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  /* Author: Ioan Sucan */
  
  #include <moveit/ompl_interface/detail/constrained_sampler.h>
  #include <moveit/ompl_interface/model_based_planning_context.h>
  #include <moveit/profiler/profiler.h>
  
  #include <utility>
  
  ompl_interface::ConstrainedSampler::ConstrainedSampler(const ModelBasedPlanningContext* pc,
                                                         constraint_samplers::ConstraintSamplerPtr cs)
    : ob::StateSampler(pc->getOMPLStateSpace().get())
    , planning_context_(pc)
    , default_(space_->allocDefaultStateSampler())
    , constraint_sampler_(std::move(cs))
    , work_state_(pc->getCompleteInitialRobotState())
    , constrained_success_(0)
    , constrained_failure_(0)
  {
    inv_dim_ = space_->getDimension() > 0 ? 1.0 / (double)space_->getDimension() : 1.0;
  }
  
  double ompl_interface::ConstrainedSampler::getConstrainedSamplingRate() const
  {
    if (constrained_success_ == 0)
      return 0.0;
    else
      return (double)constrained_success_ / (double)(constrained_success_ + constrained_failure_);
  }
  
  bool ompl_interface::ConstrainedSampler::sampleC(ob::State* state)
  {
    //  moveit::Profiler::ScopedBlock sblock("sampleWithConstraints");
  
    if (constraint_sampler_->sample(work_state_, planning_context_->getCompleteInitialRobotState(),
                                    planning_context_->getMaximumStateSamplingAttempts()))
    {
      planning_context_->getOMPLStateSpace()->copyToOMPLState(state, work_state_);
      if (space_->satisfiesBounds(state))
      {
        ++constrained_success_;
        return true;
      }
    }
    ++constrained_failure_;
    return false;
  }
  
  void ompl_interface::ConstrainedSampler::sampleUniform(ob::State* state)
  {
    if (!sampleC(state) && !sampleC(state) && !sampleC(state))
      default_->sampleUniform(state);
  }
  
  void ompl_interface::ConstrainedSampler::sampleUniformNear(ob::State* state, const ob::State* near,
                                                             const double distance)
  {
    if (sampleC(state) || sampleC(state) || sampleC(state))
    {
      double total_d = space_->distance(state, near);
      if (total_d > distance)
      {
        double dist = pow(rng_.uniform01(), inv_dim_) * distance;
        space_->interpolate(near, state, dist / total_d, state);
      }
    }
    else
      default_->sampleUniformNear(state, near, distance);
  }
  
  void ompl_interface::ConstrainedSampler::sampleGaussian(ob::State* state, const ob::State* mean, const double stdDev)
  {
    if (sampleC(state) || sampleC(state) || sampleC(state))
    {
      double total_d = space_->distance(state, mean);
      double distance = rng_.gaussian(0.0, stdDev);
      if (total_d > distance)
      {
        double dist = pow(rng_.uniform01(), inv_dim_) * distance;
        space_->interpolate(mean, state, dist / total_d, state);
      }
    }
    else
      default_->sampleGaussian(state, mean, stdDev);
  }
  