371 lines
13 KiB
C++
371 lines
13 KiB
C++
// 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 "straighten_seams.h"
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#include "LinSpaced.h"
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#include "on_boundary.h"
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#include "sparse.h"
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#include "max.h"
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#include "count.h"
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#include "any.h"
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#include "slice_mask.h"
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#include "slice_into.h"
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#include "unique_simplices.h"
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#include "adjacency_matrix.h"
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#include "setxor.h"
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#include "edges_to_path.h"
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#include "ramer_douglas_peucker.h"
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#include "vertex_components.h"
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#include "list_to_matrix.h"
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#include "ears.h"
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#include "slice.h"
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#include "sum.h"
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#include "find.h"
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#include <iostream>
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template <
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typename DerivedV,
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typename DerivedF,
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typename DerivedVT,
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typename DerivedFT,
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typename Scalar,
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typename DerivedUE,
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typename DerivedUT,
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typename DerivedOT>
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IGL_INLINE void igl::straighten_seams(
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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<DerivedVT> & VT,
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const Eigen::MatrixBase<DerivedFT> & FT,
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const Scalar tol,
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Eigen::PlainObjectBase<DerivedUE> & UE,
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Eigen::PlainObjectBase<DerivedUT> & UT,
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Eigen::PlainObjectBase<DerivedOT> & OT)
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{
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using namespace Eigen;
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// number of faces
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assert(FT.rows() == F.rows() && "#FT must == #F");
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assert(F.cols() == 3 && "F should contain triangles");
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assert(FT.cols() == 3 && "FT should contain triangles");
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const int m = F.rows();
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// Boundary edges of the texture map and 3d meshes
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Array<bool,Dynamic,1> _;
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Array<bool,Dynamic,3> BT,BF;
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on_boundary(FT,_,BT);
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on_boundary(F,_,BF);
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assert((!((BF && (BT!=true)).any())) &&
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"Not dealing with boundaries of mesh that get 'stitched' in texture mesh");
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typedef Matrix<typename DerivedF::Scalar,Dynamic,2> MatrixX2I;
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const MatrixX2I ET = (MatrixX2I(FT.rows()*3,2)
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<<FT.col(1),FT.col(2),FT.col(2),FT.col(0),FT.col(0),FT.col(1)).finished();
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// "half"-edges with indices into 3D-mesh
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const MatrixX2I EF = (MatrixX2I(F.rows()*3,2)
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<<F.col(1),F.col(2),F.col(2),F.col(0),F.col(0),F.col(1)).finished();
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// Find unique (undirected) edges in F
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VectorXi EFMAP;
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{
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MatrixX2I _1;
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VectorXi _2;
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unique_simplices(EF,_1,_2,EFMAP);
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}
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Array<bool,Dynamic,1>vBT = Map<Array<bool,Dynamic,1> >(BT.data(),BT.size(),1);
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Array<bool,Dynamic,1>vBF = Map<Array<bool,Dynamic,1> >(BF.data(),BF.size(),1);
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MatrixX2I OF;
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slice_mask(ET,vBT,1,OT);
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slice_mask(EF,vBT,1,OF);
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VectorXi OFMAP;
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slice_mask(EFMAP,vBT,1,OFMAP);
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// Two boundary edges on the texture-mapping are "equivalent" to each other on
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// the 3D-mesh if their 3D-mesh vertex indices match
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SparseMatrix<bool> OEQ;
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{
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SparseMatrix<bool> OEQR;
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sparse(
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igl::LinSpaced<VectorXi >(OT.rows(),0,OT.rows()-1),
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OFMAP,
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Array<bool,Dynamic,1>::Ones(OT.rows(),1),
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OT.rows(),
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m*3,
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OEQR);
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OEQ = OEQR * OEQR.transpose();
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// Remove diagonal
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OEQ.prune([](const int r, const int c, const bool)->bool{return r!=c;});
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}
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// For each edge in OT, for each endpoint, how many _other_ texture-vertices
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// are images of all the 3d-mesh vertices in F who map from "corners" in F/FT
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// mapping to this endpoint.
