 begin();
Stream_line_iterator_2 end();
// for visualizing streamlines
void print_stream_lines(std::ofstream & fw);
void print_stream_lines_eps(std::ofstream & fw);
std::list<Point_2> get_pq();
unsigned int number_of_lines() { return _number_of_lines; }
std::list< std::pair<Point_2, Point_2> > get_tr()
{
std::list< std::pair<Point_2, Point_2> > _list;
Edge_iterator eit = m_DT.edges_begin();
for (;eit != m_DT.edges_end();eit++)
{
Point_2 p1 = (*eit).first->vertex(m_DT.ccw((*eit).second))->point();
Point_2 p2 = (*eit).first->vertex(m_DT.cw((*eit).second))->point();
_list.push_front(std::pair<Point_2, Point_2>(p1, p2));
}
return _list;
}
std::pair<Point_2, FT> get_biggest_circle()
{
Pq_element m_Pq = Biggest_circle;
std::pair<Point_2, FT> circle(m_Pq.fourth.first, m_Pq.fourth.second);
return circle;
}
protected:
FT max_x;
FT min_x;
FT max_y;
FT min_y;
protected:
Stream_line_iterator_2 begin_iterator;
Stream_line_iterator_2 end_iterator;
private:
int number_of_points;
};
template <class VectorField_2, class Integrator_2>
Stream_lines_2<VectorField_2, Integrator_2>::Stream_lines_2(const Vector_field_2 &
vector_field_2, const Integrator_2 & m_integrator, const FT & m_separating_distance, const FT
& m_saturation_ratio, const int & sampling_step, const bool &
step_by_step)
{
separating_distance = m_separating_distance;
saturation_ratio = m_saturation_ratio;
ir = il = 0; // initialization
fSepStl_seed = separating_distance*saturation_ratio;
max_x = vector_field_2.bbox().xmax();
min_x = vector_field_2.bbox().xmin();
max_y = vector_field_2.bbox().ymax();
min_y = vector_field_2.bbox().ymin();
m_DT.clear();
Point_2 pPoint;
pPoint = Point_2(min_x-separating_distance,min_y-separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(min_x-separating_distance,max_y+separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(max_x+separating_distance,min_y-separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(max_x+separating_distance,max_y+separating_distance);
m_DT.insert(pPoint);
for (int i=(int) (min_x-separating_distance);i<max_x+(int)
separating_distance;i=i+(int) (fSepStl_seed))
{
pPoint = Point_2((FT)i,(FT)max_y+separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2((FT)max_x+separating_distance,(FT)i);
m_DT.insert(pPoint);
pPoint = Point_2((FT)i,min_y-separating_distance);
m_DT.insert(pPoint);
pPoint = Point_2(min_x-separating_distance,(FT)i);
m_DT.insert(pPoint);
}
_number_of_lines = 0;
vf_2 = new Vector_field_2(vector_field_2);
int_2 = new Integrator_2(m_integrator);
samp_step = sampling_step;
stl_container.clear();
place_stream_lines(vector_field_2, m_integrator,
sampling_step, step_by_step);
}
template <class VectorField_2, class Integrator_2>
void Stream_lines_2<VectorField_2, Integrator_2>::place_stream_lines(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, const int & sampling_step, const bool & step_by_step)
{
seed_point = Point_2((max_x+min_x)/2.0,(max_y+min_y)/2.0);
// the first chosen point can be not valid
FT xrange = max_x - min_x;
FT yrange = max_y - min_y;
while(!vector_field_2.is_in_domain(seed_point))
{
// std::cout << "searching valid seed point..\n";
FT x = min_x + (FT) (((FT) std::rand() * xrange)/((FT) RAND_MAX));
FT y = min_y + (FT) (((FT) std::rand() * yrange)/((FT) RAND_MAX));
