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

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// 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 "arap_linear_block.h"
#include "verbose.h"
#include "cotmatrix_entries.h"
#include <Eigen/Dense>
template <typename MatV, typename MatF, typename Scalar>
IGL_INLINE void igl::arap_linear_block(
const MatV & V,
const MatF & F,
const int d,
const igl::ARAPEnergyType energy,
Eigen::SparseMatrix<Scalar> & Kd)
{
switch(energy)
{
case ARAP_ENERGY_TYPE_SPOKES:
return igl::arap_linear_block_spokes(V,F,d,Kd);
break;
case ARAP_ENERGY_TYPE_SPOKES_AND_RIMS:
return igl::arap_linear_block_spokes_and_rims(V,F,d,Kd);
break;
case ARAP_ENERGY_TYPE_ELEMENTS:
return igl::arap_linear_block_elements(V,F,d,Kd);
break;
default:
verbose("Unsupported energy type: %d\n",energy);
assert(false);
}
}
template <typename MatV, typename MatF, typename Scalar>
IGL_INLINE void igl::arap_linear_block_spokes(
const MatV & V,
const MatF & F,
const int d,
Eigen::SparseMatrix<Scalar> & Kd)
{
using namespace std;
using namespace Eigen;
// simplex size (3: triangles, 4: tetrahedra)
int simplex_size = F.cols();
// Number of elements
int m = F.rows();
// Temporary output
Matrix<int,Dynamic,2> edges;
Kd.resize(V.rows(), V.rows());
vector<Triplet<Scalar> > Kd_IJV;
if(simplex_size == 3)
{
// triangles
Kd.reserve(7*V.rows());
Kd_IJV.reserve(7*V.rows());
edges.resize(3,2);
edges <<
1,2,
2,0,
0,1;
}else if(simplex_size == 4)
{
// tets
Kd.reserve(17*V.rows());
Kd_IJV.reserve(17*V.rows());
edges.resize(6,2);
edges <<
1,2,
2,0,
0,1,
3,0,
3,1,
3,2;
}
// gather cotangent weights
Matrix<Scalar,Dynamic,Dynamic> C;
cotmatrix_entries(V,F,C);
// should have weights for each edge
assert(C.cols() == edges.rows());
// loop over elements
for(int i = 0;i<m;i++)
{
// loop over edges of element
for(int e = 0;e<edges.rows();e++)
{
int source = F(i,edges(e,0));
int dest = F(i,edges(e,1));
double v = 0.5*C(i,e)*(V(source,d)-V(dest,d));
Kd_IJV.push_back(Triplet<Scalar>(source,dest,v));
Kd_IJV.push_back(Triplet<Scalar>(dest,source,-v));
Kd_IJV.push_back(Triplet<Scalar>(source,source,v));
Kd_IJV.push_back(Triplet<Scalar>(dest,dest,-v));
}
}
Kd.setFromTriplets(Kd_IJV.begin(),Kd_IJV.end());
Kd.makeCompressed();
}
template <typename MatV, typename MatF, typename Scalar>
IGL_INLINE void igl::arap_linear_block_spokes_and_rims(
const MatV & V,
const MatF & F,
const int d,
Eigen::SparseMatrix<Scalar> & Kd)
{
using namespace std;
using namespace Eigen;
// simplex size (3: triangles, 4: tetrahedra)
int simplex_size = F.cols();
// Number of elements
int m = F.rows();
// Temporary output
Kd.resize(V.rows(), V.rows());
vector<Triplet<Scalar> > Kd_IJV;
Matrix<int,Dynamic,2> edges;
if(simplex_size == 3)
{
// triangles
Kd.reserve(7*V.rows());
Kd_IJV.reserve(7*V.rows());
