cgal/Mesh_3/include/CGAL/Mesh_3/Triangulation_sizing_field.h

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// Copyright (c) 2009 INRIA Sophia-Antipolis (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s) : Stephane Tayeb
//
//******************************************************************************
// File Description : Defines a sizing field which use an internal triangulation
// to store the sizes
//******************************************************************************
#ifndef CGAL_MESH_3_TRIANGULATION_SIZING_FIELD_H
#define CGAL_MESH_3_TRIANGULATION_SIZING_FIELD_H
#include <CGAL/license/Mesh_3.h>
#include <CGAL/Triangulation_data_structure_3.h>
#include <CGAL/Regular_triangulation_3.h>
#include <CGAL/Regular_triangulation_cell_base_3.h>
#include <CGAL/Regular_triangulation_vertex_base_3.h>
#include <CGAL/Triangulation_cell_base_3.h>
#include <CGAL/Triangulation_vertex_base_with_info_3.h>
#include <CGAL/functional.h>
#include <CGAL/boost/iterator/transform_iterator.hpp>
namespace CGAL {
namespace Mesh_3
{
/**
* @class Triangulation_sizing_field
*/
template <typename Tr>
class Triangulation_sizing_field
{
// Types
typedef typename Tr::Geom_traits Gt;
typedef typename Tr::Bare_point Bare_point;
typedef typename Tr::Weighted_point Weighted_point;
typedef typename Gt::FT FT;
typedef Triangulation_vertex_base_with_info_3<FT, Gt> Vbb;
typedef Regular_triangulation_vertex_base_3<Gt, Vb> Vb;
typedef Triangulation_cell_base_3<Gt> Cbb;
typedef Regular_triangulation_cell_base_3<
Gt, Cbb, Discard_hidden_points> Cb;
typedef Triangulation_data_structure_3<Vb, Cb> Tds;
typedef Regular_triangulation_3<Gt,Tds> Compact_triangulation;
typedef Compact_triangulation Ctr;
typedef typename Tr::Vertex_handle Vertex_handle;
typedef typename Tr::Cell_handle Cell_handle;
typedef typename Ctr::Cell_handle CCell_handle;
typedef typename Ctr::Vertex_handle CVertex_handle;
public:
// Vertices of mesh triangulation do not need to be updated
static const bool is_vertex_update_needed = false;
public:
/**
* Constructor
*/
Triangulation_sizing_field(const Tr& tr);
/**
* Fill sizing field, using size associated to point in \c value_map.
*/
void fill(const std::map<Weighted_point, FT>& value_map);
/**
* Returns size at point \c p.
*/
FT operator()(const Weighted_point& p) const;
/**
* Returns size at point \c p. (needed for compatibility)
*/
template <typename Handle>
FT operator()(const Weighted_point& p, const Handle&) const
{ return this->operator()(p); }
private:
/**
* Returns size at point \c p, by interpolation into tetrahedron.
*/
FT interpolate_on_cell_vertices(const Weighted_point& p,
const CCell_handle& cell) const;
/**
* Returns size at point \c p, by interpolation into facet (\c cell is assumed
* to be an infinite cell).
*/
FT interpolate_on_facet_vertices(const Weighted_point& p,
const CCell_handle& cell) const;
/**
* Returns a hint for \c p location.
*/
CCell_handle get_hint(const Weighted_point& p) const
{ return last_cell_; }
/**
* A functor which extract the point from a vertex handle.
* Used by boost transform iterator
*/
struct Extract_point :
public CGAL::cpp98::unary_function<typename Tr::Vertex, Weighted_point>
{
Weighted_point operator()(const typename Tr::Vertex& v) const { return v.point(); }
};
private:
Compact_triangulation ctr_;
mutable CCell_handle last_cell_;
};
template <typename Tr>
Triangulation_sizing_field<Tr>::
Triangulation_sizing_field(const Tr& tr)
: ctr_(boost::make_transform_iterator(tr.finite_vertices_begin(),
Extract_point()),
boost::make_transform_iterator(tr.finite_vertices_end(),
Extract_point()) )
, last_cell_(CCell_handle())
{
}
template <typename Tr>
void
Triangulation_sizing_field<Tr>::
fill(const std::map<Weighted_point, FT>& value_map)
{
typedef typename Ctr::Finite_vertices_iterator Fvi;
for ( Fvi vit = ctr_.finite_vertices_begin() ;
vit != ctr_.finite_vertices_end() ;
++ vit )
{
typename std::map<Weighted_point, FT>::const_iterator find_result =
value_map.find(ctr_.point(vit));
if ( find_result != value_map.end() )
vit->info() = find_result->second;
else
vit->info() = FT(0);
}
}
template <typename Tr>
typename Triangulation_sizing_field<Tr>::FT
Triangulation_sizing_field<Tr>::
operator()(const Weighted_point& p) const
{
CCell_handle hint = get_hint(p);
CCell_handle cell = ctr_.locate(p,hint);
last_cell_ = cell;
if ( !ctr_.is_infinite(cell) )
return interpolate_on_cell_vertices(p,cell);
else
return interpolate_on_facet_vertices(p,cell);
}
template <typename Tr>
typename Triangulation_sizing_field<Tr>::FT
Triangulation_sizing_field<Tr>::
interpolate_on_cell_vertices(const Weighted_point& p, const CCell_handle& cell) const
{
typename Gt::Construct_point_3 cp = ctr_.geom_traits().construct_point_3_object();
typename Gt::Compute_volume_3 volume = ctr_.geom_traits().compute_volume_3_object();
// Interpolate value using tet vertices values
const FT& va = cell->vertex(0)->info();
const FT& vb = cell->vertex(1)->info();
const FT& vc = cell->vertex(2)->info();
const FT& vd = cell->vertex(3)->info();
const Weighted_point& wa = ctr_.point(cell, 0);
const Weighted_point& wb = ctr_.point(cell, 1);
const Weighted_point& wc = ctr_.point(cell, 2);
const Weighted_point& wd = ctr_.point(cell, 3);
const Bare_point& a = cp(wa);
const Bare_point& b = cp(wb);
const Bare_point& c = cp(wc);
const Bare_point& d = cp(wd);
const FT abcp = CGAL::abs(volume(a,b,c,p));
const FT abdp = CGAL::abs(volume(a,b,d,p));
const FT acdp = CGAL::abs(volume(a,c,d,p));
const FT bcdp = CGAL::abs(volume(b,c,d,p));
// TODO: improve this (static filter ?)
// If volume is 0, then compute the average value
if ( is_zero(abcp+abdp+acdp+bcdp) )
return (va+vb+vc+vd)/4.;
return ( (abcp*vd + abdp*vc + acdp*vb + bcdp*va) / (abcp+abdp+acdp+bcdp) );
}
template <typename Tr>
typename Triangulation_sizing_field<Tr>::FT
Triangulation_sizing_field<Tr>::
interpolate_on_facet_vertices(const Weighted_point& p, const CCell_handle& cell) const
{
typename Gt::Construct_point_3 cp = ctr_.geom_traits().construct_point_3_object();
typename Gt::Compute_area_3 area = ctr_.geom_traits().compute_area_3_object();
// Find infinite vertex and put it in k0
int k0 = 0;
int k1 = 1;
int k2 = 2;
int k3 = 3;
if ( ctr_.is_infinite(cell->vertex(1)) )
std::swap(k0,k1);
if ( ctr_.is_infinite(cell->vertex(2)) )
std::swap(k0,k2);
if ( ctr_.is_infinite(cell->vertex(3)) )
std::swap(k0,k3);
// Interpolate value using tet vertices values
const FT& va = cell->vertex(k1)->info();
const FT& vb = cell->vertex(k2)->info();
const FT& vc = cell->vertex(k3)->info();
const Weighted_point& wa = ctr_.point(cell, k1);
const Weighted_point& wb = ctr_.point(cell, k2);
const Weighted_point& wc = ctr_.point(cell, k3);
const Bare_point& a = cp(wa);
const Bare_point& b = cp(wb);
const Bare_point& c = cp(wc);
const FT abp = area(a,b,p);
const FT acp = area(a,c,p);
const FT bcp = area(b,c,p);
// TODO: improve this (static filter ?)
// If area is 0, then compute the average value
if ( is_zero(abp+acp+bcp) )
return (va+vb+vc)/3.;
return ( (abp*vc + acp*vb + bcp*va ) / (abp+acp+bcp) );
}
} // end namespace Mesh_3
} //namespace CGAL
#endif // CGAL_MESH_3_TRIANGULATION_SIZING_FIELD_H