Class Quaternion

java.lang.Object

com.codename1.gpu.Quaternion

public final class Quaternion
extends Object

Portable quaternion math used by the 3D, AR and VR APIs. Every operation works on plain float[4] arrays laid out as {x, y, z, w} so it behaves identically on every platform. A quaternion of this form represents a rotation; {0, 0, 0, 1} is the identity (no rotation). Rotation matrices produced by toMatrix(float[], float[]) use the same column-major layout as Matrix4.

Method Summary

Modifier and Type	Method	Description
static void	conjugate(float[] q, float[] dst)	Stores the conjugate of q (the inverse rotation for a unit quaternion) into dst.
static void	copy(float[] src, float[] dst)	Copies the contents of src into dst.
static float[]	fromAxisAngle(float angleRadians, float x, float y, float z)	Returns a quaternion representing a rotation of angleRadians around the axis (x, y, z).
static float[]	identity()	Allocates a new identity quaternion {0, 0, 0, 1}.
static void	integrateGyro(float[] q, float gx, float gy, float gz, float dtSeconds, float[] dst)	Integrates a body-frame angular velocity into the orientation quaternion q, storing the result in dst.
static void	multiply(float[] a, float[] b, float[] dst)	Multiplies a * b (apply b first, then a) and stores the result in dst.
static void	normalize(float[] q)	Normalizes q in place to unit length.
static void	rotateVector(float[] q, float[] xyzInOut)	Rotates the vector stored in xyzInOut (3 floats) by the unit quaternion q, writing the result back in place.
static void	setAxisAngle(float[] q, float angleRadians, float x, float y, float z)	Stores a rotation of angleRadians around the axis (x, y, z) into q.
static void	setIdentity(float[] q)	Resets the supplied quaternion to the identity rotation.
static void	slerp(float[] a, float[] b, float t, float[] dst)	Spherically interpolates between the unit quaternions a and b by the factor t in [0, 1], storing the result in dst.
static void	toMatrix(float[] q, float[] dst16)	Writes the rotation matrix equivalent of the unit quaternion q into the 16 element column-major matrix dst16.

Methods inherited from class Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

identity

public static float[] identity()

Allocates a new identity quaternion {0, 0, 0, 1}.

setIdentity

public static void setIdentity(float[] q)

Resets the supplied quaternion to the identity rotation.

copy

public static void copy(float[] src,
 float[] dst)

Copies the contents of src into dst. Both arrays must hold 4 floats.

multiply

public static void multiply(float[] a,
 float[] b,
 float[] dst)

Multiplies a * b (apply b first, then a) and stores the result in dst. dst may alias a or b.

fromAxisAngle

public static float[] fromAxisAngle(float angleRadians,
 float x,
 float y,
 float z)

Returns a quaternion representing a rotation of angleRadians around the axis (x, y, z). The axis need not be normalized; a zero axis returns the identity.

setAxisAngle

public static void setAxisAngle(float[] q,
 float angleRadians,
 float x,
 float y,
 float z)

Stores a rotation of angleRadians around the axis (x, y, z) into q. The axis need not be normalized; a zero axis produces the identity.

normalize

public static void normalize(float[] q)

Normalizes q in place to unit length. A zero quaternion is reset to the identity.

conjugate

public static void conjugate(float[] q,
 float[] dst)

Stores the conjugate of q (the inverse rotation for a unit quaternion) into dst. dst may alias q.

toMatrix

public static void toMatrix(float[] q,
 float[] dst16)

Writes the rotation matrix equivalent of the unit quaternion q into the 16 element column-major matrix dst16. The result matches Matrix4.rotation(float, float, float, float) for the same axis and angle.

rotateVector

public static void rotateVector(float[] q,
 float[] xyzInOut)

Rotates the vector stored in xyzInOut (3 floats) by the unit quaternion q, writing the result back in place.

slerp

public static void slerp(float[] a,
 float[] b,
 float t,
 float[] dst)

Spherically interpolates between the unit quaternions a and b by the factor t in [0, 1], storing the result in dst. Takes the shortest arc; falls back to linear interpolation when the quaternions are nearly parallel.

integrateGyro

public static void integrateGyro(float[] q,
 float gx,
 float gy,
 float gz,
 float dtSeconds,
 float[] dst)

Integrates a body-frame angular velocity into the orientation quaternion q, storing the result in dst. gx, gy and gz are rotation rates in radians per second around the body X, Y and Z axes (the convention used by gyroscope sensors) and dtSeconds is the integration interval. dst may alias q. The result is normalized.