Representation of a space in which planning can be performed. Topology specific sampling, interpolation and distance are defined. More...
#include <ompl/base/StateSpace.h>
Classes  
struct  SubstateLocation 
Representation of the address of a substate in a state. This structure stores the indexing information needed to access a particular substate of a state. More...  
struct  ValueLocation 
Representation of the address of a value in a state. This structure stores the indexing information needed to access elements of a state (no pointer values are stored) More...  
Public Types  
enum  SanityChecks { STATESPACE_DISTANCE_DIFFERENT_STATES = (1 << 1), STATESPACE_DISTANCE_SYMMETRIC = (1 << 2), STATESPACE_INTERPOLATION = (1 << 3), STATESPACE_TRIANGLE_INEQUALITY = (1 << 4), STATESPACE_DISTANCE_BOUND = (1 << 5), STATESPACE_RESPECT_BOUNDS = (1 << 6), STATESPACE_ENFORCE_BOUNDS_NO_OP = (1 << 7), STATESPACE_SERIALIZATION = (1 << 8) } 
Flags to use in a bit mask for state space sanity checks. Some basic checks do not have flags associated (they are always executed; for example, whether copyState() works as expected) More...  
typedef ompl::base::State  StateType 
Define the type of state allocated by this space.  
Public Member Functions  
StateSpace (const StateSpace &)=delete  
StateSpace &  operator= (const StateSpace &)=delete 
StateSpace ()  
Constructor. Assigns a unique name to the space.  
template<class T >  
T *  as () 
Cast this instance to a desired type. More...  
template<class T >  
const T *  as () const 
Cast this instance to a desired type. More...  
virtual void  setup () 
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 reinstantiated, but their setup() method is still called.  
Generic functionality for state spaces  
virtual bool  isCompound () const 
Check if the state space is compound.  
virtual bool  isDiscrete () const 
Check if the set of states is discrete. More...  
virtual bool  isHybrid () const 
Check if this is a hybrid state space (i.e., both discrete and continuous components exist)  
virtual bool  isMetricSpace () const 
Return true if the distance function associated with the space is a metric.  
virtual bool  hasSymmetricDistance () const 
Check if the distance function on this state space is symmetric, i.e. distance(s1,s2) = distance(s2,s1). Default implementation returns true.  
virtual bool  hasSymmetricInterpolate () const 
Check if the interpolation function on this state space is symmetric, i.e. interpolate(from, to, t, state) = interpolate(to, from, 1t, state). Default implementation returns true.  
const std::string &  getName () const 
Get the name of the state space.  
void  setName (const std::string &name) 
Set the name of the state space.  
int  getType () const 
Get the type of the state space. The type can be used to verify whether two space instances are of the same type (e.g., SO2)  
bool  includes (const StateSpacePtr &other) const 
Return true if other is a space included (perhaps equal, perhaps a subspace) in this one.  
bool  includes (const StateSpace *other) const 
Return true if other is a space included (perhaps equal, perhaps a subspace) in this one.  
bool  covers (const StateSpacePtr &other) const 
Return true if other is a space that is either included (perhaps equal, perhaps a subspace) in this one, or all of its subspaces are included in this one.  
bool  covers (const StateSpace *other) const 
Return true if other is a space that is either included (perhaps equal, perhaps a subspace) in this one, or all of its subspaces are included in this one.  
ParamSet &  params () 
Get the parameters for this space.  
const ParamSet &  params () const 
Get the parameters for this space.  
virtual double  getLongestValidSegmentFraction () const 
When performing discrete validation of motions, the length of the longest segment that does not require state validation needs to be specified. This function returns this length, for this state space, as a fraction of the space's maximum extent.  
virtual void  setLongestValidSegmentFraction (double segmentFraction) 
When performing discrete validation of motions, the length of the longest segment that does not require state validation needs to be specified. This function sets this length as a fraction of the space's maximum extent. More...  
virtual unsigned int  validSegmentCount (const State *state1, const State *state2) const 
Count how many segments of the "longest valid length" fit on the motion from state1 to state2.  
void  setValidSegmentCountFactor (unsigned int factor) 
Set factor to be the value to multiply the return value of validSegmentCount(). By default, this value is 1. The higher the value, the smaller the size of the segments considered valid. The effect of this function is immediate (setup() does not need to be called).  
unsigned int  getValidSegmentCountFactor () const 
Get the value used to multiply the return value of validSegmentCount().  
double  getLongestValidSegmentLength () const 
Get the longest valid segment at the time setup() was called.  
void  computeSignature (std::vector< int > &signature) const 
Compute an array of ints that uniquely identifies the structure of the state space. The first element of the signature is the number of integers that follow.  
Functionality specific to state spaces (to be implemented by derived state spaces)  
virtual unsigned int  getDimension () const =0 
Get the dimension of the space (not the dimension of the surrounding ambient space)  
virtual double  getMaximumExtent () const =0 
Get the maximum value a call to distance() can return (or an upper bound). For unbounded state spaces, this function can return infinity. More...  
virtual double  getMeasure () const =0 
Get a measure of the space (this can be thought of as a generalization of volume)  
virtual void  enforceBounds (State *state) const =0 
Bring the state within the bounds of the state space. For unbounded spaces this function can be a noop.  
virtual bool  satisfiesBounds (const State *state) const =0 
Check if a state is inside the bounding box. For unbounded spaces this function can always return true.  
virtual void  copyState (State *destination, const State *source) const =0 
Copy a state to another. The memory of source and destination should NOT overlap. More...  
State *  cloneState (const State *source) const 
Clone a state.  
virtual double  distance (const State *state1, const State *state2) const =0 
Computes distance between two states. This function satisfies the properties of a metric if isMetricSpace() is true, and its return value will always be between 0 and getMaximumExtent()  
virtual unsigned int  getSerializationLength () const 
Get the number of chars in the serialization of a state in this space.  
virtual void  serialize (void *serialization, const State *state) const 
Write the binary representation of state to serialization.  
virtual void  deserialize (State *state, const void *serialization) const 
Read the binary representation of a state from serialization and write it to state.  
virtual bool  equalStates (const State *state1, const State *state2) const =0 
Checks whether two states are equal.  
virtual void  interpolate (const State *from, const State *to, const double t, State *state) const =0 
Computes the state that lies at time t in [0, 1] on the segment that connects from state to to state. The memory location of state is not required to be different from the memory of either from or to.  
virtual StateSamplerPtr  allocDefaultStateSampler () const =0 
Allocate an instance of the default uniform state sampler for this space.  
virtual StateSamplerPtr  allocStateSampler () const 
Allocate an instance of the state sampler for this space. This sampler will be allocated with the sampler allocator that was previously specified by setStateSamplerAllocator() or, if no sampler allocator was specified, allocDefaultStateSampler() is called.  
void  setStateSamplerAllocator (const StateSamplerAllocator &ssa) 
Set the sampler allocator to use.  
void  clearStateSamplerAllocator () 
Clear the state sampler allocator (reset to default)  
virtual State *  allocState () const =0 
Allocate a state that can store a point in the described space.  
virtual void  freeState (State *state) const =0 
Free the memory of the allocated state.  
Functionality specific to accessing real values in a state  
virtual double *  getValueAddressAtIndex (State *state, const unsigned int index) const 
Many states contain a number of double values. This function provides a means to get the memory address of a double value from state state located at position index. The first double value is returned for index = 0. If index is too large (does not point to any double values in the state), the return value is nullptr. More...  
const double *  getValueAddressAtIndex (const State *state, const unsigned int index) const 
Const variant of the same function as above;.  
const std::vector< ValueLocation > &  getValueLocations () const 
Get the locations of values of type double contained in a state from this space. The order of the values is consistent with getValueAddressAtIndex(). The setup() function must have been previously called.  
const std::map< std::string, ValueLocation > &  getValueLocationsByName () const 
Get the named locations of values of type double contained in a state from this space. The setup() function must have been previously called.  
double *  getValueAddressAtLocation (State *state, const ValueLocation &loc) const 
Get a pointer to the double value in state that loc points to.  
const double *  getValueAddressAtLocation (const State *state, const ValueLocation &loc) const 
Const variant of the same function as above;.  
double *  getValueAddressAtName (State *state, const std::string &name) const 
Get a pointer to the double value in state that name points to.  
const double *  getValueAddressAtName (const State *state, const std::string &name) const 
Const variant of the same function as above;.  
void  copyToReals (std::vector< double > &reals, const State *source) const 
Copy all the real values from a state source to the array reals using getValueAddressAtLocation()  
void  copyFromReals (State *destination, const std::vector< double > &reals) const 
Copy the values from reals to the state destination using getValueAddressAtLocation()  
Management of projections from this state space to Euclidean spaces  
void  registerProjection (const std::string &name, const ProjectionEvaluatorPtr &projection) 
Register a projection for this state space under a specified name.  
void  registerDefaultProjection (const ProjectionEvaluatorPtr &projection) 
Register the default projection for this state space.  
virtual void  registerProjections () 
Register the projections for this state space. Usually, this is at least the default projection. These are implicit projections, set by the implementation of the state space. This is called by setup().  
