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DiscreteStateSpace.cpp
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34 
35 /* Author: Elizabeth Fudge */
36 
37 #include "ompl/base/spaces/DiscreteStateSpace.h"
38 #include "ompl/util/Exception.h"
39 #include <limits>
40 #include <cstdlib>
41 
43 {
44  state->as<DiscreteStateSpace::StateType>()->value =
46  space_->as<DiscreteStateSpace>()->getUpperBound());
47 }
48 
49 void ompl::base::DiscreteStateSampler::sampleUniformNear(State *state, const State *near, const double distance)
50 {
51  const int d = (int)floor(distance + 0.5);
52  state->as<DiscreteStateSpace::StateType>()->value =
53  rng_.uniformInt(near->as<DiscreteStateSpace::StateType>()->value - d,
54  near->as<DiscreteStateSpace::StateType>()->value + d);
55  space_->enforceBounds(state);
56 }
57 
58 void ompl::base::DiscreteStateSampler::sampleGaussian(State *state, const State *mean, const double stdDev)
59 {
60  state->as<DiscreteStateSpace::StateType>()->value =
61  (int)floor(rng_.gaussian(mean->as<DiscreteStateSpace::StateType>()->value, stdDev) + 0.5);
62  space_->enforceBounds(state);
63 }
64 
66 {
67  return true;
68 }
69 
71 {
72  return 1;
73 }
74 
76 {
77  return upperBound_ - lowerBound_;
78 }
79 
81 {
82  if (state->as<StateType>()->value < lowerBound_)
83  state->as<StateType>()->value = lowerBound_;
84  else
85  if (state->as<StateType>()->value > upperBound_)
86  state->as<StateType>()->value = upperBound_;
87 }
88 
90 {
91  return state->as<StateType>()->value >= lowerBound_ && state->as<StateType>()->value <= upperBound_;
92 }
93 
94 void ompl::base::DiscreteStateSpace::copyState(State *destination, const State *source) const
95 {
96  destination->as<StateType>()->value = source->as<StateType>()->value;
97 }
98 
100 {
101  return sizeof(int);
102 }
103 
104 void ompl::base::DiscreteStateSpace::serialize(void *serialization, const State *state) const
105 {
106  memcpy(serialization, &state->as<StateType>()->value, sizeof(int));
107 }
108 
109 void ompl::base::DiscreteStateSpace::deserialize(State *state, const void *serialization) const
110 {
111  memcpy(&state->as<StateType>()->value, serialization, sizeof(int));
112 }
113 
114 double ompl::base::DiscreteStateSpace::distance(const State *state1, const State *state2) const
115 {
116  return abs(state1->as<StateType>()->value - state2->as<StateType>()->value);
117 }
118 
119 bool ompl::base::DiscreteStateSpace::equalStates(const State *state1, const State *state2) const
120 {
121  return state1->as<StateType>()->value == state2->as<StateType>()->value;
122 }
123 
124 void ompl::base::DiscreteStateSpace::interpolate(const State *from, const State *to, const double t, State *state) const
125 {
126  state->as<StateType>()->value = (int)floor(from->as<StateType>()->value +
127  (to->as<StateType>()->value - from->as<StateType>()->value) * t + 0.5);
128 }
129 
131 {
132  return StateSamplerPtr(new DiscreteStateSampler(this));
133 }
134 
136 {
137  return new StateType();
138 }
139 
141 {
142  delete static_cast<StateType*>(state);
143 }
144 
146 {
147  class DiscreteDefaultProjection : public ProjectionEvaluator
148  {
149  public:
150 
151  DiscreteDefaultProjection(const StateSpace *space) : ProjectionEvaluator(space)
152  {
153  }
154 
155  virtual unsigned int getDimension(void) const
156  {
157  return 1;
158  }
159 
160  virtual void defaultCellSizes(void)
161  {
162  bounds_.resize(1);
163  bounds_.low[0] = space_->as<DiscreteStateSpace>()->lowerBound_;
164  bounds_.high[0] = space_->as<DiscreteStateSpace>()->upperBound_;
165  cellSizes_.resize(1);
166  cellSizes_[0] = 1.0;
167  }
168 
169  virtual void project(const State *state, EuclideanProjection &projection) const
170  {
171  projection(0) = state->as<DiscreteStateSpace::StateType>()->value;
172  }
173  };
174 
175  registerDefaultProjection(ProjectionEvaluatorPtr(dynamic_cast<ProjectionEvaluator*>(new DiscreteDefaultProjection(this))));
176 }
177 
179 {
180  if (lowerBound_ > upperBound_)
181  throw Exception("Lower bound cannot be larger than upper bound for a discrete space");
183 }
184 
185 void ompl::base::DiscreteStateSpace::printState(const State *state, std::ostream &out) const
186 {
187  out << "DiscreteState [";
188  if (state)
189  out << state->as<StateType>()->value;
190  else
191  out << "NULL";
192  out << ']' << std::endl;
193 }
194 
196 {
197  out << "Discrete state space '" << getName() << "' with bounds [" << lowerBound_ << ", " << upperBound_ << "]" << std::endl;
198 }
virtual State * allocState(void) const
Allocate a state that can store a point in the described space.
const StateSpace * space_
The state space this sampler samples.
