package greenfoot.collision;

import greenfoot.Actor;
import greenfoot.ActorVisitor;




| Checks collisions between GreenfooObjects.
|
| @author Poul Henriksen
|
public class GOCollisionQuery
implements CollisionQuery{    
   private Class<?> cls;
   
   private Actor compareObject;

   
   


| Initialise.
|
| @param cls   If not null, the compared object must be of this class. If null, the compared
|              object's class is not considered.
| @param actor Object to compare against other objects.
|
public void init(Class<?> cls, Actor actor)
   {        
      this.cls = cls;
       
      this.compareObject = actor;     
      }        
    
   
   


| Checks if the other object collides with this object and if it is of the given class.
|
public boolean checkCollision(Actor other)
   {   
      if (cls != null && !cls.isInstance(other)) {            
         return false;         
         }
        
      if (compareObject == null) {            
         return true;         
         }

      else if (ActorVisitor.intersects(compareObject, other)) {            
         return true;         
         } 
       
      return false;     
      }      
   }