ProjectionEvaluatorPtr  getProjection (const std::string &name) const 
Get the projection registered under a specific name.  
ProjectionEvaluatorPtr  getDefaultProjection () const 
Get the default projection.  
bool  hasProjection (const std::string &name) const 
Check if a projection with a specified name is available.  
bool  hasDefaultProjection () const 
Check if a default projection is available.  
const std::map< std::string, ProjectionEvaluatorPtr > &  getRegisteredProjections () const 
Get all the registered projections.  
Operations with substates  
StateSamplerPtr  allocSubspaceStateSampler (const StateSpacePtr &subspace) const 
Allocate a sampler that actually samples only components that are part of subspace.  
virtual StateSamplerPtr  allocSubspaceStateSampler (const StateSpace *subspace) const 
Allocate a sampler that actually samples only components that are part of subspace.  
State *  getSubstateAtLocation (State *state, const SubstateLocation &loc) const 
Get the substate of state that is pointed to by loc.  
const State *  getSubstateAtLocation (const State *state, const SubstateLocation &loc) const 
Get the substate of state that is pointed to by loc.  
const std::map< std::string, SubstateLocation > &  getSubstateLocationsByName () const 
Get the list of known substate locations (keys of the map corrspond to names of subspaces)  
void  getCommonSubspaces (const StateSpacePtr &other, std::vector< std::string > &subspaces) const 
Get the set of subspaces that this space and other have in common. The computed list of subspaces does not contain spaces that cover each other, even though they may be common, as that is redundant information.  
void  getCommonSubspaces (const StateSpace *other, std::vector< std::string > &subspaces) const 
Get the set of subspaces that this space and other have in common. The computed list of subspaces does not contain spaces that cover each other, even though they may be common, as that is redundant information.  
virtual void  computeLocations () 
Compute the location information for various components of the state space. Either this function or setup() must be called before any calls to getValueAddressAtName(), getValueAddressAtLocation() (and other functions where those are used).  
Protected Attributes  
int  type_ 
A type assigned for this state space.  
StateSamplerAllocator  ssa_ 
An optional state sampler allocator.  
double  maxExtent_ 
The extent of this space at the time setup() was called.  
double  longestValidSegmentFraction_ 
The fraction of the longest valid segment.  
double  longestValidSegment_ 
The longest valid segment at the time setup() was called.  
unsigned int  longestValidSegmentCountFactor_ 
The factor to multiply the value returned by validSegmentCount(). Rarely used but useful for things like doubling the resolution.  
std::map< std::string, ProjectionEvaluatorPtr >  projections_ 
List of available projections.  
ParamSet  params_ 
The set of parameters for this space.  
std::vector< ValueLocation >  valueLocationsInOrder_ 
The value locations for all varliables of type double contained in a state; The locations point to values in the same order as that returned by getValueAddressAtIndex()  
std::map< std::string, ValueLocation >  valueLocationsByName_ 
All the known value locations, by name. The names of state spaces access the first element of a state. RealVectorStateSpace dimensions are used to access individual dimensions.  
std::map< std::string, SubstateLocation >  substateLocationsByName_ 
All the known substat locations, by name.  
Static Protected Attributes  
static const std::string  DEFAULT_PROJECTION_NAME = "" 
The name used for the default projection.  
Debugging tools  
virtual void  printState (const State *state, std::ostream &out=std::cout) const 
Print a state to a stream.  
virtual void  printSettings (std::ostream &out) const 
Print the settings for this state space to a stream.  
virtual void  printProjections (std::ostream &out) const 
Print the list of registered projections. This function is also called by printSettings()  
virtual void  sanityChecks (double zero, double eps, unsigned int flags) const 
Perform sanity checks for this state space. Throws an exception if failures are found. More...  
virtual void  sanityChecks () const 
Convenience function that allows derived state spaces to choose which checks should pass (see SanityChecks flags) and how strict the checks are. This just calls sanityChecks() with some default arguments.  
void  diagram (std::ostream &out) const 
Print a Graphviz digraph that represents the containment diagram for the state space.  
void  list (std::ostream &out) const 
Print the list of all contained state space instances.  
static void  Diagram (std::ostream &out) 
Print a Graphviz digraph that represents the containment diagram for all the instantiated state spaces.  
static void  List (std::ostream &out) 
Print the list of available state space instances.  
Detailed Description
Representation of a space in which planning can be performed. Topology specific sampling, interpolation and distance are defined.
See Implementing State Spaces.
Definition at line 70 of file StateSpace.h.
Member Enumeration Documentation
◆ SanityChecks
Flags to use in a bit mask for state space sanity checks. Some basic checks do not have flags associated (they are always executed; for example, whether copyState() works as expected)
Enumerator  

