FMT.h

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/* Authors: Ashley Clark (Stanford) and Wolfgang Pointner (AIT) */
/* Co-developers: Brice Rebsamen (Stanford), Tim Wheeler (Stanford)
                  Edward Schmerling (Stanford), and Javier V. Gómez (UC3M - Stanford)*/
/* Algorithm design: Lucas Janson (Stanford) and Marco Pavone (Stanford) */
/* Acknowledgements for insightful comments: Oren Salzman (Tel Aviv University),
 *                                           Joseph Starek (Stanford) */

#ifndef OMPL_GEOMETRIC_PLANNERS_FMT_
#define OMPL_GEOMETRIC_PLANNERS_FMT_

#include <ompl/geometric/planners/PlannerIncludes.h>
#include <ompl/base/goals/GoalSampleableRegion.h>
#include <ompl/datastructures/NearestNeighbors.h>
#include <ompl/datastructures/BinaryHeap.h>
#include <ompl/base/OptimizationObjective.h>
#include <map>


namespace ompl
{

    namespace geometric
    {

        class FMT : public ompl::base::Planner
        {
        public:

            FMT(const base::SpaceInformationPtr &si);

            virtual ~FMT();

            virtual void setup();

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

            virtual void clear();

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

            void setNumSamples(const unsigned int numSamples)
            {
                numSamples_ = numSamples;
            }

            unsigned int getNumSamples() const
            {
                return numSamples_;
            }

            void setNearestK(bool nearestK)
            {
                nearestK_ = nearestK;
            }

            bool getNearestK() const
            {
                return nearestK_;
            }

            void setRadiusMultiplier(const double radiusMultiplier)
            {
                if (radiusMultiplier <= 0.0)
                    throw Exception("Radius multiplier must be greater than zero");
                radiusMultiplier_ = radiusMultiplier;
            }

            double getRadiusMultiplier() const
            {
                return radiusMultiplier_;
            }

            void setFreeSpaceVolume(const double freeSpaceVolume)
            {
                if (freeSpaceVolume < 0.0)
                    throw Exception("Free space volume should be greater than zero");
                freeSpaceVolume_ = freeSpaceVolume;
            }

            double getFreeSpaceVolume() const
            {
                return freeSpaceVolume_;
            }

            void setCacheCC(bool ccc)
            {
                cacheCC_ = ccc;
            }

            bool getCacheCC() const
            {
                return cacheCC_;
            }

           void setHeuristics(bool h)
           {
               heuristics_ = h;
           }

            bool getHeuristics() const
            {
                return heuristics_;
            }

           void setExtendedFMT(bool e)
           {
               extendedFMT_ = e;
           }

           bool getExtendedFMT() const
           {
               return extendedFMT_;
           }

        protected:
            class Motion
            {
                public:

                    enum SetType { SET_CLOSED, SET_OPEN, SET_UNVISITED };

                    Motion()
                        : state_(nullptr), parent_(nullptr), cost_(0.0), currentSet_(SET_UNVISITED)
                    {
                    }

                    Motion(const base::SpaceInformationPtr &si)
                        : state_(si->allocState()), parent_(nullptr), cost_(0.0), currentSet_(SET_UNVISITED)
                    {
                    }

                    ~Motion()
                    {
                    }

                    void setState(base::State *state)
                    {
                        state_ = state;
                    }

                    base::State* getState() const
                    {
                        return state_;
                    }

                    void setParent(Motion *parent)
                    {
                        parent_ = parent;
                    }

                    Motion* getParent() const
                    {
                        return parent_;
                    }

                    void setCost(const base::Cost cost)
                    {
                        cost_ = cost;
                    }

                    base::Cost getCost() const
                    {
                        return cost_;
                    }

                    void setSetType(const SetType currentSet)
                    {
                        currentSet_ = currentSet;
                    }

                    SetType getSetType() const
                    {
                        return currentSet_;
                    }

                    bool alreadyCC(Motion *m)
                    {
                        if (collChecksDone_.find(m) == collChecksDone_.end())
                            return false;
                        return true;
                    }

                    void addCC(Motion *m)
                    {
                        collChecksDone_.insert(m);
                    }

                    void setHeuristicCost(const base::Cost h)
                    {
                        hcost_ = h;
                    }

                    base::Cost getHeuristicCost() const
                    {
                        return hcost_;
                    }

                    std::vector<Motion*>& getChildren()
                    {
                        return children_;
                    }

                protected:

                    base::State *state_;

                    Motion *parent_;

                    base::Cost cost_;

                    base::Cost hcost_;

                    SetType currentSet_;

                    std::set<Motion*> collChecksDone_;

                    std::vector<Motion*> children_;
            };

            struct MotionCompare
            {
                MotionCompare() : opt_(nullptr), heuristics_(false)
                {
                }

                /* Returns true if m1 is lower cost than m2. m1 and m2 must
                   have been instantiated with the same optimization objective */
                bool operator()(const Motion *m1, const Motion *m2) const
                {
                    if (heuristics_)
                        return opt_->isCostBetterThan(opt_->combineCosts(m1->getCost(), m1->getHeuristicCost()),
                                                      opt_->combineCosts(m2->getCost(), m2->getHeuristicCost()));
                    else
                        return opt_->isCostBetterThan(m1->getCost(), m2->getCost());
                }

                base::OptimizationObjective* opt_;
                bool heuristics_;
            };

            double distanceFunction(const Motion *a, const Motion *b) const
            {
                return opt_->motionCost(a->getState(), b->getState()).value();
            }

            void freeMemory();

            void sampleFree(const ompl::base::PlannerTerminationCondition &ptc);

            void assureGoalIsSampled(const ompl::base::GoalSampleableRegion *goal);

            double calculateUnitBallVolume(const unsigned int dimension) const;

            double calculateRadius(unsigned int dimension, unsigned int n) const;

            void saveNeighborhood(Motion *m);

            void traceSolutionPathThroughTree(Motion *goalMotion);

            bool expandTreeFromNode(Motion **z);

            void updateNeighborhood(Motion *m, const std::vector<Motion *> nbh);

            Motion* getBestParent(Motion *m, std::vector<Motion*> &neighbors, base::Cost &cMin);

            typedef ompl::BinaryHeap<Motion*, MotionCompare> MotionBinHeap;

            MotionBinHeap Open_;

            std::map<Motion*, std::vector<Motion*> > neighborhoods_;

            unsigned int numSamples_;

            unsigned int collisionChecks_;

            bool nearestK_;

            bool cacheCC_;

            bool heuristics_;

            double NNr_;

            unsigned int NNk_;

            double freeSpaceVolume_;

            double radiusMultiplier_;

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

            base::StateSamplerPtr sampler_;

            base::OptimizationObjectivePtr opt_;

            Motion *lastGoalMotion_;

            base::State* goalState_;

            bool extendedFMT_;

            // For sorting a list of costs and getting only their sorted indices
            struct CostIndexCompare
            {
                CostIndexCompare(const std::vector<base::Cost>& costs,
                                 const base::OptimizationObjective &opt) :
                    costs_(costs), opt_(opt)
                {}
                bool operator()(unsigned i, unsigned j)
                {
                    return opt_.isCostBetterThan(costs_[i],costs_[j]);
                }
                const std::vector<base::Cost>& costs_;
                const base::OptimizationObjective &opt_;
            };

        };
    }
}

#endif // OMPL_GEOMETRIC_PLANNERS_FMT_