Labelled 4x4 FIFF affine: source frame, destination frame, rotation, translation and cached inverse. More...

#include <fiff_coord_trans.h>

Public Types
using	SPtr = QSharedPointer<FiffCoordTrans>
using	ConstSPtr = QSharedPointer<const FiffCoordTrans>
using	UPtr = std::unique_ptr<FiffCoordTrans>
using	ConstUPtr = std::unique_ptr<const FiffCoordTrans>

Public Member Functions
	FiffCoordTrans ()
	FiffCoordTrans (QIODevice &p_IODevice)
	FiffCoordTrans (const FiffCoordTrans &p_FiffCoordTrans)
	FiffCoordTrans (int from, int to, const Eigen::Matrix3f &rot, const Eigen::Vector3f &move)
	FiffCoordTrans (int from, int to, const Eigen::Matrix4f &matTrans, bool bStandard=false)
	~FiffCoordTrans ()
void	clear ()
bool	invert_transform ()
bool	isEmpty () const
Eigen::MatrixX3f	apply_trans (const Eigen::MatrixX3f &rr, bool do_move=true) const
Eigen::MatrixX3f	apply_inverse_trans (const Eigen::MatrixX3f &rr, bool do_move=true) const
FiffCoordTrans	inverted () const
void	print () const
void	write (QIODevice &p_IODevice)
	Writes the transformation to file.
void	writeToStream (FiffStream *p_pStream)
	Writes the transformation to a FIFF stream.
float	angleTo (Eigen::MatrixX4f mTransDest)
float	translationTo (Eigen::MatrixX4f mTransDest)
Rotation/Translation Accessors
Provide Matrix3f/Vector3f views into the 4×4 homogeneous matrices, matching the legacy FiffCoordTransOld member layout (rot, move, invrot, invmove). Mutable overloads allow direct modification of the underlying matrix blocks.
auto	rot ()
auto	rot () const
auto	move ()
auto	move () const
auto	invrot ()
auto	invrot () const
auto	invmove ()
auto	invmove () const

Static Public Member Functions
static bool	read (QIODevice &p_IODevice, FiffCoordTrans &p_Trans)
static FiffCoordTrans	readTransform (const QString &name, int from, int to)
static FiffCoordTrans	readMriTransform (const QString &name)
static FiffCoordTrans	readMeasTransform (const QString &name)
static FiffCoordTrans	readTransformAscii (const QString &name, int from, int to)
static FiffCoordTrans	readFShead2mriTransform (const QString &name)
static void	apply_trans (float r[3], const FiffCoordTrans &t, bool do_move)
static void	apply_inverse_trans (float r[3], const FiffCoordTrans &t, bool do_move)
static QString	frame_name (int frame)
static FiffCoordTrans	identity (int from, int to)
static FiffCoordTrans	combine (int from, int to, const FiffCoordTrans &t1, const FiffCoordTrans &t2)
static FiffCoordTrans	fromCardinalPoints (int from, int to, const float rL, const float rN, const float *rR)
static bool	addInverse (FiffCoordTrans &t)
static qint32	storageSize ()
static FiffCoordTrans	readFromTag (const std::unique_ptr< FiffTag > &tag)
static FiffCoordTrans	readTransformFromNode (FiffStream::SPtr &stream, const FiffDirNode::SPtr &node, int from, int to)
static FiffCoordTrans	procrustesAlign (int from_frame, int to_frame, const Eigen::MatrixXf &fromp, const Eigen::MatrixXf &top, const Eigen::VectorXf &w, float max_diff)

Public Attributes
fiff_int_t	from
fiff_int_t	to
Eigen::Matrix< float, 4, 4, Eigen::DontAlign >	trans
Eigen::Matrix< float, 4, 4, Eigen::DontAlign >	invtrans

Friends
bool	operator== (const FiffCoordTrans &a, const FiffCoordTrans &b)

Detailed Description

Labelled 4x4 FIFF affine: source frame, destination frame, rotation, translation and cached inverse.

Each transform carries its source (from) and destination (to) FIFFV_COORD_* frame identifiers so the inverse and any chained composition can be type-checked at runtime. The inverse is stored alongside the forward transform because both directions are routinely needed (device→head for head-position tracking, head→MRI for source space registration, etc.).

