A Class which provides coordinate transforms between any two frames in a system. More...

#include <buffer_core.h>

Classes
struct	RemoveRequestByCallback

struct	RemoveRequestByID

struct	TransformableRequest

Public Types
typedef boost::function< void(TransformableRequestHandle request_handle, const std::string &target_frame, const std::string &source_frame, ros::Time time, TransformableResult result)>	TransformableCallback

Public Member Functions
boost::signals2::connection	_addTransformsChangedListener (boost::function< void(void)> callback)
	Add a callback that happens when a new transform has arrived. More...

std::string	_allFramesAsDot (double current_time) const
	Backwards compatabilityA way to see what frames have been cached Useful for debugging. More...

std::string	_allFramesAsDot () const

void	_chainAsVector (const std::string &target_frame, ros::Time target_time, const std::string &source_frame, ros::Time source_time, const std::string &fixed_frame, std::vector< std::string > &output) const
	Backwards compatabilityA way to see what frames are in a chain Useful for debugging. More...

bool	_frameExists (const std::string &frame_id_str) const
	Check if a frame exists in the tree. More...

void	_getFrameStrings (std::vector< std::string > &ids) const
	A way to get a std::vector of available frame ids. More...

int	_getLatestCommonTime (CompactFrameID target_frame, CompactFrameID source_frame, ros::Time &time, std::string *error_string) const

bool	_getParent (const std::string &frame_id, ros::Time time, std::string &parent) const
	Fill the parent of a frame. More...

CompactFrameID	_lookupFrameNumber (const std::string &frameid_str) const

CompactFrameID	_lookupOrInsertFrameNumber (const std::string &frameid_str)

void	_removeTransformsChangedListener (boost::signals2::connection c)

CompactFrameID	_validateFrameId (const char *function_name_arg, const std::string &frame_id) const

TransformableCallbackHandle	addTransformableCallback (const TransformableCallback &cb)
	Internal use only. More...

TransformableRequestHandle	addTransformableRequest (TransformableCallbackHandle handle, const std::string &target_frame, const std::string &source_frame, ros::Time time)
	Internal use only. More...

std::string	allFramesAsString () const
	A way to see what frames have been cached Useful for debugging. More...

std::string	allFramesAsYAML (double current_time) const
	A way to see what frames have been cached in yaml format Useful for debugging tools. More...

std::string	allFramesAsYAML () const

	BufferCore (ros::Duration cache_time_=ros::Duration(DEFAULT_CACHE_TIME))

void	cancelTransformableRequest (TransformableRequestHandle handle)
	Internal use only. More...

bool	canTransform (const std::string &target_frame, const std::string &source_frame, const ros::Time &time, std::string *error_msg=NULL) const
	Test if a transform is possible. More...

bool	canTransform (const std::string &target_frame, const ros::Time &target_time, const std::string &source_frame, const ros::Time &source_time, const std::string &fixed_frame, std::string *error_msg=NULL) const
	Test if a transform is possible. More...

void	clear ()
	Clear all data. More...

ros::Duration	getCacheLength ()
	Get the duration over which this transformer will cache. More...

bool	isUsingDedicatedThread () const

geometry_msgs::TransformStamped	lookupTransform (const std::string &target_frame, const std::string &source_frame, const ros::Time &time) const
	Get the transform between two frames by frame ID. More...

geometry_msgs::TransformStamped	lookupTransform (const std::string &target_frame, const ros::Time &target_time, const std::string &source_frame, const ros::Time &source_time, const std::string &fixed_frame) const
	Get the transform between two frames by frame ID assuming fixed frame. More...

void	removeTransformableCallback (TransformableCallbackHandle handle)
	Internal use only. More...

bool	setTransform (const geometry_msgs::TransformStamped &transform, const std::string &authority, bool is_static=false)
	Add transform information to the tf data structure. More...

void	setUsingDedicatedThread (bool value)

virtual	~BufferCore (void)

Static Public Attributes
static const int	DEFAULT_CACHE_TIME = 10
	The default amount of time to cache data in seconds. More...

static const uint32_t	MAX_GRAPH_DEPTH = 1000UL
	Maximum graph search depth (deeper graphs will be assumed to have loops) More...

Private Types
typedef boost::unordered_map< std::string, CompactFrameID >	M_StringToCompactFrameID
	A map from string frame ids to CompactFrameID. More...

typedef boost::unordered_map< TransformableCallbackHandle, TransformableCallback >	M_TransformableCallback

typedef boost::signals2::signal< void(void)>	TransformsChangedSignal

typedef std::vector< TimeCacheInterfacePtr >	V_TimeCacheInterface
	The pointers to potential frames that the tree can be made of. The frames will be dynamically allocated at run time when set the first time. More...

typedef std::vector< TransformableRequest >	V_TransformableRequest

Private Member Functions
std::string	allFramesAsStringNoLock () const
	A way to see what frames have been cached Useful for debugging. Use this call internally. More...

TimeCacheInterfacePtr	allocateFrame (CompactFrameID cfid, bool is_static)

bool	canTransformInternal (CompactFrameID target_id, CompactFrameID source_id, const ros::Time &time, std::string *error_msg) const

bool	canTransformNoLock (CompactFrameID target_id, CompactFrameID source_id, const ros::Time &time, std::string *error_msg) const

void	createConnectivityErrorString (CompactFrameID source_frame, CompactFrameID target_frame, std::string *out) const

TimeCacheInterfacePtr	getFrame (CompactFrameID c_frame_id) const
	An accessor to get a frame, which will throw an exception if the frame is no there. More...

int	getLatestCommonTime (CompactFrameID target_frame, CompactFrameID source_frame, ros::Time &time, std::string *error_string) const
	Return the latest rostime which is common across the spanning set zero if fails to cross. More...

CompactFrameID	lookupFrameNumber (const std::string &frameid_str) const
	String to number for frame lookup with dynamic allocation of new frames. More...

const std::string &	lookupFrameString (CompactFrameID frame_id_num) const
	Number to string frame lookup may throw LookupException if number invalid. More...

CompactFrameID	lookupOrInsertFrameNumber (const std::string &frameid_str)
	String to number for frame lookup with dynamic allocation of new frames. More...

void	testTransformableRequests ()

CompactFrameID	validateFrameId (const char *function_name_arg, const std::string &frame_id) const

template<typename F >
int	walkToTopParent (F &f, ros::Time time, CompactFrameID target_id, CompactFrameID source_id, std::string *error_string) const

template<typename F >
int	walkToTopParent (F &f, ros::Time time, CompactFrameID target_id, CompactFrameID source_id, std::string error_string, std::vector< CompactFrameID > frame_chain) const
	Traverse the transform tree. If frame_chain is not NULL, store the traversed frame tree in vector frame_chain. More...

bool	warnFrameId (const char *function_name_arg, const std::string &frame_id) const

Private Attributes
TransformsChangedSignal	_transforms_changed_
	Signal which is fired whenever new transform data has arrived, from the thread the data arrived in. More...

ros::Duration	cache_time_
	How long to cache transform history. More...

std::map< CompactFrameID, std::string >	frame_authority_
	A map to lookup the most recent authority for a given frame. More...

boost::mutex	frame_mutex_
	A mutex to protect testing and allocating new frames on the above vector. More...

M_StringToCompactFrameID	frameIDs_

std::vector< std::string >	frameIDs_reverse
	A map from CompactFrameID frame_id_numbers to string for debugging and output. More...

V_TimeCacheInterface	frames_

M_TransformableCallback	transformable_callbacks_

uint32_t	transformable_callbacks_counter_

boost::mutex	transformable_callbacks_mutex_

V_TransformableRequest	transformable_requests_

uint64_t	transformable_requests_counter_

boost::mutex	transformable_requests_mutex_

bool	using_dedicated_thread_

Friends
class	TestBufferCore

Detailed Description

A Class which provides coordinate transforms between any two frames in a system.

This class provides a simple interface to allow recording and lookup of relationships between arbitrary frames of the system.

libTF assumes that there is a tree of coordinate frame transforms which define the relationship between all coordinate frames. For example your typical robot would have a transform from global to real world. And then from base to hand, and from base to head. But Base to Hand really is composed of base to shoulder to elbow to wrist to hand. libTF is designed to take care of all the intermediate steps for you.