seed_point = Point_2(x, y);
}
// std::cout << seed_point << " first seed point\n";
// std::cout << "creating the placement..\n";
FT distance = (FT) max_x * (1.0/2.0);
bool b = (distance>fSepStl_seed);
// int i=0;
if (!step_by_step)
while(b)
{
Point_container_2 stl;
Vertex_container_2 stl_vertices;
integrate_streamline(vector_field_2, integrator, stl, seed_point, stl_vertices, sampling_step);
insert_streamline(vector_field_2, stl, stl_vertices);
_number_of_lines++;
b = get_next_seed_point(distance,seed_point);
}
else
{
Point_container_2 stl;
Vertex_container_2 stl_vertices;
integrate_streamline(vector_field_2, integrator, stl, seed_point, stl_vertices, sampling_step);
insert_streamline(vector_field_2, stl, stl_vertices);
_number_of_lines++;
b = get_next_seed_point(distance,seed_point);
}
make_iterator();
}
template <class VectorField_2, class Integrator_2>
bool Stream_lines_2<VectorField_2, Integrator_2>::continue_next(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, const int & sampling_step)
{
FT distance;
Point_container_2 stl;
Vertex_container_2 stl_vertices;
integrate_streamline(vector_field_2, integrator, stl, seed_point, stl_vertices, sampling_step);
insert_streamline(vector_field_2, stl, stl_vertices);
_number_of_lines++;
make_iterator();
return get_next_seed_point(distance,seed_point);
}
// get the next seed point
template <class VectorField_2, class Integrator_2>
void
Stream_lines_2<VectorField_2,Integrator_2>::integrate_streamline(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, Point_container_2& stl, Point_2&
seed_point_, Vertex_container_2& stl_vertices, const int & sampling_step)
{
integrate_forward(vector_field_2, integrator, stl, seed_point_, stl_vertices, sampling_step);
integrate_backward(vector_field_2, integrator, stl, stl_vertices, sampling_step);
}
template <class VectorField_2, class Integrator_2>
inline
typename Stream_lines_2<VectorField_2, Integrator_2>::FT
Stream_lines_2<VectorField_2, Integrator_2>::find_smallest_circle(const Vertex_handle & pVertex_handle)
{
Face_circulator pFace_handle = m_DT.incident_faces(pVertex_handle);
Face_circulator pEnd = pFace_handle;
FT fMin = max_x;
CGAL_For_all(pFace_handle,pEnd)
{
FT fDist =
CGAL::squared_radius(
pFace_handle->vertex(0)->point(),
pFace_handle->vertex(1)->point(),
pFace_handle->vertex(2)->point()) * 4.0;
fDist = sqrt(fDist);
if (fDist < fMin)
{
fMin = fDist;
}
}
return fMin;
}
template <class VectorField_2, class Integrator_2>
inline
typename Stream_lines_2<VectorField_2, Integrator_2>::Vertex_handle
Stream_lines_2<VectorField_2, Integrator_2>::insert_point(const Point_2 & pPoint, FT& fDist,bool bDistanceCalculation)
{
Vertex_handle pVertex_handle = m_DT.insert(pPoint);
if (bDistanceCalculation)
fDist = find_smallest_circle(pVertex_handle);
else
fDist = 0.0;
return (pVertex_handle);
}
template <class VectorField_2, class Integrator_2>
inline
typename Stream_lines_2<VectorField_2, Integrator_2>::Vertex_handle
Stream_lines_2<VectorField_2,Integrator_2>::insert_point(const Point_2 & pPoint, const Face_handle & m_Face_handle, FT& fDist,bool bDistanceCalculation)
{
Vertex_handle pVertex_handle = m_DT.insert(pPoint,m_Face_handle);
if (bDistanceCalculation)
