ompl/base/objectives/src/MinimaxObjective.cpp
00001 /*********************************************************************
00002 * Software License Agreement (BSD License)
00003 *
00004 *  Copyright (c) 2010, Rice University
00005 *  All rights reserved.
00006 *
00007 *  Redistribution and use in source and binary forms, with or without
00008 *  modification, are permitted provided that the following conditions
00009 *  are met:
00010 *
00011 *   * Redistributions of source code must retain the above copyright
00012 *     notice, this list of conditions and the following disclaimer.
00013 *   * Redistributions in binary form must reproduce the above
00014 *     copyright notice, this list of conditions and the following
00015 *     disclaimer in the documentation and/or other materials provided
00016 *     with the distribution.
00017 *   * Neither the name of the Rice University nor the names of its
00018 *     contributors may be used to endorse or promote products derived
00019 *     from this software without specific prior written permission.
00020 *
00021 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00022 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00023 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00024 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
00025 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00026 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00027 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00028 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00029 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00030 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00031 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00032 *  POSSIBILITY OF SUCH DAMAGE.
00033 *********************************************************************/
00034 
00035 /* Author: Luis G. Torres */
00036 
00037 #include "ompl/base/objectives/MinimaxObjective.h"
00038 
00039 ompl::base::MinimaxObjective::MinimaxObjective(const SpaceInformationPtr &si) :
00040     OptimizationObjective(si)
00041 {
00042 }
00043 
00044 ompl::base::Cost ompl::base::MinimaxObjective::stateCost(const State *s) const
00045 {
00046     return Cost(1.0);
00047 }
00048 
00049 ompl::base::Cost ompl::base::MinimaxObjective::motionCost(const State *s1, const State *s2) const
00050 {
00051     Cost worstCost = this->identityCost();
00052 
00053     int nd = si_->getStateSpace()->validSegmentCount(s1, s2);
00054 
00055     if (nd > 1)
00056     {
00057         State *test = si_->allocState();
00058         for (int j = 1; j < nd; ++j)
00059         {
00060             si_->getStateSpace()->interpolate(s1, s2, (double) j / (double) nd, test);
00061             Cost testStateCost = this->stateCost(test);
00062             if (this->isCostBetterThan(worstCost, testStateCost))
00063                 worstCost = testStateCost;
00064         }
00065         si_->freeState(test);
00066     }
00067 
00068     // Lastly, check s2
00069     Cost lastCost = this->stateCost(s2);
00070     if (this->isCostBetterThan(worstCost, lastCost))
00071         worstCost = lastCost;
00072 
00073     return worstCost;
00074 }
00075 
00076 ompl::base::Cost ompl::base::MinimaxObjective::combineCosts(Cost c1, Cost c2) const
00077 {
00078     if (this->isCostBetterThan(c1, c2))
00079         return c2;
00080     else
00081         return c1;
00082 }
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines