dust3d/thirdparty/cgal/CGAL-5.1/include/CGAL/Polygon_mesh_processing/measure.h

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// Copyright (c) 2015 GeometryFactory (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v5.1/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/measure.h $
// $Id: measure.h 80f6f65 2020-04-05T17:56:50+02:00 Mael Rouxel-Labbé
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s) : Andreas Fabri
#ifndef CGAL_POLYGON_MESH_PROCESSING_MEASURE_H
#define CGAL_POLYGON_MESH_PROCESSING_MEASURE_H
#include <CGAL/license/Polygon_mesh_processing/measure.h>
#include <CGAL/disable_warnings.h>
#include <CGAL/assertions.h>
#include <CGAL/boost/graph/iterator.h>
#include <CGAL/boost/graph/helpers.h>
#include <CGAL/boost/graph/properties.h>
#include <CGAL/Polygon_mesh_processing/internal/named_function_params.h>
#include <CGAL/Polygon_mesh_processing/internal/named_params_helper.h>
#include <CGAL/squared_distance_3.h>
#include <CGAL/Kernel/global_functions_3.h>
#include <CGAL/Lazy.h> // needed for CGAL::exact(FT)/CGAL::exact(Lazy_exact_nt<T>)
#include <boost/unordered_set.hpp>
#include <boost/graph/graph_traits.hpp>
#include <utility>
#ifdef DOXYGEN_RUNNING
#define CGAL_PMP_NP_TEMPLATE_PARAMETERS NamedParameters
#define CGAL_PMP_NP_CLASS NamedParameters
#endif
namespace CGAL {
// workaround for area(face_range, tm) overload
template<typename CGAL_PMP_NP_TEMPLATE_PARAMETERS, typename NP>
class GetGeomTraits<CGAL_PMP_NP_CLASS, NP>
{
public:
struct type{};
};
namespace Polygon_mesh_processing {
/**
* \ingroup measure_grp
* computes the length of an edge of a given polygon mesh.
* The edge is given by one of its halfedges, or the edge itself.
*
* @tparam PolygonMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param h one halfedge of the edge to compute the length
* @param pmesh the polygon mesh to which `h` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `pmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<PolygonMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, pmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the length of `h`. The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `pmesh`.
*
* \warning This function involves a square root computation.
* If `FT` does not have a `sqrt()` operation, the square root computation
* will be done approximately.
*
* @sa `face_border_length()`
*/
template<typename PolygonMesh,
typename NamedParameters>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<PolygonMesh, NamedParameters>::type::FT
#endif
edge_length(typename boost::graph_traits<PolygonMesh>::halfedge_descriptor h,
const PolygonMesh& pmesh,
const NamedParameters& np)
{
using parameters::choose_parameter;
using parameters::get_parameter;
typename GetVertexPointMap<PolygonMesh, NamedParameters>::const_type
vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, pmesh));
return CGAL::approximate_sqrt(CGAL::squared_distance(get(vpm, source(h, pmesh)),
get(vpm, target(h, pmesh))));
}
template<typename PolygonMesh>
typename CGAL::Kernel_traits<typename property_map_value<PolygonMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
edge_length(typename boost::graph_traits<PolygonMesh>::halfedge_descriptor h,
const PolygonMesh& pmesh)
{
return edge_length(h, pmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
// edge overloads
template<typename PolygonMesh,
typename NamedParameters>
typename GetGeomTraits<PolygonMesh, NamedParameters>::type::FT
edge_length(typename boost::graph_traits<PolygonMesh>::edge_descriptor e,
const PolygonMesh& pmesh,
const NamedParameters& np)
{
return edge_length(halfedge(e, pmesh), pmesh, np);
}
template<typename PolygonMesh>
typename CGAL::Kernel_traits<typename property_map_value<PolygonMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
edge_length(typename boost::graph_traits<PolygonMesh>::edge_descriptor e,
const PolygonMesh& pmesh)
{
return edge_length(halfedge(e, pmesh), pmesh);
}
/**
* \ingroup measure_grp
* computes the length of the border polyline
* that contains a given halfedge.