Definition at line 81 of file fiff_coord_trans.h.

Member Typedef Documentation

◆ ConstSPtr

using FIFFLIB::FiffCoordTrans::ConstSPtr = QSharedPointer<const FiffCoordTrans>

Const shared pointer type for FiffCoordTrans.

Definition at line 85 of file fiff_coord_trans.h.

◆ ConstUPtr

using FIFFLIB::FiffCoordTrans::ConstUPtr = std::unique_ptr<const FiffCoordTrans>

Const unique pointer type for FiffCoordTrans.

Definition at line 87 of file fiff_coord_trans.h.

◆ SPtr

using FIFFLIB::FiffCoordTrans::SPtr = QSharedPointer<FiffCoordTrans>

Shared pointer type for FiffCoordTrans.

Definition at line 84 of file fiff_coord_trans.h.

◆ UPtr

using FIFFLIB::FiffCoordTrans::UPtr = std::unique_ptr<FiffCoordTrans>

Unique pointer type for FiffCoordTrans.

Definition at line 86 of file fiff_coord_trans.h.

Constructor & Destructor Documentation

◆ FiffCoordTrans() [1/5]

FIFFLIB::FiffCoordTrans::FiffCoordTrans ( )

Constructs the coordinate transformation descriptor.

◆ FiffCoordTrans() [2/5]

FIFFLIB::FiffCoordTrans::FiffCoordTrans ( QIODevice & p_IODevice )

Constructs a coordinate transformation, by reading from a IO device.

Parameters

[in] p_IODevice IO device to read from the coordinate transform.

◆ FiffCoordTrans() [3/5]

FIFFLIB::FiffCoordTrans::FiffCoordTrans ( const FiffCoordTrans & p_FiffCoordTrans )

Copy constructor.

Parameters

[in] p_FiffCoordTrans Coordinate transformation description which should be copied.

◆ FiffCoordTrans() [4/5]

FIFFLIB::FiffCoordTrans::FiffCoordTrans	(	int	from,
		int	to,
		const Eigen::Matrix3f &	rot,
		const Eigen::Vector3f &	move )

Constructs a coordinate transformation from a rotation matrix and translation vector.

Parameters

[in]	from	Source coordinate system.
[in]	to	Destination coordinate system.
[in]	rot	The forward transform (3×3 rotation matrix).
[in]	move	The forward transform (3×1 translation vector).

◆ FiffCoordTrans() [5/5]

FIFFLIB::FiffCoordTrans::FiffCoordTrans	(	int	from,
		int	to,
		const Eigen::Matrix4f &	matTrans,
		bool	bStandard = false )

Constructs a coordinate transformation from a 4×4 homogeneous matrix.

Parameters

[in]	from	Source coordinate system.
[in]	to	Destination coordinate system.
[in]	matTrans	The 4×4 forward transform.
[in]	bStandard	When true, enforce standard transform (last row = [0,0,0,1]). Defaults to false.

◆ ~FiffCoordTrans()

FIFFLIB::FiffCoordTrans::~FiffCoordTrans ( )

Destroys the coordinate transformation descriptor.

Member Function Documentation

◆ addInverse()

bool FIFFLIB::FiffCoordTrans::addInverse ( FiffCoordTrans & t )

static

Parameters

[in] t Fiff coordinate transform to which the inverse should be added.

Returns: True when successful.

◆ angleTo()

float FIFFLIB::FiffCoordTrans::angleTo ( Eigen::MatrixX4f mTransDest )

Calculate rotation as angle between two rotation matrices

Parameters

[in] mTransDest The destination transformation matrix.

Returns: The angle of rotation between two rotation matrices in degrees.

◆ apply_inverse_trans() [1/2]

Eigen::MatrixX3f FIFFLIB::FiffCoordTrans::apply_inverse_trans	(	const Eigen::MatrixX3f &	rr,
		bool	do_move = true ) const

Applies the inverse coordinate transform to given coordinates and returns the transformed coordinates

Parameters

[in]	rr	The coordinates.
[in]	do_move	Perform translation next to rotation yes/no.

Returns: Transformed coordinates.

