BambuStudio/libigl/igl/slice_tets.cpp

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2024-12-20 06:44:50 +00:00
// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2015 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 "slice_tets.h"
#include "LinSpaced.h"
#include "sort.h"
#include "edges.h"
#include "slice.h"
#include "cat.h"
#include "ismember.h"
#include "unique_rows.h"
#include <cassert>
#include <algorithm>
#include <vector>
template <
typename DerivedV,
typename DerivedT,
typename DerivedS,
typename DerivedSV,
typename DerivedSF,
typename DerivedJ,
typename BCType>
IGL_INLINE void igl::slice_tets(
const Eigen::MatrixBase<DerivedV>& V,
const Eigen::MatrixBase<DerivedT>& T,
const Eigen::MatrixBase<DerivedS> & S,
Eigen::PlainObjectBase<DerivedSV>& SV,
Eigen::PlainObjectBase<DerivedSF>& SF,
Eigen::PlainObjectBase<DerivedJ>& J,
Eigen::SparseMatrix<BCType> & BC)
{
Eigen::MatrixXi sE;
Eigen::Matrix<typename DerivedSV::Scalar,Eigen::Dynamic,1> lambda;
igl::slice_tets(V,T,S,SV,SF,J,sE,lambda);
const int ns = SV.rows();
std::vector<Eigen::Triplet<BCType> > BCIJV(ns*2);
for(int i = 0;i<ns;i++)
{
BCIJV[2*i+0] = Eigen::Triplet<BCType>(i,sE(i,0), lambda(i));
BCIJV[2*i+1] = Eigen::Triplet<BCType>(i,sE(i,1),1.0-lambda(i));
}
BC.resize(SV.rows(),V.rows());
BC.setFromTriplets(BCIJV.begin(),BCIJV.end());
}
template <
typename DerivedV,
typename DerivedT,
typename DerivedS,
typename DerivedSV,
typename DerivedSF,
typename DerivedJ>
IGL_INLINE void igl::slice_tets(
const Eigen::MatrixBase<DerivedV>& V,
const Eigen::MatrixBase<DerivedT>& T,
const Eigen::MatrixBase<DerivedS> & S,
Eigen::PlainObjectBase<DerivedSV>& SV,
Eigen::PlainObjectBase<DerivedSF>& SF,
Eigen::PlainObjectBase<DerivedJ>& J)
{
Eigen::MatrixXi sE;
Eigen::Matrix<typename DerivedSV::Scalar,Eigen::Dynamic,1> lambda;
igl::slice_tets(V,T,S,SV,SF,J,sE,lambda);
}
template <
typename DerivedV,
typename DerivedT,
typename DerivedS,
typename DerivedSV,
typename DerivedSF,
typename DerivedJ,
typename DerivedsE,
typename Derivedlambda>
IGL_INLINE void igl::slice_tets(
const Eigen::MatrixBase<DerivedV>& V,
const Eigen::MatrixBase<DerivedT>& T,
const Eigen::MatrixBase<DerivedS> & S,
Eigen::PlainObjectBase<DerivedSV>& SV,
Eigen::PlainObjectBase<DerivedSF>& SF,
Eigen::PlainObjectBase<DerivedJ>& J,
Eigen::PlainObjectBase<DerivedsE>& sE,
Eigen::PlainObjectBase<Derivedlambda>& lambda)
{
using namespace Eigen;
using namespace std;
assert(V.cols() == 3 && "V should be #V by 3");
assert(T.cols() == 4 && "T should be #T by 4");
static const Eigen::Matrix<int,12,4> flipped_order =
(Eigen::Matrix<int,12,4>(12,4)<<
3,2,0,1,
3,1,2,0,
3,0,1,2,
2,3,1,0,
2,1,0,3,
2,0,3,1,
1,3,0,2,
1,2,3,0,
1,0,2,3,
