ImplicitGraph.h

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/*********************************************************************
 * Attribution Notice:
 *
 * This file contains code largely derived from the AIT* or BIT* planner
 * in the Open Motion Planning Library (OMPL). Specific structural components,
 * including sampling mechanisms, nearest neighbor routines, and priority
 * queue management, are adapted from that planner.
 *
 * The `addSample()` function and the core efficiency logic of BLIT* were
 * independently developed and modified by Yi Wang.
 *********************************************************************/
 
// Authors: Yi Wang, Eyal Weiss, Bingxian Mu, Oren Salzman
#ifndef OMPL_GEOMETRIC_PLANNERS_INFORMEDTREES_BLITSTAR_IMPLICITGRAPH_
#define OMPL_GEOMETRIC_PLANNERS_INFORMEDTREES_BLITSTAR_IMPLICITGRAPH_
 
#include <memory>
 
#include "ompl/base/samplers/InformedStateSampler.h"
#include "ompl/base/SpaceInformation.h"
#include "ompl/base/ProblemDefinition.h"
#include "ompl/base/PlannerTerminationCondition.h"
#include "ompl/base/Planner.h"
#include "ompl/datastructures/NearestNeighborsGNATNoThreadSafety.h"
#include "ompl/geometric/planners/lazyinformedtrees/blitstar/Vertex.h"
 
namespace ompl
{
    namespace geometric
    {
        namespace blitstar
        {
            class ImplicitGraph
            {
            public:
                ImplicitGraph(const ompl::base::Cost &solutionCost);

                virtual ~ImplicitGraph() = default;

                void setup(const ompl::base::SpaceInformationPtr &spaceInformation,
                           const ompl::base::ProblemDefinitionPtr &problemDefinition,
                           ompl::base::PlannerInputStates *inputStates);

                void clear();

                void setRewireFactor(double rewireFactor);

                double getRewireFactor() const;

                void setMaxNumberOfGoals(unsigned int maxNumberOfGoals);

                unsigned int getMaxNumberOfGoals() const;

                void setUseKNearest(bool useKNearest);

                bool getUseKNearest() const;

                void setTrackApproximateSolution(bool track);

                bool addSamples(std::size_t numNewSamples,
                                const ompl::base::PlannerTerminationCondition &terminationCondition, bool need_prune);

                std::size_t getNumVertices() const;
                std::size_t getNumNeighbors() const;
                double getConnectionRadius() const;
                ompl::base::Cost EculideanDistanceToStart(const std::shared_ptr<Vertex> &vertex) const;
                ompl::base::Cost EculideanDistanceToGoal(const std::shared_ptr<Vertex> &vertex) const;

                void registerStartState(const ompl::base::State *const startState);

                void registerGoalState(const ompl::base::State *const goalState);

                bool hasAStartState() const;

                bool hasAGoalState() const;

                void updateStartAndGoalStates(const ompl::base::PlannerTerminationCondition &terminationCondition,
                                              ompl::base::PlannerInputStates *inputStates);

                std::vector<std::shared_ptr<Vertex>> getNeighbors(const std::shared_ptr<Vertex> &vertex) const;

                bool isStart(const std::shared_ptr<Vertex> &vertex) const;

                bool isGoal(const std::shared_ptr<Vertex> &vertex) const;

                const std::vector<std::shared_ptr<Vertex>> &getStartVertices() const;

                const std::vector<std::shared_ptr<Vertex>> &getGoalVertices() const;

                std::vector<std::shared_ptr<Vertex>> getVertices() const;

                void prune();

                std::size_t getNumberOfSampledStates() const;

                std::size_t getNumberOfValidSamples() const;

                std::size_t getNumberOfStateCollisionChecks() const;

                std::size_t getNumberOfNearestNeighborCalls() const;
 
            private:
                std::size_t computeNumberOfSamplesInInformedSet() const;

                double computeConnectionRadius(std::size_t numSamples) const;

                std::size_t computeNumberOfNeighbors(std::size_t numSamples) const;

                bool canPossiblyImproveSolution(const std::shared_ptr<Vertex> &vertex) const;

                ompl::base::SpaceInformationPtr spaceInformation_;

                ompl::base::ProblemDefinitionPtr problemDefinition_;

                ompl::base::OptimizationObjectivePtr objective_;

                std::size_t batchId_;

                double rewireFactor_{1.001};

                bool trackApproximateSolution_{false};

                std::shared_ptr<Vertex> bestApproximateGoal_;

                bool useKNearest_{true};

                unsigned int maxNumGoals_{10u};

                double radius_{std::numeric_limits<double>::infinity()};

                std::size_t numNeighbors_{std::numeric_limits<std::size_t>::max()};

                std::size_t k_rgg_{std::numeric_limits<std::size_t>::max()};

                const ompl::base::Cost &solutionCost_;

                ompl::base::InformedSamplerPtr sampler_;

                ompl::NearestNeighborsGNATNoThreadSafety<std::shared_ptr<Vertex>> vertices_;

                std::vector<std::shared_ptr<Vertex>> startVertices_;

                std::vector<std::shared_ptr<Vertex>> goalVertices_;

                std::vector<std::shared_ptr<Vertex>> prunedStartVertices_;

                std::vector<std::shared_ptr<Vertex>> prunedGoalVertices_;

                std::vector<std::shared_ptr<Vertex>> newSamples_;

                mutable std::size_t numValidSamples_{0u};

                mutable std::size_t numSampledStates_{0u};

                mutable std::size_t numNearestNeighborsCalls_{0u};
            };
 
        }  // namespace blitstar
 
    }  // namespace geometric
 
}  // namespace ompl
 
#endif  // OMPL_GEOMETRIC_PLANNERS_INFORMEDTREES_BLITSTAR_IMPLICITGRAPH_