QSDK 1.1 Documentation

Maths::Quat4f Struct Reference
[QMaths]

#include <Q/maths.h>

List of all members.

Public Member Functions
	Quat4f ()
	Quat4f (float v)
	Quat4f (const Quat4f &q)
	Quat4f (const Vec4f &v)
	Quat4f (float x1, float y1, float z1, float w1)
	Quat4f (const Vec3f &axis, float angle)
	Quat4f (const Vec3f &)
	Quat4f (const Matrix3f &m)
	Quat4f (const Vec3f &dir, const Vec3f &up)
	Quat4f (const Matrix4f &m, bool normalise=false)
	Quat4f (const Affine4f &m, bool normalise=false)
void	setIdentity ()
void	setRotation (const Vec3f &axis, float angle)
void	setRotation (const Vec3f &direction, const Vec3f &up)
void	setMatrix (const Matrix3f &m, bool normalise=false)
void	addRotation (const Vec3f &axis, float angle)
bool	isIdentity () const
void	mult (float)
void	mult (const Quat4f &q)
void	imult (const Quat4f &q)
void	mult (const Quat4f &a, const Quat4f &b)
void	getDirection (Vec3f &dir) const
void	getUpVector (Vec3f &up) const
void	getAxis (Vec3f &axis) const
Quat4f &	operator *= (const Quat4f &q)
Quat4f &	operator *= (float v)
Vec3f	up () const
Vec3f	direction () const
Quat4f	invert () const
Vec3f	axis () const
float	angle () const
bool	equal (const Quat4f &v, float e=Epsilon) const
Protected Member Functions
Vec3f &	vec3 ()
const Vec3f &	vec3 () const
Friends
Quat4f	operator * (const Quat4f &a, const Quat4f &b)
Quat4f	interpolate (float t, const Quat4f &a, const Quat4f &b)
Quat4f	sInterpolate (float t, const Quat4f &a, const Quat4f &b)

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Detailed Description

Quaternion algebra representation. Although it is not enforced, all quaternions should be of unit length for them to work as expected.

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Constructor & Destructor Documentation

Maths::Quat4f::Quat4f (   )  [inline]

Build an uninitialised quaternion.

Maths::Quat4f::Quat4f (  float  v  )  [inline, explicit]

Initialise all elements of the quaternion to v.

Maths::Quat4f::Quat4f (  const Quat4f &  q  )  [inline]

Copy the value of q into this quaternion.

Maths::Quat4f::Quat4f (  const Vec4f &  v  )  [inline]

Copy the values held in v into this quaterion.

Maths::Quat4f::Quat4f (  float  x1, float  y1, float  z1, float  w1 )  [inline]

Write the values of the quaternion directly.

Maths::Quat4f::Quat4f (  const Vec3f &  axis, float  angle )  [inline]

Build a quaternion from a unit direction vector and a rotation angle about that vector.

Maths::Quat4f::Quat4f (  const Vec3f &   )  [explicit]

Build a quaternion from a unit direction vector and a rotation angle specified by the modulus of the vector.

Maths::Quat4f::Quat4f (  const Matrix3f &  m  )  [inline]

Build a quaternion from a rotation matrix. The matrix should be orthonormal and not contain any scale.

Maths::Quat4f::Quat4f (  const Vec3f &  dir, const Vec3f &  up )  [inline]

Build a quaternion from a direction vector and an up vector. The vectors do not need to be normalized or orthogonal. The up vector will be adjusted within the plane of the two vectors to be orthogonal to the direction vector. The result is undefined if the two vectors are parallel.

Maths::Quat4f::Quat4f (  const Matrix4f &  m, bool  normalise = false )

Build a quaternion from a matrix. If the matrix contains scale then normalise should be set to true.

Maths::Quat4f::Quat4f (  const Affine4f &  m, bool  normalise = false )  [explicit]

Build a quaternion from a matrix. If the matrix contains scale then normalise should be set to true.

