ompl/base/samplers/src/ObstacleBasedValidStateSampler.cpp
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00034 
00035 /* Author: Ioan Sucan */
00036 
00037 #include "ompl/base/samplers/ObstacleBasedValidStateSampler.h"
00038 #include "ompl/base/SpaceInformation.h"
00039 
00040 ompl::base::ObstacleBasedValidStateSampler::ObstacleBasedValidStateSampler(const SpaceInformation *si) :
00041     ValidStateSampler(si), sampler_(si->allocStateSampler())
00042 {
00043     name_ = "obstacle_based";
00044 }
00045 
00046 bool ompl::base::ObstacleBasedValidStateSampler::sample(State *state)
00047 {
00048     // find invalid state
00049     unsigned int attempts = 0;
00050     bool valid = true;
00051     do
00052     {
00053         sampler_->sampleUniform(state);
00054         valid = si_->isValid(state);
00055         ++attempts;
00056     } while (valid && attempts < attempts_);
00057     if (valid)
00058         return false;
00059 
00060     // find a valid state
00061     State *temp = si_->allocState();
00062     attempts = 0;
00063     do
00064     {
00065         sampler_->sampleUniform(temp);
00066         valid = si_->isValid(temp);
00067         ++attempts;
00068     } while (!valid && attempts < attempts_);
00069 
00070 
00071     // keep the last valid state, before collision
00072     if (valid)
00073     {
00074         std::pair<State*, double> fail(state, 0.0);
00075         si_->checkMotion(temp, state, fail);
00076     }
00077 
00078     si_->freeState(temp);
00079 
00080     return valid;
00081 }
00082 
00083 bool ompl::base::ObstacleBasedValidStateSampler::sampleNear(State *state, const State *near, const double distance)
00084 {
00085     // find invalid state nearby
00086     unsigned int attempts = 0;
00087     bool valid = true;
00088     do
00089     {
00090         sampler_->sampleUniformNear(state, near, distance);
00091         valid = si_->isValid(state);
00092         ++attempts;
00093     } while (valid && attempts < attempts_);
00094     if (valid)
00095         return false;
00096 
00097     // find a valid state
00098     State *temp = si_->allocState();
00099     attempts = 0;
00100     do
00101     {
00102         sampler_->sampleUniform(temp);
00103         valid = si_->isValid(temp);
00104         ++attempts;
00105     } while (!valid && attempts < attempts_);
00106 
00107 
00108     // keep the last valid state, before collision
00109     if (valid)
00110     {
00111         std::pair<State*, double> fail(state, 0.0);
00112         si_->checkMotion(temp, state, fail);
00113     }
00114 
00115     si_->freeState(temp);
00116 
00117     return valid;
00118 }
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