0,3,2,1,
0,2,1,3,
0,1,3,2
).finished();
// number of tets
const size_t m = T.rows();
typedef typename DerivedS::Scalar Scalar;
typedef typename DerivedT::Scalar Index;
typedef Matrix<Scalar,Dynamic,1> VectorXS;
typedef Matrix<Scalar,Dynamic,4> MatrixX4S;
typedef Matrix<Scalar,Dynamic,3> MatrixX3S;
typedef Matrix<Scalar,Dynamic,2> MatrixX2S;
typedef Matrix<Index,Dynamic,4> MatrixX4I;
typedef Matrix<Index,Dynamic,3> MatrixX3I;
typedef Matrix<Index,Dynamic,2> MatrixX2I;
typedef Matrix<Index,Dynamic,1> VectorXI;
typedef Array<bool,Dynamic,1> ArrayXb;
MatrixX4S IT(m,4);
for(size_t t = 0;t<m;t++)
{
for(size_t c = 0;c<4;c++)
{
IT(t,c) = S(T(t,c));
}
}
// Essentially, just a glorified slice(X,1)
//
// Inputs:
// T #T by 4 list of tet indices into V
// IT #IT by 4 list of isosurface values at each tet
// I #I list of bools whether to grab data corresponding to each tet
const auto & extract_rows = [](
const MatrixBase<DerivedT> & T,
const MatrixX4S & IT,
const ArrayXb & I,
MatrixX4I & TI,
MatrixX4S & ITI,
VectorXI & JI)
{
const Index num_I = std::count(I.data(),I.data()+I.size(),true);
TI.resize(num_I,4);
ITI.resize(num_I,4);
JI.resize(num_I,1);
{
size_t k = 0;
for(size_t t = 0;t<(size_t)T.rows();t++)
{
if(I(t))
{
TI.row(k) = T.row(t);
ITI.row(k) = IT.row(t);
JI(k) = t;
k++;
}
}
assert(k == num_I);
}
};
ArrayXb I13 = (IT.array()<0).rowwise().count()==1;
ArrayXb I31 = (IT.array()>0).rowwise().count()==1;
ArrayXb I22 = (IT.array()<0).rowwise().count()==2;
MatrixX4I T13,T31,T22;
MatrixX4S IT13,IT31,IT22;
VectorXI J13,J31,J22;
extract_rows(T,IT,I13,T13,IT13,J13);
extract_rows(T,IT,I31,T31,IT31,J31);
extract_rows(T,IT,I22,T22,IT22,J22);
const auto & apply_sort4 = [] (
const MatrixX4I & T,
const MatrixX4I & sJ,
MatrixX4I & sT)
{
sT.resize(T.rows(),4);
for(size_t t = 0;t<(size_t)T.rows();t++)
{
for(size_t c = 0;c<4;c++)
{
sT(t,c) = T(t,sJ(t,c));
}
}
};
const auto & apply_sort2 = [] (
const MatrixX2I & E,
const MatrixX2I & sJ,
Eigen::PlainObjectBase<DerivedsE>& sE)
{
sE.resize(E.rows(),2);
for(size_t t = 0;t<(size_t)E.rows();t++)
{
for(size_t c = 0;c<2;c++)
{
sE(t,c) = E(t,sJ(t,c));
}
}
};
const auto & one_below = [&apply_sort4](
const MatrixX4I & T,
const MatrixX4S & IT,
MatrixX2I & U,
MatrixX3I & SF)
{
// Number of tets
const size_t m = T.rows();
if(m == 0)
{
U.resize(0,2);
SF.resize(0,3);
return;
}
MatrixX4S sIT;
MatrixX4I sJ;
sort(IT,2,true,sIT,sJ);
MatrixX4I sT;
apply_sort4(T,sJ,sT);
U.resize(3*m,2);
U<<
sT.col(0),sT.col(1),
sT.col(0),sT.col(2),
sT.col(0),sT.col(3);
SF.resize(m,3);
for(size_t c = 0;c<3;c++)
{
SF.col(c) =
igl::LinSpaced<
Eigen::Matrix<typename DerivedSF::Scalar,Eigen::Dynamic,1> >
(m,0+c*m,(m-1)+c*m);
}
ArrayXb flip;
{
VectorXi _;