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//
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// Adjacency matrix between 3d-vertices and texture-vertices
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SparseMatrix<bool> V2VT;
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sparse(
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F,
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FT,
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Array<bool,Dynamic,3>::Ones(F.rows(),F.cols()),
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V.rows(),
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VT.rows(),
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V2VT);
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// For each 3d-vertex count how many different texture-coordinates its getting
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// from different incident corners
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VectorXi DV;
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count(V2VT,2,DV);
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VectorXi M,I;
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max(V2VT,1,M,I);
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assert( (M.array() == 1).all() );
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VectorXi DT;
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// Map counts onto texture-vertices
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slice(DV,I,1,DT);
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// Boundary in 3D && UV
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Array<bool,Dynamic,1> BTF;
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slice_mask(vBF, vBT, 1, BTF);
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// Texture-vertex is "sharp" if incident on "half-"edge that is not a
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// boundary in the 3D mesh but is a boundary in the texture-mesh AND is not
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// "cut cleanly" (the vertex is mapped to exactly 2 locations)
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Array<bool,Dynamic,1> SV = Array<bool,Dynamic,1>::Zero(VT.rows(),1);
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//std::cout<<"#SV: "<<SV.count()<<std::endl;
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assert(BTF.size() == OT.rows());
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for(int h = 0;h<BTF.size();h++)
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{
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if(!BTF(h))
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{
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SV(OT(h,0)) = true;
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SV(OT(h,1)) = true;
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}
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}
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//std::cout<<"#SV: "<<SV.count()<<std::endl;
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Array<bool,Dynamic,1> CL = DT.array()==2;
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SparseMatrix<bool> VTOT;
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{
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Eigen::MatrixXi I =
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igl::LinSpaced<VectorXi >(OT.rows(),0,OT.rows()-1).replicate(1,2);
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sparse(
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OT,
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I,
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Array<bool,Dynamic,2>::Ones(OT.rows(),OT.cols()),
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VT.rows(),
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OT.rows(),
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VTOT);
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Array<int,Dynamic,1> cuts;
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count( (VTOT*OEQ).eval(), 2, cuts);
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CL = (CL && (cuts.array() == 2)).eval();
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}
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//std::cout<<"#CL: "<<CL.count()<<std::endl;
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assert(CL.size() == SV.size());
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for(int c = 0;c<CL.size();c++) if(CL(c)) SV(c) = false;
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{}
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//std::cout<<"#SV: "<<SV.count()<<std::endl;
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{
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// vertices at the corner of ears are declared to be sharp. This is
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// conservative: for example, if the ear is strictly convex and stays
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// strictly convex then the ear won't be flipped.
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VectorXi ear,ear_opp;
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ears(FT,ear,ear_opp);
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//std::cout<<"#ear: "<<ear.size()<<std::endl;
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// There might be an ear on one copy, so mark vertices on other copies, too
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// ears as they live on the 3D mesh
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Array<bool,Dynamic,1> earT = Array<bool,Dynamic,1>::Zero(VT.rows(),1);
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for(int e = 0;e<ear.size();e++) earT(FT(ear(e),ear_opp(e))) = 1;
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//std::cout<<"#earT: "<<earT.count()<<std::endl;
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// Even if ear-vertices are marked as sharp if it changes, e.g., from
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// convex to concave then it will _force_ a flip of the ear triangle. So,
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// declare that neighbors of ears are also sharp.
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SparseMatrix<bool> A;
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adjacency_matrix(FT,A);
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earT = (earT || (A*earT.matrix()).array()).eval();
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//std::cout<<"#earT: "<<earT.count()<<std::endl;
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assert(earT.size() == SV.size());
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for(int e = 0;e<earT.size();e++) if(earT(e)) SV(e) = true;
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//std::cout<<"#SV: "<<SV.count()<<std::endl;
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}
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{
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SparseMatrix<bool> V2VTSV,V2VTC;
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slice_mask(V2VT,SV,2,V2VTSV);
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Array<bool,Dynamic,1> Cb;
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any(V2VTSV,2,Cb);
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slice_mask(V2VT,Cb,1,V2VTC);
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any(V2VTC,1,SV);
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}
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//std::cout<<"#SV: "<<SV.count()<<std::endl;
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SparseMatrix<bool> OTVT = VTOT.transpose();
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int nc;
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ArrayXi C;
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{
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// Doesn't Compile on older Eigen:
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//SparseMatrix<bool> A = OTVT * (!SV).matrix().asDiagonal() * VTOT;
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SparseMatrix<bool> A = OTVT * (SV!=true).matrix().asDiagonal() * VTOT;
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vertex_components(A,C);
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nc = C.maxCoeff()+1;
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}
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//std::cout<<"nc: "<<nc<<std::endl;
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// New texture-vertex locations
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UT = VT;
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// Indices into UT of coarse output polygon edges
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std::vector<std::vector<typename DerivedUE::Scalar> > vUE;
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// loop over each component
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std::vector<bool> done(nc,false);
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for(int c = 0;c<nc;c++)
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{
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if(done[c])
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{
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continue;
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}
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done[c] = true;
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// edges of this component
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Eigen::VectorXi Ic;
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find(C==c,Ic);
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if(Ic.size() == 0)
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{
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continue;
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}
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SparseMatrix<bool> OEQIc;
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slice(OEQ,Ic,1,OEQIc);
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Eigen::VectorXi N;
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sum(OEQIc,2,N);
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const int ncopies = N(0)+1;
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assert((N.array() == ncopies-1).all());
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assert((ncopies == 1 || ncopies == 2) &&
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"Not dealing with non-manifold meshes");
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Eigen::VectorXi vpath,epath,eend;
