cgal/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/triangle.h

92 lines
3.4 KiB
C++

// Copyright (c) 2015 GeometryFactory (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) : Jane Tournois
#ifndef CGAL_POLYGON_MESH_PROCESSING_TRIANGLE_H
#define CGAL_POLYGON_MESH_PROCESSING_TRIANGLE_H
#include <CGAL/license/Polygon_mesh_processing/core.h>
#include <boost/graph/graph_traits.hpp>
#include <CGAL/Named_function_parameters.h>
#include <CGAL/boost/graph/named_params_helper.h>
namespace CGAL {
namespace Polygon_mesh_processing {
/*!
* \ingroup PkgPolygonMeshProcessingRef
*
* computes a triangle for a face descriptor of a triangle mesh.
*
* @tparam TriangleMesh a model of `FaceGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param tmesh the triangulated surface mesh
* @param fd the descriptor of the face to construct the triangle from
* @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
*/
template<typename TriangleMesh, typename CGAL_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
Triangle_3
#else
typename GetGeomTraits<TriangleMesh, CGAL_NP_CLASS>::type::Triangle_3
#endif
triangle(typename boost::graph_traits<TriangleMesh>::face_descriptor fd,
const TriangleMesh& tmesh,
const CGAL_NP_CLASS& np = parameters::default_values())
{
using CGAL::parameters::choose_parameter;
using CGAL::parameters::get_parameter;
CGAL_precondition(is_valid_face_descriptor(fd, tmesh));
typename GetVertexPointMap<TriangleMesh, CGAL_NP_CLASS>::const_type
vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, tmesh));
typedef typename GetGeomTraits<TriangleMesh, CGAL_NP_CLASS>::type GT;
GT gt = choose_parameter<GT>(get_parameter(np, internal_np::geom_traits));
typename GT::Construct_triangle_3 construct_triangle = gt.construct_triangle_3_object();
typedef typename boost::graph_traits<TriangleMesh>::vertex_descriptor vertex_descriptor;
typedef typename boost::graph_traits<TriangleMesh>::halfedge_descriptor halfedge_descriptor;
halfedge_descriptor h = halfedge(fd, tmesh);
vertex_descriptor v1 = target(h, tmesh);
vertex_descriptor v2 = target(next(h, tmesh), tmesh);
vertex_descriptor v3 = target(next(next(h, tmesh), tmesh), tmesh);
return construct_triangle(get(vpm, v1), get(vpm, v2), get(vpm, v3));
}
}
}
#endif //CGAL_POLYGON_MESH_PROCESSING_TRIANGLE_H