A class to store quaternions. More...

#include <Quaternion.h>

Public Member Functions
	Quaternion ()

	Quaternion (const fpType(&data)[4])

	Quaternion (fpType x, fpType y, fpType z, fpType w)

	Quaternion (const Quaternion< fpType > &quat)

	Quaternion (const Vector3< fpType > &vec)

	Quaternion (Vector3< fpType > axis, fpType angle)

	Quaternion (const Matrix3< fpType > &mat)

virtual	~Quaternion ()

virtual void	set (const fpType *data)

virtual void	set (const Matrix3< fpType > &mat)

virtual void	get (fpType *storage) const

virtual fpType	getAngle () const

virtual Vector3< fpType >	getAxis () const

virtual fpType	getNorm () const

virtual void	normalize ()

virtual bool	isUnit () const

virtual Quaternion< fpType >	getSqrtRotation () const

virtual Quaternion< fpType >	getSqrtRotationTowards (const Quaternion< fpType > &quat) const

virtual void	operator= (const Quaternion< fpType > &quat)

virtual const fpType &	operator[] (int ind) const

virtual fpType &	operator[] (int ind)

virtual bool	compareRotations (const Quaternion< fpType > &quat, fpType precision=PRECISION) const

virtual bool	compare (const Quaternion< fpType > &quat, const fpType &precision=PRECISION) const

virtual bool	operator== (const Quaternion< fpType > &quat) const

virtual bool	operator!= (const Quaternion< fpType > &quat) const

virtual Quaternion< fpType >	inv () const

virtual void	operator*= (const Quaternion< fpType > &quat)

virtual Quaternion< fpType >	operator* (const Quaternion< fpType > &quat) const

virtual void	scaleAngle (const fpType &mult)

virtual Quaternion< fpType >	getScaledAngleRotation (const fpType &mult) const

virtual Vector3< fpType >	operator* (const Vector3< fpType > &vec) const

Public Attributes
fpType &	x

fpType &	y

fpType &	z

fpType &	w

Protected Attributes
fpType	data [4]

Friends
template<class fpT >
std::istream &	operator>> (std::istream &stream, Quaternion< fpT > &quat)

Detailed Description

template<class fpType>
class algebra3d::Quaternion< fpType >

A class to store quaternions.

The main goal is to represent rotations, however the functionality is not limited to that.

Author: Jarek Glowacki

Constructor & Destructor Documentation

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion ( )

Creates an instance of a identity quaternion.

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion ( const fpType(&) data[4] )

Creates an instance using the provided data.

Parameters

[in] data Reference to the data to initialize the quaternion with.

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion	(	fpType	x,
		fpType	y,
		fpType	z,
		fpType	w
	)

Initializes the vector with the provided values.

Parameters

[in]	x	The first element.
[in]	y	The second element.
[in]	z	The third element.
[in]	w	The fourth element.

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion ( const Quaternion< fpType > & quat )

Copies elements of the provided quaternion into this one.

Parameters

[in] quat The quaternion to copy.

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion ( const Vector3< fpType > & vec )

Copies the provided rotation represented by a Cayley vector.

Parameters

[in] vec The Cayley vector to copy.

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion	(	Vector3< fpType >	axis,
		fpType	angle
	)

Creates a quaternion for the provided rotation given by axis and angle.

Parameters

[in]	axis	The rotation axis (not necessary a unit vector).
[in]	angle	The angle of rotation.

template<class fpType>

algebra3d::Quaternion< fpType >::Quaternion ( const Matrix3< fpType > & mat )

Copies the provided rotation represented by a matrix.

Parameters

[in] mat The matrix to copy.

template<class fpType>

virtual algebra3d::Quaternion< fpType >::~Quaternion ( )

virtual

Does nothing. Virtual classes require virtual destructors.

Member Function Documentation

template<class fpType>

virtual bool algebra3d::Quaternion< fpType >::compare	(	const Quaternion< fpType > &	quat,
		const fpType &	precision = `PRECISION`
	)		const

virtual

Checks if all elements of the provided quaternion are the same as in this one up to the provided precision. The comparison is simply checking if the difference between numbers is smaller or equal the precision.

Parameters

[in]	quat	The quaternion to compare this with.
[in]	precision	The precision to use; by default the global PRECISION is used.

Returns: true if all entries are equal up to the precision, false otherwise.

template<class fpType>

virtual bool algebra3d::Quaternion< fpType >::compareRotations	(	const Quaternion< fpType > &	quat,
		fpType	precision = `PRECISION`
	)		const

virtual

Checks if the rotation represented by this quaternion is identical with the one represented by the argument.

Parameters

[in]	quat	The quaternion to compare this with.
[in]	precision	The precision to use; by default the global PRECISION is used.

Returns: true if the rotations are identical, false otherwise.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::get ( fpType * storage ) const

virtual

Copies the quaternion data to the provided array. First 4 positions from the given pointer are written).

Parameters

[out] storage The array to copy the data to.

template<class fpType>

virtual fpType algebra3d::Quaternion< fpType >::getAngle ( ) const

virtual

Returns the angle of the rotation represented by this quaternion. If the quaternions is not a unit one the value is meaningless.

Returns: The angle of the rotation represented by this quaternion.

template<class fpType>

virtual Vector3<fpType> algebra3d::Quaternion< fpType >::getAxis ( ) const

virtual

Returns the axis of the rotation represented by this quaternion. If the quaternions is not a unit one the value is meaningless.

Returns: The axis of the rotation represented by this quaternion.

template<class fpType>

virtual fpType algebra3d::Quaternion< fpType >::getNorm ( ) const

virtual

Returns the L2 norm of the quaternion.

