[adam405]

thanks, works well. I am trying to add in a brick to hit. I am again struggling with the logic. The problem is that the brick sometime disappears even though the ball i no where near brick. This happens if i just let the game run with no keyboard interaction at the start

Code:

//  <applet code="FullBallRx" width="400" height="400"></applet>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;

public class FullBall extends Applet implements Runnable {
   
    //position of the ball
    int x_pos = 12;
    int y_pos = 12;
    
    //position of the ball ** slider **
    int sliderx_pos = 50;
    int slidery_pos = 150;
    
    //ball size
    int radius = 5;
    
    //size of slider
    int swidth = 60;
    int sheight = 1;
    Rectangle box = new Rectangle(swidth, sheight);
   
    //balldirection
    int x_speed = 6;
    int y_speed = 8;
    
    //slider direcion
    int sliderx_speed = 0;
    
    //applet size
    int appletsize_top = getHeight();
    int appletsize_bottom = appletsize_top + 20 * 10;  
    int appletsize_left = getWidth(); 
    int appletsize_right = appletsize_left + 35 * 10; 
   
    //random movement
    Random rnd = new Random ();
    
    //Drawing image off screen
    private Image dbImage;
    private Graphics dbg;

    Thread thread;
    boolean running = false;
    
    //level stuff
    
    int lx_pos = 100;
    int ly_pos = appletsize_top +20;
    int lwidth = 50;
    int lheight =1;
    Rectangle brick = new Rectangle(lwidth, lheight);
    

    


    public void init()
    {
        enableEvents(AWTEvent.KEY_EVENT_MASK);
        setFocusable(true);
        
    }
  
    public void start ()
    {
        // define a new thread 
        running = true;
        thread = new Thread (this);
        // start this thread
        thread.start ();
        System.out.println("start");
    }

    public void stop()
    {
        running = false;
        if(thread != null)
            thread.interrupt();
        thread = null;
        System.out.println("stop");
    }

    public void run () 
    {
        while (running)
        {
           
          //change direct if the ball hits the left or right wall
          // stop ball if out
             if (x_pos - radius + x_speed < appletsize_left ||
                 x_pos + radius + x_speed > appletsize_right )
	    {
                x_speed *= -1;
            }

            if (y_pos - radius + y_speed < appletsize_top)
	    {
                y_speed *= -1;
            }
            
            if(y_pos + radius + y_speed > appletsize_bottom )
            {
               stop();
            }
             
          

         //what to do if we hit the slider
            
             if(x_pos + radius   > sliderx_pos &&
               x_pos - radius   < sliderx_pos + swidth) {
                // Ball is in vertical plane of slider.
                // Check for possible horizontal contact.
                if(y_pos + radius + y_speed > slidery_pos) {
                    // We have an imminent collision -> bounce!
                    y_speed *= -1;
                }
            }
             
             //what to do if we hit a brick
             
              else if(x_pos - radius   > lx_pos &&
                   x_pos + radius   < lx_pos + lwidth) {
                    // Ball is in vertical plane of slider.
                    // Check for possible horizontal contact.
                    if(y_pos - radius - y_speed > ly_pos) {
                        // We have an imminent collision -> bounce!
                        y_speed *= -1;
                        lx_pos = 10000;
                        ly_pos = 10000;
                    }
                }
            
             
            

            x_pos += x_speed;
            y_pos += y_speed;

            //repaint applet
            repaint();

            try
            {
                // Stop thread for the speed
                Thread.sleep (90);
            }
            catch (InterruptedException ex)
            {
                running = false;
                break;
            }

  
        }
    }

    //create an image off screen and loads it into the applet
    public void update (Graphics g)
    {
        // initialize buffer
        if (dbImage == null)
        {
            dbImage = createImage (this.getSize().width, this.getSize().height);
            dbg = dbImage.getGraphics ();
        }

        // clear screen in background
        dbg.setColor (getBackground ());
        dbg.fillRect (0, 0, this.getSize().width, this.getSize().height);

        // draw elements in background
        dbg.setColor (getForeground());
        paint (dbg);

        // draw image on the screen
        g.drawImage (dbImage, 0, 0, this);
    }

   
    public void paint (Graphics g) 
    { 
        //DRAWING THE BALL
        Graphics2D g2 = (Graphics2D) g;
        g.setColor (Color.red);    
        g.fillOval (x_pos - radius, y_pos - radius, 2 * radius, 2 * radius);
        
        //DRAWING THE SLIDER
        box.setLocation(sliderx_pos, slidery_pos);
        g2.setColor (Color.blue);
        g2.draw(box);
        
        //DRAWING THE BRICKS
        brick.setLocation(lx_pos, ly_pos);
        g2.setColor (Color.pink);
        g2.draw(brick);
    
    }

    protected void processKeyEvent(KeyEvent e)
    {
        int keyCode = e.getKeyCode();
    //move if left key is pressed
        if (keyCode == KeyEvent.VK_LEFT)
        {
           
            if (sliderx_pos -10 > appletsize_left)
                sliderx_pos = sliderx_pos -20;
        }
        //move if right key is pressed
        else if (keyCode == KeyEvent.VK_RIGHT)
        {
            if (sliderx_pos + swidth +10 < appletsize_right)
                sliderx_pos = sliderx_pos +20;
        }
    } 
}