Classes | Public Types | Public Member Functions | Static Public Attributes | Private Types | Private Member Functions | Private Attributes
tf2::BufferCore Class Reference

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

#include <buffer_core.h>

Inheritance diagram for tf2::BufferCore:
Inheritance graph
[legend]

List of all members.

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::signals::connection _addTransformsChangedListener (boost::function< void(void)> callback)
 Add a callback that happens when a new transform has arrived.
std::string _allFramesAsDot () const
 Backwards compatabilityA way to see what frames have been cached Useful for debugging.
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.
bool _frameExists (const std::string &frame_id_str) const
 Check if a frame exists in the tree.
void _getFrameStrings (std::vector< std::string > &ids) const
 A way to get a std::vector of available frame ids.
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.
CompactFrameID _lookupFrameNumber (const std::string &frameid_str) const
CompactFrameID _lookupOrInsertFrameNumber (const std::string &frameid_str)
void _removeTransformsChangedListener (boost::signals::connection c)
CompactFrameID _validateFrameId (const char *function_name_arg, const std::string &frame_id) const
TransformableCallbackHandle addTransformableCallback (const TransformableCallback &cb)
 Internal use only.
TransformableRequestHandle addTransformableRequest (TransformableCallbackHandle handle, const std::string &target_frame, const std::string &source_frame, ros::Time time)
 Internal use only.
std::string allFramesAsString () const
 A way to see what frames have been cached Useful for debugging.
std::string allFramesAsYAML () const
 A way to see what frames have been cached in yaml format Useful for debugging tools.
 BufferCore (ros::Duration cache_time_=ros::Duration(DEFAULT_CACHE_TIME))
void cancelTransformableRequest (TransformableRequestHandle handle)
 Internal use only.
bool canTransform (const std::string &target_frame, const std::string &source_frame, const ros::Time &time, std::string *error_msg=NULL) const
 Lookup the twist of the tracking_frame with respect to the observation frame in the reference_frame using the reference point.
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.
void clear ()
 Clear all data.
ros::Duration getCacheLength ()
 Get the duration over which this transformer will cache.
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.
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.
void removeTransformableCallback (TransformableCallbackHandle handle)
 Internal use only.
bool setTransform (const geometry_msgs::TransformStamped &transform, const std::string &authority, bool is_static=false)
 Add transform information to the tf data structure.
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.
static const uint32_t MAX_GRAPH_DEPTH = 1000UL
 The default amount of time to cache data in seconds.

Private Types

typedef boost::unordered_map
< std::string, CompactFrameID
M_StringToCompactFrameID
 A map from string frame ids to CompactFrameID.
typedef boost::unordered_map
< TransformableCallbackHandle,
TransformableCallback
M_TransformableCallback
typedef boost::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.
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.
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.
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.
CompactFrameID lookupFrameNumber (const std::string &frameid_str) const
 String to number for frame lookup with dynamic allocation of new frames.
const std::string & lookupFrameString (CompactFrameID frame_id_num) const
 Number to string frame lookup may throw LookupException if number invalid.
CompactFrameID lookupOrInsertFrameNumber (const std::string &frameid_str)
 String to number for frame lookup with dynamic allocation of new frames.
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
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.
ros::Duration cache_time_
 How long to cache transform history.
std::map< CompactFrameID,
std::string > 
frame_authority_
 A map to lookup the most recent authority for a given frame.
boost::mutex frame_mutex_
 A mutex to protect testing and allocating new frames on the above vector.
M_StringToCompactFrameID frameIDs_
std::vector< std::string > frameIDs_reverse
 A map from CompactFrameID frame_id_numbers to string for debugging and output.
V_TimeCacheInterface frames_
std::vector< P_TimeAndFrameIDlct_cache_
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_

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 322 of file buffer_core.h.

Definition at line 335 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 223 of file buffer_core.h.

typedef boost::signal<void(void)> tf2::BufferCore::TransformsChangedSignal [private]

Definition at line 356 of file buffer_core.h.

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 315 of file buffer_core.h.

Definition at line 350 of file buffer_core.h.


Constructor & Destructor Documentation

Constructor

Parameters:
interpolatingWhether to interpolate, if this is false the closest value will be returned
cache_timeHow long to keep a history of transforms in nanoseconds

Definition at line 164 of file buffer_core.cpp.

tf2::BufferCore::~BufferCore ( void  ) [virtual]

Definition at line 175 of file buffer_core.cpp.


Member Function Documentation

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

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

Parameters:
callbackThe callback, of the form void func();
Returns:
A boost::signals::connection object that can be used to remove this listener

Definition at line 1198 of file buffer_core.cpp.