fDist = find_smallest_circle(pVertex_handle);
else
fDist = 0.0;
return (pVertex_handle);
}
template <class VectorField_2, class Integrator_2>
void
Stream_lines_2<VectorField_2, Integrator_2>::integrate_forward(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, Point_container_2& stl, Point_2& seed_point_, Vertex_container_2& stl_vertices, const int & sampling_step)
{
int sampling = 0; // sampling step;
int insertion = 0; // insertion order;
int insertion_step = 0;
Point_container_2 list_of_point;
Vertex_container_2 list_of_vertex;
number_of_points = 0;
Point_2 pPoint1;
bool bEnd = false;
FT dist;
Point_2 new_point = Point_2 (seed_point_.x(), seed_point_.y());
Vertex_handle m_Vertex_handle = insert_point(new_point, dist, true);
stl_vertices.push_front(m_Vertex_handle);
stl.push_front(new_point);
number_of_points++;
Point_2 old_point = seed_point_;
insertion_step = (int) (((dist)-fSepStl_seed) / (std::max)((FT) sampling_step,vector_field_2.get_integration_step()));
if (insertion_step < 0) insertion_step = 0;
while (!bEnd)
{
Point_2 ex_old_point = old_point;
old_point = new_point;
CGAL_streamlines_precondition(vector_field_2.is_in_domain(old_point));
new_point = integrator(old_point,vector_field_2,true);
bEnd = !vector_field_2.is_in_domain(new_point);
bEnd = bEnd || (new_point == old_point);/* to review */
if(number_of_points > 30)
bEnd = bEnd || ((distance(stl.front(), stl.back()))<vector_field_2.get_integration_step());
FT dist_ = distance(ex_old_point,new_point);
bEnd = bEnd || dist_ < 0.9*vector_field_2.get_integration_step();
if (!bEnd)
{
if(sampling != sampling_step)
{
stl.push_front(new_point);
number_of_points ++;
sampling++;
}
else
{
if (insertion != insertion_step)
{
stl.push_front(new_point);
number_of_points++;
insertion++;
list_of_point.push_front(new_point);
}
else
{
stl.push_front(new_point);
number_of_points++;
list_of_point.push_front(new_point);
list_of_point.pop_front();
m_Vertex_handle = insert_point(new_point, stl_vertices.front()->face(), dist, true);
while ((dist <= separating_distance)&&(!list_of_point.empty()))
{
m_DT.remove(m_Vertex_handle);
for (int i=0;i<=sampling_step;i++){
stl.pop_front();
number_of_points--;}
new_point = list_of_point.front();
list_of_point.pop_front();
m_Vertex_handle = insert_point(new_point, stl_vertices.front()->face(), dist,true);
}
// adaptive insertion order coefficient
insertion_step = (int) (((dist)-fSepStl_seed) /
(std::max)((FT) sampling_step,vector_field_2.get_integration_step()));
if (insertion_step < 0) insertion_step = 0;
list_of_vertex.push_front(m_Vertex_handle);
(bEnd) = (((bEnd))||(dist<separating_distance));
while (!list_of_point.empty())
{
Point_2 p = list_of_point.front();
m_Vertex_handle = insert_point(p, stl_vertices.front()->face(), dist, false);
list_of_vertex.push_front(m_Vertex_handle);
list_of_point.pop_front();
}
while(!list_of_vertex.empty())
{
stl_vertices.push_front(list_of_vertex.front());
list_of_vertex.pop_front();
}
insertion = 0;
}
sampling = 0;
}
}
else
{
if (!list_of_point.empty())
{
new_point = list_of_point.front();
list_of_point.pop_front();
Vertex_handle m_Vertex_handle = insert_point(new_point, dist, true);
while ((dist <= separating_distance)&&(!list_of_point.empty()))
{
m_DT.remove(m_Vertex_handle);
