Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
A simple Snake clone implementation in Java
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
class Game extends JPanel implements ActionListener {
final int TIMEOUT = 125;
final int SIZE = 25;
final int BOARD_COLS = 10;
final int BOARD_ROWS = 10;
final int BOARD_SIZE = (BOARD_COLS * BOARD_ROWS);
int head = 0;
int apple = 45;
int direction = 1;
int[] tail = new int[BOARD_SIZE];
int length = 0;
int i = 0;
Timer timer = new Timer(TIMEOUT, this);
Graphics ctx = null;
public static void main(String[] args) {
JFrame window = new JFrame();
window.add(new Game());
window.setResizable(false);
window.pack();
window.setTitle("Snake");
window.setLocationRelativeTo(null);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
public Game() {
addKeyListener(new KeyAdapter() {
@Override public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_UP) setDirection(-BOARD_COLS);
else if (e.getKeyCode() == KeyEvent.VK_DOWN) setDirection( BOARD_COLS);
else if (e.getKeyCode() == KeyEvent.VK_LEFT) setDirection(-1);
else if (e.getKeyCode() == KeyEvent.VK_RIGHT) setDirection( 1);
}
});
setBackground(Color.black);
setFocusable(true);
setDoubleBuffered(true);
setPreferredSize(new Dimension(BOARD_COLS * SIZE, BOARD_ROWS * SIZE));
timer.start();
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
ctx = g;
update();
drawBoard();
}
@Override
public void actionPerformed(ActionEvent e) { repaint(); }
void draw(int position, Color color) {
int x = position % BOARD_COLS;
int y = position / BOARD_COLS;
ctx.setColor(color);
ctx.fillRect( x * SIZE, y * SIZE, SIZE, SIZE );
}
int random() {
return (int) (Math.random() * BOARD_SIZE);
}
boolean isOnLimits() {
return (direction == 1 && head % BOARD_COLS == 0) ||
(direction == -1 && (head + 1) % BOARD_COLS == 0);
}
boolean hasCollisionWithTail(int position) {
for (int i = 0; i < length; i++)
if (tail[i] == position) return true;
return false;
}
void placeApple() {
do apple = random();
while (head == apple || hasCollisionWithTail(apple));
}
void setDirection(int dir) {
if (dir != -direction || length == 0)
direction = dir;
}
void drawBoard() {
for (int i = 0; i < length; ++i)
draw(tail[i], Color.GREEN);
draw(head, Color.BLUE);
draw(apple, Color.RED);
}
void move() {
tail[i] = head;
head += direction;
if (++i >= length) i = 0;
if (isOnLimits())
head -= BOARD_COLS * direction;
else if (head < 0)
head += BOARD_SIZE;
else if (head >= BOARD_SIZE)
head -= BOARD_SIZE;
}
void update() {
move();
if (head == apple) {
placeApple();
tail[length++] = head;
} else if (hasCollisionWithTail(head)) timer.stop();
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.