Internal Representation libTF will store frames with the parameters necessary for generating the transform into that frame from it's parent and a reference to the parent frame. Frames are designated using an std::string 0 is a frame without a parent (the top of a tree) The positions of frames over time must be pushed in.

All function calls which pass frame ids can potentially throw the exception tf::LookupException

Definition at line 88 of file buffer_core.h.

Member Typedef Documentation

typedef boost::unordered_map<std::string, CompactFrameID> tf2::BufferCore::M_StringToCompactFrameID

private

A map from string frame ids to CompactFrameID.

Definition at line 327 of file buffer_core.h.

typedef boost::unordered_map<TransformableCallbackHandle, TransformableCallback> tf2::BufferCore::M_TransformableCallback

private

Definition at line 338 of file buffer_core.h.

typedef boost::function<void(TransformableRequestHandle request_handle, const std::string& target_frame, const std::string& source_frame, ros::Time time, TransformableResult result)> tf2::BufferCore::TransformableCallback

Definition at line 227 of file buffer_core.h.

typedef boost::signals2::signal<void(void)> tf2::BufferCore::TransformsChangedSignal

private

Definition at line 359 of file buffer_core.h.

typedef std::vector<TimeCacheInterfacePtr> tf2::BufferCore::V_TimeCacheInterface

private

The pointers to potential frames that the tree can be made of. The frames will be dynamically allocated at run time when set the first time.

Definition at line 320 of file buffer_core.h.

typedef std::vector<TransformableRequest> tf2::BufferCore::V_TransformableRequest

private

Definition at line 353 of file buffer_core.h.

Constructor & Destructor Documentation

tf2::BufferCore::BufferCore ( ros::Duration cache_time_ = ros::Duration(DEFAULT_CACHE_TIME) )

Constructor

Parameters

interpolating	Whether to interpolate, if this is false the closest value will be returned
cache_time	How long to keep a history of transforms in nanoseconds

Definition at line 168 of file buffer_core.cpp.

tf2::BufferCore::~BufferCore ( void )

virtual

Definition at line 179 of file buffer_core.cpp.

Member Function Documentation

boost::signals2::connection tf2::BufferCore::_addTransformsChangedListener ( boost::function< void(void)> callback )

Add a callback that happens when a new transform has arrived.

Parameters

callback The callback, of the form void func();

Returns: A boost::signals2::connection object that can be used to remove this listener

Definition at line 1349 of file buffer_core.cpp.

std::string tf2::BufferCore::_allFramesAsDot ( double current_time ) const

Backwards compatabilityA way to see what frames have been cached Useful for debugging.

Definition at line 1488 of file buffer_core.cpp.

std::string tf2::BufferCore::_allFramesAsDot ( ) const

Definition at line 1572 of file buffer_core.cpp.

void tf2::BufferCore::_chainAsVector	(	const std::string &	target_frame,
		ros::Time	target_time,
		const std::string &	source_frame,
		ros::Time	source_time,
		const std::string &	fixed_frame,
		std::vector< std::string > &	output
	)		const

Backwards compatabilityA way to see what frames are in a chain Useful for debugging.

Definition at line 1577 of file buffer_core.cpp.

bool tf2::BufferCore::_frameExists ( const std::string & frame_id_str ) const

Check if a frame exists in the tree.

Parameters

frame_id_str The frame id in question

Definition at line 1362 of file buffer_core.cpp.

void tf2::BufferCore::_getFrameStrings ( std::vector< std::string > & ids ) const

A way to get a std::vector of available frame ids.

Definition at line 1386 of file buffer_core.cpp.

int tf2::BufferCore::_getLatestCommonTime	(	CompactFrameID	target_frame,
		CompactFrameID	source_frame,
		ros::Time &	time,
		std::string *	error_string
	)		const

inline

Definition at line 285 of file buffer_core.h.

bool tf2::BufferCore::_getParent	(	const std::string &	frame_id,
		ros::Time	time,
		std::string &	parent
	)		const

Fill the parent of a frame.