for (int i=0;i<=sampling_step;i++)
{
stl.pop_front();
number_of_points--;
}
new_point = list_of_point.front();
list_of_point.pop_front();
m_Vertex_handle = insert_point(new_point, stl_vertices.front()->face(), dist, true);
}
insertion_step = (int) (((dist)-fSepStl_seed) /
(std::max)((FT) sampling_step,vector_field_2.get_integration_step()));
if (insertion_step < 0) insertion_step = 0;
(bEnd) = (((bEnd))||(dist<separating_distance));
}
while (!list_of_point.empty())
{
Point_2 p = list_of_point.front();
m_Vertex_handle = insert_point(p, stl_vertices.front()->face(), dist, false);
list_of_vertex.push_front(m_Vertex_handle);
list_of_point.pop_front();
}
while(!list_of_vertex.empty())
{
stl_vertices.push_front(list_of_vertex.front());
list_of_vertex.pop_front();
}
}
}
}
template <class VectorField_2, class Integrator_2>
void Stream_lines_2<VectorField_2, Integrator_2>::integrate_backward(const Vector_field_2 & vector_field_2, const Integrator_2 & integrator, Point_container_2& stl, Vertex_container_2& stl_vertices, const int & sampling_step)
{
int sampling = 0; // sampling step;
int insertion = 0; // insertion order;
int insertion_step = 0;
Point_container_2 list_of_point;
Vertex_container_2 list_of_vertex;
Point_2 pPoint1;
bool bEnd = false;
FT dist;
Point_2 new_point = Point_2 (stl.back().x(),stl.back().y());
// to not have duplicate points in the streamline
stl.pop_back();
Vertex_handle m_Vertex_handle = insert_point(new_point, stl_vertices.back()->face(), dist,true);
stl_vertices.push_back(m_Vertex_handle);
stl.push_back(new_point);
number_of_points++;
Point_2 old_point = new_point;
while (!bEnd)
{
Point_2 ex_old_point = old_point;
old_point = new_point;
std::pair<Vector_2, FT> field_vector;
CGAL_streamlines_precondition(vector_field_2.is_in_domain(old_point));
new_point = integrator(old_point,vector_field_2,false);
bEnd = !vector_field_2.is_in_domain(new_point);
FT dist_ = distance(ex_old_point,new_point);
bEnd = bEnd || dist_ < 0.9*vector_field_2.get_integration_step() || (new_point == old_point);/* to review */
if(number_of_points > 30)
bEnd = bEnd || ((distance(stl.front(), stl.back()))<vector_field_2.get_integration_step());
// bEnd = bEnd || (number_of_points > 3000);
if (!bEnd)
{
if(sampling != sampling_step)
{
stl.push_back(new_point);
number_of_points ++;
sampling++;
}
else
{
if (insertion != insertion_step)
{
stl.push_back(new_point);
number_of_points++;
insertion++;
list_of_point.push_back(new_point);
}
else
{
stl.push_back(new_point);
number_of_points++;
list_of_point.push_back(new_point);
list_of_point.pop_back();
m_Vertex_handle = insert_point(new_point, stl_vertices.back()->face(), dist,true);
while ((dist <= separating_distance)&&(!list_of_point.empty()))
{
m_DT.remove(m_Vertex_handle);
for (int i=0;i<=sampling_step;i++)
{
stl.pop_back();
number_of_points--;
}
new_point = list_of_point.back();
list_of_point.pop_back();
m_Vertex_handle = insert_point(new_point, stl_vertices.back()->face(), dist,true);
}
// adaptive insertion order coefficient
insertion_step = (int) (((dist)-fSepStl_seed) /
(std::max)((FT) sampling_step,vector_field_2.get_integration_step()));
if (insertion_step < 0) insertion_step = 0;
list_of_vertex.push_back(m_Vertex_handle);