*
* @tparam PolygonMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param h a halfedge of the border polyline of which the length is computed
* @param pmesh the polygon mesh to which `h` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `pmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<PolygonMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, pmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the length of the sequence of border edges of `face(h, pmesh)`.
* The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `pmesh`.
*
* \warning This function involves a square root computation.
* If `Kernel::FT` does not have a `sqrt()` operation, the square root computation
* will be done approximately.
*
* @sa `edge_length()`
*/
template<typename PolygonMesh,
typename NamedParameters>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<PolygonMesh, NamedParameters>::type::FT
#endif
face_border_length(typename boost::graph_traits<PolygonMesh>::halfedge_descriptor h,
const PolygonMesh& pmesh,
const NamedParameters& np)
{
typename GetGeomTraits<PolygonMesh, NamedParameters>::type::FT result = 0;
for(typename boost::graph_traits<PolygonMesh>::halfedge_descriptor haf : halfedges_around_face(h, pmesh))
{
result += edge_length(haf, pmesh, np);
exact(result);
}
return result;
}
template<typename PolygonMesh>
typename CGAL::Kernel_traits<typename property_map_value<PolygonMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
face_border_length(typename boost::graph_traits<PolygonMesh>::halfedge_descriptor h,
const PolygonMesh& pmesh)
{
return face_border_length(h, pmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* finds the longest border of a given triangulated surface and returns
* a halfedge that is part of this border and the length of this border.
*
* @tparam PolygonMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param pmesh the polygon mesh
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `pmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<PolygonMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, pmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return a pair composed of two members:
* - `first`: a halfedge on the longest border.
* The return type `halfedge_descriptor` is a halfedge descriptor. It is
* deduced from the graph traits corresponding to the type `PolygonMesh`.
* - `second`: the length of the longest border
* The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `pmesh`
*
*/
template<typename PolygonMesh,
typename NamedParameters>
#ifdef DOXYGEN_RUNNING
std::pair<halfedge_descriptor, FT>
#else
std::pair<typename boost::graph_traits<PolygonMesh>::halfedge_descriptor,
typename GetGeomTraits<PolygonMesh, NamedParameters>::type::FT>
#endif
longest_border(const PolygonMesh& pmesh,
const NamedParameters& np)
{
typedef typename CGAL::Kernel_traits<
typename property_map_value<PolygonMesh, CGAL::vertex_point_t>::type>::Kernel::FT FT;
typedef typename boost::graph_traits<PolygonMesh>::halfedge_descriptor halfedge_descriptor;
boost::unordered_set<halfedge_descriptor> visited;
halfedge_descriptor result_halfedge = boost::graph_traits<PolygonMesh>::null_halfedge();
FT result_len = 0;
for(halfedge_descriptor h : halfedges(pmesh))
{
if(visited.find(h)== visited.end())
{
if(is_border(h, pmesh))
{
FT len = 0;
for(halfedge_descriptor haf : halfedges_around_face(h, pmesh))
{
len += edge_length(haf, pmesh, np);
visited.insert(haf);
}
if(result_len < len)
{
result_len = len;
result_halfedge = h;
}
}
}
}
return std::make_pair(result_halfedge, result_len);
}
template<typename PolygonMesh>
std::pair<typename boost::graph_traits<PolygonMesh>::halfedge_descriptor,
typename CGAL::Kernel_traits<typename property_map_value<PolygonMesh,
CGAL::vertex_point_t>::type>::Kernel::FT>
longest_border(const PolygonMesh& pmesh)
{
return longest_border(pmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* computes the area of a face of a given
* triangulated surface mesh.
*
* @tparam TriangleMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param f the face of which the area is computed
* @param tmesh the triangulated surface mesh to which `f` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @pre `f != boost::graph_traits<TriangleMesh>::%null_face()`
*
* @return the area of `f`.
* The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `tmesh`.