Parameters

frame_id	The frame id of the frame in question
parent	The reference to the string to fill the parent Returns true unless "NO_PARENT"

Definition at line 1368 of file buffer_core.cpp.

CompactFrameID tf2::BufferCore::_lookupFrameNumber ( const std::string & frameid_str ) const

inline

Definition at line 278 of file buffer_core.h.

CompactFrameID tf2::BufferCore::_lookupOrInsertFrameNumber ( const std::string & frameid_str )

inline

Definition at line 281 of file buffer_core.h.

void tf2::BufferCore::_removeTransformsChangedListener ( boost::signals2::connection c )

Definition at line 1355 of file buffer_core.cpp.

CompactFrameID tf2::BufferCore::_validateFrameId	(	const char *	function_name_arg,
		const std::string &	frame_id
	)		const

inline

Definition at line 290 of file buffer_core.h.

TransformableCallbackHandle tf2::BufferCore::addTransformableCallback ( const TransformableCallback & cb )

Internal use only.

Definition at line 1226 of file buffer_core.cpp.

TransformableRequestHandle tf2::BufferCore::addTransformableRequest	(	TransformableCallbackHandle	handle,
		const std::string &	target_frame,
		const std::string &	source_frame,
		ros::Time	time
	)

Internal use only.

Definition at line 1266 of file buffer_core.cpp.

std::string tf2::BufferCore::allFramesAsString ( ) const

A way to see what frames have been cached Useful for debugging.

Definition at line 948 of file buffer_core.cpp.

std::string tf2::BufferCore::allFramesAsStringNoLock ( ) const

private

A way to see what frames have been cached Useful for debugging. Use this call internally.

regular transforms

Definition at line 954 of file buffer_core.cpp.

std::string tf2::BufferCore::allFramesAsYAML ( double current_time ) const

A way to see what frames have been cached in yaml format Useful for debugging tools.

Definition at line 1164 of file buffer_core.cpp.

std::string tf2::BufferCore::allFramesAsYAML ( ) const

Backwards compatibility for #84

Definition at line 1221 of file buffer_core.cpp.

TimeCacheInterfacePtr tf2::BufferCore::allocateFrame	(	CompactFrameID	cfid,
		bool	is_static
	)

private

Definition at line 287 of file buffer_core.cpp.

void tf2::BufferCore::cancelTransformableRequest ( TransformableRequestHandle handle )

Internal use only.

Definition at line 1335 of file buffer_core.cpp.

bool tf2::BufferCore::canTransform	(	const std::string &	target_frame,
		const std::string &	source_frame,
		const ros::Time &	time,
		std::string *	error_msg = `NULL`
	)		const

Test if a transform is possible.

Parameters

target_frame	The frame into which to transform
source_frame	The frame from which to transform
time	The time at which to transform
error_msg	A pointer to a string which will be filled with why the transform failed, if not NULL

Returns: True if the transform is possible, false otherwise

Definition at line 799 of file buffer_core.cpp.

bool tf2::BufferCore::canTransform	(	const std::string &	target_frame,
		const ros::Time &	target_time,
		const std::string &	source_frame,
		const ros::Time &	source_time,
		const std::string &	fixed_frame,
		std::string *	error_msg = `NULL`
	)		const

Test if a transform is possible.

Parameters

target_frame	The frame into which to transform
target_time	The time into which to transform
source_frame	The frame from which to transform
source_time	The time from which to transform
fixed_frame	The frame in which to treat the transform as constant in time
error_msg	A pointer to a string which will be filled with why the transform failed, if not NULL

Returns: True if the transform is possible, false otherwise

Definition at line 838 of file buffer_core.cpp.

bool tf2::BufferCore::canTransformInternal	(	CompactFrameID	target_id,
		CompactFrameID	source_id,
		const ros::Time &	time,
		std::string *	error_msg
	)		const

private

Definition at line 792 of file buffer_core.cpp.

bool tf2::BufferCore::canTransformNoLock	(	CompactFrameID	target_id,
		CompactFrameID	source_id,
		const ros::Time &	time,
		std::string *	error_msg
	)		const

private

Definition at line 755 of file buffer_core.cpp.

void tf2::BufferCore::clear ( )

Clear all data.

