msim.trajectory

Class TrajectoryObserver

java.lang.Object

msim.trajectory.TrajectoryActor

msim.trajectory.TrajectoryObserver

@ThreadSafe
public abstract class TrajectoryObserver
extends TrajectoryActor

Base class for observers of Joint sub-transform trajectories.

Default impl provides for time-threshold and/or motion-threshold waypoints. Each update() constitutes a waypoint, and waypoints may also be explicitly recorded via waypoint().

Copyright (C) 2008 Marsette A. Vona, III

Author:

Marsette A. Vona, III

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	cvsid
static double	DEF_MOTION_THRESHOLD default motionThreshold
static double	DEF_TIME_THRESHOLD default timeThreshold
protected boolean	forceWaypointPending whether a forced waypoint has been requested
protected double	motionThreshold see getMotionThreshold()
protected double	timeThreshold see getTimeThreshold()
protected vona.math.RX[]	waypointRX snapshot of TrajectoryActor.xform at most recent waypoint
protected double	waypointTime TrajectoryActor.clock timestamp of last update() since activation or NaN if none.

Fields inherited from class msim.trajectory.TrajectoryActor

active, clock, joint, slackID, wasOnlySetChangedGoalComponents, xform, xformID

Constructor Summary

Constructors

Constructor and Description
TrajectoryObserver() Makes a new trajectory observer using a default Clock (wall-clock time), DEF_TIME_THRESHOLD, and DEF_MOTION_THRESHOLD.
TrajectoryObserver(double motionThreshold) Makes a new trajectory observer using a default Clock (wall-clock time) and DEF_TIME_THRESHOLD.
TrajectoryObserver(double motionThreshold, double timeThreshold) Makes a new trajectory observer using a default Clock (wall-clock time).
TrajectoryObserver(double motionThreshold, double timeThreshold, vona.time.Clock clock) makes a new trajectory observer

Method Summary

Methods

Modifier and Type	Method and Description
void	activate() extends superclass impl to un-set waypointTime
int	bind(java.lang.Object... specs) Fill the set of transforms which this TrajectoryActor reads/writes, in order.
protected boolean	compareXFormsToWaypoint() Compare waypointRX with TrajectoryActor.xform.
void	forceWaypoint() force generation of at least one waypoint
double	getMotionThreshold() Get the maximum TXEM component diff for compareXFormsToWaypoint() or NaN to disable motion-threshold waypoints.
double	getTimeThreshold() Get the maximum time in TrajectoryActor.clock time between calls to needsUpdate() which return true, or NaN to disable time-threshold waypoints.
boolean	needsUpdate() Called by the update thread when this TrajectoryActor is active to check whether TrajectoryActor.update() needs to be called soon.
void	setMotionThreshold(double threshold) Set motionThreshold.
void	setTimeThreshold(double threshold) Set timeThreshold.
void	unbind() Clear the set of transforms which this TrajectoryActor reads/writes.
void	update() Read/write transform state from/to model.
void	waypoint() Saves a new waypoint.
protected abstract void	waypointChanged() Hook called when a new waypoint is generated in update().

Methods inherited from class msim.trajectory.TrajectoryActor

checkBindings, clampXForms, compareXFormsToModel, deactivate, getBoundJoint, getBoundXForm, getConstrainedInterpolationType, getDefaultXForm, getNumBindings, getOriginalUnsetGoal, getUnconstrainedInterpolationType, isActive, modelStateChanged, modelStructureChanged, onlySetChangedGoalComponents, readXFormsFromModel, writeXFormsToModel

Methods inherited from class java.lang.Object

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

Field Detail

cvsid

private static final java.lang.String cvsid

See Also:

Constant Field Values

DEF_TIME_THRESHOLD

public static final double DEF_TIME_THRESHOLD

default timeThreshold

See Also:

Constant Field Values

DEF_MOTION_THRESHOLD

public static final double DEF_MOTION_THRESHOLD

default motionThreshold

See Also:

Constant Field Values

timeThreshold

protected volatile double timeThreshold

see getTimeThreshold()

motionThreshold

protected volatile double motionThreshold

see getMotionThreshold()

forceWaypointPending

protected volatile boolean forceWaypointPending

whether a forced waypoint has been requested

waypointRX

protected vona.math.RX[] waypointRX

snapshot of TrajectoryActor.xform at most recent waypoint

waypointTime

protected double waypointTime

TrajectoryActor.clock timestamp of last update() since activation or NaN if none.

