Dot.java

public class Dot
{
  private static final int MAXDX=2;
  private static final int MAXDY=2;
  private double x;
  private double y;
  private double dx;
  private double dy;

  public Dot()
  {
    x=0.0;
    y=0.0;
    dx=0.0;
    dy=0.0;
  }

  public int getX() { return (int)(x+0.5); }
  public int getY() { return (int)(y+0.5); }

  /**
   * TODO: Randomize somewhat.
   */
  public void updateDot(int targetX, int targetY) {
    //    System.out.print("Was: "+x+","+y);
    dx += (targetX-x)*0.1;
    if(Math.abs(dx)>MAXDX) {
      dx = Math.abs(dx)/dx*MAXDX;
    }
    dx += Math.random()*4-2;
    dy += (targetY-y)*0.1;
    if(Math.abs(dy)>MAXDY) {
      dy = Math.abs(dy)/dy*MAXDY;
    }
    dy += Math.random()*4-2;
    x += dx;
    y += dy;
    //    System.out.println("  is: "+x+","+y);
  }
}