Definition at line 184 of file buffer_core.cpp.

void tf2::BufferCore::createConnectivityErrorString	(	CompactFrameID	source_frame,
		CompactFrameID	target_frame,
		std::string *	out
	)		const

private

Definition at line 937 of file buffer_core.cpp.

ros::Duration tf2::BufferCore::getCacheLength ( )

inline

Get the duration over which this transformer will cache.

Definition at line 295 of file buffer_core.h.

tf2::TimeCacheInterfacePtr tf2::BufferCore::getFrame ( CompactFrameID c_frame_id ) const

private

An accessor to get a frame, which will throw an exception if the frame is no there.

Parameters

frame_number The frameID of the desired Reference Frame

This is an internal function which will get the pointer to the frame associated with the frame id Possible Exception: tf::LookupException

Definition at line 885 of file buffer_core.cpp.

int tf2::BufferCore::getLatestCommonTime	(	CompactFrameID	target_frame,
		CompactFrameID	source_frame,
		ros::Time &	time,
		std::string *	error_string
	)		const

private

Return the latest rostime which is common across the spanning set zero if fails to cross.

Definition at line 995 of file buffer_core.cpp.

bool tf2::BufferCore::isUsingDedicatedThread ( ) const

inline

Definition at line 245 of file buffer_core.h.

CompactFrameID tf2::BufferCore::lookupFrameNumber ( const std::string & frameid_str ) const

private

String to number for frame lookup with dynamic allocation of new frames.

Definition at line 895 of file buffer_core.cpp.

const std::string & tf2::BufferCore::lookupFrameString ( CompactFrameID frame_id_num ) const

private

Number to string frame lookup may throw LookupException if number invalid.

Definition at line 925 of file buffer_core.cpp.

CompactFrameID tf2::BufferCore::lookupOrInsertFrameNumber ( const std::string & frameid_str )

private

String to number for frame lookup with dynamic allocation of new frames.

Definition at line 908 of file buffer_core.cpp.

geometry_msgs::TransformStamped tf2::BufferCore::lookupTransform	(	const std::string &	target_frame,
		const std::string &	source_frame,
		const ros::Time &	time
	)		const

Get the transform between two frames by frame ID.

Parameters

target_frame	The frame to which data should be transformed
source_frame	The frame where the data originated
time	The time at which the value of the transform is desired. (0 will get the latest)

Returns: The transform between the frames

Possible exceptions tf2::LookupException, tf2::ConnectivityException, tf2::ExtrapolationException, tf2::InvalidArgumentException

Definition at line 591 of file buffer_core.cpp.

geometry_msgs::TransformStamped tf2::BufferCore::lookupTransform	(	const std::string &	target_frame,
		const ros::Time &	target_time,
		const std::string &	source_frame,
		const ros::Time &	source_time,
		const std::string &	fixed_frame
	)		const

Get the transform between two frames by frame ID assuming fixed frame.

Parameters

target_frame	The frame to which data should be transformed
target_time	The time to which the data should be transformed. (0 will get the latest)
source_frame	The frame where the data originated
source_time	The time at which the source_frame should be evaluated. (0 will get the latest)
fixed_frame	The frame in which to assume the transform is constant in time.

Returns: The transform between the frames

Possible exceptions tf2::LookupException, tf2::ConnectivityException, tf2::ExtrapolationException, tf2::InvalidArgumentException

Definition at line 647 of file buffer_core.cpp.

void tf2::BufferCore::removeTransformableCallback ( TransformableCallbackHandle handle )

Internal use only.

Definition at line 1252 of file buffer_core.cpp.

bool tf2::BufferCore::setTransform	(	const geometry_msgs::TransformStamped &	transform,
		const std::string &	authority,
		bool	is_static = `false`
	)

Add transform information to the tf data structure.

Parameters

transform	The transform to store
authority	The source of the information for this transform
is_static	Record this transform as a static transform. It will be good across all time. (This cannot be changed after the first call.)

