Snake/Java

An good Snake Game by IZzSaken

edited on 21th May 2023

import java.awt.*; import java.awt.event.*; import javax.swing.*;

public class SnakeGame extends JPanel implements ActionListener {

   private static final int WIDTH = 300;
   private static final int HEIGHT = 300;
   private static final int UNIT_SIZE = 10;
   private static final int GAME_UNITS = (WIDTH * HEIGHT) / (UNIT_SIZE * UNIT_SIZE);
   private static final int DELAY = 75;

   private final int[] x = new int[GAME_UNITS];
   private final int[] y = new int[GAME_UNITS];
   private int bodyParts = 6;
   private int applesEaten;
   private int appleX;
   private int appleY;
   private char direction = 'R';
   private boolean running = false;
   private Timer timer;

   public SnakeGame() {
       setPreferredSize(new Dimension(WIDTH, HEIGHT));
       setBackground(Color.BLACK);
       setFocusable(true);
       addKeyListener(new MyKeyAdapter());
       startGame();
   }

   private void startGame() {
       newApple();
       running = true;
       timer = new Timer(DELAY, this);
       timer.start();
   }

   @Override
   public void paintComponent(Graphics g) {
       super.paintComponent(g);
       draw(g);
   }

   private void draw(Graphics g) {
       if (running) {
           g.setColor(Color.RED);
           g.fillOval(appleX, appleY, UNIT_SIZE, UNIT_SIZE);

           for (int i = 0; i < bodyParts; i++) {
               if (i == 0) {
                   g.setColor(Color.GREEN);
                   g.fillRect(x[i], y[i], UNIT_SIZE, UNIT_SIZE);
               } else {
                   g.setColor(new Color(45, 180, 0));
                   g.fillRect(x[i], y[i], UNIT_SIZE, UNIT_SIZE);
               }
           }

           g.setColor(Color.WHITE);
           g.setFont(new Font("Arial", Font.BOLD, 14));
           FontMetrics metrics = getFontMetrics(g.getFont());
           g.drawString("Score: " + applesEaten, (WIDTH - metrics.stringWidth("Score: " + applesEaten)) / 2, g.getFont().getSize());
       } else {
           gameOver(g);
       }
   }

   private void newApple() {
       appleX = (int) (Math.random() * (WIDTH / UNIT_SIZE)) * UNIT_SIZE;
       appleY = (int) (Math.random() * (HEIGHT / UNIT_SIZE)) * UNIT_SIZE;
   }

   private void move() {
       for (int i = bodyParts; i > 0; i--) {
           x[i] = x[i - 1];
           y[i] = y[i - 1];
       }

       switch (direction) {
           case 'U':
               y[0] = y[0] - UNIT_SIZE;
               break;
           case 'D':
               y[0] = y[0] + UNIT_SIZE;
               break;
           case 'L':
               x[0] = x[0] - UNIT_SIZE;
               break;
           case 'R':
               x[0] = x[0] + UNIT_SIZE;
               break;
       }
   }

   private void checkApple() {
       if ((x[0] == appleX) && (y[0] == appleY)) {
           bodyParts++;
           applesEaten++;
           newApple();
       }
   }

   private void checkCollisions() {
       // Check if head collides with body
       for (int i = bodyParts; i > 0; i--) {
           if ((x[0] == x[i]) && (y[0] == y[i])) {
               running = false;
           }
       }

       // Check if head touches left border
       if (x[0] < 0) {
           running = false;
       }

       // Check if head touches right border
       if (x[0] >= WIDTH) {
           running = false;
       }

       // Check if head touches top border
       if (y[0] < 0) {
           running = false;
       }

       // Check if head touches bottom border
       if (y[0] >= HEIGHT) {
           running = false;
       }

       if (!running) {
           timer.stop();
       }
   }

   private void gameOver(Graphics g) {
       g.setColor(Color.WHITE);
       g.setFont(new Font("Arial", Font.BOLD, 20));
       FontMetrics metrics1 = getFontMetrics(g.getFont());
       g.drawString("Game Over", (WIDTH - metrics1.stringWidth("Game Over")) / 2, HEIGHT / 2);

       g.setColor(Color.WHITE);
       g.setFont(new Font("Arial", Font.BOLD, 14));
       FontMetrics metrics2 = getFontMetrics(g.getFont());
       g.drawString("Score: " + applesEaten, (WIDTH - metrics2.stringWidth("Score: " + applesEaten)) / 2, g.getFont().getSize());
   }

   @Override
   public void actionPerformed(ActionEvent e) {
       if (running) {
           move();
           checkApple();
           checkCollisions();
       }
       repaint();
   }

   private class MyKeyAdapter extends KeyAdapter {
       @Override
       public void keyPressed(KeyEvent e) {
           switch (e.getKeyCode()) {
               case KeyEvent.VK_LEFT:
                   if (direction != 'R') {
                       direction = 'L';
                   }
                   break;
               case KeyEvent.VK_RIGHT:
                   if (direction != 'L') {
                       direction = 'R';
                   }
                   break;
               case KeyEvent.VK_UP:
                   if (direction != 'D') {
                       direction = 'U';
                   }
                   break;
               case KeyEvent.VK_DOWN:
                   if (direction != 'U') {
                       direction = 'D';
                   }
                   break;
           }
       }
   }

   public static void main(String[] args) {
       JFrame frame = new JFrame("Snake Game");
       SnakeGame game = new SnakeGame();
       frame.add(game);
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       frame.setResizable(false);
       frame.pack();
       frame.setLocationRelativeTo(null);
       frame.setVisible(true);
   }

}