SST.h

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/* Authors: Zakary Littlefield */

#ifndef OMPL_CONTROL_PLANNERS_SST_SST_
#define OMPL_CONTROL_PLANNERS_SST_SST_

#include "ompl/control/planners/PlannerIncludes.h"
#include "ompl/datastructures/NearestNeighbors.h"

namespace ompl
{
    namespace control
    {
        class SST : public base::Planner
        {
        public:

            SST(const SpaceInformationPtr &si);

            virtual ~SST();

            virtual void setup();

            virtual base::PlannerStatus solve(const base::PlannerTerminationCondition &ptc);

            virtual void getPlannerData(base::PlannerData &data) const;

            virtual void clear();

            void setGoalBias(double goalBias)
            {
                goalBias_ = goalBias;
            }

            double getGoalBias() const
            {
                return goalBias_;
            }

            void setSelectionRadius(double selectionRadius)
            {
                selectionRadius_  = selectionRadius;
            }

            double getSelectionRadius() const
            {
                return selectionRadius_;
            }


            void setPruningRadius(double pruningRadius)
            {
                pruningRadius_  = pruningRadius;
            }

            double getPruningRadius() const
            {
                return pruningRadius_;
            }

            template<template<typename T> class NN>
            void setNearestNeighbors()
            {
                nn_.reset(new NN<Motion*>());
                witnesses_.reset(new NN<Motion*>());
            }

        protected:


            class Motion
            {
            public:

                Motion() : accCost_(0), state_(nullptr), control_(nullptr), steps_(0), parent_(nullptr), numChildren_(0), inactive_(false)
                {
                }

                Motion(const SpaceInformation *si) : accCost_(0), state_(si->allocState()), control_(si->allocControl()), steps_(0), parent_(nullptr), numChildren_(0), inactive_(false)
                {
                }

                virtual ~Motion()
                {
                }

                virtual base::State* getState() const
                {
                    return state_;
                }
                virtual Motion* getParent() const
                {
                    return parent_;
                }

                base::Cost accCost_;

                base::State       *state_;

                Control           *control_;

                unsigned int       steps_;

                Motion            *parent_;

                unsigned numChildren_;

                bool inactive_;


            };

            class Witness : public Motion
            {
            public:

                Witness() : Motion(), rep_(nullptr)
                {
                }

                Witness(const SpaceInformation *si) : Motion(si), rep_(nullptr)
                {
                }
                virtual base::State* getState() const
                {
                    return rep_->state_;
                }
                virtual Motion* getParent() const
                {
                    return rep_->parent_;
                }

                void linkRep(Motion *lRep)
                {
                    rep_ = lRep;
                }

                Motion* rep_;
            };

            Motion* selectNode(Motion *sample);

            Witness* findClosestWitness(Motion *node);

            void freeMemory();

            double distanceFunction(const Motion *a, const Motion *b) const
            {
                return si_->distance(a->state_, b->state_);
            }

            base::StateSamplerPtr                          sampler_;

            ControlSamplerPtr                              controlSampler_;

            const SpaceInformation                        *siC_;

            std::shared_ptr< NearestNeighbors<Motion*> > nn_;


            std::shared_ptr< NearestNeighbors<Motion*> > witnesses_;

            double                                         goalBias_;

            double                                         selectionRadius_;

            double                                         pruningRadius_;

            RNG                                            rng_;

            std::vector<base::State*>                      prevSolution_;
            std::vector<Control*>                          prevSolutionControls_;
            std::vector<unsigned>                          prevSolutionSteps_;

            base::Cost                                     prevSolutionCost_;

            base::OptimizationObjectivePtr                 opt_;

        };
    }
}

#endif