*
* @sa `area()`
*/
template<typename TriangleMesh,
typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT
#endif
face_area(typename boost::graph_traits<TriangleMesh>::face_descriptor f,
const TriangleMesh& tmesh,
const CGAL_PMP_NP_CLASS& np)
{
using parameters::choose_parameter;
using parameters::get_parameter;
typedef typename boost::graph_traits<TriangleMesh>::halfedge_descriptor halfedge_descriptor;
CGAL_precondition(boost::graph_traits<TriangleMesh>::null_face() != f);
typename GetVertexPointMap<TriangleMesh, CGAL_PMP_NP_CLASS>::const_type
vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, tmesh));
halfedge_descriptor hd = halfedge(f, tmesh);
halfedge_descriptor nhd = next(hd, tmesh);
typedef typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type GT;
GT traits = choose_parameter<GT>(get_parameter(np, internal_np::geom_traits));
return approximate_sqrt(traits.compute_squared_area_3_object()(get(vpm, source(hd, tmesh)),
get(vpm, target(hd, tmesh)),
get(vpm, target(nhd, tmesh))));
}
template<typename TriangleMesh>
typename CGAL::Kernel_traits<typename property_map_value<TriangleMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
face_area(typename boost::graph_traits<TriangleMesh>::face_descriptor f,
const TriangleMesh& tmesh)
{
return face_area(f, tmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* computes the area of a range of faces of a given
* triangulated surface mesh.
*
* @tparam FaceRange range of `boost::graph_traits<PolygonMesh>::%face_descriptor`,
model of `Range`.
Its iterator type is `InputIterator`.
* @tparam TriangleMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param face_range the range of faces of which the area is computed
* @param tmesh the triangulated surface mesh to which the faces of `face_range` belong
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return sum of face areas of `faces`.
* The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `tmesh`.
*
* \warning This function involves a square root computation.
* If `Kernel::FT` does not have a `sqrt()` operation, the square root computation
* will be done approximately.
*
* @sa `face_area()`
*/
template<typename FaceRange,
typename TriangleMesh,
typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT
#endif
area(FaceRange face_range,
const TriangleMesh& tmesh,
const CGAL_PMP_NP_CLASS& np)
{
typedef typename boost::graph_traits<TriangleMesh>::face_descriptor face_descriptor;
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT result = 0;
for(face_descriptor f : face_range)
{
result += face_area(f, tmesh, np);
exact(result);
}
return result;
}
template<typename FaceRange, typename TriangleMesh>
typename GetGeomTraits<TriangleMesh>::type::FT
area(FaceRange face_range, const TriangleMesh& tmesh)
{
return area(face_range, tmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* computes the surface area of a triangulated surface mesh.
*
* @tparam TriangleMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param tmesh the triangulated surface mesh
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the surface area of `tmesh`.
* The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `tmesh`.
*
* \warning This function involves a square root computation.
* If `Kernel::FT` does not have a `sqrt()` operation, the square root computation
* will be done approximately.
*
* @sa `face_area()`
*/
template<typename TriangleMesh,
typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT
#endif
area(const TriangleMesh& tmesh, const CGAL_PMP_NP_CLASS& np)
{
return area(faces(tmesh), tmesh, np);
}
template<typename TriangleMesh>
typename CGAL::Kernel_traits<typename property_map_value<TriangleMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
area(const TriangleMesh& tmesh)
{
return area(faces(tmesh), tmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* computes the volume of the domain bounded by
* a closed triangulated surface mesh.
*
* @tparam TriangleMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param tmesh the closed triangulated surface mesh bounding the volume
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* @pre `tmesh` is closed
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the volume bounded by `tmesh`.
* The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map
* of `tmesh`.
*/
template<typename TriangleMesh,
typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT
#endif
volume(const TriangleMesh& tmesh,
const CGAL_PMP_NP_CLASS& np)
{
CGAL_assertion(is_triangle_mesh(tmesh));
CGAL_assertion(is_closed(tmesh));
using parameters::choose_parameter;
using parameters::get_parameter;
typename GetVertexPointMap<TriangleMesh, CGAL_PMP_NP_CLASS>::const_type
vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, tmesh));
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::Point_3 origin(0, 0, 0);
typedef typename boost::graph_traits<TriangleMesh>::face_descriptor face_descriptor;
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT volume = 0;
typename CGAL::Kernel_traits<typename property_map_value<TriangleMesh,
CGAL::vertex_point_t>::type>::Kernel::Compute_volume_3 cv3;
for(face_descriptor f : faces(tmesh))
{
volume += cv3(origin,
get(vpm, target(halfedge(f, tmesh), tmesh)),
get(vpm, target(next(halfedge(f, tmesh), tmesh), tmesh)),
get(vpm, target(prev(halfedge(f, tmesh), tmesh), tmesh)));
exact(volume);
}
return volume;
}
template<typename TriangleMesh>
typename CGAL::Kernel_traits<typename property_map_value<TriangleMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
volume(const TriangleMesh& tmesh)
{
return volume(tmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* computes the aspect ratio of a face of a given triangulated surface mesh.
