WakeupOnBehaviorPost

[esvxm]

Hi!

Can any one explain how WakeupOnBehavior works, a code snippet would be very helpful and would be ok to use it for a character animation to synchronise the movements of varioius limbs

Thanks

[rdcarvallo]

In a game project, I used Behavior posts to comunicate the Movement Behavior (wakeuponAWTEvent) with the bullet Animation Behavior (wakeupOnEllapsedTime).
In my case, I called the constructor setting the Behavior to listen.
When the player press the fire/attack button the Movement Behavior posts an id indicating to the bullet animation Behavior to start its animation/simulation.
When the bullet hits something the Animation Behavior post an id indicating wich object was hit.

Now the code:

class BulletAnim extends Behavior{
  ...
  private WakeupOr wor;
  private WakeupOnBehaviorPost waiting;
  public BulletAnim(...){
    ...
    WakeupCriterion[] criterio = new WakeupCriterion[2];
    criterio[0]= new WakeupOnElapsedTime(1000/60);
    criterio[1]=new WakeupOnCollisionEntry(sphere,WakeupOnCollisionEntry.USE_GEOMETRY);
    wor=new WakeupOr(criterio);
  }
  public void setPartner(Behavior b){
    //Here I set the movement Behavior as the source of the posts.
    //I will receive any id (id == 0).
    waiting = new WakeupOnBehaviorPost(b, 0);
  }
  public void initialize()
  {
    this.wakeupOn(waiting);
  }
  public void processStimulus(Enumeration criteria){
    boolean moving = false;
    while (criteria.hasMoreElements()) {
      WakeupCriterion wakeup = (WakeupCriterion) criteria.nextElement();
      if(wakeup instanceof WakeupOnBehaviorPost){
        //now it wakes up with the time or collision
        moving = true ;
      }
      else if(wakeup instanceof WakeupOnElapsedTime){
        //do the animation
        ...
        moving = true ;
      }
      else if(wakeup instanceof WakeupOnCollisionEntry){
        //get the object hit
        int objectId = ...  //Collision info.
        postId(objectId);  //send the signal to the movement behavior
        moving = false;
      }
    }
    if(moving)
      this.wakeupOn(wor);
    else
      this.wakeupOn(waiting);
  }
}

class TankMovement extends Behavior{
  ...
  private WakeupOnAWTEvent trigger;
  private WakeupOnBehaviorPost waiting;
  public TankMovement(...){
    ...
    trigger=new WakeupOnAWTEvent(KeyEvent.KEY_PRESSED);
  }
  public void setPartner(Behavior b){
    //Here I set the movement Behavior as the source of the posts.
    //I will receive any id (id == 0).
    waiting = new WakeupOnBehaviorPost(b, 0);
  }
  public void initialize()
  {
    this.wakeupOn(trigger);
  }
  public void processStimulus(Enumeration criteria){
    boolean moving = false;
    while (criteria.hasMoreElements()) {
      WakeupCriterion wakeup = (WakeupCriterion) criteria.nextElement();
      if(wakeup instanceof WakeupOnBehaviorPost){
        //now it wakes up returns to receive input
        moving = true ;
      }
      else if(wakeup instanceof WakeupOnAWTEvent){
        //receive and process the input
        ...
        if(shot!=0){
          postId(shot);  //send the signal
          moving = false ;
        }
      }
    }
    if(moving)
      this.wakeupOn(trigger);
    else
      this.wakeupOn(waiting);
  }
}

Then in the scene creation:

  ...
  BulletAnim anim = new BulletAnim(...);
  ...
  TankMovement tankMove= new TankMovement(...);
  ...
  //set the partners first
  anim.setPartner(tankMove);
  tankMove.setPartner(anim);
  ...
  //then add to the scenegraph
  bg1.addChild(anim);
  bg2.addChild(tankMove);
  ...

For the character animation, you can use the constructor without Behavior and send signals to all the behaviors, each will know when and how much to move.

Rafael