cgal/Surface_mesh_parameterization/include/CGAL/Barycentric_mapping_paramet...

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// Copyright (c) 2005 INRIA (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// 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.
//
// 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.
//
// $URL$
// $Id$
//
//
// Author(s) : Laurent Saboret, Pierre Alliez, Bruno Levy
#ifndef CGAL_BARYCENTRIC_MAPPING_PARAMETERIZER_3_H
#define CGAL_BARYCENTRIC_MAPPING_PARAMETERIZER_3_H
#include <CGAL/Fixed_border_parameterizer_3.h>
#include <CGAL/surface_mesh_parameterization_assertions.h>
/// \file Barycentric_mapping_parameterizer_3.h
namespace CGAL {
/// \ingroup PkgSurfaceParameterizationMethods
///
/// The class Barycentric_mapping_parameterizer_3 implements <i>Tutte Barycentric Mapping algorithm</i> \cite t-hdg-63.
/// This algorithm is also called <i>Tutte Uniform Weights</i> by other authors.
///
/// One-to-one mapping is guaranteed if the surface's border is mapped to a convex polygon.
///
/// This class is used by the main
/// parameterization algorithm Fixed_border_parameterizer_3::parameterize().
/// - It provides default BorderParameterizer_3 and SparseLinearAlgebraTraits_d template
/// parameters that make sense.
/// - It implements compute_w_ij() to compute `w_ij = (i,j)` coefficient of matrix A
/// for `j` neighbor vertex of `i` based on Tutte Barycentric Mapping method.
/// - It implements an optimized version of is_one_to_one_mapping().
///
/// \cgalModels `ParameterizerTraits_3`
///
///
/// \tparam ParameterizationMesh_3 3D surface mesh.
/// \tparam BorderParameterizer_3 Strategy to parameterize the surface border.
/// \tparam SparseLinearAlgebraTraits_d Traits class to solve a sparse linear system.
/// Note: the system is *not* symmetric because `Fixed_border_parameterizer_3`
/// does not remove (yet) border vertices from the system.
/*!
\sa `CGAL::Parameterizer_traits_3<ParameterizationMesh_3>`
\sa `CGAL::Fixed_border_parameterizer_3<ParameterizationMesh_3, BorderParameterizer_3, SparseLinearAlgebraTraits_d>`
\sa `CGAL::Discrete_authalic_parameterizer_3<ParameterizationMesh_3, BorderParameterizer_3, SparseLinearAlgebraTraits_d>`
\sa `CGAL::Discrete_conformal_map_parameterizer_3<ParameterizationMesh_3, BorderParameterizer_3, SparseLinearAlgebraTraits_d>`
\sa `CGAL::LSCM_parameterizer_3<ParameterizationMesh_3, BorderParameterizer_3, SparseLinearAlgebraTraits_d>`
\sa `CGAL::Mean_value_coordinates_parameterizer_3<ParameterizationMesh_3, BorderParameterizer_3, SparseLinearAlgebraTraits_d>`
*/
template
<
class ParameterizationMesh_3,
class BorderParameterizer_3
= Circular_border_arc_length_parameterizer_3<ParameterizationMesh_3>,
class SparseLinearAlgebraTraits_d
= OpenNL::DefaultLinearSolverTraits<typename ParameterizationMesh_3::NT>
>
class Barycentric_mapping_parameterizer_3
: public Fixed_border_parameterizer_3<ParameterizationMesh_3,
BorderParameterizer_3,
SparseLinearAlgebraTraits_d>
{
// Private types
private:
// Superclass
typedef Fixed_border_parameterizer_3<ParameterizationMesh_3,
BorderParameterizer_3,
SparseLinearAlgebraTraits_d>
Base;
// Public types
public:
// We have to repeat the types exported by superclass
/// @cond SKIP_IN_MANUAL
typedef typename Base::Error_code Error_code;
typedef ParameterizationMesh_3 Adaptor;
typedef BorderParameterizer_3 Border_param;
typedef SparseLinearAlgebraTraits_d Sparse_LA;
/// @endcond
// Private types
private:
// Mesh_Adaptor_3 subtypes:
typedef typename Adaptor::NT NT;
typedef typename Adaptor::Point_2 Point_2;
typedef typename Adaptor::Point_3 Point_3;
typedef typename Adaptor::Vector_2 Vector_2;
typedef typename Adaptor::Vector_3 Vector_3;
typedef typename Adaptor::Facet Facet;
typedef typename Adaptor::Facet_handle Facet_handle;
typedef typename Adaptor::Facet_const_handle
Facet_const_handle;
typedef typename Adaptor::Facet_iterator Facet_iterator;
typedef typename Adaptor::Facet_const_iterator
Facet_const_iterator;
typedef typename Adaptor::Vertex Vertex;
typedef typename Adaptor::Vertex_handle Vertex_handle;
typedef typename Adaptor::Vertex_const_handle
Vertex_const_handle;
typedef typename Adaptor::Vertex_iterator Vertex_iterator;
typedef typename Adaptor::Vertex_const_iterator
Vertex_const_iterator;
typedef typename Adaptor::Border_vertex_iterator
Border_vertex_iterator;
typedef typename Adaptor::Border_vertex_const_iterator
Border_vertex_const_iterator;
typedef typename Adaptor::Vertex_around_facet_circulator
Vertex_around_facet_circulator;
typedef typename Adaptor::Vertex_around_facet_const_circulator
Vertex_around_facet_const_circulator;
typedef typename Adaptor::Vertex_around_vertex_circulator
Vertex_around_vertex_circulator;
typedef typename Adaptor::Vertex_around_vertex_const_circulator
Vertex_around_vertex_const_circulator;
// SparseLinearAlgebraTraits_d subtypes:
typedef typename Sparse_LA::Vector Vector;
typedef typename Sparse_LA::Matrix Matrix;
// Public operations
public:
/// Constructor
Barycentric_mapping_parameterizer_3(Border_param border_param = Border_param(),
///< object that maps the surface's border to 2D space.
Sparse_LA sparse_la = Sparse_LA())
///< Traits object to access a sparse linear system.
: Fixed_border_parameterizer_3<Adaptor,
Border_param,
Sparse_LA>(border_param, sparse_la)
{}
// Default copy constructor and operator =() are fine
// Protected operations
protected:
/// Compute w_ij = (i,j) coefficient of matrix A for j neighbor vertex of i.
virtual NT compute_w_ij(const Adaptor& /* mesh */,
Vertex_const_handle /* main_vertex_v_i */,
Vertex_around_vertex_const_circulator /* neighbor_vertex_v_j */ )
{
/// Tutte Barycentric Mapping algorithm is the most simple one:
/// w_ij = 1 for j neighbor vertex of i.
return 1;
}
/// Check if 3D -> 2D mapping is one-to-one.
virtual bool is_one_to_one_mapping (const Adaptor& /* mesh */,
const Matrix& /* A */,
const Vector& /* Bu */,
const Vector& /* Bv */)
{
/// Theorem: one-to-one mapping is guaranteed if all w_ij coefficients
/// are > 0 (for j vertex neighbor of i) and if the surface
/// border is mapped onto a 2D convex polygon.
/// All w_ij coefficients = 1 (for j vertex neighbor of i), thus mapping
/// is guaranteed if the surface border is mapped onto a 2D convex polygon.
return Base::get_border_parameterizer().is_border_convex ();
}
};
} //namespace CGAL
#endif //CGAL_BARYCENTRIC_MAPPING_PARAMETERIZER_3_H