Representation of a space in which planning can be performed. Topology specific sampling, interpolation and distance are defined. More...

#include <ompl/base/StateSpace.h>

Inheritance diagram for ompl::base::StateSpace:

[legend]

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...

using	StateType = ompl::base::State
	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 re-instantiated, 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, 1-t, 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.

virtual 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).

virtual unsigned int	getValidSegmentCountFactor () const
	Get the value used to multiply the return value of validSegmentCount().

virtual double	getLongestValidSegmentLength () const
	Get the longest valid segment at the time setup() was called.

virtual 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 no-op.

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, 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, 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, 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;.

virtual 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()

virtual 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 134 of file StateSpace.h.

Member Enumeration Documentation

◆ SanityChecks

enum ompl::base::StateSpace::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 non-equal 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 198 of file StateSpace.h.

Member Function Documentation

◆ as() [1/2]

template<class T >

T* ompl::base::StateSpace::as ( )

inline

Cast this instance to a desired type.

Make sure the type we are casting to is indeed a state space

Definition at line 151 of file StateSpace.h.

◆ as() [2/2]

template<class T >

const T* ompl::base::StateSpace::as ( ) const

inline

Cast this instance to a desired type.

Make sure the type we are casting to is indeed a state space

Definition at line 161 of file StateSpace.h.

◆ copyState()

virtual void ompl::base::StateSpace::copyState	(	State *	destination,
		const State *	source
	)		const

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::base::WrapperStateSpace, ompl::base::RealVectorStateSpace, ompl::base::MorseStateSpace, ompl::base::AtlasStateSpace, ompl::base::SO3StateSpace, ompl::base::TimeStateSpace, ompl::base::CForestStateSpaceWrapper, ompl::base::DiscreteStateSpace, ompl::base::SO2StateSpace, and ompl::control::OpenDEStateSpace.

◆ getMaximumExtent()

virtual double ompl::base::StateSpace::getMaximumExtent ( ) const

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::WrapperStateSpace, ompl::base::RealVectorStateSpace, ompl::base::SpaceTimeStateSpace, ompl::base::SO3StateSpace, ompl::base::EmptyStateSpace, ompl::base::CForestStateSpaceWrapper, ompl::base::DiscreteStateSpace, ompl::base::SO2StateSpace, and ompl::base::TimeStateSpace.

◆ getValueAddressAtIndex()

double * ompl::base::StateSpace::getValueAddressAtIndex	(	State *	state,
		unsigned int	index
	)		const

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::WrapperStateSpace, ompl::base::RealVectorStateSpace, ompl::base::SO3StateSpace, ompl::base::TimeStateSpace, ompl::base::SO2StateSpace, and ompl::base::CForestStateSpaceWrapper.

Definition at line 306 of file StateSpace.cpp.

◆ isDiscrete()

bool ompl::base::StateSpace::isDiscrete ( ) const

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::WrapperStateSpace, ompl::base::DiscreteStateSpace, and ompl::base::CForestStateSpaceWrapper.

Definition at line 770 of file StateSpace.cpp.

◆ sanityChecks()

void ompl::base::StateSpace::sanityChecks	(	double	zero,
		double	eps,
		unsigned int	flags
	)		const

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::WrapperStateSpace, and ompl::base::CForestStateSpaceWrapper.

Definition at line 609 of file StateSpace.cpp.

◆ setLongestValidSegmentFraction()

void ompl::base::StateSpace::setLongestValidSegmentFraction ( double segmentFraction )

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, ompl::base::WrapperStateSpace, and ompl::base::CForestStateSpaceWrapper.

Definition at line 828 of file StateSpace.cpp.

The documentation for this class was generated from the following files:

ompl/base/StateSpace.h
ompl/base/src/StateSpace.cpp

Classes

Public Types

Public Member Functions

Protected Attributes

Static Protected Attributes

Debugging tools

Detailed Description

Member Enumeration Documentation

◆ SanityChecks

Member Function Documentation

◆ as() [1/2]

◆ as() [2/2]

◆ copyState()

◆ getMaximumExtent()

◆ getValueAddressAtIndex()

◆ isDiscrete()

◆ sanityChecks()

◆ setLongestValidSegmentFraction()