*
* @tparam TriangleMesh a model of `HalfedgeGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param f the face of which the aspect ratio is computed
* @param tmesh the triangulated surface mesh to which `f` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @pre `f != boost::graph_traits<TriangleMesh>::%null_face()`
*
* @return the aspect ratio of `f`. The return type `FT` is a number type. It is
* either deduced from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map of `tmesh`.
*
*/
template<typename TriangleMesh,
typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::FT
#endif
face_aspect_ratio(typename boost::graph_traits<TriangleMesh>::face_descriptor f,
const TriangleMesh& tmesh,
const CGAL_PMP_NP_CLASS& np)
{
CGAL_precondition(is_triangle(f, tmesh));
typedef typename boost::graph_traits<TriangleMesh>::halfedge_descriptor halfedge_descriptor;
typedef typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type Geom_traits;
typedef typename Geom_traits::FT FT;
using parameters::choose_parameter;
using parameters::get_parameter;
typename GetVertexPointMap<TriangleMesh, CGAL_PMP_NP_CLASS>::const_type
vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, tmesh));
halfedge_descriptor h = halfedge(f, tmesh);
Geom_traits gt = choose_parameter<Geom_traits>(get_parameter(np, internal_np::geom_traits));
#if 0
const FT sq_triangle_area = gt.compute_squared_area_3_object()(get(vpm, source(h, tmesh)),
get(vpm, target(h, tmesh)),
get(vpm, target(next(h, tmesh), tmesh)));
const FT sq_d12 = gt.compute_squared_distance_2_object()(get(vpm, source(h, tmesh)),
get(vpm, target(h, tmesh)));
const FT sq_d13 = gt.compute_squared_distance_2_object()(get(vpm, source(h, tmesh)),
get(vpm, target(next(h, tmesh), tmesh)));
const FT sq_d23 = gt.compute_squared_distance_2_object()(get(vpm, target(h, tmesh)),
get(vpm, target(next(h, tmesh), tmesh)));
const FT min_sq_d123 = (std::min)(sq_d12, (std::min)(sq_d13, sq_d23));
const FT aspect_ratio = 4*sq_triangle_area*min_sq_d123 / (sq_d12*sq_d13*sq_d23);
#else // below requires SQRT
typedef typename Geom_traits::Line_3 Line_3;
FT sq_max_edge_length = gt.compute_squared_distance_3_object()(get(vpm, source(h, tmesh)),
get(vpm, target(h, tmesh)));
FT sq_min_alt = gt.compute_squared_distance_3_object()(get(vpm, target(next(h, tmesh), tmesh)),
Line_3(get(vpm, source(h, tmesh)),
get(vpm, target(h, tmesh))));
h = next(h, tmesh);
for(int i=1; i<3; ++i)
{
FT sq_edge_length = gt.compute_squared_distance_3_object()(get(vpm, source(h, tmesh)),
get(vpm, target(h, tmesh)));
FT sq_alt = gt.compute_squared_distance_3_object()(get(vpm, target(next(h, tmesh), tmesh)),
Line_3(get(vpm, source(h, tmesh)),
get(vpm, target(h, tmesh))));
if(sq_alt < sq_min_alt)
sq_min_alt = sq_alt;
if(sq_edge_length > sq_max_edge_length)
sq_max_edge_length = sq_edge_length;
h = next(h, tmesh);
}
CGAL_assertion(sq_min_alt > 0);
const FT aspect_ratio = CGAL::approximate_sqrt(sq_max_edge_length / sq_min_alt);
#endif
return aspect_ratio;
}
template<typename TriangleMesh>
typename CGAL::Kernel_traits<typename property_map_value<TriangleMesh,
CGAL::vertex_point_t>::type>::Kernel::FT
face_aspect_ratio(typename boost::graph_traits<TriangleMesh>::face_descriptor f,
const TriangleMesh& tmesh)
{
return face_aspect_ratio(f, tmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
/**
* \ingroup measure_grp
* computes the centroid of a volume bounded by
* a closed triangulated surface mesh.
