## Public API Reference

- Main Page
- Modules
- Namespaces
- Classes
- Files
- Related Pages

- Alphabetical List
- Class List
- Class Hierarchy
- Class Members

# csQuaternion Class Reference
[Geometry utilities]

Class for a quaternion. More...

`#include <csgeom/quaternion.h>`

List of all members.

## Public Member Functions

void | Conjugate ()
| Set this quaternion to its own conjugate.
| csQuaternion (const csQuaternion &q)
| Copy-constructor.
| csQuaternion (const csVector3 &v, float w)
| Construct from a vector and given w value.
| csQuaternion (float x, float y, float z, float w)
| Initialize with given values. Does not normalize.
| csQuaternion ()
| Initialize with identity.
float | Dot (const csQuaternion &q) const
| Return euclidian inner-product (dot).
csQuaternion | Exp () const
| Get quaternion exp.
void | GetAxisAngle (csVector3 &axis, float &angle) const
| Get a quaternion as axis-angle representation.
csQuaternion | GetConjugate () const
| Get the conjugate quaternion.
csVector3 | GetEulerAngles () const
| Get quaternion as three Euler angles X, Y, Z, expressed in radians.
csMatrix3 | GetMatrix () const
| Get quaternion as a 3x3 rotation matrix.
csQuaternion | Log () const
| Get quaternion log.
csQuaternion | NLerp (const csQuaternion &q2, float t) const
| Interpolate this quaternion with another using normalized linear interpolation (nlerp) using given interpolation factor.
float | Norm () const
| Get the norm of this quaternion.
csQuaternion & | operator *= (const csQuaternion &q)
| Multiply this quaternion by another.
csQuaternion & | operator+= (const csQuaternion &q)
| Add quaternion to this one.
csQuaternion & | operator-= (const csQuaternion &q)
| Subtract quaternion from this one.
csVector3 | Rotate (const csVector3 &src) const
| Rotate vector by quaternion.
void | SetAxisAngle (const csVector3 &axis, float angle)
| Set a quaternion using axis-angle representation.
void | SetEulerAngles (const csVector3 &angles)
| Set quaternion using Euler angles X, Y, Z, expressed in radians.
void | SetIdentity ()
| Set quaternion to identity rotation.
void | SetMatrix (const csMatrix3 &matrix)
| Set quaternion using 3x3 rotation matrix.
csQuaternion | SLerp (const csQuaternion &q2, float t) const
| Interpolate this quaternion with another using spherical linear interpolation (slerp) using given interpolation factor.
csQuaternion | Squad (const csQuaternion &t1, const csQuaternion &t2, const csQuaternion &q, float t) const
| Interpolate this quaternion with another (q) using cubic linear interpolation (squad) using given interpolation factor (t) and tangents (t1 and t2).
float | SquaredNorm () const
| Get the squared norm of this quaternion (equals dot with itself).
csQuaternion | Unit () const
| Return a unit-lenght version of this quaternion (also called sgn) Attempting to normalize a zero-length quaternion will result in a divide by zero error.

## Public Attributes

csVector3 | v
float | w

## Friends

csQuaternion | operator * (float f, const csQuaternion q)
| Multiply by scalar.
csQuaternion | operator * (const csQuaternion q, float f)
| Multiply by scalar.
csQuaternion | operator * (const csQuaternion &q1, const csQuaternion &q2)
| Multiply two quaternions, Grassmann product.
csQuaternion | operator+ (const csQuaternion &q1, const csQuaternion &q2)
| Add two quaternions.
csQuaternion | operator- (const csQuaternion &q)
| Get the negative quaternion (unary minus).
csQuaternion | operator- (const csQuaternion &q1, const csQuaternion &q2)
| Subtract two quaternions.
csQuaternion | operator/ (float f, const csQuaternion q)
| Divide by scalar.
csQuaternion | operator/ (const csQuaternion q, float f)
| Divide by scalar.

## Detailed Description

Class for a quaternion.

A SE3 rotation represented as a normalized quaternion

Definition at line 41 of file quaternion.h.

## Constructor & Destructor Documentation

csQuaternion::csQuaternion | ( |  | ) | `[inline]`

Initialize with identity.

Definition at line 47 of file quaternion.h.

csQuaternion::csQuaternion | ( | float | x,
|  | float | y,
|  | float | z,
|  | float | w |
| ) |  |  | `[inline]`

Initialize with given values. Does not normalize.

Definition at line 52 of file quaternion.h.

csQuaternion::csQuaternion | ( | const csVector3 & | v,
|  | float | w |
| ) |  |  | `[inline]`

Construct from a vector and given w value.

Definition at line 57 of file quaternion.h.

csQuaternion::csQuaternion | ( | const csQuaternion & | q | ) | `[inline]`

Copy-constructor.

Definition at line 62 of file quaternion.h.

## Member Function Documentation

void csQuaternion::Conjugate | ( |  | ) | `[inline]`

Set this quaternion to its own conjugate.

Definition at line 156 of file quaternion.h.

float csQuaternion::Dot | ( | const csQuaternion & | q | ) | const`[inline]`

Return euclidian inner-product (dot).

Definition at line 162 of file quaternion.h.

References v, and w.

csQuaternion csQuaternion::Exp | ( |  | ) | const

Get quaternion exp.

void csQuaternion::GetAxisAngle | ( | csVector3 & | axis,
|  | float & | angle |
| ) |  |  | const`[inline]`

Get a quaternion as axis-angle representation.

