101 lines
3.4 KiB
C++
101 lines
3.4 KiB
C++
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// This file is part of libigl, a simple c++ geometry processing library.
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//
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// Copyright (C) 2017 Alec Jacobson <alecjacobson@gmail.com>
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//
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// This Source Code Form is subject to the terms of the Mozilla Public License
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// v. 2.0. If a copy of the MPL was not distributed with this file, You can
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// obtain one at http://mozilla.org/MPL/2.0/.
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#include "crouzeix_raviart_cotmatrix.h"
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#include "unique_simplices.h"
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#include "oriented_facets.h"
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#include "is_edge_manifold.h"
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#include "cotmatrix_entries.h"
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template <typename DerivedV, typename DerivedF, typename LT, typename DerivedE, typename DerivedEMAP>
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void igl::crouzeix_raviart_cotmatrix(
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const Eigen::MatrixBase<DerivedV> & V,
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const Eigen::MatrixBase<DerivedF> & F,
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Eigen::SparseMatrix<LT> & L,
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Eigen::PlainObjectBase<DerivedE> & E,
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Eigen::PlainObjectBase<DerivedEMAP> & EMAP)
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{
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// All occurrences of directed "facets"
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Eigen::MatrixXi allE;
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oriented_facets(F,allE);
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Eigen::VectorXi _1;
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unique_simplices(allE,E,_1,EMAP);
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return crouzeix_raviart_cotmatrix(V,F,E,EMAP,L);
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}
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template <typename DerivedV, typename DerivedF, typename DerivedE, typename DerivedEMAP, typename LT>
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void igl::crouzeix_raviart_cotmatrix(
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const Eigen::MatrixBase<DerivedV> & V,
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const Eigen::MatrixBase<DerivedF> & F,
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const Eigen::MatrixBase<DerivedE> & E,
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const Eigen::MatrixBase<DerivedEMAP> & EMAP,
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Eigen::SparseMatrix<LT> & L)
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{
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// number of rows
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const int m = F.rows();
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// Element simplex size
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const int ss = F.cols();
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// Mesh should be edge-manifold
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assert(F.cols() != 3 || is_edge_manifold(F));
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typedef Eigen::Matrix<LT,Eigen::Dynamic,Eigen::Dynamic> MatrixXS;
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MatrixXS C;
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cotmatrix_entries(V,F,C);
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Eigen::MatrixXi F2E(m,ss);
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{
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int k =0;
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for(int c = 0;c<ss;c++)
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{
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for(int f = 0;f<m;f++)
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{
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F2E(f,c) = k++;
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}
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}
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}
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// number of entries inserted per facet
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const int k = ss*(ss-1)*2;
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std::vector<Eigen::Triplet<LT> > LIJV;LIJV.reserve(k*m);
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Eigen::VectorXi LI(k),LJ(k),LV(k);
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// Compensation factor to match scales in matlab version
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double factor = 2.0;
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switch(ss)
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{
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default: assert(false && "unsupported simplex size");
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case 3:
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factor = 4.0;
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LI<<0,1,2,1,2,0,0,1,2,1,2,0;
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LJ<<1,2,0,0,1,2,0,1,2,1,2,0;
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LV<<2,0,1,2,0,1,2,0,1,2,0,1;
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break;
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case 4:
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factor *= -1.0;
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LI<<0,3,3,3,1,2,1,0,1,2,2,0,0,3,3,3,1,2,1,0,1,2,2,0;
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LJ<<1,0,1,2,2,0,0,3,3,3,1,2,0,3,3,3,1,2,1,0,1,2,2,0;
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LV<<2,3,4,5,0,1,2,3,4,5,0,1,2,3,4,5,0,1,2,3,4,5,0,1;
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break;
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}
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for(int f=0;f<m;f++)
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{
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for(int c = 0;c<k;c++)
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{
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LIJV.emplace_back(
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EMAP(F2E(f,LI(c))),
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EMAP(F2E(f,LJ(c))),
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(c<(k/2)?-1.:1.) * factor *C(f,LV(c)));
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}
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}
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L.resize(E.rows(),E.rows());
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L.setFromTriplets(LIJV.begin(),LIJV.end());
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}
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#ifdef IGL_STATIC_LIBRARY
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// Explicit template instantiation
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// generated by autoexplicit.sh
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template void igl::crouzeix_raviart_cotmatrix<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, 1, 0, -1, 1>, double>(Eigen::MatrixBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::MatrixBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> > const&, Eigen::SparseMatrix<double, 0, int>&);
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#endif
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