DiscreteMotionValidator.cpp

/*********************************************************************
* Software License Agreement (BSD License)
*
*  Copyright (c) 2010, Rice University
*  All rights reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*   * Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   * Redistributions in binary form must reproduce the above
*     copyright notice, this list of conditions and the following
*     disclaimer in the documentation and/or other materials provided
*     with the distribution.
*   * Neither the name of the Rice University nor the names of its
*     contributors may be used to endorse or promote products derived
*     from this software without specific prior written permission.
*
*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
*  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
*  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
*  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
*  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
*  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
*  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
*  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
*  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
*  POSSIBILITY OF SUCH DAMAGE.
*********************************************************************/
 
/* Author: Ioan Sucan */
 
#include "ompl/base/DiscreteMotionValidator.h"
#include "ompl/util/Exception.h"
#include <queue>
 
void ompl::base::DiscreteMotionValidator::defaultSettings()
{
    stateSpace_ = si_->getStateSpace().get();
    if (stateSpace_ == nullptr)
        throw Exception("No state space for motion validator");
}
 
bool ompl::base::DiscreteMotionValidator::checkMotion(const State *s1, const State *s2,
                                                      std::pair<State *, double> &lastValid) const
{
    /* 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, test);
            if (!si_->isValid(test))
            {
                lastValid.second = (double)(j - 1) / (double)nd;
                if (lastValid.first != nullptr)
                    stateSpace_->interpolate(s1, s2, lastValid.second, 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, lastValid.first);
            result = false;
        }
 
    if (result)
        valid_++;
    else
        invalid_++;
 
    return result;
}
 
bool ompl::base::DiscreteMotionValidator::checkMotion(const State *s1, const State *s2) const
{
    /* assume motion starts in a valid configuration so s1 is valid */
    if (!si_->isValid(s2))
    {
        invalid_++;
        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, 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;
}