(bEnd) = (((bEnd))||(dist<separating_distance));
while (!list_of_point.empty())
{
Point_2 p = list_of_point.back();
m_Vertex_handle = insert_point(p, stl_vertices.back()->face(), dist, false);
list_of_vertex.push_front(m_Vertex_handle);
list_of_point.pop_back();
}
while(!list_of_vertex.empty())
{
stl_vertices.push_back(list_of_vertex.back());
list_of_vertex.pop_back();
}
insertion = 0;
}
sampling = 0;
}
}
else
{
if (!list_of_point.empty())
{
new_point = list_of_point.back();
list_of_point.pop_back();
Vertex_handle m_Vertex_handle = insert_point(new_point, stl_vertices.back()->face(), dist, true);
while ((dist <= separating_distance)&&(!list_of_point.empty()))
{
m_DT.remove(m_Vertex_handle);
for (int i=0;i<=sampling_step;i++)
{
stl.pop_back();
number_of_points--;
}
new_point = list_of_point.back();
list_of_point.pop_back();
m_Vertex_handle = insert_point(new_point, stl_vertices.back()->face(), dist, true);
}
// adaptive insertion order coefficient
insertion_step = (int) (((dist)-fSepStl_seed) /
(std::max)((FT) sampling_step,vector_field_2.get_integration_step()));
if (insertion_step < 0) insertion_step = 0;
// list_of_vertex.push_front(m_Vertex_handle);
(bEnd) = (((bEnd))||(dist<separating_distance));
}
while (!list_of_point.empty())
{
Point_2 p = list_of_point.back();
m_Vertex_handle = insert_point(p, stl_vertices.back()->face(), dist, false);
list_of_vertex.push_back(m_Vertex_handle);
list_of_point.pop_back();
}
while(!list_of_vertex.empty())
{
stl_vertices.push_back(list_of_vertex.back());
list_of_vertex.pop_back();
}
}
}
}
template <class VectorField_2, class Integrator_2>
inline void
Stream_lines_2<VectorField_2, Integrator_2>::
insert_streamline(const Vector_field_2 & vector_field_2,
Point_container_2 stl, Vertex_container_2
stl_vertices)
{
stl_container.push_back(stl);
Vertex_handle m_Vertex_handle = NULL;
int i = 1;
unsigned int size_ = (int) (stl_vertices.size());
ir = il = 0;
while (!stl_vertices.empty())
{
pq_elements(vector_field_2, stl_vertices, i, m_Vertex_handle, size_);
m_Vertex_handle = stl_vertices.front();
stl_vertices.pop_front();
i++;
}
}
template <class VectorField_2, class Integrator_2>
void Stream_lines_2<VectorField_2, Integrator_2>::
pq_elements(const Vector_field_2 & vector_field_2, Vertex_container_2 stl_vertices, int i,
const Vertex_handle & m_Vertex_handle, int size_)
{
if ((i!=0) && (i!=(size_))){// && (std::div(i,10).rem!=0)){
Vertex_handle pVertex_handle = stl_vertices.front();
Face_handle pFace_handle;
int iIndex;
if
(m_DT.is_edge(pVertex_handle,m_Vertex_handle,pFace_handle,iIndex))
{
Point_2 p0 = pVertex_handle->point();
Point_2 c = m_DT.circumcenter(pFace_handle);
FT fDist = distance(p0,c);
bool b = vector_field_2.is_in_domain(c) && (fDist >= fSepStl_seed);
if (b)
{
Circle pCircle(c,fDist);
Pq_element m_Pq_element = Pq_element(
pFace_handle->vertex(0),
pFace_handle->vertex(1),
pFace_handle->vertex(2),
pCircle);
if (ir == 0)
{
Pq_previous_r = m_Pq_element;
Pq_element_max_r = m_Pq_element;
ir++;
}
else if (ir == 1)
{
Pq_current_r =
m_Pq_element;ir++;
}
else
{
Pq_next_r = m_Pq_element;
if (Pq_element_max_r.fourth.second <= Pq_next_r.fourth.second)
Pq_element_max_r = Pq_next_r;
if ((Pq_current_r.fourth.second>=Pq_previous_r.fourth.second)