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Member Function Documentation

void Maths::Quat4f::addRotation (  const Vec3f &  axis, float  angle )

Create a temporary quaternion from an axis and an angle and multiply the quaternion by it.

float Maths::Quat4f::angle (   )  const [inline]

Return the angle part of the quaternion.

Vec3f Maths::Quat4f::axis (   )  const [inline]

Return the axis part of the quaternion.

Vec3f Maths::Quat4f::direction (   )  const [inline]

Return the direction vector represented by the vector.

bool Maths::Quat4f::equal (  const Quat4f &  v, float  e = Epsilon )  const

Return true if v represents the same rotation as this quaternion, with an error of e. This method expects unit quaternions.

void Maths::Quat4f::getAxis (  Vec3f &  axis  )  const [inline]

Get the axis part of the quaternion.

void Maths::Quat4f::getDirection (  Vec3f &  dir  )  const [inline]

Get the direction vector represented by the quaternion.

void Maths::Quat4f::getUpVector (  Vec3f &  up  )  const [inline]

Get the up vector represented by the quaternion.

void Maths::Quat4f::imult (  const Quat4f &  q  )

Set the quaternion to be q rotated by the quaternion.

Quat4f Maths::Quat4f::invert (   )  const

Return the inverse quaternion. This does not modify the existing quaternion. This method expects unit quaternions.

bool Maths::Quat4f::isIdentity (   )  const [inline]

Return true if the quaternion is the identity quaternion.

void Maths::Quat4f::mult (  const Quat4f &  a, const Quat4f &  b )

Set the quaternion to be a rotated by b

void Maths::Quat4f::mult (  const Quat4f &  q  )

Rotate the quaternion by the quaternion q

void Maths::Quat4f::mult (  float   )

Scale the quaternion by the value.

Quat4f& Maths::Quat4f::operator *= (  float  v  )  [inline]

Scale the quaternion by and return the answer.

Quat4f& Maths::Quat4f::operator *= (  const Quat4f &  q  )  [inline]

Rotate the quaternion by q and return the answer.

void Maths::Quat4f::setIdentity (   )

Set the quaternion to the identity quaternion.

void Maths::Quat4f::setMatrix (  const Matrix3f &  m, bool  normalise = false )

Set the quaternion to the value represented by a matrix. If the matrix contains scale then normalise should be set to true.

void Maths::Quat4f::setRotation (  const Vec3f &  direction, const Vec3f &  up )

Set the quaternion to the value represented by a direction vector and an up vector. The vectors do not need to be normalized or orthogonal. The up vector will be adjusted within the plane of the two vectors to be orthogonal to the direction vector. The result is undefined if the two vectors are parallel.

void Maths::Quat4f::setRotation (  const Vec3f &  axis, float  angle )

Set the quaternion to the value represented by a unit direction vector and a rotation angle about that vector.

Vec3f Maths::Quat4f::up (   )  const [inline]

Return the up vector represented by the vector.

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Friends And Related Function Documentation

Quat4f interpolate (  float  t, const Quat4f &  a, const Quat4f &  b )  [friend]

Linearly interpolate between a and b. This method is faster than sInterpolate, but less accurate and does not conserve the normality of the quaternions. For reasonable accuracy, the quaternions should not be too dissimilar. In particular, interpolation between a quaternion and its inverse should be avoided. t should be in the range [0, 1]. If t is 0 then a is returned and if t is 1 then b is returned. This method expects unit quaternions.

Quat4f operator * (  const Quat4f &  a, const Quat4f &  b )  [friend]

Return the rotation of a by b.

Quat4f sInterpolate (  float  t, const Quat4f &  a, const Quat4f &  b )  [friend]

Spherical linear interpolate between a and b. t should be in the range [0, 1]. If t is 0 then a is returned and if t is 1 then b is returned. Interpolation between a quaternion and its inverse is handled without singularity. This method expects unit quaternions.

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