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vertex_triangle_adjacency.h
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vertex_triangle_adjacency.h
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// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2014 Daniele Panozzo <daniele.panozzo@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#ifndef IGL_VERTEX_TRIANGLE_ADJACENCY_H
#define IGL_VERTEX_TRIANGLE_ADJACENCY_H
#include "igl_inline.h"
#include <Eigen/Dense>
#include <vector>
namespace igl
{
/// vertex_face_adjacency constructs the vertex-face topology of a given mesh (V,F)
///
/// @param[in] n number of vertices #V (e.g. `F.maxCoeff()+1` or `V.rows()`)
/// @param[in] F #F by dim list of mesh faces (must be triangles)
/// @param[out] VF #V list of lists of incident faces (adjacency list)
/// @param[out] VI #V list of lists of index of incidence within incident faces listed
/// in VF
///
/// \see edges, cotmatrix, diag, vv
///
/// \bug this should not take V as an input parameter.
/// \bug if a facet is combinatorially degenerate then faces will appear
/// multiple times in VF and correspondingly in VFI (j appears twice in
/// F.row(i) then i will appear twice in VF[j])
template <typename DerivedF, typename VFType, typename VFiType>
IGL_INLINE void vertex_triangle_adjacency(
const typename DerivedF::Scalar n,
const Eigen::MatrixBase<DerivedF>& F,
std::vector<std::vector<VFType> >& VF,
std::vector<std::vector<VFiType> >& VFi);
/// \overload
template <typename DerivedV, typename DerivedF, typename IndexType>
IGL_INLINE void vertex_triangle_adjacency(
const Eigen::MatrixBase<DerivedV>& V,
const Eigen::MatrixBase<DerivedF>& F,
std::vector<std::vector<IndexType> >& VF,
std::vector<std::vector<IndexType> >& VFi);
/// \overload
///
/// @param[in] F #F by 3 list of triangle indices into some vertex list V
/// @param[in] n number of vertices, #V (e.g., F.maxCoeff()+1)
/// @param[out] VF 3*#F list List of faces indice on each vertex, so that VF(NI(i)+j) =
/// f, means that face f is the jth face (in no particular order) incident
/// on vertex i.
/// @param[out] NI #V+1 list cumulative sum of vertex-triangle degrees with a
/// preceeding zero. "How many faces" have been seen before visiting this
/// vertex and its incident faces.
template <
typename DerivedF,
typename DerivedVF,
typename DerivedNI>
IGL_INLINE void vertex_triangle_adjacency(
const Eigen::MatrixBase<DerivedF> & F,
const int n,
Eigen::PlainObjectBase<DerivedVF> & VF,
Eigen::PlainObjectBase<DerivedNI> & NI);
}
#ifndef IGL_STATIC_LIBRARY
# include "vertex_triangle_adjacency.cpp"
#endif
#endif