ConstrainedStateSpace.h

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/* Author: Zachary Kingston */
 
#ifndef OMPL_BASE_SPACES_CONSTRAINED_STATE_SPACE_
#define OMPL_BASE_SPACES_CONSTRAINED_STATE_SPACE_
 
#include "ompl/base/Constraint.h"
#include "ompl/base/StateSampler.h"
#include "ompl/base/ValidStateSampler.h"
#include "ompl/base/MotionValidator.h"
#include "ompl/base/spaces/WrapperStateSpace.h"
#include "ompl/base/SpaceInformation.h"
 
#include <Eigen/Core>
 
namespace ompl
{
    namespace magic
    {
        static const double CONSTRAINED_STATE_SPACE_DELTA = 0.05;
        static const double CONSTRAINED_STATE_SPACE_LAMBDA = 2.0;
    }  // namespace magic
 
    namespace base
    {

        OMPL_CLASS_FORWARD(ConstrainedStateSpace);

        class ConstrainedMotionValidator : public MotionValidator
        {
        public:
            ConstrainedMotionValidator(SpaceInformation *si);

            ConstrainedMotionValidator(const SpaceInformationPtr &si);

            bool checkMotion(const State *s1, const State *s2) const override;

            bool checkMotion(const State *s1, const State *s2, std::pair<State *, double> &lastValid) const override;
 
        protected:
            const ConstrainedStateSpace &ss_;
        };


        class ConstrainedStateSpace : public WrapperStateSpace
        {
        public:
            enum SanityChecks
            {
                CONSTRAINED_STATESPACE_SAMPLERS = (1 << 1),

                CONSTRAINED_STATESPACE_GEODESIC_SATISFY = (1 << 2),

                CONSTRAINED_STATESPACE_GEODESIC_CONTINUITY = (1 << 3),

                CONSTRAINED_STATESPACE_GEODESIC_INTERPOLATE = (1 << 4),

                CONSTRAINED_STATESPACE_JACOBIAN = (1 << 5)
            };

            class StateType : public WrapperStateSpace::StateType, public Eigen::Map<Eigen::VectorXd>
            {
            public:
                StateType(const ConstrainedStateSpace *space)
                  : WrapperStateSpace::StateType(space->getSpace()->allocState())
                  , Eigen::Map<Eigen::VectorXd>(space->getValueAddressAtIndex(this, 0), space->getDimension())
                {
                }

                void copy(const Eigen::Ref<const Eigen::VectorXd> &other)
                {
                    // Explicitly cast and call `=` on the state as an
                    // Eigen::Map<...>. This copies the other.
                    static_cast<Eigen::Map<Eigen::VectorXd> *>(this)->operator=(other);
                }
            };

            ConstrainedStateSpace(const StateSpacePtr &ambientSpace, const ConstraintPtr &constraint);


            bool isMetricSpace() const override
            {
                return false;
            }

            void setSpaceInformation(SpaceInformation *si);

            void setup() override;

            virtual void clear();

            State *allocState() const override;

            void constrainedSanityChecks(unsigned int flags) const;

            void sanityChecks() const override;

            unsigned int validSegmentCount(const State *s1, const State *s2) const override
            {
                return distance(s1, s2) * (1. / delta_) * lambda_;
            }



            void interpolate(const State *from, const State *to, double t, State *state) const override;

            virtual bool discreteGeodesic(const State *from, const State *to, bool interpolate = false,
                                          std::vector<State *> *geodesic = nullptr) const = 0;

            virtual State *geodesicInterpolate(const std::vector<State *> &geodesic, double t) const;



            void setDelta(double delta);

            void setLambda(double lambda)
            {
                if (lambda <= 1)
                    throw ompl::Exception("ompl::base::AtlasStateSpace::setLambda(): "
                                          "lambda must be > 1.");
                lambda_ = lambda;
            }

            double getDelta() const
            {
                return delta_;
            }

            double getLambda() const
            {
                return lambda_;
            }

            unsigned int getAmbientDimension() const
            {
                return n_;
            }

            unsigned int getManifoldDimension() const
            {
                return k_;
            }

            const ConstraintPtr getConstraint() const
            {
                return constraint_;
            }

 
        protected:
            SpaceInformation *si_{nullptr};

            const ConstraintPtr constraint_;

            const unsigned int n_;

            const unsigned int k_;

            double delta_;

            double lambda_{ompl::magic::CONSTRAINED_STATE_SPACE_LAMBDA};

            bool setup_{false};
        };
    }  // namespace base
}  // namespace ompl
 
#endif