cgal/Surface_mesh_approximation/include/CGAL/Approximation_l21_traits.h

191 lines
7.6 KiB
C++

#ifndef CGAL_APPROXIMATION_L21_TRAITS_H
#define CGAL_APPROXIMATION_L21_TRAITS_H
#include <CGAL/license/Surface_mesh_approximation.h>
#include <CGAL/Kernel/global_functions.h>
#include <CGAL/squared_distance_3.h>
#include <boost/graph/graph_traits.hpp>
#include <boost/unordered_map.hpp>
namespace CGAL {
/*!
* \ingroup PkgTSMA
* @brief Approximation traits for L21 metric.
*
* \cgalModels`Approximation_traits`
*
* @tparam TriangleMesh a triangle `FaceListGraph`
* @tparam VertexPointMap a property map with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
as key type, GeomTraits::Point_3 as value type
* @tparam with_area_weighing set `true` to activate area weighing
* @tparam GeomTraits geometric traits
*/
template <typename TriangleMesh,
typename VertexPointMap
= typename boost::property_map<TriangleMesh, boost::vertex_point_t>::type,
bool with_area_weighing = true,
typename GeomTraits
= typename TriangleMesh::Traits>
class Approximation_l21_traits {
typedef typename GeomTraits::FT FT;
typedef typename GeomTraits::Vector_3 Vector_3;
typedef typename GeomTraits::Point_3 Point_3;
typedef typename GeomTraits::Construct_scaled_vector_3 Construct_scaled_vector_3;
typedef typename GeomTraits::Construct_sum_of_vectors_3 Construct_sum_of_vectors_3;
typedef typename GeomTraits::Compute_scalar_product_3 Compute_scalar_product_3;
typedef typename boost::graph_traits<TriangleMesh>::face_descriptor face_descriptor;
typedef typename boost::graph_traits<TriangleMesh>::halfedge_descriptor halfedge_descriptor;
typedef CGAL::internal::face_property_t<Vector_3> Face_normal_tag;
typedef CGAL::internal::face_property_t<FT> Face_area_tag;
typedef typename CGAL::internal::dynamic_property_map<TriangleMesh, Face_normal_tag >::type Face_normal_map;
typedef typename CGAL::internal::dynamic_property_map<TriangleMesh, Face_area_tag >::type Face_area_map;
public:
// type required by the `Approximation_traits` concept
typedef typename GeomTraits::Vector_3 Proxy;
// constructor
Approximation_l21_traits(const TriangleMesh &tm, const VertexPoint_map &vpmap) {
GeomTraits traits;
m_scalar_product_functor = traits.compute_scalar_product_3_object();
m_sum_functor = traits.construct_sum_of_vectors_3_object();
m_scale_functor = traits.construct_scaled_vector_3_object();
m_fnmap = CGAL::internal::add_property(
Face_normal_tag("VSA-face_normal"), const_cast<TriangleMesh &>(tm));
m_famap = CGAL::internal::add_property(
Face_area_tag("VSA-face_area"), const_cast<TriangleMesh &>(tm));
// construct internal facet normal & area map
BOOST_FOREACH(face_descriptor f, faces(tm)) {
const halfedge_descriptor he = halfedge(f, tm);
const Point_3 &p0 = vpmap[source(he, tm)];
const Point_3 &p1 = vpmap[target(he, tm)];
const Point_3 &p2 = vpmap[target(next(he, tm), tm)];
put(m_fnmap, f, CGAL::unit_normal(p0, p1, p2));
put(m_famap, f, std::sqrt(CGAL::to_double(CGAL::squared_area(p0, p1, p2))));
}
}
// member function required by the `Approximation_traits` concept
// It is a function that takes a facet and a proxy, returns the L21 error between them.
FT compute_error(const face_descriptor &f, const Proxy &px) const {
Vector_3 v = m_sum_functor(get(m_fnmap, f), m_scale_functor(px.normal, FT(-1.0)));
return get(m_famap, f) * m_scalar_product_functor(v, v);
}
// member function required by the `Approximation_traits` concept
// It returns the proxy fitted from the facets from beg to end.