ismember_rows(sJ,flipped_order,flip,_);
}
for(int i = 0;i<m;i++)
{
if(flip(i))
{
SF.row(i) = SF.row(i).reverse().eval();
}
}
};
const auto & two_below = [&apply_sort4](
const MatrixX4I & T,
const MatrixX4S & IT,
MatrixX2I & U,
MatrixX3I & SF)
{
// Number of tets
const size_t m = T.rows();
if(m == 0)
{
U.resize(0,2);
SF.resize(0,3);
return;
}
MatrixX4S sIT;
MatrixX4I sJ;
sort(IT,2,true,sIT,sJ);
MatrixX4I sT;
apply_sort4(T,sJ,sT);
U.resize(4*m,2);
U<<
sT.col(0),sT.col(2),
sT.col(0),sT.col(3),
sT.col(1),sT.col(2),
sT.col(1),sT.col(3);
SF.resize(2*m,3);
SF.block(0,0,m,1) = igl::LinSpaced<VectorXI >(m,0+0*m,(m-1)+0*m);
SF.block(0,1,m,1) = igl::LinSpaced<VectorXI >(m,0+1*m,(m-1)+1*m);
SF.block(0,2,m,1) = igl::LinSpaced<VectorXI >(m,0+3*m,(m-1)+3*m);
SF.block(m,0,m,1) = igl::LinSpaced<VectorXI >(m,0+0*m,(m-1)+0*m);
SF.block(m,1,m,1) = igl::LinSpaced<VectorXI >(m,0+3*m,(m-1)+3*m);
SF.block(m,2,m,1) = igl::LinSpaced<VectorXI >(m,0+2*m,(m-1)+2*m);
ArrayXb flip;
{
VectorXi _;
ismember_rows(sJ,flipped_order,flip,_);
}
for(int i = 0;i<m;i++)
{
if(flip(i))
{
SF.row(i ) = SF.row(i ).reverse().eval();
SF.row(i+m) = SF.row(i+m).reverse().eval();
}
}
};
MatrixX3I SF13,SF31,SF22;
MatrixX2I U13,U31,U22;
one_below(T13, IT13,U13,SF13);
one_below(T31,-IT31,U31,SF31);
two_below(T22, IT22,U22,SF22);
// https://forum.kde.org/viewtopic.php?f=74&t=107974
const MatrixX2I U =
(MatrixX2I(U13.rows()+ U31.rows()+ U22.rows(),2)<<U13,U31,U22).finished();
MatrixX2I sU;
{
MatrixX2I _;
sort(U,2,true,sU,_);
}
MatrixX2I E;
VectorXI uI,uJ;
unique_rows(sU,E,uI,uJ);
MatrixX2S IE(E.rows(),2);
for(size_t t = 0;t<E.rows();t++)
{
for(size_t c = 0;c<2;c++)
{
IE(t,c) = S(E(t,c));
}
}
MatrixX2S sIE;
MatrixX2I sJ;
sort(IE,2,true,sIE,sJ);
apply_sort2(E,sJ,sE);
lambda = sIE.col(1).array() / (sIE.col(1)-sIE.col(0)).array();
SV.resize(sE.rows(),V.cols());
for(int e = 0;e<sE.rows();e++)
{
SV.row(e) = V.row(sE(e,0)).template cast<Scalar>()*lambda(e) +
V.row(sE(e,1)).template cast<Scalar>()*(1.0-lambda(e));
}
SF.resize( SF13.rows()+SF31.rows()+SF22.rows(),3);
SF<<
SF13,
U13.rows()+ SF31.rowwise().reverse().array(),
U13.rows()+U31.rows()+SF22.array();
std::for_each(
SF.data(),
SF.data()+SF.size(),
[&uJ](typename DerivedSF::Scalar & i){i=uJ(i);});
J.resize(SF.rows());
J<<J13,J31,J22,J22;
}
#ifdef IGL_STATIC_LIBRARY
// Explicit template instantiation
template void igl::slice_tets<Eigen::Matrix<double, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<double, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -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<double, -1, 1, 0, -1, 1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&, Eigen::SparseMatrix<double, 0, int>&);
#endif