&&(Pq_current_r.fourth.second>=Pq_next_r.fourth.second))
{
pq.push(Pq_current_r);
}
Pq_previous_r = Pq_current_r;
Pq_current_r = Pq_next_r;
ir++;
}
}
p0 = pFace_handle->neighbor(iIndex)->vertex(0)->point();
c = m_DT.circumcenter(pFace_handle->neighbor(iIndex));
fDist = distance(p0,c);
b = vector_field_2.is_in_domain(c) && (fDist >= fSepStl_seed);
if (b)
{
Circle pCircle(c,fDist);
Pq_element m_Pq_element = Pq_element(
pFace_handle->neighbor(iIndex)->vertex(0),
pFace_handle->neighbor(iIndex)->vertex(1),
pFace_handle->neighbor(iIndex)->vertex(2),
pCircle);
if (il == 0)
{
Pq_previous_l = m_Pq_element;
Pq_element_max_l = m_Pq_element;
il++;
}
else if (il == 1)
{
Pq_current_l =
m_Pq_element;il++;
}
else
{
Pq_next_l = m_Pq_element;
if (Pq_element_max_l.fourth.second <= Pq_next_l.fourth.second)
Pq_element_max_l = Pq_next_l;
if ((Pq_current_l.fourth.second>=Pq_previous_l.fourth.second)
&&(Pq_current_l.fourth.second>=Pq_next_l.fourth.second))
{
pq.push(Pq_current_l);
}
Pq_previous_l = Pq_current_l;
Pq_current_l = Pq_next_l;
il++;
}
}
}
if ((ir+il == (int) size_-2)&&(size_>2))
{
pq.push(Pq_element_max_l);
pq.push(Pq_element_max_r);
}
}
else{
Vertex_handle pVertex_handle = stl_vertices.front();
Face_circulator pFace_handle = m_DT.incident_faces(pVertex_handle);
Face_circulator pEnd = pFace_handle;
CGAL_For_all(pFace_handle,pEnd)
{
Point_2 p0 = pFace_handle->vertex(0)->point();
Point_2 c = m_DT.circumcenter(pFace_handle);
bool b = vector_field_2.is_in_domain(c);
if (b){
FT fDist = distance(p0,c);
if (fDist >= fSepStl_seed)
{
Circle pCircle(c,fDist);
Pq_element m_Pq_element = Pq_element(
pFace_handle->vertex(0),
pFace_handle->vertex(1),
pFace_handle->vertex(2),
pCircle);
pq.push(m_Pq_element);
}
}
}
}
}
// get the next seed point
template <class VectorField_2, class Integrator_2>
inline
bool
Stream_lines_2<VectorField_2, Integrator_2>::get_next_seed_point(FT &
distance, Point_2 & seed_point_)
{
Vertex_handle v0, v1, v2;
Face_handle fr;
bool b0,b;
Pq_element m_Pq_element;
do{
CGAL_assertion(!pq.empty());
m_Pq_element = pq.top();
v0 = m_Pq_element.first;
v1 = m_Pq_element.second;
v2 = m_Pq_element.third;
distance = m_Pq_element.fourth.second;
pq.pop();
b0 = m_DT.is_face(v0,v1,v2,fr);
if (b0){
seed_point_ = m_Pq_element.fourth.first;}
b = (!pq.empty());
}while ((b)&&(!b0));
Biggest_circle = m_Pq_element;
return b;
}
template <class VectorField_2, class Integrator_2>
typename Stream_lines_2<VectorField_2, Integrator_2>::Stream_line_iterator_2
Stream_lines_2<VectorField_2, Integrator_2>::begin()
{
return begin_iterator;
}
template <class VectorField_2, class Integrator_2>
typename Stream_lines_2<VectorField_2, Integrator_2>::Stream_line_iterator_2
Stream_lines_2<VectorField_2, Integrator_2>::end()
{
return end_iterator;
}
template <class VectorField_2, class Integrator_2>
inline
void Stream_lines_2<VectorField_2, Integrator_2>::make_iterator()
{
iterator_container.clear();
for(typename Stream_line_container_2::iterator
begin=stl_container.begin();
begin!=stl_container.end();begin++)
{
std::pair<Point_iterator_2, Point_iterator_2>
iterator_pair((*begin).begin(), (*begin).end());
iterator_container.push_front(iterator_pair);
}
begin_iterator = iterator_container.begin();
end_iterator = iterator_container.end();
}
