Dubins3DMotionValidator.h

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/* Author: Mark Moll */
 
#ifndef OMPL_BASE_SPACES_DUBINS3D_MOTION_VALIDATOR_
#define OMPL_BASE_SPACES_DUBINS3D_MOTION_VALIDATOR_
 
#include "ompl/base/SpaceInformation.h"
#include <queue>
 
namespace ompl::base
{

    template <class Dubins3DStateSpace>
    class Dubins3DMotionValidator : public MotionValidator
    {
    public:
        Dubins3DMotionValidator(SpaceInformation *si) : MotionValidator(si)
        {
            defaultSettings();
        }
        Dubins3DMotionValidator(const SpaceInformationPtr &si) : MotionValidator(si)
        {
            defaultSettings();
        }
        ~Dubins3DMotionValidator() override = default;
        bool checkMotion(const State *s1, const State *s2) const override
        {
            /* assume motion starts in a valid configuration so s1 is valid */
            if (!si_->isValid(s2))
                return false;
            auto path = stateSpace_->getPath(s1, s2);
            if (!path)
                return false;
 
            bool result = true;
            int nd = stateSpace_->validSegmentCount(s1, s2);
 
            /* initialize the queue of test positions */
            std::queue<std::pair<int, int>> pos;
            if (nd >= 2)
            {
                pos.emplace(1, nd - 1);
 
                /* temporary storage for the checked state */
                State *test = si_->allocState();
 
                /* repeatedly subdivide the path segment in the middle (and check the middle) */
                while (!pos.empty())
                {
                    std::pair<int, int> x = pos.front();
 
                    int mid = (x.first + x.second) / 2;
                    stateSpace_->interpolate(s1, s2, (double)mid / (double)nd, *path, test);
 
                    if (!si_->isValid(test))
                    {
                        result = false;
                        break;
                    }
 
                    pos.pop();
 
                    if (x.first < mid)
                        pos.emplace(x.first, mid - 1);
                    if (x.second > mid)
                        pos.emplace(mid + 1, x.second);
                }
 
                si_->freeState(test);
            }
 
            if (result)
                valid_++;
            else
                invalid_++;
 
            return result;
        }
        bool checkMotion(const State *s1, const State *s2, std::pair<State *, double> &lastValid) const override
        {
            auto path = stateSpace_->getPath(s1, s2);
            if (!path)
                return false;
 
            /* assume motion starts in a valid configuration so s1 is valid */
            bool result = true;
            int nd = stateSpace_->validSegmentCount(s1, s2);
 
            if (nd > 1)
            {
                /* temporary storage for the checked state */
                State *test = si_->allocState();
 
                for (int j = 1; j < nd; ++j)
                {
                    stateSpace_->interpolate(s1, s2, (double)j / (double)nd, *path, test);
                    if (!si_->isValid(test))
                    {
                        lastValid.second = (double)(j - 1) / (double)nd;
                        if (lastValid.first != nullptr)
                            stateSpace_->interpolate(s1, s2, lastValid.second, *path, lastValid.first);
                        result = false;
                        break;
                    }
                }
                si_->freeState(test);
            }
 
            if (result)
                if (!si_->isValid(s2))
                {
                    lastValid.second = (double)(nd - 1) / (double)nd;
                    if (lastValid.first != nullptr)
                        stateSpace_->interpolate(s1, s2, lastValid.second, *path, lastValid.first);
                    result = false;
                }
 
            if (result)
                valid_++;
            else
                invalid_++;
 
            return result;
        }
 
    private:
        Dubins3DStateSpace *stateSpace_;
        void defaultSettings()
        {
            stateSpace_ = dynamic_cast<Dubins3DStateSpace *>(si_->getStateSpace().get());
            if (stateSpace_ == nullptr)
                throw Exception("No state space for motion validator");
        }
    };
}  // namespace ompl::base
 
#endif