dust3d/third_party/libigl/include/igl/adjacency_matrix.h

52 lines
1.5 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2013 Alec Jacobson <alecjacobson@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_ADJACENCY_MATRIX_H
#define IGL_ADJACENCY_MATRIX_H
#include "igl_inline.h"
#define EIGEN_YES_I_KNOW_SPARSE_MODULE_IS_NOT_STABLE_YET
#include <Eigen/Dense>
#include <Eigen/Sparse>
namespace igl
{
// Constructs the graph adjacency matrix of a given mesh (V,F)
// Templates:
// T should be a eigen sparse matrix primitive type like int or double
// Inputs:
// F #F by dim list of mesh simplices
// Outputs:
// A max(F) by max(F) cotangent matrix, each row i corresponding to V(i,:)
//
// Example:
// // Mesh in (V,F)
// Eigen::SparseMatrix<double> A;
// adjacency_matrix(F,A);
// // sum each row
// SparseVector<double> Asum;
// sum(A,1,Asum);
// // Convert row sums into diagonal of sparse matrix
// SparseMatrix<double> Adiag;
// diag(Asum,Adiag);
// // Build uniform laplacian
// SparseMatrix<double> U;
// U = A-Adiag;
//
// See also: edges, cotmatrix, diag
template <typename DerivedF, typename T>
IGL_INLINE void adjacency_matrix(
const Eigen::MatrixBase<DerivedF> & F,
Eigen::SparseMatrix<T>& A);
}
#ifndef IGL_STATIC_LIBRARY
# include "adjacency_matrix.cpp"
#endif
#endif