Returns: The L2 norm of the quaternion.

template<class fpType>

virtual Quaternion<fpType> algebra3d::Quaternion< fpType >::getScaledAngleRotation ( const fpType & mult ) const

virtual

Returns a quaternion representing a rotation around the same axis by an angle that is a given multiply of this rotation angle.

Parameters

mult	The value to multiply the angle by.

template<class fpType>

virtual Quaternion<fpType> algebra3d::Quaternion< fpType >::getSqrtRotation ( ) const

virtual

Returns the quaternion representation of half of the rotation represented by this instance.

Returns: the quaternion representation of half of the rotation represented by this instance.

template<class fpType>

virtual Quaternion<fpType> algebra3d::Quaternion< fpType >::getSqrtRotationTowards ( const Quaternion< fpType > & quat ) const

virtual

Computes the rotation that is half the transition between this one and the provided one. That is to say that:

Quaternion q1, q2;
...
Quaternion trans = q1.getSqrtRotationTowards(q2);
// The following is true:
q1 * trans * trans == q2;

Returns it as a Quaternion.

Parameters

[in] quat The other rotation.

Returns: the Quaternion that represents the square root of transition.

template<class fpType>

virtual Quaternion<fpType> algebra3d::Quaternion< fpType >::inv ( ) const

virtual

Returns a quaternion that represents inverse of this rotation, i.e. same angle, negative axis the axis of this rotation. For a non-unit quaternion may result in an error.

Returns: A quaternion that represents a rotation that is inverse of this one.

template<class fpType>

virtual bool algebra3d::Quaternion< fpType >::isUnit ( ) const

virtual

Returns true if this is a unit quaternion, false otherwise.

Returns: true if this is a unit quaternion, false otherwise.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::normalize ( )

virtual

Normalizes the quaternion (divides all elements by the norm).

template<class fpType>

virtual bool algebra3d::Quaternion< fpType >::operator!= ( const Quaternion< fpType > & quat ) const

virtual

Comparing operator. Checks if any element of this quaternion differs from respective element of the parameter.

Parameters

[in] quat The quaternion vector to compare this with.

Returns: false if all entries are equal, true otherwise.

template<class fpType>

virtual Quaternion<fpType> algebra3d::Quaternion< fpType >::operator* ( const Quaternion< fpType > & quat ) const

virtual

Returns the product of this quaternion and the provided one.

Parameters

[in] quat The matrix to multiply this vector.

Returns: The product of this quaternion and the provided one.

template<class fpType>

virtual Vector3<fpType> algebra3d::Quaternion< fpType >::operator* ( const Vector3< fpType > & vec ) const

virtual

Returns the effect of rotating the vector according to this quaternion. If this is not a unit quaternion this might result in an error.

Parameters

[in] vec The vector to transform according to this quaternion.

Returns: The effect of rotating the vector according to this quaternion.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::operator*= ( const Quaternion< fpType > & quat )

virtual

Post-multiplies this quaternion by the provided one.

Parameters

[in] quat The quaternion to post-multiply this by.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::operator= ( const Quaternion< fpType > & quat )

virtual

Copies elements of the provided quaternion into this one.

Parameters

[in] quat The quaternion to copy.

template<class fpType>

virtual bool algebra3d::Quaternion< fpType >::operator== ( const Quaternion< fpType > & quat ) const

virtual

Checks if all elements of the provided quaternion are the same as this.

Parameters

[in] quat The quaternion to compare this with.

Returns: true if all entries are equal, false otherwise.

template<class fpType>

virtual const fpType& algebra3d::Quaternion< fpType >::operator[] ( int ind ) const

virtual

Returns a reference to the element of the quaternion with the provided index. If the index is incorrect the closest correct one is used is returned. Version for constant instances.

Parameters

[in] ind Index of the element to return.

Returns: Reference to the selected element.

template<class fpType>

virtual fpType& algebra3d::Quaternion< fpType >::operator[] ( int ind )

virtual

Returns a reference to the element of the quaternion with the provided index. If the index is incorrect the closest correct one is used is returned.

Parameters

[in] ind Index of the element to return.

Returns: Reference to the selected element.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::scaleAngle ( const fpType & mult )

virtual

Changes the angle of rotation represented by this quaternion by multiplying it by the provided number.

Parameters

mult	The value to multiply the angle by.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::set ( const fpType * data )

virtual

Set the quaternion data to the values in the provided array. First 4 positions from the given pointer are read.

Parameters

[in] data The array with values to set.

template<class fpType>

virtual void algebra3d::Quaternion< fpType >::set ( const Matrix3< fpType > & mat )

virtual

Set the quaternion data to represent the rotation given as a matrix.

Parameters

[in] mat The rotation matrix.

Member Data Documentation

template<class fpType>

fpType algebra3d::Quaternion< fpType >::data[4]

protected

The quaternion data.

template<class fpType>

fpType& algebra3d::Quaternion< fpType >::w

Reference to the fourth element of data.

template<class fpType>

fpType& algebra3d::Quaternion< fpType >::x

Reference to the first element of data.

template<class fpType>

fpType& algebra3d::Quaternion< fpType >::y

Reference to the second element of data.

template<class fpType>

fpType& algebra3d::Quaternion< fpType >::z

Reference to the third element of data.

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

include/algebra3d/Matrix3.h
include/algebra3d/Quaternion.h

Public Member Functions

Public Attributes

Protected Attributes

Friends

Detailed Description

template<class fpType> class algebra3d::Quaternion< fpType >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class fpType>
class algebra3d::Quaternion< fpType >