openvrml::rotation Struct Reference

A POD-struct comprising a rotation. More...

#include <openvrml/basetypes.h>

Public Member Functions
rotation &	operator*= (const rotation &rot) throw ()
	Multiply rotations.
const float &	operator[] (std::size_t index) const throw ()
	Index-based element access.
float	x () const throw ()
	Get the x axis component.
float	y () const throw ()
	Get the y axis component.
float	z () const throw ()
	Get the z axis component.
const vec3f	axis () const throw ()
	Get the axis of rotation.
float	angle () const throw ()
	Get the rotation angle.
void	x (float value) throw ()
	Set the x axis component.
void	y (float value) throw ()
	Set the y axis component.
void	z (float value) throw ()
	Set the z axis component.
void	axis (const vec3f &axis) throw ()
	Set the axis of rotation.
void	angle (float value) throw ()
	Set the rotation angle.
const rotation	inverse () const throw ()
	Inverse rotation.
const rotation	slerp (const rotation &dest_rot, float t) const throw ()
	Spherical Linear intERPolation.
Public Attributes
float	rot [4]
	Rotation components.
Related Functions
(Note that these are not member functions.)
const openvrml::rotation	make_rotation () throw()
	Create a default `rotation`.
const openvrml::rotation	make_rotation (const float(&rot)[4]) throw()
	Create a `rotation` from an array.
const openvrml::rotation	make_rotation (const float x, const float y, const float z, const float angle) throw()
	Create a `rotation` from `x`, `y`, `z`, and `angle` components.
const openvrml::rotation	make_rotation (const vec3f &axis, const float angle) throw()
	Create a `rotation` from an axis vector and an angle.
const openvrml::rotation	make_rotation (const vec3f &from_vec, const vec3f &to_vec) throw()
	Create a `rotation` equal to the rotation between two different vectors.
const openvrml::rotation	make_rotation (const quatf &quat) throw()
	Create a `rotation` from a quaternion.
const openvrml::rotation	operator* (const rotation &lhs, const rotation &rhs) throw()
	Multiply rotations.
bool	operator== (const rotation &lhs, const rotation &rhs) throw()
	Compare for equality.
bool	operator!= (const rotation &lhs, const rotation &rhs) throw()
	Compare for inequality.
std::istream &	operator>> (std::istream &in, rotation &rot)
	Stream input.
std::ostream &	operator<< (std::ostream &out, const rotation &r)
	Stream output.

Detailed Description

A POD-struct comprising a rotation.

VRML rotations are represented with four single-precision floating point components. The first three are an axis of rotation, and the last is rotation in radians.

Per the VRML97 specification, the axis of a rotation is a normalized vector (5.8). The specification leaves undefined how to deal with an attempt to construct a rotation from an axis vector that is not normalized. In order to allow users of the library to minimize the number of normalizations, OpenVRML takes the following approach:

Attempts to construct a rotation axis from a vector that is not normalized will yield an assertion failure (abort) unless NDEBUG is defined when compiling the library (in which case truly wacky behavior could result).
Assignment to individual components of the axis will result in the axis being renormalized upon each assignment.

Member Function Documentation

openvrml::rotation & openvrml::rotation::operator*= ( const rotation & rot ) throw ()

Multiply rotations.

Parameters:

[in] rot the rotation by which to multiply.

Returns:: a reference to the object.

const float & openvrml::rotation::operator[] ( std::size_t index ) const throw () [inline]

Index-based element access.

Parameters:

[in] index 0 is the x axis component, 1 is the y axis component, 2 is the z axis component, and 3 is the angle.

float openvrml::rotation::x ( ) const throw () [inline]

Get the x axis component.

Returns:: the x axis component.

float openvrml::rotation::y ( ) const throw () [inline]

Get the y axis component.

Returns:: the y axis component.

float openvrml::rotation::z ( ) const throw () [inline]

Get the z axis component.

Returns:: the z axis component.

const vec3f openvrml::rotation::axis ( ) const throw () [inline]

Get the axis of rotation.

Returns:: the axis of rotation.

float openvrml::rotation::angle ( ) const throw () [inline]

Get the rotation angle.

Returns:: the rotation angle.

void openvrml::rotation::x ( float value ) throw ()

Set the x axis component.

Parameters:

[in] value new x axis component value.

void openvrml::rotation::y ( float value ) throw ()

Set the y axis component.

Parameters:

[in] value new y axis component value.

void openvrml::rotation::z ( float value ) throw ()

Set the z axis component.