// output an eps file
template <class VectorField_2, class Integrator_2>
void
Stream_lines_2<VectorField_2, Integrator_2>::print_stream_lines_eps(std::ofstream & fw)
{
typename Stream_line_container_2::iterator it;
Stream_line_container_2 stl_container_temp = stl_container;
fw << "%!PS-Adobe-2.0 EPSF-2.0\n";
fw << "%%BoundingBox: 0 0" << " " << max_x - min_x << " " << max_y - min_y << "\n";
fw << "gsave\n";
fw << "/L {moveto lineto stroke} bind def\n";
fw << 0.5 << " setlinewidth\n";
fw << 0.0 << " " << 0.0 << " " << 0.0 << " setrgbcolor\n";
for(it=stl_container_temp.begin(); it!=stl_container_temp.end(); ++it)
{
typename Point_container_2::iterator begin_point_iterator = (*it).begin();
typename Point_container_2::iterator end_point_iterator = (*it).end();
FT i_prec = (*begin_point_iterator).x() - min_x;
FT j_prec = (*begin_point_iterator).y() - min_y;
begin_point_iterator++;
FT i , j;
for(;begin_point_iterator!=end_point_iterator;begin_point_iterator++)
{
Point_2 p = *begin_point_iterator;
i = p.x() - min_x;
j = p.y() - min_y;
fw << i_prec << " " << j_prec << " " << i << " " << j << " L\n";
i_prec = i;
j_prec = j;
}
}
fw << "grestore\n";
fw << "showpage\n";
fw.close();
}
// output an stl file
template <class VectorField_2, class Integrator_2>
void
Stream_lines_2<VectorField_2, Integrator_2>::print_stream_lines(std::ofstream & fw)
{
typename Stream_line_container_2::iterator it;
Stream_line_container_2 stl_container_temp = stl_container;
fw << max_x - min_x << " " << max_y - min_y << "\n";
fw << stl_container.size() << "\n";
for(it=stl_container_temp.begin(); it!=stl_container_temp.end(); ++it)
{
fw << (*it).size() << "\n";
typename Point_container_2::iterator begin_point_iterator = (*it).begin();
typename Point_container_2::iterator end_point_iterator = (*it).end();
FT i , j;
for(;begin_point_iterator!=end_point_iterator;begin_point_iterator++){
Point_2 p = *begin_point_iterator;
i = p.x() - min_x;
j = p.y() - min_y;
fw << i << " " << j << "\n";
}
}
fw.close();
}
template <class VectorField_2, class Integrator_2>
std::list<typename Stream_lines_2<VectorField_2, Integrator_2>::Point_2>
Stream_lines_2<VectorField_2, Integrator_2>::get_pq()
{
std::list<Point_2> _list;
std::priority_queue<Pq_element, std::vector<Pq_element>, C> pq_temp;
pq_temp = pq;
while (!pq_temp.empty())
{
Pq_element m_Pq_element = pq_temp.top();
Vertex_handle v0 = m_Pq_element.first;
Vertex_handle v1 = m_Pq_element.second;
Vertex_handle v2 = m_Pq_element.third;
pq_temp.pop();
Face_handle fr;
bool b0 = m_DT.is_face(v0,v1,v2,fr);
Point_2 sdPoint = m_Pq_element.fourth.first;
if (b0)
_list.push_front(sdPoint);
}
return _list;
}
CGAL_END_NAMESPACE
#endif
- A question about streamline demo of CGAL 3.3, dmyan, 11/15/2007
- Re: [cgal-discuss] A question about streamline demo of CGAL 3.3, Abdelkrim Mebarki, 11/15/2007
- Re: [cgal-discuss] A question about streamline demo of CGAL 3.3, dmyan, 11/17/2007
- Re: [cgal-discuss] A question about streamline demo of CGAL 3.3, Abdelkrim Mebarki, 11/19/2007
- Re: [cgal-discuss] A question about streamline demo of CGAL 3.3, dmyan, 11/17/2007
- Re: [cgal-discuss] A question about streamline demo of CGAL 3.3, Abdelkrim Mebarki, 11/15/2007
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