org.jeospace.navigation
Class QuaternionInterpolator

java.lang.Object
  org.jeospace.navigation.QuaternionInterpolator

All Implemented Interfaces:

Orientation, OrientationInterpolator

public class QuaternionInterpolator

extends java.lang.Object

implements OrientationInterpolator

An orientation interpolator that takes quaternions as arguments. The interpolation follows the shortest path from initial orientation to final orientation along a "great circle" path. The algorithm implemented is known as: SLERP or "Spherical linear interpolation of unit quaternions".

Version:

$Revision: 1.2 $

Author:

Rex Melton

Constructor Summary

QuaternionInterpolator(Quaternion begin, Quaternion end)
Construct a QuaternionInterpolator

Method Summary

void	addInterpolationListener(InterpolationListener il) Add a listener to this interpolator
void	enableOrientation(boolean enabled) Set the state of the interpolator to update it's Alpha in response to update( ) calls.
protected void	fireInterpolationEvent(int id) Deliver events to the listeners
void	get(Attitude attitude) Return the orientation data in the argument object.
void	get(Quaternion quat) Return the orientation value as a Quaternion
Alpha	getAlpha() Return the Alpha object
void	removeInterpolationListener(InterpolationListener il) Remove a listener from this interpolator
void	setAlpha(Alpha alpha) Set the Alpha object to drive the interpolator
void	updateOrientation(double timeValue) Process any position changes for the next simulation frame.

Methods inherited from class java.lang.Object

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

Constructor Detail

QuaternionInterpolator

public QuaternionInterpolator(Quaternion begin,
                              Quaternion end)

Construct a QuaternionInterpolator

Parameters:

begin - the initial orientation

end - the final orientation

Method Detail

setAlpha

public void setAlpha(Alpha alpha)

Set the Alpha object to drive the interpolator

Specified by:

setAlpha in interface OrientationInterpolator

Parameters:

alpha - the Alpha object to install

getAlpha

public Alpha getAlpha()

Return the Alpha object

Specified by:

getAlpha in interface OrientationInterpolator

Returns:

the Alpha object

updateOrientation

public void updateOrientation(double timeValue)

Process any position changes for the next simulation frame. This method updates the Alpha of this interpolator by a single increment.

Specified by:

updateOrientation in interface Orientation

Parameters:

timeValue - the time value is ignored

enableOrientation

public void enableOrientation(boolean enabled)

Set the state of the interpolator to update it's Alpha in response to update( ) calls.

Specified by:

enableOrientation in interface Orientation

Parameters:

enabled - true if the object should update it's Alpha in response to update( ) calls, false if the object should NOT update it's Alpha in response to update( ) calls.

get

public void get(Quaternion quat)

Return the orientation value as a Quaternion

Specified by:

get in interface Orientation

Parameters:

quat - the Quaternion object to initialize with the orientation value calculated at the fraction value of the Alpha

get

public void get(Attitude attitude)

Return the orientation data in the argument object.

Specified by:

get in interface Orientation

Parameters:

attitude - the Attitude coordinate object to initialize with the current orientation data.

addInterpolationListener

public void addInterpolationListener(InterpolationListener il)

Add a listener to this interpolator

Specified by:

addInterpolationListener in interface OrientationInterpolator

Parameters:

il - the InterpolationListener

removeInterpolationListener

public void removeInterpolationListener(InterpolationListener il)

Remove a listener from this interpolator

Specified by:

removeInterpolationListener in interface OrientationInterpolator

Parameters:

il - the InterpolationListener

fireInterpolationEvent

protected void fireInterpolationEvent(int id)

Deliver events to the listeners

Parameters:

id - the InterpolationEvent id