template <typename FacetIterator>
Proxy fit_proxy(const FacetIterator beg, const FacetIterator end) const {
CGAL_assertion(beg != end);
// fitting normal
Vector_3 norm = CGAL::NULL_VECTOR;
for (FacetIterator fitr = beg; fitr != end; ++fitr) {
norm = m_sum_functor(norm,
m_scale_functor(get(m_fnmap, *fitr), get(m_famap, *fitr)));
}
norm = m_scale_functor(norm,
FT(1.0 / std::sqrt(CGAL::to_double(norm.squared_length()))));
return norm;
}
private:
Face_normal_map m_fnmap;
Face_area_map m_famap;
Construct_scaled_vector_3 m_scale_functor;
Compute_scalar_product_3 m_scalar_product_functor;
Construct_sum_of_vectors_3 m_sum_functor;
};
// specialization for vertex point map without area weighing
template <typename TriangleMesh, typename GeomTraits>
class Approximation_l21_traits<TriangleMesh,
typename boost::property_map<TriangleMesh, boost::vertex_point_t>::type,
false,
GeomTraits> {
typedef typename GeomTraits::FT FT;
typedef typename GeomTraits::Vector_3 Vector_3;
typedef typename GeomTraits::Point_3 Point_3;
typedef typename GeomTraits::Construct_scaled_vector_3 Construct_scaled_vector_3;
typedef typename GeomTraits::Construct_sum_of_vectors_3 Construct_sum_of_vectors_3;
typedef typename GeomTraits::Compute_scalar_product_3 Compute_scalar_product_3;
typedef typename boost::graph_traits<TriangleMesh>::face_descriptor face_descriptor;
typedef typename boost::graph_traits<TriangleMesh>::halfedge_descriptor halfedge_descriptor;
typedef typename boost::property_map<TriangleMesh, boost::vertex_point_t>::type Vertex_point_map;
typedef CGAL::internal::face_property_t<Vector_3> Face_normal_tag;
typedef CGAL::internal::face_property_t<FT> Face_area_tag;
typedef typename CGAL::internal::dynamic_property_map<TriangleMesh, Face_normal_tag >::type Face_normal_map;
typedef typename CGAL::internal::dynamic_property_map<TriangleMesh, Face_area_tag >::type Face_area_map;
public:
// type required by the `Approximation_traits` concept
typedef typename GeomTraits::Vector_3 Proxy;
// constructor
Approximation_l21_traits(const TriangleMesh &tm) {
GeomTraits traits;
m_scalar_product_functor = traits.compute_scalar_product_3_object();
m_sum_functor = traits.construct_sum_of_vectors_3_object();
m_scale_functor = traits.construct_scaled_vector_3_object();
Vertex_point_map vpmap = get(boost::vertex_point, const_cast<TriangleMesh &>(tm));
m_fnmap = CGAL::internal::add_property(
Face_normal_tag("VSA-face_normal"), const_cast<TriangleMesh &>(tm));
// construct internal facet normal & area map
BOOST_FOREACH(face_descriptor f, faces(tm)) {
const halfedge_descriptor he = halfedge(f, tm);
const Point_3 &p0 = vpmap[source(he, tm)];
const Point_3 &p1 = vpmap[target(he, tm)];
const Point_3 &p2 = vpmap[target(next(he, tm), tm)];
put(m_fnmap, f, CGAL::unit_normal(p0, p1, p2));
}
}
// member function required by the `Approximation_traits` concept
// It is a function that takes a facet and a proxy, returns the L21 error between them.
FT compute_error(const face_descriptor &f, const Proxy &px) const {
Vector_3 v = m_sum_functor(get(m_fnmap, f), m_scale_functor(px.normal, FT(-1.0)));
return m_scalar_product_functor(v, v);
}
// member function required by the `Approximation_traits` concept
// It returns the proxy fitted from the facets from beg to end.
template <typename FacetIterator>
Proxy fit_proxy(const FacetIterator beg, const FacetIterator end) const {
CGAL_assertion(beg != end);
// fitting normal
Vector_3 norm = CGAL::NULL_VECTOR;
for (FacetIterator fitr = beg; fitr != end; ++fitr) {
norm = m_sum_functor(norm,
m_scale_functor(get(m_fnmap, *fitr), get(m_famap, *fitr)));
}
norm = m_scale_functor(norm,
FT(1.0 / std::sqrt(CGAL::to_double(norm.squared_length()))));
return norm;
}
private:
Face_normal_map m_fnmap;
Construct_scaled_vector_3 m_scale_functor;
Compute_scalar_product_3 m_scalar_product_functor;
Construct_sum_of_vectors_3 m_sum_functor;
};
} // namespace CGAL
#endif // CGAL_APPROXIMATION_L21_TRAITS_H