Wander (libGDX AI)

java.lang.Object
- com.badlogic.gdx.ai.steer.SteeringBehavior<T>
- - com.badlogic.gdx.ai.steer.behaviors.ReachOrientation<T>
  - - com.badlogic.gdx.ai.steer.behaviors.Face<T>
    - - com.badlogic.gdx.ai.steer.behaviors.Wander<T>

Type Parameters:

T - Type of vector, either 2D or 3D, implementing the Vector interface
```
public class Wander<T extends com.badlogic.gdx.math.Vector<T>>
extends Face<T>
```
Wander behavior is designed to produce a steering acceleration that will give the impression of a random walk through the agent's environment. You'll often find it a useful ingredient when creating an agent's behavior.
There is a circle in front of the owner (where front is determined by its current facing direction) on which the target is constrained. Each time the behavior is run, we move the target around the circle a little, by a random amount. Now there are 2 ways to implement wander behavior:
- The owner seeks the target, using the Seek behavior, and performs a LookWhereYouAreGoing behavior to correct its orientation.
- The owner tries to face the target in each frame, using the Face behavior to align to the target, and applies full linear acceleration in the direction of its current orientation.
In either case, the orientation of the owner is retained between calls (so smoothing the changes in orientation). The angles that the edges of the circle subtend to the owner determine how fast it will turn. If the target is on one of these extreme points, it will turn quickly. The target will twitch and jitter around the edge of the circle, but the owner's orientation will change smoothly.
This implementation uses the second approach. However, if you manually align owner's orientation to its linear velocity on each time step, Face behavior should not be used (which is the default case). On the other hand, if the owner has independent facing you should explicitly call setFaceEnabled(true) before using Wander behavior.
Note that this behavior internally calls the GdxAI.getTimepiece().getTime() method to get the current AI time and make the wanderRate FPS independent. This means that
- if you forget to update the timepiece the wander orientation won't change.
- ideally the timepiece should be always updated before this steering behavior runs.
This steering behavior can be used to produce a whole range of random motion, from very smooth undulating turns to wild Strictly Ballroom type whirls and pirouettes depending on the size of the circle, its distance from the agent, and the amount of random displacement each frame.

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`faceEnabled` The flag indicating whether to use `Face` behavior or not.
`protected float`	`lastTime` The last time the orientation of the wander target has been updated
`protected float`	`wanderOffset` The forward offset of the wander circle
`protected float`	`wanderOrientation` The current orientation of the wander target
`protected float`	`wanderRadius` The radius of the wander circle
`protected float`	`wanderRate` The rate, expressed in radian per second, at which the wander orientation can change

Fields inherited from class com.badlogic.gdx.ai.steer.behaviors.ReachOrientation
alignTolerance, decelerationRadius, target, timeToTarget

Fields inherited from class com.badlogic.gdx.ai.steer.SteeringBehavior
enabled, limiter, owner

Constructor Summary

Constructors
Constructor and Description

Wander(Steerable<T> owner)
Creates a Wander behavior for the specified owner.

