package greenfoot.collision.ibsp;

import greenfoot.Actor;




| An ActorNode represents a piece (or whole) of an Actor within the IBSP collision
| checking tree. Because an actor can be split over several tree nodes, it may be
| represented by several ActorNodes, which are linked together in a linked list.
|
| @author Davin McCall
|
public final class ActorNode
{       
private Actor actor;
   
   private BSPNode node;
   
   private ActorNode next;
   
   private ActorNode prev;
   
   private boolean mark;
    
   
   public ActorNode(Actor actor, BSPNode node)
   {        
      this.actor = actor;
       
      this.node = node;
        
       
      
      ActorNode first = IBSPColChecker.getNodeForActor(actor);
       
      this.next = first;
      IBSPColChecker.setNodeForActor(actor, this);
      if (next != null) {            
         next.prev = this;         
         }
        
       
      mark = true;     
      }
    
   
   


| Clar the mark on this ActorNode. This is used by the collision
| checker when actors reposition or resize.
|
public void clearMark()
   {        
      mark = false;     
      }
    
   
   


| Mark this ActorNode. This is used by the collision checker when
| actors reposition or resize.
|
public void mark()
   {        
      mark = true;     
      }
    
   
   


| Check, and clear, the mark on this ActorNode. This is used by the
| collision checker when actors reposition or resize. Returns the
| mark value before it was cleared.
|
public boolean checkMark()
   {        
      boolean markVal = mark;
       
      mark = false;
       
      return markVal;     
      }
    
   
   public Actor getActor()
   {        
      return actor;     
      }
    
   
   public BSPNode getBSPNode()
   {        
      return node;     
      }
    
   
   


| Get the next ActorNode for the same actor. Returns null if this
| is the last ActorNode for the actor.
|
public ActorNode getNext()
   {        
      return next;     
      }
    
   
   


| Remove this actor node. The node is removed from both the BSPNode
| which contains it, and the linked list of actor nodes for the actor.
| The next() call will still be valid, unless the next actor is also
| removed.
|
public void remove()
   {
      removed();
      node.actorRemoved(actor);     
      }
    
   
   


| Notify this actor node that it has been removed from the BSPNode.
| It must remove itself from the linked list of actor nodes for the
| actor.
|
public void removed()
   {
      if (prev == null) {
         IBSPColChecker.setNodeForActor(actor, next);         
         }
       

      else {
           
      prev.next = next;         
      }
        
   if (next != null) {            
      next.prev = prev;         
      }     
   } 
}