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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";
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     valid = false;
00064     do
00065     {
00066         sampler_->sampleUniform(temp);
00067         valid = si_->isValid(temp);
00068         ++attempts;
00069     } while (!valid && attempts < attempts_);
00070 
00071 
00072     // keep the last valid state, before collision
00073     if (valid)
00074     {
00075         std::pair<State*, double> fail(state, 0.0);
00076         si_->checkMotion(temp, state, fail);
00077     }
00078 
00079     si_->freeState(temp);
00080 
00081     return valid;
00082 }
00083 
00084 bool ompl::base::ObstacleBasedValidStateSampler::sampleNear(State *state, const State *near, const double distance)
00085 {
00086     // find invalid state nearby
00087     unsigned int attempts = 0;
00088     bool valid = true;
00089     do
00090     {
00091         sampler_->sampleUniformNear(state, near, distance);
00092         valid = si_->isValid(state);
00093         ++attempts;
00094     } while (valid && attempts < attempts_);
00095     if (valid)
00096         return false;
00097 
00098     // find a valid state
00099     State *temp = si_->allocState();
00100     attempts = 0;
00101     valid = false;
00102     do
00103     {
00104         sampler_->sampleUniform(temp);
00105         valid = si_->isValid(temp);
00106         ++attempts;
00107     } while (!valid && attempts < attempts_);
00108 
00109 
00110     // keep the last valid state, before collision
00111     if (valid)
00112     {
00113         std::pair<State*, double> fail(state, 0.0);
00114         si_->checkMotion(temp, state, fail);
00115     }
00116 
00117     si_->freeState(temp);
00118 
00119     return valid;
00120 }