Constructors
Constructor and Description
`Wander(Steerable<T> owner)` Creates a `Wander` behavior for the specified owner.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected SteeringAcceleration<T>`	`calculateRealSteering(SteeringAcceleration<T> steering)` Calculates the steering acceleration produced by this behavior and writes it to the given steering output.
`T`	`getInternalTargetPosition()` Returns the current position of the wander target.
`T`	`getWanderCenter()` Returns the current center of the wander circle.
`float`	`getWanderOffset()` Returns the forward offset of the wander circle.
`float`	`getWanderOrientation()` Returns the current orientation of the wander target.
`float`	`getWanderRadius()` Returns the radius of the wander circle.
`float`	`getWanderRate()` Returns the rate, expressed in radian per second, at which the wander orientation can change.
`boolean`	`isFaceEnabled()` Returns the flag indicating whether to use `Face` behavior or not.
`Wander<T>`	`setAlignTolerance(float alignTolerance)` Sets the tolerance for aligning to the target without letting small errors keep the owner swinging.
`Wander<T>`	`setDecelerationRadius(float decelerationRadius)` Sets the radius for beginning to slow down
`Wander<T>`	`setEnabled(boolean enabled)` Sets this steering behavior on/off.
`Wander<T>`	`setFaceEnabled(boolean faceEnabled)` Sets the flag indicating whether to use `Face` behavior or not.
`Wander<T>`	`setLimiter(Limiter limiter)` Sets the limiter of this steering behavior.
`Wander<T>`	`setOwner(Steerable<T> owner)` Sets the owner of this steering behavior.
`Wander<T>`	`setTarget(Location<T> target)` Sets the target to align to.
`Wander<T>`	`setTimeToTarget(float timeToTarget)` Sets the time over which to achieve target rotation speed
`Wander<T>`	`setWanderOffset(float wanderOffset)` Sets the forward offset of the wander circle.
`Wander<T>`	`setWanderOrientation(float wanderOrientation)` Sets the current orientation of the wander target.
`Wander<T>`	`setWanderRadius(float wanderRadius)` Sets the radius of the wander circle.
`Wander<T>`	`setWanderRate(float wanderRate)` Sets the rate, expressed in radian per second, at which the wander orientation can change.

Methods inherited from class com.badlogic.gdx.ai.steer.behaviors.Face
face

Methods inherited from class com.badlogic.gdx.ai.steer.behaviors.ReachOrientation
getAlignTolerance, getDecelerationRadius, getTarget, getTimeToTarget, reachOrientation

Methods inherited from class com.badlogic.gdx.ai.steer.SteeringBehavior
calculateSteering, getActualLimiter, getLimiter, getOwner, isEnabled, newVector

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - wanderOffset
```
protected float wanderOffset
```
    The forward offset of the wander circle
  - wanderRadius
```
protected float wanderRadius
```
    The radius of the wander circle
  - wanderRate
```
protected float wanderRate
```
    The rate, expressed in radian per second, at which the wander orientation can change
  - lastTime
```
protected float lastTime
```
    The last time the orientation of the wander target has been updated
  - wanderOrientation
```
protected float wanderOrientation
```
    The current orientation of the wander target
  - faceEnabled
```
protected boolean faceEnabled
```
    The flag indicating whether to use Face behavior or not. This should be set to true when independent facing is used.
- Constructor Detail
  - Wander
```
public Wander(Steerable<T> owner)
```
    Creates a Wander behavior for the specified owner.
    
    Parameters:
    
    owner - the owner of this behavior.
- Method Detail
  - calculateRealSteering
```
protected SteeringAcceleration<T> calculateRealSteering(SteeringAcceleration<T> steering)
```
    Description copied from class: SteeringBehavior
    
    Calculates the steering acceleration produced by this behavior and writes it to the given steering output.
    This method is called by SteeringBehavior.calculateSteering(SteeringAcceleration) when this steering behavior is enabled.
    
    Overrides:
    
    calculateRealSteering in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Parameters:
    
    steering - the steering acceleration to be calculated.
    
    Returns:
    
    the calculated steering acceleration for chaining.
  - getWanderOffset
```
public float getWanderOffset()
```
    Returns the forward offset of the wander circle.
  - setWanderOffset
```
public Wander<T> setWanderOffset(float wanderOffset)
```
    Sets the forward offset of the wander circle.
    
    Returns:
    
    this behavior for chaining.
  - getWanderRadius
```
public float getWanderRadius()
```
    Returns the radius of the wander circle.
  - setWanderRadius
```
public Wander<T> setWanderRadius(float wanderRadius)
```
    Sets the radius of the wander circle.
    
    Returns:
    
    this behavior for chaining.
  - getWanderRate
```
public float getWanderRate()
```
    Returns the rate, expressed in radian per second, at which the wander orientation can change.
  - setWanderRate
```
public Wander<T> setWanderRate(float wanderRate)
```
    Sets the rate, expressed in radian per second, at which the wander orientation can change.
    
