Iam getting an error that I cant fix...
java.lang.NullPointerException
at PongWorld.updateScore(PongWorld.java:49)
at Ball.ballMove(Ball.java:54)
at Ball.act(Ball.java:39)
at greenfoot.core.Simulation.actActor(Simulation.java:507)
at greenfoot.core.Simulation.runOneLoop(Simulation.java:470)
at greenfoot.core.Simulation.runContent(Simulation.java:204)
at greenfoot.core.Simulation.run(Simulation.java:194)
...... I have this in the world...
public PongWorld()
{
// Create a new world with 700x500 cells with a cell size of 1x1 pixels.
super(700, 500, 1);
p1 = new Paddle("a", "s", "John"); // added arguments key control // step 1 and 2
addObject(p1, 350, 30);
p2 = new Paddle("left", "right", "Joe");
addObject(p2, 350, 470);
ball = new Ball();
addObject(ball, 350, 250);
Label Txt1= new Label(p1.getName()+ ": " + p1.getScore() ); // add text to world + score count
addObject(Txt1, 72, 59);
Label Txt2 = new Label(p2.getName()+ ": " + p2.getScore() ); // get name and score from paddle getter and setter method
addObject(Txt2, 72, 453);
}
/**
* update paddle scores from paddle methods (getter / setter) getScore setScore
*/
public void updateScore(Ball ball)
{
if (ball.getY() == 0) // noth paddle score
{
p2.setScore(p2.getScore() +1); // updateScore (getScore add 1)
Txt2.setText(p2.getName() + ": " + p2.getScore());
}
if (ball.getY() == 500-1) // south paddle score lagest y is 499(500-1) world 0-499 on Y
{
p1.setScore(p1.getScore() +1);
Txt1.setText(p1.getName() + ": " + p1.getScore());
}
.... this in my ball
public void ballMove() // NEW MOVE METHOD for setting the ball in center of screen
{
if (getY() == 0 || getY() == 500-1)
{
((PongWorld)getWorld()).updateScore(this);
setLocation( 350, 250 ); // ball set or reset
wait = 80; // added wait for reset ball position
ySpeed = Greenfoot.getRandomNumber(3)+1;
if (Greenfoot.getRandomNumber(2)==0) // Y up or down 50/50 chance (0-1) if 0 do this
{
ySpeed = ySpeed *(-1); // chance to be negative or positive
}
xSpeed = Greenfoot.getRandomNumber(3)+1;
if (Greenfoot.getRandomNumber(2)==0) // X right or left 50/50 chance
{
xSpeed = xSpeed *(-1);
}
}
else
{
setLocation(getX() +xSpeed,getY() +ySpeed); //movement and speed
bounceOffPaddle(); // new call for bounceOffPaddle
}
... can anyone help me?