edges.resize(3,2);
edges <<
1,2,
2,0,
0,1;
}else if(simplex_size == 4)
{
// tets
Kd.reserve(17*V.rows());
Kd_IJV.reserve(17*V.rows());
edges.resize(6,2);
edges <<
1,2,
2,0,
0,1,
3,0,
3,1,
3,2;
// Not implemented yet for tets
assert(false);
}
// gather cotangent weights
Matrix<Scalar,Dynamic,Dynamic> C;
cotmatrix_entries(V,F,C);
// should have weights for each edge
assert(C.cols() == edges.rows());
// loop over elements
for(int i = 0;i<m;i++)
{
// loop over edges of element
for(int e = 0;e<edges.rows();e++)
{
int source = F(i,edges(e,0));
int dest = F(i,edges(e,1));
double v = C(i,e)*(V(source,d)-V(dest,d))/3.0;
// loop over edges again
for(int f = 0;f<edges.rows();f++)
{
int Rs = F(i,edges(f,0));
int Rd = F(i,edges(f,1));
if(Rs == source && Rd == dest)
{
Kd_IJV.push_back(Triplet<Scalar>(Rs,Rd,v));
Kd_IJV.push_back(Triplet<Scalar>(Rd,Rs,-v));
}else if(Rd == source)
{
Kd_IJV.push_back(Triplet<Scalar>(Rd,Rs,v));
}else if(Rs == dest)
{
Kd_IJV.push_back(Triplet<Scalar>(Rs,Rd,-v));
}
}
Kd_IJV.push_back(Triplet<Scalar>(source,source,v));
Kd_IJV.push_back(Triplet<Scalar>(dest,dest,-v));
}
}
Kd.setFromTriplets(Kd_IJV.begin(),Kd_IJV.end());
Kd.makeCompressed();
}
template <typename MatV, typename MatF, typename Scalar>
IGL_INLINE void igl::arap_linear_block_elements(
const MatV & V,
const MatF & F,
const int d,
Eigen::SparseMatrix<Scalar> & Kd)
{
using namespace std;
using namespace Eigen;
// simplex size (3: triangles, 4: tetrahedra)
int simplex_size = F.cols();
// Number of elements
int m = F.rows();
// Temporary output
Kd.resize(V.rows(), F.rows());
vector<Triplet<Scalar> > Kd_IJV;
Matrix<int,Dynamic,2> edges;
if(simplex_size == 3)
{
// triangles
Kd.reserve(7*V.rows());
Kd_IJV.reserve(7*V.rows());
edges.resize(3,2);
edges <<
1,2,
2,0,
0,1;
}else if(simplex_size == 4)
{
// tets
Kd.reserve(17*V.rows());
Kd_IJV.reserve(17*V.rows());
edges.resize(6,2);
edges <<
1,2,
2,0,
0,1,
3,0,
3,1,
3,2;
}
// gather cotangent weights
Matrix<Scalar,Dynamic,Dynamic> C;
cotmatrix_entries(V,F,C);
// should have weights for each edge
assert(C.cols() == edges.rows());
// loop over elements
for(int i = 0;i<m;i++)
{
// loop over edges of element
for(int e = 0;e<edges.rows();e++)
{
int source = F(i,edges(e,0));
int dest = F(i,edges(e,1));
double v = C(i,e)*(V(source,d)-V(dest,d));
Kd_IJV.push_back(Triplet<Scalar>(source,i,v));
Kd_IJV.push_back(Triplet<Scalar>(dest,i,-v));
}
}
Kd.setFromTriplets(Kd_IJV.begin(),Kd_IJV.end());
Kd.makeCompressed();
}
#ifdef IGL_STATIC_LIBRARY
// Explicit template instantiation
template IGL_INLINE void igl::arap_linear_block<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, double>(Eigen::Matrix<double, -1, -1, 0, -1, -1> const&, Eigen::Matrix<int, -1, -1, 0, -1, -1> const&, int, igl::ARAPEnergyType, Eigen::SparseMatrix<double, 0, int>&);
#endif