    Returns:
    
    this behavior for chaining.
  - getWanderOrientation
```
public float getWanderOrientation()
```
    Returns the current orientation of the wander target.
  - setWanderOrientation
```
public Wander<T> setWanderOrientation(float wanderOrientation)
```
    Sets the current orientation of the wander target.
    
    Returns:
    
    this behavior for chaining.
  - isFaceEnabled
```
public boolean isFaceEnabled()
```
    Returns the flag indicating whether to use Face behavior or not.
  - setFaceEnabled
```
public Wander<T> setFaceEnabled(boolean faceEnabled)
```
    Sets the flag indicating whether to use Face behavior or not. This should be set to true when independent facing is used.
    
    Returns:
    
    this behavior for chaining.
  - getInternalTargetPosition
```
public T getInternalTargetPosition()
```
    Returns the current position of the wander target. This method is useful for debug purpose.
  - getWanderCenter
```
public T getWanderCenter()
```
    Returns the current center of the wander circle. This method is useful for debug purpose.
  - setOwner
```
public Wander<T> setOwner(Steerable<T> owner)
```
    Description copied from class: SteeringBehavior
    
    Sets the owner of this steering behavior.
    
    Overrides:
    
    setOwner in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.
  - setEnabled
```
public Wander<T> setEnabled(boolean enabled)
```
    Description copied from class: SteeringBehavior
    
    Sets this steering behavior on/off.
    
    Overrides:
    
    setEnabled in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.
  - setLimiter
```
public Wander<T> setLimiter(Limiter limiter)
```
    Sets the limiter of this steering behavior. The given limiter must at least take care of the maximum linear acceleration; additionally, if the flag faceEnabled is true, it must take care of the maximum angular speed and acceleration.
    
    Overrides:
    
    setLimiter in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.
  - setTarget
```
public Wander<T> setTarget(Location<T> target)
```
    Sets the target to align to. Notice that this method is inherited from ReachOrientation, but is completely useless for Wander because owner's orientation is determined by the internal target, which is moving on the wander circle.
    
    Overrides:
    
    setTarget in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.
  - setAlignTolerance
```
public Wander<T> setAlignTolerance(float alignTolerance)
```
    Description copied from class: ReachOrientation
    
    Sets the tolerance for aligning to the target without letting small errors keep the owner swinging.
    
    Overrides:
    
    setAlignTolerance in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.
  - setDecelerationRadius
```
public Wander<T> setDecelerationRadius(float decelerationRadius)
```
    Description copied from class: ReachOrientation
    
    Sets the radius for beginning to slow down
    
    Overrides:
    
    setDecelerationRadius in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.
  - setTimeToTarget
```
public Wander<T> setTimeToTarget(float timeToTarget)
```
    Description copied from class: ReachOrientation
    
    Sets the time over which to achieve target rotation speed
    
    Overrides:
    
    setTimeToTarget in class Face<T extends com.badlogic.gdx.math.Vector<T>>
    
    Returns:
    
    this behavior for chaining.

Class Wander<T extends com.badlogic.gdx.math.Vector<T>>

Field Summary

Fields inherited from class com.badlogic.gdx.ai.steer.behaviors.ReachOrientation

Fields inherited from class com.badlogic.gdx.ai.steer.SteeringBehavior

Constructor Summary

Method Summary

Methods inherited from class com.badlogic.gdx.ai.steer.behaviors.Face

Methods inherited from class com.badlogic.gdx.ai.steer.behaviors.ReachOrientation

Methods inherited from class com.badlogic.gdx.ai.steer.SteeringBehavior

Methods inherited from class java.lang.Object

Field Detail

wanderOffset

wanderRadius

wanderRate

lastTime

wanderOrientation

faceEnabled

Constructor Detail

Wander

Method Detail

calculateRealSteering

getWanderOffset

setWanderOffset

getWanderRadius

setWanderRadius

getWanderRate

setWanderRate

getWanderOrientation

setWanderOrientation

isFaceEnabled

setFaceEnabled

getInternalTargetPosition

getWanderCenter

setOwner

setEnabled

setLimiter

setTarget

setAlignTolerance

setDecelerationRadius

setTimeToTarget