# LQuaterniond¶

class LQuaterniond

Bases: LVecBase4d

This is the base quaternion class

Inheritance diagram

LQuaterniond(void)
LQuaterniond(LVecBase4d const &copy)
LQuaterniond(double r, LVecBase3d const &copy)
LQuaterniond(double r, double i, double j, double k)
LQuaterniond(LQuaterniond const&) = default
bool almost_equal(LQuaterniond const &other) const
bool almost_equal(LQuaterniond const &other, double threshold) const

Returns true if two quaternions are memberwise equal within a default tolerance based on the numeric type.

Returns true if two quaternions are memberwise equal within a specified tolerance.

bool almost_same_direction(LQuaterniond const &other, double threshold) const

Returns true if two quaternions represent the same rotation within a specified tolerance.

double angle_deg(LQuaterniond const &other) const

Returns the angle between the orientation represented by this quaternion and the other one, expressed in degrees.

double angle_rad(LQuaterniond const &other) const

Returns the angle between the orientation represented by this quaternion and the other one, expressed in radians.

LQuaterniond conjugate(void) const

Returns the complex conjugate of this quat.

bool conjugate_from(LQuaterniond const &other)

Computes the conjugate of the other quat, and stores the result in this quat. This is a fully general operation and makes no assumptions about the type of transform represented by the quat.

The other quat must be a different object than this quat. However, if you need to get a conjugate of a quat in place, see conjugate_in_place().

The return value is true if the quat was successfully inverted, false if there was a singularity.

bool conjugate_in_place(void)

Sets this to be the conjugate of the current quat. Returns true if the successful, false if the quat was singular.

void extract_to_matrix(LMatrix3d &m) const
void extract_to_matrix(LMatrix4d &m) const

Based on the quat lib from VRPN.

double get_angle(void) const

This, along with get_axis(), returns the rotation represented by the quaternion as an angle about an arbitrary axis. This returns the angle, in degrees counterclockwise about the axis.

It is necessary to ensure the quaternion has been normalized (for instance, with a call to normalize()) before calling this method.

double get_angle_rad(void) const

This, along with get_axis(), returns the rotation represented by the quaternion as an angle about an arbitrary axis. This returns the angle, in radians counterclockwise about the axis.

It is necessary to ensure the quaternion has been normalized (for instance, with a call to normalize()) before calling this method.

LVector3d get_axis(void) const

This, along with get_angle(), returns the rotation represented by the quaternion as an angle about an arbitrary axis. This returns the axis; it is not normalized.

LVector3d get_axis_normalized(void) const

This, along with get_angle(), returns the rotation represented by the quaternion as an angle about an arbitrary axis. This returns the normalized axis.

static TypeHandle get_class_type(void)
LVector3d get_forward(CoordinateSystem cs = ::CS_default) const

Returns the orientation represented by this quaternion, expressed as a forward vector.

LVecBase3d get_hpr(CoordinateSystem cs = ::CS_default) const

Extracts the equivalent Euler angles from the unit quaternion.

double get_i(void) const
double get_j(void) const
double get_k(void) const
double get_r(void) const
LVector3d get_right(CoordinateSystem cs = ::CS_default) const

Returns the orientation represented by this quaternion, expressed as a right vector.

LVector3d get_up(CoordinateSystem cs = ::CS_default) const

Returns the orientation represented by this quaternion, expressed as an up vector.

LQuaterniond const &ident_quat(void)

Returns an identity quaternion.

bool invert_from(LQuaterniond const &other)

Computes the inverse of the other quat, and stores the result in this quat. This is a fully general operation and makes no assumptions about the type of transform represented by the quat.

The other quat must be a different object than this quat. However, if you need to invert a quat in place, see invert_in_place().

The return value is true if the quat was successfully inverted, false if there was a singularity.

bool invert_in_place(void)

Inverts the current quat. Returns true if the inverse is successful, false if the quat was singular.

bool is_almost_identity(double tolerance) const

Returns true if this quaternion represents the identity transformation within a given tolerance.

bool is_identity(void) const

Returns true if this quaternion represents the identity transformation: no rotation.

bool is_same_direction(LQuaterniond const &other) const

Returns true if two quaternions represent the same rotation within a default tolerance based on the numeric type.

LQuaterniond multiply(LQuaterniond const &rhs) const

actual multiply call (non virtual)

bool normalize(void)
void output(std::ostream&) const
static LQuaterniond pure_imaginary(LVector3d const &v)
void set_from_axis_angle(double angle_deg, LVector3d const &axis)

angle_deg() is the angle about the axis in degrees. axis must be normalized.

void set_from_axis_angle_rad(double angle_rad, LVector3d const &axis)

angle_rad() is the angle about the axis in radians. axis must be normalized.

void set_from_matrix(LMatrix3d const &m)
void set_from_matrix(LMatrix4d const &m)

Sets the quaternion according to the rotation represented by the matrix. Originally we tried an algorithm presented by Do-While Jones, but that turned out to be broken. This is based on the quat lib from UNC.

void set_hpr(LVecBase3d const &hpr, CoordinateSystem cs = ::CS_default)

Sets the quaternion as the unit quaternion that is equivalent to these Euler angles. (from Real-time Rendering, p.49)

void set_i(double i)
void set_j(double j)
void set_k(double k)
void set_r(double r)
LVecBase3d xform(LVecBase3d const &v) const
LVecBase4d xform(LVecBase4d const &v) const

Transforms a 3-d vector by the indicated rotation

Transforms a 4-d vector by the indicated rotation