BFMT.h

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/* Authors: Joseph Starek (Stanford) */
/* Co-developers: Javier V Gomez (UC3M)*/
/* Algorithm design: Joseph Starek (Stanford), Ed Schmerling (Stanford), Lucas Janson (Stanford) and Marco Pavone (Stanford) */
/* Acknowledgements for insightful comments: Ashley Clark (Stanford) */

#ifndef OMPL_GEOMETRIC_PLANNERS_BIDIRECTIONALFMT_H
#define OMPL_GEOMETRIC_PLANNERS_BIDIRECTIONALFMT_H

#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 BFMT : public ompl::base::Planner {
        public:

            enum TreeType { FWD = 0, REV = 1 };

            enum ExploreType { SWAP_EVERY_TIME = 0, CHOOSE_SMALLEST_Z = 1 };

            enum TerminateType { FEASIBILITY = 0, OPTIMALITY = 1 };

            BFMT(const base::SpaceInformationPtr &si);

            virtual ~BFMT();

            virtual void setup(void);

            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_;
            }

            void setExploration(bool balanced)
            {
                exploration_ = SWAP_EVERY_TIME;
                if (balanced) {
                    exploration_ = CHOOSE_SMALLEST_Z;
                }
            }

            bool getExploration() const
            {
                return (exploration_ == CHOOSE_SMALLEST_Z);
            }

            void setTermination(bool optimality)
            {
                termination_ = FEASIBILITY;
                if (optimality) {
                    termination_ = OPTIMALITY;
                }
            }

            bool getTermination() const
            {
                return (termination_ == OPTIMALITY);
            }

            void setPrecomputeNN(bool p)
            {
                precomputeNN_ = p;
            }

            bool setPrecomputeNN() const
            {
                return precomputeNN_;
            }

            class BiDirMotion {
            public:

                enum SetType { SET_CLOSED, SET_OPEN, SET_UNVISITED };

                BiDirMotion(TreeType* tree)
                    : state_(NULL), tree_(tree)
                {
                    parent_[FWD]        = NULL;
                    parent_[REV]        = NULL;
                    cost_[FWD]          = base::Cost(0.0);
                    cost_[REV]          = base::Cost(0.0);
                    hcost_[FWD]         = base::Cost(0.0);
                    hcost_[REV]         = base::Cost(0.0);
                    currentSet_[FWD]    = SET_UNVISITED;
                    currentSet_[REV]    = SET_UNVISITED;
                }

                BiDirMotion(const base::SpaceInformationPtr &si, TreeType* tree)
                    : state_(si->allocState()), tree_(tree)
                {
                    parent_[FWD]        = NULL;
                    parent_[REV]        = NULL;
                    cost_[FWD]          = base::Cost(0.0);
                    cost_[REV]          = base::Cost(0.0);
                    hcost_[FWD]         = base::Cost(0.0);
                    hcost_[REV]         = base::Cost(0.0);
                    currentSet_[FWD]    = SET_UNVISITED;
                    currentSet_[REV]    = SET_UNVISITED;
                }

                typedef std::vector<BiDirMotion*> BiDirMotionPtrs;

                base::State             *state_;

                BiDirMotion*            parent_[2];

                BiDirMotionPtrs         children_[2];

                SetType                 currentSet_[2];

                TreeType*               tree_;

                base::Cost              cost_[2];

                base::Cost              hcost_[2];

                std::set<BiDirMotion *> collChecksDone_;

                inline base::Cost getCost(void) const
                {
                    return this->cost_[*tree_];
                }

                inline base::Cost getOtherCost(void) const
                {
                    return this->cost_[(*tree_+1) % 2];

                }

                inline void setCost(base::Cost cost)
                {
                    this->cost_[*tree_] = cost;
                }

                inline void setParent(BiDirMotion* parent)
                {
                    this->parent_[*tree_] = parent;
                }

                inline BiDirMotion* getParent(void) const
                {
                    return this->parent_[*tree_];
                }

                inline void setChildren(BiDirMotionPtrs children)
                {
                    this->children_[*tree_] = children;
                }

                inline BiDirMotionPtrs getChildren(void) const
                {
                    return this->children_[*tree_];
                }

                inline void setCurrentSet(SetType set)
                {
                    this->currentSet_[*tree_] = set;
                }

                inline SetType getCurrentSet(void) const
                {
                    return this->currentSet_[*tree_];
                }

                inline SetType getOtherSet(void) const
                {
                    return this->currentSet_[(*tree_+1) % 2];
                }

                inline void setTreeType(TreeType* treePtr)
                {
                    this->tree_ = treePtr;
                }

                inline TreeType getTreeType(void) const
                {
                    return *tree_;
                }

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

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

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

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

                void setHeuristicCost(const base::Cost h)
                {
                    hcost_[*tree_] = h;
                }

                base::Cost getHeuristicCost() const
                {
                    return hcost_[*tree_];
                }
            };

            typedef std::vector<BiDirMotion*> BiDirMotionPtrs;

        protected:

            struct BiDirMotionCompare {
                bool operator()(const BiDirMotion* p1, const BiDirMotion* p2) const {
                    if (heuristics_)
                        return ( opt_->combineCosts(p1->getCost(), p1->getHeuristicCost()).value() < opt_->combineCosts(p2->getCost(), p2->getHeuristicCost()).value() );
                    else
                        return (p1->getCost().value() < p2->getCost().value());
                }

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

            typedef ompl::BinaryHeap<BiDirMotion*, BiDirMotionCompare> BiDirMotionBinHeap;

            void swapTrees();

            void useFwdTree()
            {
                tree_ = FWD;
            }

            void useRevTree()
            {
                tree_ = REV;
            }

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

            double calculateUnitBallVolume(const unsigned int dimension) const;

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

            void freeMemory();

            void saveNeighborhood(std::shared_ptr< NearestNeighbors<BiDirMotion*> > nn, BiDirMotion* m);

            void sampleFree(std::shared_ptr<NearestNeighbors<BiDirMotion*> > nn,
                const base::PlannerTerminationCondition &ptc );

            void initializeProblem(base::GoalSampleableRegion*& goal_s);

            void expandTreeFromNode(BiDirMotion *&z, BiDirMotion *&connection_point);

            bool plan(BiDirMotion *x_init, BiDirMotion *x_goal, BiDirMotion *&z, const base::PlannerTerminationCondition& ptc);

            bool termination(BiDirMotion *&z, BiDirMotion *&connection_point, const base::PlannerTerminationCondition& ptc);

            void chooseTreeAndExpansionNode(BiDirMotion *&z);

            void tracePath(BiDirMotion *z, BiDirMotionPtrs& path);

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

            void insertNewSampleInOpen(const base::PlannerTerminationCondition& ptc);

            unsigned int                numSamples_;

            double                      radiusMultiplier_;

            double                      freeSpaceVolume_;

            unsigned int                collisionChecks_;

            bool                        nearestK_;

            double                      NNr_;

            unsigned int                NNk_;

            TreeType                    tree_;

            ExploreType                 exploration_;

            TerminateType               termination_;

            bool                  precomputeNN_;

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

            std::map<BiDirMotion*, BiDirMotionPtrs >                neighborhoods_;

            BiDirMotionBinHeap                                      Open_[2];

            std::map<BiDirMotion*, BiDirMotionBinHeap::Element*>    Open_elements[2];

            base::StateSamplerPtr sampler_;

            base::OptimizationObjectivePtr opt_;

            bool heuristics_;

            base::State* heurGoalState_[2];

            bool cacheCC_;

            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 (costs_[i].value() < costs_[j].value());
                }
                const std::vector<base::Cost>& costs_;
                const base::OptimizationObjective &opt_;
            };

        };

    }   // End "geometric" namespace
}       // End "ompl" namespace


#endif  /* OMPL_GEOMETRIC_PLANNERS_BIDIRECTIONALFMT_H */