Ping Pong Game

by Amit Rawat · Published September 12, 2017 · Updated May 28, 2019

Ping Pong is a game which is similar to the game Table Tennis. It is a two-player game. Like in the previous BreakOut game, In this also the players have to prevent the ball to escape through their side. And the points will be given to the respective player. And the best of the three sets will win the game.

Explaining the code:-

Let's create a new project in Eclipse IDE named PingPong. In this, I have made two classes, one class is the main class where the frame is shown and another class has two inner classes which control scoreboard and another gamepanel. Now let's see these classes one by one.

Firstly, let's see the MainPanel class. In this class, we have two inner classes ScoreBoard class which control the score of the game and another class is GamePanel class which controls the game.

Let's see the ScoreBoard class. In this class, we have different variables to collect the points by each player and also score of each set. And also graphics are used to print these scores and the title of the game Ping Pong.

public class ScorePanel extends JPanel {
  
  int scorepanelwidth=1280,scorepanelheight=220;
  int player1score=0, player2score=0;
  int aset[] = new int[3];
  int bset[] = new int[3];
  
  int awon=0,bwon=0;
  
  public ScorePanel(){
    
    this.setPreferredSize(new Dimension(scorepanelwidth,scorepanelheight));
    this.setBorder(BorderFactory.createLineBorder(Color.cyan));
    this.setBackground(Color.BLUE);
    
  }
  
  public void paintComponent(Graphics g){
    super.paintComponent(g);
    g.setColor(Color.WHITE);
    g.setFont(new Font("Times New Roman",Font.PLAIN,48));
    g.drawString("PING - PONG", scorepanelwidth/2- 120, scorepanelheight/2-50);
    
    g.setColor(Color.WHITE);
    g.setFont(new Font("Times New Roman",Font.PLAIN,36));
    g.drawString("Player 1", 50, 120);
    
    g.drawString("Player 2", scorepanelwidth-170, 120);
    
    g.setColor(Color.green);
    g.fill3DRect(75, 150, 60, 50,true);
    g.fill3DRect(scorepanelwidth-80-60, 150, 60, 50,true);
    
    g.setColor(Color.WHITE);
    g.drawRect(75, 150, 60, 50);
    g.drawRect(scorepanelwidth-80-60, 150, 60, 50);
    
    g.setColor(Color.WHITE);
    g.drawString(Integer.toString(player1score), 90, 185);
    g.drawString(Integer.toString(player2score), scorepanelwidth-80-45, 185);
    
    g.setColor(Color.white);
    g.setFont(new Font("Times New Roman",Font.PLAIN,30));
    g.drawString("Player 1", scorepanelwidth/2-220, 115);
    
    g.drawString("Player 2", scorepanelwidth/2-220, 175);
    
    for(int i=1;i <= 3;i++){
      g.setColor(Color.GREEN);
      g.fill3DRect(scorepanelwidth/2-170+70*i, 80, 70, 60,true);
      g.fill3DRect(scorepanelwidth/2-170+70*i, 140, 70, 60,true);
      g.setColor(Color.white);
      g.draw3DRect(scorepanelwidth/2-170+70*i, 80, 70, 60,true);
      g.draw3DRect(scorepanelwidth/2-170+70*i, 140, 70, 60,true);
    }
    
    for(int i=1;i <= 3;i++){
      g.setColor(Color.white);
      g.setFont(new Font("Times new roman",Font.PLAIN,46));
      g.drawString(Integer.toString(aset[i-1]), scorepanelwidth/2-170+70*i+15, 125);
      g.drawString(Integer.toString(bset[i-1]), scorepanelwidth/2-170+70*i+15, 185);
      
    }
    
    g.setColor(Color.GREEN);
    g.fill3DRect(scorepanelwidth/2-190+80*4, 80, 70, 60,true);
    g.fill3DRect(scorepanelwidth/2-190+80*4, 140, 70, 60,true);
    g.setColor(Color.white);
    g.draw3DRect(scorepanelwidth/2-190+80*4, 80, 70, 60,true);
    g.draw3DRect(scorepanelwidth/2-190+80*4, 140, 70, 60,true);
    
    g.setColor(Color.white);
    g.setFont(new Font("Times new roman",Font.PLAIN,46));
    g.drawString(Integer.toString(awon), scorepanelwidth/2-190+70*4+55, 125);
    g.drawString(Integer.toString(bwon), scorepanelwidth/2-190+70*4+55, 185);
    
  }
  
  
}

Now, we have GamePanel class where the game is played.

Let's see what all variables are declared here.

int screenwidth=1280,screenheight=720;

int batwidth=10,batheight=140;
int batax=20,batay= screenheight/2 - batheight/2;
int batavel=0;

int batbx=screenwidth-30,batby=screenheight/2 - batheight/2;
int batbvel=0;

int ballrad=30;
int ballx=screenwidth/2-ballrad/2,bally=screenheight/2-ballrad/2;
int ballxvel=2,ballyvel=2;

int set=0;

boolean gamestart=false;
boolean winner=false;

String winningplayer;

boolean acollide=false;
boolean bcollide=false;


Timer t;

These variables give their purpose from their names.

