151 lines
4.9 KiB
C++
151 lines
4.9 KiB
C++
#include "ramer_douglas_peucker.h"
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#include "LinSpaced.h"
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#include "find.h"
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#include "cumsum.h"
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#include "histc.h"
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#include "slice.h"
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#include "project_to_line.h"
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#include "EPS.h"
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#include "slice_mask.h"
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template <typename DerivedP, typename DerivedS, typename DerivedJ>
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IGL_INLINE void igl::ramer_douglas_peucker(
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const Eigen::MatrixBase<DerivedP> & P,
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const typename DerivedP::Scalar tol,
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Eigen::PlainObjectBase<DerivedS> & S,
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Eigen::PlainObjectBase<DerivedJ> & J)
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{
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typedef typename DerivedP::Scalar Scalar;
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// number of vertices
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const int n = P.rows();
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// Trivial base case
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if(n <= 1)
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{
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J = DerivedJ::Zero(n);
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S = P;
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return;
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}
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// number of dimensions
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const int m = P.cols();
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Eigen::Array<bool,Eigen::Dynamic,1> I =
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Eigen::Array<bool,Eigen::Dynamic,1>::Constant(n,1,true);
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const auto stol = tol*tol;
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std::function<void(const int,const int)> simplify;
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simplify = [&I,&P,&stol,&simplify](const int ixs, const int ixe)->void
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{
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assert(ixe>ixs);
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Scalar sdmax = 0;
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typename Eigen::Matrix<Scalar,Eigen::Dynamic,1>::Index ixc = -1;
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if((ixe-ixs)>1)
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{
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Scalar sdes = (P.row(ixe)-P.row(ixs)).squaredNorm();
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Eigen::Matrix<Scalar,Eigen::Dynamic,1> sD;
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const auto & Pblock = P.block(ixs+1,0,((ixe+1)-ixs)-2,P.cols());
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if(sdes<=EPS<Scalar>())
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{
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sD = (Pblock.rowwise()-P.row(ixs)).rowwise().squaredNorm();
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}else
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{
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Eigen::Matrix<Scalar,Eigen::Dynamic,1> T;
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project_to_line(Pblock,P.row(ixs).eval(),P.row(ixe).eval(),T,sD);
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}
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sdmax = sD.maxCoeff(&ixc);
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// Index full P
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ixc = ixc+(ixs+1);
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}
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if(sdmax <= stol)
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{
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if(ixs != ixe-1)
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{
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I.block(ixs+1,0,((ixe+1)-ixs)-2,1).setConstant(false);
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}
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}else
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{
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simplify(ixs,ixc);
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simplify(ixc,ixe);
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}
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};
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simplify(0,n-1);
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slice_mask(P,I,1,S);
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find(I,J);
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}
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template <
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typename DerivedP,
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typename DerivedS,
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typename DerivedJ,
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typename DerivedQ>
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IGL_INLINE void igl::ramer_douglas_peucker(
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const Eigen::MatrixBase<DerivedP> & P,
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const typename DerivedP::Scalar tol,
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Eigen::PlainObjectBase<DerivedS> & S,
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Eigen::PlainObjectBase<DerivedJ> & J,
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Eigen::PlainObjectBase<DerivedQ> & Q)
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{
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typedef typename DerivedP::Scalar Scalar;
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ramer_douglas_peucker(P,tol,S,J);
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const int n = P.rows();
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assert(n>=2 && "Curve should be at least 2 points");
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typedef Eigen::Matrix<Scalar,Eigen::Dynamic,1> VectorXS;
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// distance traveled along high-res curve
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VectorXS L(n);
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L(0) = 0;
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L.block(1,0,n-1,1) = (P.bottomRows(n-1)-P.topRows(n-1)).rowwise().norm();
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// Give extra on end
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VectorXS T;
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cumsum(L,1,T);
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T.conservativeResize(T.size()+1);
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T(T.size()-1) = T(T.size()-2);
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// index of coarse point before each fine vertex
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Eigen::VectorXi B;
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{
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Eigen::VectorXi N;
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histc(igl::LinSpaced<Eigen::VectorXi >(n,0,n-1),J,N,B);
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}
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// Add extra point at end
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J.conservativeResize(J.size()+1);
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J(J.size()-1) = J(J.size()-2);
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Eigen::VectorXi s,d;
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// Find index in original list of "start" vertices
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slice(J,B,s);
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// Find index in original list of "destination" vertices
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slice(J,(B.array()+1).eval(),d);
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// Parameter between start and destination is linear in arc-length
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VectorXS Ts,Td;
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slice(T,s,Ts);
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slice(T,d,Td);
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T = ((T.head(T.size()-1)-Ts).array()/(Td-Ts).array()).eval();
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for(int t =0;t<T.size();t++)
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{
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if(!std::isfinite(T(t)) || T(t)!=T(t))
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{
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T(t) = 0;
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}
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}
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DerivedS SB;
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slice(S,B,1,SB);
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Eigen::VectorXi MB = B.array()+1;
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for(int b = 0;b<MB.size();b++)
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{
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if(MB(b) >= S.rows())
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{
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MB(b) = S.rows()-1;
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}
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}
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DerivedS SMB;
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slice(S,MB,1,SMB);
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Q = SB.array() + ((SMB.array()-SB.array()).colwise()*T.array());
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// Remove extra point at end
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J.conservativeResize(J.size()-1);
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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::ramer_douglas_peucker<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<double, -1, -1, 0, -1, -1> >(Eigen::MatrixBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, Eigen::Matrix<double, -1, -1, 0, -1, -1>::Scalar, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> >&);
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// generated by autoexplicit.sh
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template void igl::ramer_douglas_peucker<Eigen::Matrix<double, -1, 2, 0, -1, 2>, Eigen::Matrix<double, -1, 2, 0, -1, 2>, Eigen::Matrix<int, -1, 1, 0, -1, 1>, Eigen::Matrix<double, -1, 2, 0, -1, 2> >(Eigen::MatrixBase<Eigen::Matrix<double, -1, 2, 0, -1, 2> > const&, Eigen::Matrix<double, -1, 2, 0, -1, 2>::Scalar, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, 2, 0, -1, 2> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, 1, 0, -1, 1> >&, Eigen::PlainObjectBase<Eigen::Matrix<double, -1, 2, 0, -1, 2> >&);
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#endif
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