STATESPACE_DISTANCE_DIFFERENT_STATES  Check whether the distances between nonequal states is strictly positive (StateSpace::distance()) 
STATESPACE_DISTANCE_SYMMETRIC  Check whether the distance function is symmetric (StateSpace::distance()) 
STATESPACE_INTERPOLATION  Check whether calling StateSpace::interpolate() works as expected. 
STATESPACE_TRIANGLE_INEQUALITY  Check whether the triangle inequality holds when using StateSpace::interpolate() and StateSpace::distance() 
STATESPACE_DISTANCE_BOUND  Check whether the StateSpace::distance() is bounded by StateSpace::getExtent() 
STATESPACE_RESPECT_BOUNDS  Check whether sampled states are always within bounds. 
STATESPACE_ENFORCE_BOUNDS_NO_OP  Check that enforceBounds() does not modify the contents of states that are within bounds. 
STATESPACE_SERIALIZATION  Check whether the StateSpace::serialize() and StateSpace::deserialize() work as expected. 
Definition at line 134 of file StateSpace.h.
Member Function Documentation
◆ as() [1/2]

inline 
Cast this instance to a desired type.
Make sure the type we are casting to is indeed a state space
Definition at line 87 of file StateSpace.h.
◆ as() [2/2]

inline 
Cast this instance to a desired type.
Make sure the type we are casting to is indeed a state space
Definition at line 97 of file StateSpace.h.
◆ copyState()

pure virtual 
Copy a state to another. The memory of source and destination should NOT overlap.
 Note
 For more advanced state copying methods (partial copy, for example), see Advanced methods for copying states.
Implemented in ompl::base::CompoundStateSpace, ompl::control::OpenDEStateSpace, ompl::base::RealVectorStateSpace, ompl::base::CForestStateSpaceWrapper, ompl::base::SO3StateSpace, ompl::base::TimeStateSpace, ompl::base::MorseStateSpace, ompl::base::DiscreteStateSpace, and ompl::base::SO2StateSpace.
◆ getMaximumExtent()

pure virtual 
Get the maximum value a call to distance() can return (or an upper bound). For unbounded state spaces, this function can return infinity.
 Note
 Tight upper bounds are preferred because the value of the extent is used in the automatic computation of parameters for planning. If the bounds are less tight, the automatically computed parameters will be less useful.
Implemented in ompl::base::CompoundStateSpace, ompl::base::RealVectorStateSpace, ompl::base::CForestStateSpaceWrapper, ompl::base::SO3StateSpace, ompl::base::DiscreteStateSpace, ompl::base::SO2StateSpace, and ompl::base::TimeStateSpace.
◆ getValueAddressAtIndex()

virtual 
Many states contain a number of double values. This function provides a means to get the memory address of a double value from state state located at position index. The first double value is returned for index = 0. If index is too large (does not point to any double values in the state), the return value is nullptr.
 Note
 This function does not map a state to an array of doubles. There may be components of a state that do not correspond to double values and they are 'invisible' to this function. Furthermore, this function is slow and is not intended for use in the implementation of planners. Ideally, state values should not be accessed by index. If accessing of individual state elements is however needed, getValueAddressAtLocation() provides a faster implementation.
Reimplemented in ompl::base::CompoundStateSpace, ompl::base::CForestStateSpaceWrapper, ompl::base::RealVectorStateSpace, ompl::base::SO3StateSpace, ompl::base::TimeStateSpace, and ompl::base::SO2StateSpace.
Definition at line 319 of file StateSpace.cpp.
◆ isDiscrete()

virtual 
Check if the set of states is discrete.
 Note
 In fact, because of limited numerical precision, the representation of all spaces is discrete; this function returns true if the corresponding mathematical object is a discrete one.
Reimplemented in ompl::base::CForestStateSpaceWrapper, and ompl::base::DiscreteStateSpace.
◆ sanityChecks()

virtual 
Perform sanity checks for this state space. Throws an exception if failures are found.
 Note
 This checks if distances are always positive, whether the integration works as expected, etc.
Reimplemented in ompl::base::CForestStateSpaceWrapper.
◆ setLongestValidSegmentFraction()

virtual 
When performing discrete validation of motions, the length of the longest segment that does not require state validation needs to be specified. This function sets this length as a fraction of the space's maximum extent.
 Note
 This function's effect is not considered until after setup() has been called. For immediate effects (i.e., during planning) use setValidSegmentCountFactor()
Reimplemented in ompl::base::CompoundStateSpace, and ompl::base::CForestStateSpaceWrapper.
The documentation for this class was generated from the following files:
 ompl/base/StateSpace.h
 ompl/base/src/StateSpace.cpp