*
* @tparam TriangleMesh a model of `FaceListGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param tmesh the closed triangulated surface mesh bounding the volume
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* @pre `tmesh` is closed
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{a class model of `Kernel`}
* \cgalParamDefault{a \cgal Kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the centroid of the domain bounded by `tmesh`.
*/
template<typename TriangleMesh, typename CGAL_PMP_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
Point_3
#else
typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type::Point_3
#endif
centroid(const TriangleMesh& tmesh, const CGAL_PMP_NP_CLASS& np)
{
// See: http://www2.imperial.ac.uk/~rn/centroid.pdf
CGAL_assertion(is_triangle_mesh(tmesh));
CGAL_assertion(is_closed(tmesh));
using parameters::choose_parameter;
using parameters::get_parameter;
typedef typename GetVertexPointMap<TriangleMesh, CGAL_PMP_NP_CLASS>::const_type Vpm;
Vpm vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, tmesh));
typedef typename GetGeomTraits<TriangleMesh, CGAL_PMP_NP_CLASS>::type Kernel;
typedef typename Kernel::Point_3 Point_3;
typedef typename Kernel::Vector_3 Vector_3;
typedef typename Kernel::Construct_translated_point_3 Construct_translated_point_3;
typedef typename Kernel::Construct_vector_3 Construct_vector_3;
typedef typename Kernel::Construct_normal_3 Construct_normal_3;
typedef typename Kernel::Compute_scalar_product_3 Scalar_product;
typedef typename Kernel::Construct_scaled_vector_3 Scale;
typedef typename Kernel::Construct_sum_of_vectors_3 Sum;
typedef typename boost::graph_traits<TriangleMesh>::face_descriptor face_descriptor;
typedef typename Kernel::FT FT;
FT volume = 0;
Vector_3 centroid(NULL_VECTOR);
Construct_translated_point_3 point;
Construct_vector_3 vector;
Construct_normal_3 normal;
Scalar_product scalar_product;
Scale scale;
Sum sum;
for(face_descriptor fd : faces(tmesh))
{
const Point_3& p = get(vpm, target(halfedge(fd, tmesh), tmesh));
const Point_3& q = get(vpm, target(next(halfedge(fd, tmesh), tmesh), tmesh));
const Point_3& r = get(vpm, target(prev(halfedge(fd, tmesh), tmesh), tmesh));
Vector_3 vp = vector(ORIGIN, p),
vq = vector(ORIGIN, q),
vr = vector(ORIGIN, r);
Vector_3 n = normal(p, q, r);
volume += (scalar_product(n,vp))/FT(6);
n = scale(n, FT(1)/FT(24));
Vector_3 v2 = sum(vp, vq);
Vector_3 v3 = Vector_3(square(v2.x()), square(v2.y()), square(v2.z()));
v2 = sum(vq, vr);
v3 = sum(v3, Vector_3(square(v2.x()), square(v2.y()), square(v2.z())));
v2 = sum(vp, vr);
v3 = sum(v3, Vector_3(square(v2.x()), square(v2.y()), square(v2.z())));
centroid = sum(centroid, Vector_3(n.x() * v3.x(), n.y() * v3.y(), n.z() * v3.z()));
}
centroid = scale(centroid, FT(1)/(FT(2)*volume));
return point(ORIGIN, centroid);
}
template<typename TriangleMesh>
typename CGAL::Kernel_traits<typename property_map_value<TriangleMesh,
CGAL::vertex_point_t>::type>::Kernel::Point_3
centroid(const TriangleMesh& tmesh)
{
return centroid(tmesh, CGAL::Polygon_mesh_processing::parameters::all_default());
}
} // namespace Polygon_mesh_processing
} // namespace CGAL
#include <CGAL/enable_warnings.h>
#endif // CGAL_POLYGON_MESH_PROCESSING_MEASURE_H