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typedef Eigen::Matrix<Scalar,Eigen::Dynamic,2> MatrixX2S;
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switch(ncopies)
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{
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case 1:
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{
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MatrixX2I OTIc;
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slice(OT,Ic,1,OTIc);
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edges_to_path(OTIc,vpath,epath,eend);
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Array<bool,Dynamic,1> SVvpath;
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slice(SV,vpath,1,SVvpath);
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assert(
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(vpath(0) != vpath(vpath.size()-1) || !SVvpath.any()) &&
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"Not dealing with 1-loops touching 'sharp' corners");
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// simple open boundary
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MatrixX2S PI;
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slice(VT,vpath,1,PI);
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const Scalar bbd =
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(PI.colwise().maxCoeff() - PI.colwise().minCoeff()).norm();
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// Do not collapse boundaries to fewer than 3 vertices
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const bool allow_boundary_collapse = false;
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assert(PI.size() >= 2);
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const bool is_closed = PI(0) == PI(PI.size()-1);
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assert(!is_closed || vpath.size() >= 4);
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Scalar eff_tol = std::min(tol,2.);
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VectorXi UIc;
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while(true)
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{
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MatrixX2S UPI,UTvpath;
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ramer_douglas_peucker(PI,eff_tol*bbd,UPI,UIc,UTvpath);
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slice_into(UTvpath,vpath,1,UT);
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if(!is_closed || allow_boundary_collapse)
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{
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break;
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}
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if(UPI.rows()>=4)
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{
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break;
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}
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eff_tol = eff_tol*0.5;
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}
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for(int i = 0;i<UIc.size()-1;i++)
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{
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vUE.push_back({vpath(UIc(i)),vpath(UIc(i+1))});
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}
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}
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break;
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case 2:
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{
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// Find copies
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VectorXi Icc;
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{
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VectorXi II;
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Array<bool,Dynamic,1> IV;
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SparseMatrix<bool> OEQIcT = OEQIc.transpose().eval();
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find(OEQIcT,Icc,II,IV);
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assert(II.size() == Ic.size() &&
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(II.array() ==
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igl::LinSpaced<VectorXi >(Ic.size(),0,Ic.size()-1).array()).all());
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assert(Icc.size() == Ic.size());
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const int cc = C(Icc(0));
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Eigen::VectorXi CIcc;
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slice(C,Icc,1,CIcc);
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assert((CIcc.array() == cc).all());
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assert(!done[cc]);
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done[cc] = true;
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}
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Array<bool,Dynamic,1> flipped;
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{
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MatrixX2I OFIc,OFIcc;
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slice(OF,Ic,1,OFIc);
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slice(OF,Icc,1,OFIcc);
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Eigen::VectorXi XOR,IA,IB;
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setxor(OFIc,OFIcc,XOR,IA,IB);
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assert(XOR.size() == 0);
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flipped = OFIc.array().col(0) != OFIcc.array().col(0);
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}
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if(Ic.size() == 1)
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{
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// No change to UT
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vUE.push_back({OT(Ic(0),0),OT(Ic(0),1)});
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assert(Icc.size() == 1);
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vUE.push_back({OT(Icc(0),flipped(0)?1:0),OT(Icc(0),flipped(0)?0:1)});
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}else
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{
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MatrixX2I OTIc;
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slice(OT,Ic,1,OTIc);
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edges_to_path(OTIc,vpath,epath,eend);
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// Flip endpoints if needed
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for(int e = 0;e<eend.size();e++)if(flipped(e))eend(e)=1-eend(e);
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VectorXi vpathc(epath.size()+1);
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for(int e = 0;e<epath.size();e++)
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{
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vpathc(e) = OT(Icc(epath(e)),eend(e));
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}
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vpathc(epath.size()) =
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OT(Icc(epath(epath.size()-1)),1-eend(eend.size()-1));
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assert(vpath.size() == vpathc.size());
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Matrix<Scalar,Dynamic,Dynamic> PI(vpath.size(),VT.cols()*2);
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for(int p = 0;p<PI.rows();p++)
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{
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for(int d = 0;d<VT.cols();d++)
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{
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PI(p, d) = VT( vpath(p),d);
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PI(p,VT.cols()+d) = VT(vpathc(p),d);
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}
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}
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const Scalar bbd =
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(PI.colwise().maxCoeff() - PI.colwise().minCoeff()).norm();
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Matrix<Scalar,Dynamic,Dynamic> UPI,SI;
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VectorXi UIc;
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ramer_douglas_peucker(PI,tol*bbd,UPI,UIc,SI);
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slice_into(SI.leftCols (VT.cols()), vpath,1,UT);
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slice_into(SI.rightCols(VT.cols()),vpathc,1,UT);
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for(int i = 0;i<UIc.size()-1;i++)
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{
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vUE.push_back({vpath(UIc(i)),vpath(UIc(i+1))});
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}
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for(int i = 0;i<UIc.size()-1;i++)
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{
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vUE.push_back({vpathc(UIc(i)),vpathc(UIc(i+1))});
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}
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}
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}
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break;
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default:
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assert(false && "Should never reach here");
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}
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}
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list_to_matrix(vUE,UE);
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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::straighten_seams<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -1, -1, 1, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, double, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -1, -1, 1, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1> >(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<double, -1, -1, 1, -1, -1> > const&, Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, double, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 1, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&);
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#endif
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