src/appletbots/balls/Kicker.java

   1 /*
   2  * Copyright (c) 2002 Erik Rasmussen - All Rights Reserverd
   3  */
   4 package appletbots.balls;
   5
   6 import appletbots.Agent;
   7 import appletbots.WorldObject;
   8 import appletbots.geometry.Vector;
   9
  10 import java.awt.*;
  11 import java.util.ArrayList;
  12 import java.util.Collection;
  13 import java.util.Iterator;
  14 import java.util.List;
  15
  16 /**
  17  * A kicker agent chooses a visible ball at random and accelerates towards it.
  18  * If no ball is visible the agent sets his acceleration to zero.
  19  *
  20  * @author Erik Rasmussen
  21  */
  22 public class Kicker extends Agent
  23 {
  24         /**
  25          * Constructs a new Kicker with the given parameters
  26          *
  27          * @param size            The agent's radius
  28          * @param sight           The distance the agent can see
  29          * @param maxSpeed        The maximum speed the agent can travel
  30          * @param maxAcceleration The maximum acceleration for this agent
  31          */
  32         public Kicker(final int size, final int sight, final double maxSpeed, final double maxAcceleration)
  33         {
  34                 super(size, sight, maxSpeed, maxAcceleration);
  35                 this.color = Color.cyan;
  36         }
  37
  38         /**
  39          * Observes the world, and follows the Kicker Algorithm.
  40          */
  41         public void observeWorld()
  42         {
  43                 final Ball ball = chooseBall();
  44                 if (ball != null)
  45                 {
  46                         setAcceleration(world.getVectorToObject(this, ball));
  47                 }
  48                 else
  49                 {
  50                         // continue in straight path until we find a ball to kick
  51                         accelerationVectorColor = null;
  52                         setAcceleration(new Vector(0, 0));
  53                 }
  54         }
  55
  56         /**
  57          * Selects a ball at random from those visible
  58          *
  59          * @return The chosen ball
  60          */
  61         protected Ball chooseBall()
  62         {
  63                 final Collection seenObjects = world.getSeenObjects(this);
  64                 final List balls = new ArrayList();
  65                 for (Iterator iterator = seenObjects.iterator(); iterator.hasNext();)
  66                 {
  67                         final WorldObject object = (WorldObject) iterator.next();
  68                         if (object instanceof Ball)
  69                                 balls.add(object);
  70                 }
  71                 if (!balls.isEmpty())
  72                         return (Ball) balls.get((int) Math.floor(Math.random() * balls.size()));
  73                 else
  74                         return null;
  75         }
  76 }