text: // g2o - General Graph Optimization
  // Copyright (C) 2011 R. Kuemmerle, G. Grisetti, H. Strasdat, W. Burgard
  // All rights reserved.
  //
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  #ifndef G2O_BASE_MULTI_EDGE_H
  #define G2O_BASE_MULTI_EDGE_H
  
  #include <iostream>
  #include <iomanip>
  #include <limits>
  
  #include <Eigen/StdVector>
  
  #include "base_edge.h"
  #include "robust_kernel.h"
  #include "g2o/config.h"
  #include "g2o/stuff/misc.h"
  #include "dynamic_aligned_buffer.hpp"
  
  namespace g2o {
  
    /**
     * \brief base class to represent an edge connecting an arbitrary number of nodes
     *
     * D - Dimension of the measurement
     * E - type to represent the measurement
     */
    template <int D, typename E>
      class BaseMultiEdge : public BaseEdge<D,E>
      {
      public:
        /**
         * \brief helper for mapping the Hessian memory of the upper triangular block
         */
        struct HessianHelper {
          Eigen::Map<MatrixXD> matrix;     ///< the mapped memory
          bool transposed;          ///< the block has to be transposed
          HessianHelper() : matrix(0, 0, 0), transposed(false) {}
        };
  
      public:
        static const int Dimension = BaseEdge<D,E>::Dimension;
        typedef typename BaseEdge<D,E>::Measurement Measurement;
        typedef MatrixXD::MapType JacobianType;
        typedef typename BaseEdge<D,E>::ErrorVector ErrorVector;
        typedef typename BaseEdge<D,E>::InformationType InformationType;
        typedef Eigen::Map<MatrixXD, MatrixXD::Flags & Eigen::PacketAccessBit ? Eigen::Aligned : Eigen::Unaligned > HessianBlockType;
  
        BaseMultiEdge() : BaseEdge<D,E>()
        {
        }
        
        virtual void linearizeOplus(JacobianWorkspace& jacobianWorkspace);
  
        /**
         * Linearizes the oplus operator in the vertex, and stores
         * the result in temporary variable vector _jacobianOplus
         */
        virtual void linearizeOplus();
        
        virtual void resize(size_t size);
  
        virtual bool allVerticesFixed() const;
  
        virtual void constructQuadraticForm() ;
  
        virtual void mapHessianMemory(double* d, int i, int j, bool rowMajor);
  
        using BaseEdge<D,E>::computeError;
  
      protected:
        using BaseEdge<D,E>::_measurement;
        using BaseEdge<D,E>::_information;
        using BaseEdge<D,E>::_error;
        using BaseEdge<D,E>::_vertices;
        using BaseEdge<D,E>::_dimension;
  
        std::vector<HessianHelper> _hessian;
        std::vector<JacobianType, Eigen::aligned_allocator<JacobianType> > _jacobianOplus; ///< jacobians of the edge (w.r.t. oplus)
  
        void computeQuadraticForm(const InformationType& omega, const ErrorVector& weightedError);
  
      public:
        EIGEN_MAKE_ALIGNED_OPERATOR_NEW
      };
  
  
  
    // PARTIAL TEMPLATE SPECIALIZATION
    template <typename E>
    class BaseMultiEdge<-1,E> : public BaseEdge<-1,E>
    {
      public:
        /**
         * \brief helper for mapping the Hessian memory of the upper triangular block
         */
        struct HessianHelper {
          Eigen::Map<MatrixXD> matrix;     ///< the mapped memory
          bool transposed;          ///< the block has to be transposed
          HessianHelper() : matrix(0, 0, 0), transposed(false) {}
        };
  
      public:
        static const int Dimension = BaseEdge<-1,E>::Dimension;
        typedef typename BaseEdge<-1,E>::Measurement Measurement;
        typedef MatrixXD::MapType JacobianType;
        typedef typename BaseEdge<-1,E>::ErrorVector ErrorVector;
        typedef typename BaseEdge<-1,E>::InformationType InformationType;
        typedef Eigen::Map<MatrixXD, MatrixXD::Flags & Eigen::PacketAccessBit ? Eigen::Aligned : Eigen::Unaligned > HessianBlockType;
  
        BaseMultiEdge() : BaseEdge<-1,E>()
      {
        // this->_variableSize = true;
      }
  
        virtual void linearizeOplus(JacobianWorkspace& jacobianWorkspace);
  
        /**
         * Linearizes the oplus operator in the vertex, and stores
         * the result in temporary variable vector _jacobianOplus
         */
        virtual void linearizeOplus();
  
        virtual void resize(size_t size);
  
        virtual bool allVerticesFixed() const;
  
        virtual void constructQuadraticForm() ;
  
        virtual void mapHessianMemory(double* d, int i, int j, bool rowMajor);
  
        using BaseEdge<-1,E>::computeError;
  
      protected:
        using BaseEdge<-1,E>::_measurement;
        using BaseEdge<-1,E>::_information;
        using BaseEdge<-1,E>::_error;
        using BaseEdge<-1,E>::_vertices;
        using BaseEdge<-1,E>::_dimension;
  
        std::vector<HessianHelper> _hessian;
        std::vector<JacobianType, Eigen::aligned_allocator<JacobianType> > _jacobianOplus; ///< jacobians of the edge (w.r.t. oplus)
  
        void computeQuadraticForm(const InformationType& omega, const ErrorVector& weightedError);
  
      public:
        EIGEN_MAKE_ALIGNED_OPERATOR_NEW;
      };
  
  
  #include "base_multi_edge.hpp"
  
  } // end namespace g2o
  
  #endif
  