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

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

Definition at line 1320 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.

regular transforms

Definition at line 1396 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_strThe frame id in question

Definition at line 1211 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 1235 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 281 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_idThe frame id of the frame in question
parentThe reference to the string to fill the parent Returns true unless "NO_PARENT"

Definition at line 1217 of file buffer_core.cpp.

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

Definition at line 274 of file buffer_core.h.

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

Definition at line 277 of file buffer_core.h.

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

Definition at line 1204 of file buffer_core.cpp.

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

Definition at line 286 of file buffer_core.h.

Internal use only.

Definition at line 1075 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 1115 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 808 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 814 of file buffer_core.cpp.

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

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

Definition at line 1021 of file buffer_core.cpp.

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

Definition at line 270 of file buffer_core.cpp.

Internal use only.

Definition at line 1184 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

Lookup the twist of the tracking_frame with respect to the observation frame in the reference_frame using the reference point.

Parameters:
tracking_frameThe frame to track
observation_frameThe frame from which to measure the twist
reference_frameThe reference frame in which to express the twist
reference_pointThe reference point with which to express the twist
reference_point_frameThe frame_id in which the reference point is expressed
timeThe time at which to get the velocity
durationThe period over which to average
Returns:
twist The twist output

This will compute the average velocity on the interval (time - duration/2, time+duration/2). If that is too close to the most recent reading, in which case it will shift the interval up to duration/2 to prevent extrapolation.

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

New in geometry 1.1lookup the twist of the tracking frame with respect to the observational frame

This is a simplified version of lookupTwist with it assumed that the reference point is the origin of the tracking frame, and the reference frame is the observation frame.

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

New in geometry 1.1Test if a transform is possible

Parameters:
target_frameThe frame into which to transform
source_frameThe frame from which to transform
timeThe time at which to transform
error_msgA 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 710 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_frameThe frame into which to transform
target_timeThe time into which to transform
source_frameThe frame from which to transform
source_timeThe time from which to transform
fixed_frameThe frame in which to treat the transform as constant in time
error_msgA 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 730 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 703 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 681 of file buffer_core.cpp.

Clear all data.

Definition at line 180 of file buffer_core.cpp.

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

Definition at line 797 of file buffer_core.cpp.

Get the duration over which this transformer will cache.

Definition at line 291 of file buffer_core.h.

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

Parameters:
frame_numberThe 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

Todo:
check larger values too

Definition at line 745 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 855 of file buffer_core.cpp.

bool tf2::BufferCore::isUsingDedicatedThread ( ) const [inline]

Definition at line 241 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 755 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 785 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 768 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_frameThe frame to which data should be transformed
source_frameThe frame where the data originated
timeThe 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 517 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_frameThe frame to which data should be transformed
target_timeThe time to which the data should be transformed. (0 will get the latest)
source_frameThe frame where the data originated
source_timeThe time at which the source_frame should be evaluated. (0 will get the latest)
fixed_frameThe 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 573 of file buffer_core.cpp.

Internal use only.

Definition at line 1101 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:
transformThe transform to store
authorityThe source of the information for this transform
is_staticRecord 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 197 of file buffer_core.cpp.

void tf2::BufferCore::setUsingDedicatedThread ( bool  value) [inline]

Definition at line 239 of file buffer_core.h.

Definition at line 1254 of file buffer_core.cpp.

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

Definition at line 137 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 291 of file buffer_core.cpp.

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

Definition at line 116 of file buffer_core.cpp.


Member Data Documentation

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

Definition at line 361 of file buffer_core.h.

How long to cache transform history.

Definition at line 331 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 327 of file buffer_core.h.

boost::mutex tf2::BufferCore::frame_mutex_ [mutable, private]

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

Definition at line 319 of file buffer_core.h.

Definition at line 323 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 325 of file buffer_core.h.

Definition at line 316 of file buffer_core.h.

std::vector<P_TimeAndFrameID> tf2::BufferCore::lct_cache_ [mutable, private]

Definition at line 333 of file buffer_core.h.

const uint32_t tf2::BufferCore::MAX_GRAPH_DEPTH = 1000UL [static]

The default amount of time to cache data in seconds.

Definition at line 93 of file buffer_core.h.

Definition at line 336 of file buffer_core.h.

Definition at line 337 of file buffer_core.h.

Definition at line 338 of file buffer_core.h.

Definition at line 351 of file buffer_core.h.

Definition at line 353 of file buffer_core.h.

Definition at line 352 of file buffer_core.h.

Definition at line 406 of file buffer_core.h.


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


tf2
Author(s): Tully Foote, Eitan Marder-Eppstein, Wim Meeussen
autogenerated on Thu Aug 27 2015 13:09:58