Parameters:

  | axis | Rotation axis.
  | angle | Angle to rotate about axis (in radians)

Definition at line 220 of file quaternion.h.

References csVector3::Set(), and csVector3::Unit().

csQuaternion csQuaternion::GetConjugate | ( |  | ) | const`[inline]`

Get the conjugate quaternion.

Definition at line 150 of file quaternion.h.

csVector3 csQuaternion::GetEulerAngles | ( |  | ) | const

Get quaternion as three Euler angles X, Y, Z, expressed in radians.

csMatrix3 csQuaternion::GetMatrix | ( |  | ) | const

Get quaternion as a 3x3 rotation matrix.

csQuaternion csQuaternion::Log | ( |  | ) | const

Get quaternion log.

csQuaternion csQuaternion::NLerp | ( | const csQuaternion & | q2,
|  | float | t |
| ) |  |  | const

Interpolate this quaternion with another using normalized linear interpolation (nlerp) using given interpolation factor.

float csQuaternion::Norm | ( |  | ) | const`[inline]`

Get the norm of this quaternion.

Definition at line 174 of file quaternion.h.

References csQsqrt().

csQuaternion& csQuaternion::operator *= | ( | const csQuaternion & | q | ) | `[inline]`

Multiply this quaternion by another.

Definition at line 115 of file quaternion.h.

References v, and w.

csQuaternion& csQuaternion::operator+= | ( | const csQuaternion & | q | ) | `[inline]`

Add quaternion to this one.

Definition at line 80 of file quaternion.h.

References v, and w.

csQuaternion& csQuaternion::operator-= | ( | const csQuaternion & | q | ) | `[inline]`

Subtract quaternion from this one.

Definition at line 94 of file quaternion.h.

References v, and w.

csVector3 csQuaternion::Rotate | ( | const csVector3 & | src | ) | const`[inline]`

Rotate vector by quaternion.

Definition at line 192 of file quaternion.h.

References v.

void csQuaternion::SetAxisAngle | ( | const csVector3 & | axis,
|  | float | angle |
| ) |  |  | `[inline]`

Set a quaternion using axis-angle representation.

Parameters:

  | axis | Rotation axis. Should be normalized before calling this function.
  | angle | Angle to rotate about axis (in radians)

Definition at line 207 of file quaternion.h.

void csQuaternion::SetEulerAngles | ( | const csVector3 & | angles | ) |

Set quaternion using Euler angles X, Y, Z, expressed in radians.

void csQuaternion::SetIdentity | ( |  | ) | `[inline]`

Set quaternion to identity rotation.

Definition at line 67 of file quaternion.h.

void csQuaternion::SetMatrix | ( | const csMatrix3 & | matrix | ) |

Set quaternion using 3x3 rotation matrix.

csQuaternion csQuaternion::SLerp | ( | const csQuaternion & | q2,
|  | float | t |
| ) |  |  | const

Interpolate this quaternion with another using spherical linear interpolation (slerp) using given interpolation factor.

csQuaternion csQuaternion::Squad | ( | const csQuaternion & | t1,
|  | const csQuaternion & | t2,
|  | const csQuaternion & | q,
|  | float | t |
| ) |  |  | const

Interpolate this quaternion with another (q) using cubic linear interpolation (squad) using given interpolation factor (t) and tangents (t1 and t2).

float csQuaternion::SquaredNorm | ( |  | ) | const`[inline]`

Get the squared norm of this quaternion (equals dot with itself).

Definition at line 168 of file quaternion.h.

csQuaternion csQuaternion::Unit | ( |  | ) | const`[inline]`

Return a unit-lenght version of this quaternion (also called sgn) Attempting to normalize a zero-length quaternion will result in a divide by zero error.

This is as it should be... fix the calling code.

Definition at line 184 of file quaternion.h.

## Friends And Related Function Documentation

csQuaternion operator * | ( | float | f,
|  | const csQuaternion | q |
| ) |  |  | `[friend]`

Multiply by scalar.

Definition at line 130 of file quaternion.h.

csQuaternion operator * | ( | const csQuaternion | q,
|  | float | f |
| ) |  |  | `[friend]`

Multiply by scalar.

Definition at line 124 of file quaternion.h.

csQuaternion operator * | ( | const csQuaternion & | q1,
|  | const csQuaternion & | q2 |
| ) |  |  | `[friend]`

Multiply two quaternions, Grassmann product.

Definition at line 107 of file quaternion.h.

csQuaternion operator+ | ( | const csQuaternion & | q1,
|  | const csQuaternion & | q2 |
| ) |  |  | `[friend]`

Add two quaternions.

Definition at line 73 of file quaternion.h.

csQuaternion operator- | ( | const csQuaternion & | q | ) | `[friend]`

Get the negative quaternion (unary minus).

Definition at line 101 of file quaternion.h.

csQuaternion operator- | ( | const csQuaternion & | q1,
|  | const csQuaternion & | q2 |
| ) |  |  | `[friend]`

Subtract two quaternions.

Definition at line 87 of file quaternion.h.

csQuaternion operator/ | ( | float | f,
|  | const csQuaternion | q |
| ) |  |  | `[friend]`

Divide by scalar.

Definition at line 143 of file quaternion.h.

csQuaternion operator/ | ( | const csQuaternion | q,
|  | float | f |
| ) |  |  | `[friend]`

Divide by scalar.

Definition at line 136 of file quaternion.h.

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

- csgeom/quaternion.h