Definition: StateSampler.h:91
virtual StateSamplerPtr allocDefaultStateSampler(void) const
Allocate an instance of the default uniform state sampler for this space.
virtual unsigned int getDimension(void) const
Get the dimension of the space (not the dimension of the surrounding ambient space) ...
virtual void sampleUniform(State *state)
Sample a state.
virtual void copyState(State *destination, const State *source) const
Copy a state to another. The memory of source and destination should NOT overlap. ...
The definition of a discrete state.
A boost shared pointer wrapper for ompl::base::StateSampler.
RNG rng_
An instance of a random number generator.
Definition: StateSampler.h:94
virtual void sampleGaussian(State *state, const State *mean, const double stdDev)
Sample a state using a Gaussian distribution with given mean and standard deviation (stdDev) ...
virtual bool equalStates(const State *state1, const State *state2) const
Checks whether two states are equal.
virtual void deserialize(State *state, const void *serialization) const
Read the binary representation of a state from serialization and write it to state.
virtual double distance(const State *state1, const State *state2) const
Computes distance between two states. This function satisfies the properties of a metric if isMetricS...
virtual void enforceBounds(State *state) const
Bring the state within the bounds of the state space. For unbounded spaces this function can be a no-...
virtual void sampleUniformNear(State *state, const State *near, const double distance)
Sample a state near another, within specified distance.
virtual void registerProjections(void)
Register the projections for this state space. Usually, this is at least the default projection...
const T * as(void) const
Cast this instance to a desired type.
Definition: State.h:74
virtual void printState(const State *state, std::ostream &out) const
Print a state to a stream.
virtual void setup(void)
Perform final setup steps. This function is automatically called by the SpaceInformation. If any default projections are to be registered, this call will set them and call their setup() functions. It is safe to call this function multiple times. At a subsequent call, projections that have been previously user configured are not re-instantiated, but their setup() method is still called.
virtual void interpolate(const State *from, const State *to, const double t, State *state) const
Computes the state that lies at time t in [0, 1] on the segment that connects from state to to state...
virtual bool isDiscrete(void) const
Check if the set of states is discrete.
int getLowerBound(void) const
Returns the lowest possible state.
State space sampler for discrete states.
A boost shared pointer wrapper for ompl::base::ProjectionEvaluator.
virtual unsigned int getSerializationLength(void) const
Get the number of chars in the serialization of a state in this space.
Representation of a space in which planning can be performed. Topology specific sampling, interpolation and distance are defined.
Definition: StateSpace.h:73
boost::numeric::ublas::vector< double > EuclideanProjection
The datatype for state projections. This class contains a real vector.
virtual bool satisfiesBounds(const State *state) const
Check if a state is inside the bounding box. For unbounded spaces this function can always return tru...
Definition of an abstract state.
Definition: State.h:50
virtual void printSettings(std::ostream &out) const
Print the settings for this state space to a stream.
The exception type for ompl.
Definition: Exception.h:47
virtual double getMaximumExtent(void) const
Get the maximum value a call to distance() can return (or an upper bound). For unbounded state spaces...
A space representing discrete states; i.e. there are a small number of discrete states the system can...
virtual void serialize(void *serialization, const State *state) const
Write the binary representation of state to serialization.
int value
The current state - an int in range [lowerBound, upperBound].
virtual void setup(void)
Perform final setup steps. This function is automatically called by the SpaceInformation. If any default projections are to be registered, this call will set them and call their setup() functions. It is safe to call this function multiple times. At a subsequent call, projections that have been previously user configured are not re-instantiated, but their setup() method is still called.
Definition: StateSpace.cpp:220
virtual void freeState(State *state) const
Free the memory of the allocated state.
int uniformInt(int lower_bound, int upper_bound)
Generate a random integer within given bounds: [lower_bound, upper_bound].
Definition: RandomNumbers.h:75
T * as(void)
Cast this instance to a desired type.
Definition: StateSpace.h:87
Abstract definition for a class computing projections to Rn. Implicit integer grids are imposed on th...