Constructor Detail

TrajectoryObserver

public TrajectoryObserver(double motionThreshold,
                  double timeThreshold,
                  vona.time.Clock clock)

makes a new trajectory observer

TrajectoryObserver

public TrajectoryObserver(double motionThreshold,
                  double timeThreshold)

Makes a new trajectory observer using a default Clock (wall-clock time).

TrajectoryObserver

public TrajectoryObserver(double motionThreshold)

Makes a new trajectory observer using a default Clock (wall-clock time) and DEF_TIME_THRESHOLD.

TrajectoryObserver

public TrajectoryObserver()

Makes a new trajectory observer using a default Clock (wall-clock time), DEF_TIME_THRESHOLD, and DEF_MOTION_THRESHOLD.

Method Detail

activate

public void activate()

extends superclass impl to un-set waypointTime

Overrides:

activate in class TrajectoryActor

bind

public int bind(java.lang.Object... specs)

Fill the set of transforms which this TrajectoryActor reads/writes, in order.

This impl extends superclass impl to allocate waypointRX.

Overrides:

bind in class TrajectoryActor

Parameters:

specs - a set of Joint sub-transform specifiers, in order, each of the the form (joint, name, or path, sub-transform ID...). If no sub-transform IDs are given then TrajectoryActor.getDefaultXForm() is implied. If more than one sub-transform ID is given then more than one binding is specified.

Returns:

the number of transforms bound

unbind

public void unbind()

Clear the set of transforms which this TrajectoryActor reads/writes.

This impl extends superclass impl to deallocate waypointRX.

Overrides:

unbind in class TrajectoryActor

update

public void update()

Read/write transform state from/to model.

This is called automatically by the update thread whenever this TrajectoryActor is active. See class header doc for details.

This impl chains to waypoint().

Specified by:

update in class TrajectoryActor

waypoint

public void waypoint()

Saves a new waypoint.

Sets waypointTime, does TrajectoryActor.readXFormsFromModel(), copies result to waypointRX and then calls waypointChanged().

waypointChanged

protected abstract void waypointChanged()

Hook called when a new waypoint is generated in update().

needsUpdate

public boolean needsUpdate()

Called by the update thread when this TrajectoryActor is active to check whether TrajectoryActor.update() needs to be called soon.

This impl returns true if

• forceWaypointPending
• there has been no update(), and hence no new waypoint, since the most recent activation
• getTimeThreshold() is not NaN and it has been at least this long since the last update in this activation
• compareXFormsToWaypoint() returns false after a fresh TrajectoryActor.readXFormsFromModel()

Specified by:

needsUpdate in class TrajectoryActor

compareXFormsToWaypoint

protected boolean compareXFormsToWaypoint()

Compare waypointRX with TrajectoryActor.xform.

Returns:

true if getMotionThreshold() is NaN or if all TXEM component diffs are smaller

getTimeThreshold

public double getTimeThreshold()

Get the maximum time in TrajectoryActor.clock time between calls to needsUpdate() which return true, or NaN to disable time-threshold waypoints.

Default impl returns timeThreshold.

setTimeThreshold

public void setTimeThreshold(double threshold)

Set timeThreshold.

Throws:

java.lang.IllegalArgumentException - if threshold is negative

getMotionThreshold

public double getMotionThreshold()

Get the maximum TXEM component diff for compareXFormsToWaypoint() or NaN to disable motion-threshold waypoints.

Default impl returns motionThreshold.

setMotionThreshold

public void setMotionThreshold(double threshold)

Set motionThreshold.

Throws:

java.lang.IllegalArgumentException - if threshold is negative

forceWaypoint

public void forceWaypoint()

force generation of at least one waypoint