Now, Let's see the constructor of this class. Which is mainly used for initializing the game variables.

public GamePanel(){
  t= new Timer(1,this);
  this.setPreferredSize(new Dimension(screenwidth,screenheight));
  this.setBorder(BorderFactory.createLineBorder(Color.black));
  this.setBackground(Color.CYAN);
  this.addKeyListener(this);
  setFocusable(true);
  this.setFocusTraversalKeysEnabled(false);
  t.start();
  
}

Now, let's discuss the actionPerformed() method which is executed every single microsecond. Here we update the position of ball and bat and also here check the collision ball with the walls and bat. And at the end, we call the repaint function to update the game panel and also scoreboard.

public void actionPerformed(ActionEvent arg0) {
  if(gamestart){
    ballx += ballxvel;
    bally += ballyvel;
  }
    batay += batavel;
    batby += batbvel;
    
    
    if(batay<0 || batay+batheight>screenheight){
      batavel=0;
    }
    if(batby<0 || batby+batheight>screenheight){
      batbvel=0;
    }
  
    
    
    if(bally < 0 || bally+ballrad > screenheight){
      ballyvel = -ballyvel;
    }
    if(ballx < 0 ){
      s.player2score++;
      ballx=screenwidth/2-ballrad/2;
      bally=screenheight/2-ballrad/2;
      
      
      try {
        Thread.sleep(1000);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
    if(ballx+ballrad > screenwidth){
      s.player1score++;
      ballx=screenwidth/2-ballrad/2;
      bally=screenheight/2-ballrad/2;
      
      
      try {
        Thread.sleep(1000);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
      
    }
    
    if(s.player1score == 10 && s.player2score == 10){
        s.player1score=7;
        s.player2score=7;
    }
    
    if(s.player1score == 11){
      s.aset[set]=s.player1score;
      s.bset[set]=s.player2score;
      s.awon++;
      s.player1score=0;
      s.player2score=0;
      set++;
    }
    
    if(s.player2score == 11){
      
        s.aset[set]=s.player1score;
        s.bset[set]=s.player2score;
        s.bwon++;
        s.player1score=0;
        s.player2score=0;
        set++;
    }
    
    
    if(set==3){
      winner=true;
      if(s.awon > s.bwon){
        winningplayer="Player 1";
      }else{
        winningplayer="Player 2";
      }
    }
    
    Rectangle bata = new Rectangle(batax,batay,batwidth,batheight);
    Rectangle batb = new Rectangle(batbx,batby,batwidth,batheight);
    Rectangle ball = new Rectangle(ballx,bally,ballrad,ballrad);
    
    if(!acollide){
    if(bata.intersects(ball)){
      ballxvel = -ballxvel;
      acollide = true;
    }
    }
    
    if(!bcollide){
    if(batb.intersects(ball)){
      ballxvel = -ballxvel;
      bcollide=true;
    }
    }
    
    if(acollide){
      if(!ball.intersects(bata)){
        acollide=false;
      }
    }
    
    if(bcollide){
      if(!ball.intersects(batb)){
        bcollide=false;
      }
    }
    
  repaint();
  s.repaint();
  
}

Now, let's see the paintComponent() method, which is used to draw the ball and bat on the game panel and also some messages.

public void paintComponent(Graphics g){
  super.paintComponent(g);
  
  g.setColor(Color.orange);
  g.fill3DRect(batax, batay, batwidth, batheight,true);
  
  g.fill3DRect(batbx, batby, batwidth, batheight,true);
  
  g.setColor(Color.blue);
  g.fillOval(ballx, bally, ballrad, ballrad);
  
  if(!gamestart){
    drawStartGame(g);
  }
  
  if(winner){
    drawWinner(g);
    t.stop();
  }
}

In this method, there are methods which are used to draw something on the screen. Let's see their definition.

public void drawWinner(Graphics g){
  g.setColor(Color.green);
  g.setFont(new Font("Times new roman",Font.ITALIC,42));
  g.drawString(winningplayer +" won by " + Integer.toString(s.awon) + " - " + Integer.toString(s.bwon), screenwidth/2-200, screenheight/2 - 100);
  g.setColor(Color.ORANGE);
  g.drawString("Press [ESC] to exit the game", screenwidth/2-280, screenheight/2 - 50);
  g.drawString("Press [R] to restart the game", screenwidth/2-280, screenheight/2 - 10);
}

public void drawStartGame(Graphics g){
  g.setColor(Color.orange);
  g.setFont(new Font("Times new roman",Font.ITALIC,42));
  g.drawString("Press [SPACE] to start the game", screenwidth/2-280, screenheight/2 - 100);
  
}

Now, Let's see a method which is used to take keyboard input and work accordingly.

public void keyPressed(KeyEvent e) {
  int key = e.getKeyCode();
  
  if(key == KeyEvent.VK_SPACE){
    gamestart=true;
  }
  
  if(key == KeyEvent.VK_ESCAPE){
    System.exit(0);
  }
  
  if(key == KeyEvent.VK_UP){
    if(batby > 0){
    batbvel = -2;
  }else
    batbvel =0;
  }
  
  if(key == KeyEvent.VK_DOWN){
      if(batby+batheight < screenheight){
      batbvel = 2;
    }else
      batbvel = 0;
  }
  
    
  if(key == KeyEvent.VK_W){
    if(batay > 0 ){
    batavel = -2;
  }else
    batavel =0;
  }
  
  
  if(key == KeyEvent.VK_S){
      if(batay+batheight < screenheight){
      batavel = 2;
    }else
      batavel = 0;
  }
    
  if(key == KeyEvent.VK_R){
       
       batax=20;batay= screenheight/2 - batheight/2;
       batavel=0;
      
       batbx=screenwidth-20;batby=screenheight/2 - batheight/2;
       batbvel=0;
      
      
       ballx=screenwidth/2-ballrad/2;bally=screenheight/2-ballrad/2;
       ballxvel=2;ballyvel=2;
      
       set=0;
      
       gamestart=false;
       winner=false;
      
       winningplayer=null;
       
       s.player1score=0;
       s.player2score=0;
       s.awon=0;
       s.bwon=0;
       for(int i=0;i<3;i++){
         s.aset[i]=0;
         s.bset[i]=0;
       }
       repaint();
       s.repaint();
    }
  
  }