Returns: True unless an error occured

Definition at line 201 of file buffer_core.cpp.

void tf2::BufferCore::setUsingDedicatedThread ( bool value )

inline

Definition at line 243 of file buffer_core.h.

void tf2::BufferCore::testTransformableRequests ( )

private

Definition at line 1405 of file buffer_core.cpp.

CompactFrameID tf2::BufferCore::validateFrameId	(	const char *	function_name_arg,
		const std::string &	frame_id
	)		const

private

Definition at line 141 of file buffer_core.cpp.

template<typename F >

int tf2::BufferCore::walkToTopParent	(	F &	f,
		ros::Time	time,
		CompactFrameID	target_id,
		CompactFrameID	source_id,
		std::string *	error_string
	)		const

private

Definition at line 309 of file buffer_core.cpp.

template<typename F >

int tf2::BufferCore::walkToTopParent	(	F &	f,
		ros::Time	time,
		CompactFrameID	target_id,
		CompactFrameID	source_id,
		std::string *	error_string,
		std::vector< CompactFrameID > *	frame_chain
	)		const

private

Traverse the transform tree. If frame_chain is not NULL, store the traversed frame tree in vector frame_chain.

Definition at line 315 of file buffer_core.cpp.

bool tf2::BufferCore::warnFrameId	(	const char *	function_name_arg,
		const std::string &	frame_id
	)		const

private

Definition at line 120 of file buffer_core.cpp.

Friends And Related Function Documentation

friend class TestBufferCore

friend

Definition at line 417 of file buffer_core.h.

Member Data Documentation

TransformsChangedSignal tf2::BufferCore::_transforms_changed_

private

Signal which is fired whenever new transform data has arrived, from the thread the data arrived in.

Definition at line 364 of file buffer_core.h.

ros::Duration tf2::BufferCore::cache_time_

private

How long to cache transform history.

Definition at line 336 of file buffer_core.h.

const int tf2::BufferCore::DEFAULT_CACHE_TIME = 10

static

The default amount of time to cache data in seconds.

Definition at line 92 of file buffer_core.h.

std::map<CompactFrameID, std::string> tf2::BufferCore::frame_authority_

private

A map to lookup the most recent authority for a given frame.

Definition at line 332 of file buffer_core.h.

boost::mutex tf2::BufferCore::frame_mutex_

mutableprivate

A mutex to protect testing and allocating new frames on the above vector.

Definition at line 324 of file buffer_core.h.

M_StringToCompactFrameID tf2::BufferCore::frameIDs_

private

Definition at line 328 of file buffer_core.h.

std::vector<std::string> tf2::BufferCore::frameIDs_reverse

private

A map from CompactFrameID frame_id_numbers to string for debugging and output.

Definition at line 330 of file buffer_core.h.

V_TimeCacheInterface tf2::BufferCore::frames_

private

Definition at line 321 of file buffer_core.h.

const uint32_t tf2::BufferCore::MAX_GRAPH_DEPTH = 1000UL

static

Maximum graph search depth (deeper graphs will be assumed to have loops)

Definition at line 93 of file buffer_core.h.

M_TransformableCallback tf2::BufferCore::transformable_callbacks_

private

Definition at line 339 of file buffer_core.h.

uint32_t tf2::BufferCore::transformable_callbacks_counter_

private

Definition at line 340 of file buffer_core.h.

boost::mutex tf2::BufferCore::transformable_callbacks_mutex_

private

Definition at line 341 of file buffer_core.h.

V_TransformableRequest tf2::BufferCore::transformable_requests_

private

Definition at line 354 of file buffer_core.h.

uint64_t tf2::BufferCore::transformable_requests_counter_

private

Definition at line 356 of file buffer_core.h.

boost::mutex tf2::BufferCore::transformable_requests_mutex_

private

Definition at line 355 of file buffer_core.h.

bool tf2::BufferCore::using_dedicated_thread_

private

Definition at line 414 of file buffer_core.h.

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

Classes

Public Types

Public Member Functions

Static Public Attributes

Private Types

Private Member Functions

Private Attributes

Friends

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation