ProductGraph.h

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/* Author: Matt Maly */

#ifndef OMPL_CONTROL_PLANNERS_LTL_PRODUCTGRAPH_
#define OMPL_CONTROL_PLANNERS_LTL_PRODUCTGRAPH_

#include "ompl/base/State.h"
#include "ompl/control/planners/ltl/Automaton.h"
#include "ompl/control/planners/ltl/PropositionalDecomposition.h"
#include "ompl/util/ClassForward.h"
#include <boost/graph/adjacency_list.hpp>
#include <functional>
#include <unordered_map>
#include <map>
#include <ostream>
#include <vector>

namespace ompl
{
    namespace control
    {

        OMPL_CLASS_FORWARD(ProductGraph);

        class ProductGraph
        {
        public:
            class State;


            struct HashState
            {
                std::size_t operator()(const State &s) const;
            };

            class State
            {
            friend class ProductGraph;
            public:
                State(void)
                    : decompRegion(-1),
                      cosafeState(-1),
                      safeState(-1) { }

                State(const State& s)
                    : decompRegion(s.decompRegion),
                      cosafeState(s.cosafeState),
                      safeState(s.safeState) { }

                bool operator==(const State& s) const;

                bool isValid(void) const;


                friend struct HashState;

                friend std::ostream& operator<<(std::ostream& out, const State& s);

                int getDecompRegion(void) const;

                int getCosafeState(void) const;

                int getSafeState(void) const;

            private:
                int decompRegion;
                int cosafeState;
                int safeState;
            };

            ProductGraph(
                const PropositionalDecompositionPtr& decomp,
                const AutomatonPtr& cosafetyAut,
                const AutomatonPtr& safetyAut
            );

            ProductGraph(
                const PropositionalDecompositionPtr& decomp,
                const AutomatonPtr& cosafetyAut
            );

            ~ProductGraph();

            const PropositionalDecompositionPtr& getDecomp() const;

            const AutomatonPtr& getCosafetyAutom() const;

            const AutomatonPtr& getSafetyAutom() const;

            std::vector<State*> computeLead(State* start, const std::function<double(State*, State*)>& edgeWeight);

            void clear();

            void buildGraph(State* start, const std::function<void(State*)>& initialize = ProductGraph::noInit);

            bool isSolution(const State* s) const;

            State* getStartState(void) const;

            double getRegionVolume(const State* s);

            int getCosafeAutDistance(const State* s) const;

            int getSafeAutDistance(const State* s) const;

            State* getState(const base::State* cs) const;

            State* getState(const base::State* cs, int cosafe, int safe) const;

            State* getState(const State* parent, int nextRegion) const;

            State* getState(const State* parent, const base::State* cs) const;

            State* getState(int region, int cosafe, int safe) const
            {
                State s;
                s.decompRegion = region;
                s.cosafeState = cosafe;
                s.safeState = safe;
                State*& ret = stateToPtr_[s];
                if (ret == nullptr) ret = new State(s);
                return ret;
            }

        protected:
            static void noInit(State* s)
            {
            }
            struct Edge
            {
                double cost;
            };

            typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, State*, Edge> GraphType;
            typedef boost::graph_traits<GraphType>::vertex_descriptor Vertex;
            typedef boost::graph_traits<GraphType>::vertex_iterator VertexIter;
            typedef boost::property_map<GraphType, boost::vertex_index_t>::type VertexIndexMap;
            typedef boost::graph_traits<GraphType>::edge_iterator EdgeIter;

            PropositionalDecompositionPtr decomp_;
            AutomatonPtr cosafety_;
            AutomatonPtr safety_;
            GraphType graph_;
            State* startState_;
            std::vector<State*> solutionStates_;

            /* Only one State pointer will be allocated for each possible State
               in the ProductGraph. There will exist situations in which
               all we have are the component values (region, automaton states)
               of a State and we want the actual State pointer.
               We use this map to access it. */
            mutable std::unordered_map<State, State*, HashState> stateToPtr_;

            /* Map from State pointer to the index of the corresponding vertex
               in the graph. */
            std::unordered_map<State*, int> stateToIndex_;
        };
    }
}
#endif