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

76 lines
2.4 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/.
#include "adjacency_matrix.h"
#include "verbose.h"
#include <vector>
template <typename DerivedF, typename T>
IGL_INLINE void igl::adjacency_matrix(
const Eigen::MatrixBase<DerivedF> & F,
Eigen::SparseMatrix<T>& A)
{
using namespace std;
using namespace Eigen;
typedef typename DerivedF::Scalar Index;
typedef Triplet<T> IJV;
vector<IJV > ijv;
ijv.reserve(F.size()*2);
// Loop over **simplex** (i.e., **not quad**)
for(int i = 0;i<F.rows();i++)
{
// Loop over this **simplex**
for(int j = 0;j<F.cols();j++)
for(int k = j+1;k<F.cols();k++)
{
// Get indices of edge: s --> d
Index s = F(i,j);
Index d = F(i,k);
ijv.push_back(IJV(s,d,1));
ijv.push_back(IJV(d,s,1));
}
}
const Index n = F.maxCoeff()+1;
A.resize(n,n);
switch(F.cols())
{
case 3:
A.reserve(6*(F.maxCoeff()+1));
break;
case 4:
A.reserve(26*(F.maxCoeff()+1));
break;
}
A.setFromTriplets(ijv.begin(),ijv.end());
// Force all non-zeros to be one
// Iterate over outside
for(int k=0; k<A.outerSize(); ++k)
{
// Iterate over inside
for(typename Eigen::SparseMatrix<T>::InnerIterator it (A,k); it; ++it)
{
assert(it.value() != 0);
A.coeffRef(it.row(),it.col()) = 1;
}
}
}
#ifdef IGL_STATIC_LIBRARY
// Explicit template instantiation
// generated by autoexplicit.sh
template void igl::adjacency_matrix<Eigen::Matrix<int, -1, -1, 0, -1, -1>, bool>(Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::SparseMatrix<bool, 0, int>&);
template void igl::adjacency_matrix<Eigen::Matrix<int, -1, -1, 0, -1, -1>, double>(Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::SparseMatrix<double, 0, int>&);
template void igl::adjacency_matrix<Eigen::Matrix<int, -1, -1, 0, -1, -1>, int>(Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::SparseMatrix<int, 0, int>&);
template void igl::adjacency_matrix<Eigen::Matrix<int, -1, 3, 0, -1, 3>, int>(Eigen::MatrixBase<Eigen::Matrix<int, -1, 3, 0, -1, 3> > const&, Eigen::SparseMatrix<int, 0, int>&);
#endif