◆ apply_inverse_trans() [2/2]

void FIFFLIB::FiffCoordTrans::apply_inverse_trans	(	float	r[3],
		const FiffCoordTrans &	t,
		bool	do_move )

static

Applies the inverse coordinate transform to a single 3D point in place.

Parameters

[in,out]	r	3-element float array to transform in place.
[in]	t	The coordinate transformation whose inverse to apply.
[in]	do_move	If true, apply translation; if false, rotation only.

◆ apply_trans() [1/2]

Eigen::MatrixX3f FIFFLIB::FiffCoordTrans::apply_trans	(	const Eigen::MatrixX3f &	rr,
		bool	do_move = true ) const

TODO: dest - The id of the destination coordinate system (FIFFV_COORD_...)

Applies the coordinate transform to given coordinates and returns the transformed coordinates

Parameters

[in]	rr	The coordinates.
[in]	do_move	Perform translation next to rotation yes/no.

Returns: Transformed coordinates.

◆ apply_trans() [2/2]

void FIFFLIB::FiffCoordTrans::apply_trans	(	float	r[3],
		const FiffCoordTrans &	t,
		bool	do_move )

static

Applies the coordinate transform to a single 3D point in place.

Parameters

[in,out]	r	3-element float array to transform in place.
[in]	t	The coordinate transformation to apply.
[in]	do_move	If true, apply translation; if false, rotation only.

◆ clear()

void FIFFLIB::FiffCoordTrans::clear ( )

Initializes the coordinate transformation descriptor.

◆ combine()

FiffCoordTrans FIFFLIB::FiffCoordTrans::combine	(	int	from,
		int	to,
		const FiffCoordTrans &	t1,
		const FiffCoordTrans &	t2 )

static

Combines two coordinate transformations to yield a transform from from to to. Automatically handles inversion and ordering of the input transforms.

Parameters

[in]	from	Desired source coordinate system.
[in]	to	Desired destination coordinate system.
[in]	t1	First transformation.
[in]	t2	Second transformation.

Returns: The combined transformation, or an empty transform on failure.

◆ frame_name()

QString FIFFLIB::FiffCoordTrans::frame_name ( int frame )

static

Map coordinate frame integers to human-readable names

Parameters

[in] frame The coordinate frame integer.

Returns: Human readable form of the coordinate frame.

◆ fromCardinalPoints()

FiffCoordTrans FIFFLIB::FiffCoordTrans::fromCardinalPoints	(	int	from,
		int	to,
		const float *	rL,
		const float *	rN,
		const float *	rR )

static

Constructs a coordinate transformation from cardinal points (LPA, Nasion, RPA).

Parameters

[in]	from	Source coordinate system.
[in]	to	Destination coordinate system (in which the points are expressed).
[in]	rL	Left auricular point (3 floats).
[in]	rN	Nasion point (3 floats).
[in]	rR	Right auricular point (3 floats).

Returns: The coordinate transformation.

◆ identity()

FiffCoordTrans FIFFLIB::FiffCoordTrans::identity	(	int	from,
		int	to )

static

Creates an identity transformation between two coordinate systems.

Parameters

[in]	from	Source coordinate system.
[in]	to	Destination coordinate system.

Returns: An identity coordinate transformation.

◆ invert_transform()

bool FIFFLIB::FiffCoordTrans::invert_transform ( )

Invert a coordinate transformation (actual obsolete - cause trans and inverse are both stored)

Returns: true if succeeded, false otherwise.

◆ inverted()

FiffCoordTrans FIFFLIB::FiffCoordTrans::inverted ( ) const

Returns a new inverted copy of this transformation (swaps from/to and trans/invtrans).

Returns: The inverted transformation.

◆ invmove() [1/2]

auto FIFFLIB::FiffCoordTrans::invmove ( )

inline

Inverse translation (column 3 of invtrans).

Definition at line 190 of file fiff_coord_trans.h.

◆ invmove() [2/2]

auto FIFFLIB::FiffCoordTrans::invmove ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 192 of file fiff_coord_trans.h.

◆ invrot() [1/2]

auto FIFFLIB::FiffCoordTrans::invrot ( )

inline

Inverse rotation (3×3 block of invtrans).

Definition at line 185 of file fiff_coord_trans.h.

◆ invrot() [2/2]

auto FIFFLIB::FiffCoordTrans::invrot ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 187 of file fiff_coord_trans.h.

◆ isEmpty()

bool FIFFLIB::FiffCoordTrans::isEmpty ( ) const

inline

Returns true if coordinate transform contains no data.

Returns: true if coordinate transform is empty.

Definition at line 160 of file fiff_coord_trans.h.

◆ move() [1/2]

auto FIFFLIB::FiffCoordTrans::move ( )

inline

Forward translation (column 3 of trans).

Definition at line 180 of file fiff_coord_trans.h.

◆ move() [2/2]

auto FIFFLIB::FiffCoordTrans::move ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 182 of file fiff_coord_trans.h.

◆ print()

void FIFFLIB::FiffCoordTrans::print ( ) const

Prints the coordinate transform.

◆ procrustesAlign()

FiffCoordTrans FIFFLIB::FiffCoordTrans::procrustesAlign	(	int	from_frame,
		int	to_frame,
		const Eigen::MatrixXf &	fromp,
		const Eigen::MatrixXf &	top,
		const Eigen::VectorXf &	w,
		float	max_diff )

static

Performs a Procrustes alignment between two sets of corresponding 3D points.

Parameters

[in]	from_frame	Source coordinate frame ID.
[in]	to_frame	Destination coordinate frame ID.
[in]	fromp	Point locations in the source frame (np×3 matrix).
[in]	top	Point locations in the destination frame (np×3 matrix).
[in]	w	Weights (np elements), or empty vector for equal weight.
[in]	max_diff	Maximum allowed difference between transformed and target.

Returns: The alignment transform, or an empty transform on failure.

◆ read()

bool FIFFLIB::FiffCoordTrans::read	(	QIODevice &	p_IODevice,
		FiffCoordTrans &	p_Trans )

static

Reads a coordinate transform from a fif file

Parameters

[in]	p_IODevice	A fiff IO device like a fiff QFile or QTCPSocket.
[out]	p_Trans	A coordinate transform from a fif file.

Returns: true if succeeded, false otherwise.

◆ readFromTag()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readFromTag ( const std::unique_ptr< FiffTag > & tag )

static

Reads a coordinate transform from a FIFF tag.

Parameters

[in] tag The FIFF tag to read from.

Returns: The coordinate transform, or an empty transform if the tag is invalid.

◆ readFShead2mriTransform()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readFShead2mriTransform ( const QString & name )

static

Reads the FreeSurfer head → MRI transform from an ASCII file.

Parameters

[in] name ASCII file path.

Returns: The head→MRI transform, or an empty transform on failure.

◆ readMeasTransform()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readMeasTransform ( const QString & name )

static

Reads the MEG device → head coordinate transform from a FIFF file.

Parameters

[in] name FIFF file path.

Returns: The device→head transform, or an empty transform if not found.

◆ readMriTransform()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readMriTransform ( const QString & name )

static

Reads the MRI → head coordinate transform from a FIFF file.

Parameters

[in] name FIFF file path.

Returns: The MRI→head transform, or an empty transform if not found.

◆ readTransform()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readTransform	(	const QString &	name,
		int	from,
		int	to )

static

Reads a specified coordinate transform from a FIFF file.

Parameters

[in]	name	FIFF file path.
[in]	from	Expected source coordinate system.
[in]	to	Expected destination coordinate system.

Returns: The coordinate transform, or an empty transform if not found.

◆ readTransformAscii()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readTransformAscii	(	const QString &	name,
		int	from,
		int	to )

static

Reads a coordinate transform from an ASCII 4×3 matrix file (mm-to-m conversion applied).

Parameters

[in]	name	ASCII file path.
[in]	from	Source coordinate system.
[in]	to	Destination coordinate system.

Returns: The coordinate transform, or an empty transform on failure.

◆ readTransformFromNode()

FiffCoordTrans FIFFLIB::FiffCoordTrans::readTransformFromNode	(	FiffStream::SPtr &	stream,
		const FiffDirNode::SPtr &	node,
		int	from,
		int	to )

static

Reads a coordinate transform from a FIFF stream node.

Parameters

[in]	stream	The FIFF stream.
[in]	node	The directory node to search.
[in]	from	Expected source coordinate system.
[in]	to	Expected destination coordinate system.

Returns: The coordinate transform, or an empty transform if not found.

◆ rot() [1/2]

auto FIFFLIB::FiffCoordTrans::rot ( )

inline

Forward rotation (3×3 block of trans).

Definition at line 175 of file fiff_coord_trans.h.

◆ rot() [2/2]

auto FIFFLIB::FiffCoordTrans::rot ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 177 of file fiff_coord_trans.h.

◆ storageSize()

qint32 FIFFLIB::FiffCoordTrans::storageSize ( )

inlinestatic

Size of the old struct (fiffCoordTransRec) 26*int = 26*4 = 104

Returns: the size of the old struct fiffCoordTransRec.

Definition at line 485 of file fiff_coord_trans.h.

◆ translationTo()

float FIFFLIB::FiffCoordTrans::translationTo ( Eigen::MatrixX4f mTransDest )

Calculate translation between two rotation matrices in meter

Parameters

[in] mTransDest The destination transformation matrix.

Returns: The translation between two rotation matrices in m.

◆ write()

void FIFFLIB::FiffCoordTrans::write ( QIODevice & p_IODevice )

Writes the transformation to file.

Parameters

[in] p_IODevice IO device to write the transformation to.

◆ writeToStream()

void FIFFLIB::FiffCoordTrans::writeToStream ( FiffStream * p_pStream )

Writes the transformation to a FIFF stream.

Parameters

[in] p_pStream Pointer to the FIFF stream to write to.

◆ operator==

bool operator==	(	const FiffCoordTrans &	a,
		const FiffCoordTrans &	b )

friend

Overloaded == operator to compare an object to this instance.

Parameters

[in] object The object which should be compared to.

Returns: true if equal, false otherwise.

Definition at line 494 of file fiff_coord_trans.h.

Member Data Documentation

◆ from

fiff_int_t FIFFLIB::FiffCoordTrans::from

Source coordinate system.

Definition at line 474 of file fiff_coord_trans.h.

◆ invtrans

Eigen::Matrix<float, 4,4, Eigen::DontAlign> FIFFLIB::FiffCoordTrans::invtrans

The inverse transform.

Definition at line 477 of file fiff_coord_trans.h.

◆ to

fiff_int_t FIFFLIB::FiffCoordTrans::to

Destination coordinate system.

Definition at line 475 of file fiff_coord_trans.h.

◆ trans

Eigen::Matrix<float, 4,4, Eigen::DontAlign> FIFFLIB::FiffCoordTrans::trans

The forward transform.

Definition at line 476 of file fiff_coord_trans.h.

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

src/libraries/fiff/fiff_coord_trans.h

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ ConstSPtr

◆ ConstUPtr

◆ SPtr

◆ UPtr

Constructor & Destructor Documentation

◆ FiffCoordTrans() [1/5]

◆ FiffCoordTrans() [2/5]

◆ FiffCoordTrans() [3/5]

◆ FiffCoordTrans() [4/5]

◆ FiffCoordTrans() [5/5]

◆ ~FiffCoordTrans()

Member Function Documentation

◆ addInverse()

◆ angleTo()

◆ apply_inverse_trans() [1/2]

◆ apply_inverse_trans() [2/2]

◆ apply_trans() [1/2]

◆ apply_trans() [2/2]

◆ clear()

◆ combine()

◆ frame_name()

◆ fromCardinalPoints()

◆ identity()

◆ invert_transform()

◆ inverted()

◆ invmove() [1/2]

◆ invmove() [2/2]

◆ invrot() [1/2]

◆ invrot() [2/2]

◆ isEmpty()

◆ move() [1/2]

◆ move() [2/2]

◆ print()

◆ procrustesAlign()

◆ read()

◆ readFromTag()

◆ readFShead2mriTransform()

◆ readMeasTransform()

◆ readMriTransform()

◆ readTransform()

◆ readTransformAscii()

◆ readTransformFromNode()

◆ rot() [1/2]

◆ rot() [2/2]

◆ storageSize()

◆ translationTo()

◆ write()

◆ writeToStream()

Friends And Related Symbol Documentation

◆ operator==

Member Data Documentation

◆ from

◆ invtrans

◆ to

◆ trans