Parameters:

[in] value new z axis component value.

void openvrml::rotation::axis ( const vec3f & axis ) throw ()

Set the axis of rotation.

Parameters:

[in] axis new axis of rotation.

void openvrml::rotation::angle ( float value ) throw () [inline]

Set the rotation angle.

Parameters:

[in] value new rotation angle value.

const openvrml::rotation openvrml::rotation::inverse ( ) const throw ()

Inverse rotation.

Returns:: the inverse rotation.

const openvrml::rotation openvrml::rotation::slerp	(	const rotation &	dest_rot,
		float	t
	)			const throw ()

Spherical Linear intERPolation.

Parameters:

`[in]`	dest_rot	destination rotation.
`[in]`	t	fraction representing the desired position between the rotation and `dest_rot`.

Returns:: the rotation corresponding to t between the rotation and dest_rot.

Friends And Related Function Documentation

const openvrml::rotation make_rotation ( ) throw() [related]

Create a default rotation.

Returns:: a default rotation.

const openvrml::rotation make_rotation ( const float(&) rot[4] ) throw() [related]

Create a rotation from an array.

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

Parameters:

[in] rot an array comprising the rotation components.

Precondition:: The vector represented by the first three components of rot is normalized.

Returns:: a rotation initialized to the values in rot.

const openvrml::rotation make_rotation	(	const float	x,
		const float	y,
		const float	z,
		const float	angle
	)			throw() `[related]`

Create a rotation from x, y, z, and angle components.

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

Parameters:

`[in]`	x	x-component of the rotation axis.
`[in]`	y	y-component of the rotation axis.
`[in]`	z	z-component of the rotation axis.
`[in]`	angle	rotation angle.

Precondition:: The vector represented by x, y, and z is normalized.

Returns:: a rotation initialized to [ x, y, z, angle ].

const openvrml::rotation make_rotation	(	const vec3f &	axis,
		const float	angle
	)			throw() `[related]`

Create a rotation from an axis vector and an angle.

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

Parameters:

`[in]`	axis	rotation axis.
`[in]`	angle	rotation angle.

Precondition:: axis is a normalized vector.

Returns:: a rotation initialized using axis and angle.

const openvrml::rotation make_rotation	(	const vec3f &	from_vec,
		const vec3f &	to_vec
	)			throw() `[related]`

Create a rotation equal to the rotation between two different vectors.

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

Parameters:

`[in]`	from_vec	the starting vector.
`[in]`	to_vec	the ending vector.

Returns:: a rotation equal to the rotation between from_vec and to_vec.

const openvrml::rotation make_rotation ( const quatf & quat ) throw() [related]

Create a rotation from a quaternion.

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

Parameters:

[in] quat a quaternion.

Returns:: a rotation corresponding to quat.

const openvrml::rotation operator*	(	const rotation &	lhs,
		const rotation &	rhs
	)			throw() `[related]`

Multiply rotations.

Parameters:

`[in]`	lhs	left-hand operand.
`[in]`	rhs	right-hand operand.

Returns:: the product of lhs and rhs.

bool operator==	(	const rotation &	lhs,
		const rotation &	rhs
	)			throw() `[related]`

Compare for equality.

Parameters:

`[in]`	lhs	left-hand operand.
`[in]`	rhs	right-hand operand.

Returns:: true if lhs is equal to rhs; false otherwise.

bool operator!=	(	const rotation &	lhs,
		const rotation &	rhs
	)			throw() `[related]`

Compare for inequality.

Parameters:

`[in]`	lhs	left-hand operand.
`[in]`	rhs	right-hand operand.

Returns:: true if lhs is not equal to rhs; false otherwise.

std::istream & operator>>	(	std::istream &	in,
		rotation &	rot
	)			`[related]`

Stream input.

Consistent with the VRML97 convention, commas (“,”) in the input are treated as whitespace.

If the axis components of the rotation do not represent a normalized vector, the failbit will be set on in and rot will not be modified.

Parameters:

`[in,out]`	in	input stream.
`[out]`	rot	a `rotation`.

Returns:: in.

std::ostream & operator<<	(	std::ostream &	out,
		const rotation &	r
	)			`[related]`

Stream output.

Parameters:

`[in,out]`	out	output stream.
`[in]`	r	a rotation.

Returns:: out.

Member Data Documentation

float openvrml::rotation::rot[4]

Rotation components.

The first three components define an axis through the origin. The fourth component is a rotation around the axis.

openvrml::rotation Struct Reference

Public Member Functions

Public Attributes

Related Functions

Detailed Description

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation