Snake/Java
< Snake
Code
<lang java>import java.awt.*; import java.awt.event.*; import static java.lang.String.format; import java.util.*; import java.util.List; import javax.swing.*;
public class Snake extends JPanel implements Runnable {
enum Dir {
up, right, down, left
};
final Random rand = new Random();
final int[][] dirs = {{0, -1}, {1, 0}, {0, 1}, {-1, 0}};
final int WALL = -1;
final int MAX_ENERGY = 1500;
volatile boolean gameOver = true;
Thread gameThread; int score, hiScore; int nRows = 44; int nCols = 64; Dir dir; int energy;
int[][] grid; List<Point> snake, treats; Font smallFont;
public Snake() {
setPreferredSize(new Dimension(640, 440));
setBackground(Color.white);
setFont(new Font("SansSerif", Font.BOLD, 48));
setFocusable(true);
smallFont = getFont().deriveFont(Font.BOLD, 18);
initGrid();
addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
if (gameOver) {
startNewGame();
repaint();
}
}
});
addKeyListener(new KeyAdapter() {
@Override
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP:
if (dir != Dir.down)
dir = Dir.up;
break;
case KeyEvent.VK_LEFT:
if (dir != Dir.right)
dir = Dir.left;
break;
case KeyEvent.VK_RIGHT:
if (dir != Dir.left)
dir = Dir.right;
break;
case KeyEvent.VK_DOWN:
if (dir != Dir.up)
dir = Dir.down;
break;
}
repaint();
}
});
}
void startNewGame() {
gameOver = false;
stop();
initGrid();
treats = new LinkedList<>();
dir = Dir.left;
energy = MAX_ENERGY;
if (score > hiScore)
hiScore = score;
score = 0;
snake = new ArrayList<>();
for (int x = 0; x < 7; x++)
snake.add(new Point(nCols / 2 + x, nRows / 2));
(gameThread = new Thread(this)).start(); }
void stop() {
if (gameThread != null) {
Thread tmp = gameThread;
gameThread = null;
tmp.interrupt();
}
}
void initGrid() {
grid = new int[nRows][nCols];
for (int r = 0; r < nRows; r++) {
for (int c = 0; c < nCols; c++) {
if (c == 0 || c == nCols - 1 || r == 0 || r == nRows - 1)
grid[r][c] = WALL;
}
}
}
@Override
public void run() {
while (Thread.currentThread() == gameThread) {
try {
Thread.sleep(Math.max(75 - score, 25));
} catch (InterruptedException e) {
return;
}
if (energyUsed() || hitsWall() || hitsSnake()) {
gameOver();
} else {
if (eatsTreat()) {
score++;
energy = MAX_ENERGY;
growSnake();
}
moveSnake();
addTreat();
}
repaint();
}
}
boolean energyUsed() {
energy -= 10;
return energy <= 0;
}
boolean hitsWall() {
Point head = snake.get(0);
int nextCol = head.x + dirs[dir.ordinal()][0];
int nextRow = head.y + dirs[dir.ordinal()][1];
return grid[nextRow][nextCol] == WALL;
}
boolean hitsSnake() {
Point head = snake.get(0);
int nextCol = head.x + dirs[dir.ordinal()][0];
int nextRow = head.y + dirs[dir.ordinal()][1];
for (Point p : snake)
if (p.x == nextCol && p.y == nextRow)
return true;
return false;
}
boolean eatsTreat() {
Point head = snake.get(0);
int nextCol = head.x + dirs[dir.ordinal()][0];
int nextRow = head.y + dirs[dir.ordinal()][1];
for (Point p : treats)
if (p.x == nextCol && p.y == nextRow) {
return treats.remove(p);
}
return false;
}
void gameOver() {
gameOver = true;
stop();
}
void moveSnake() {
for (int i = snake.size() - 1; i > 0; i--) {
Point p1 = snake.get(i - 1);
Point p2 = snake.get(i);
p2.x = p1.x;
p2.y = p1.y;
}
Point head = snake.get(0);
head.x += dirs[dir.ordinal()][0];
head.y += dirs[dir.ordinal()][1];
}
void growSnake() {
Point tail = snake.get(snake.size() - 1);
int x = tail.x + dirs[dir.ordinal()][0];
int y = tail.y + dirs[dir.ordinal()][1];
snake.add(new Point(x, y));
}
void addTreat() {
if (treats.size() < 3) {
if (rand.nextInt(10) == 0) { // 1 in 10
if (rand.nextInt(4) != 0) { // 3 in 4
int x, y;
while (true) {
x = rand.nextInt(nCols);
y = rand.nextInt(nRows);
if (grid[y][x] != 0)
continue;
Point p = new Point(x, y);
if (snake.contains(p) || treats.contains(p))
continue;
treats.add(p);
break;
}
} else if (treats.size() > 1)
treats.remove(0);
}
}
}
void drawGrid(Graphics2D g) {
g.setColor(Color.lightGray);
for (int r = 0; r < nRows; r++) {
for (int c = 0; c < nCols; c++) {
if (grid[r][c] == WALL)
g.fillRect(c * 10, r * 10, 10, 10);
}
}
}
void drawSnake(Graphics2D g) {
g.setColor(Color.blue);
for (Point p : snake)
g.fillRect(p.x * 10, p.y * 10, 10, 10);
g.setColor(energy < 500 ? Color.red : Color.orange);
Point head = snake.get(0);
g.fillRect(head.x * 10, head.y * 10, 10, 10);
}
void drawTreats(Graphics2D g) {
g.setColor(Color.green);
for (Point p : treats)
g.fillRect(p.x * 10, p.y * 10, 10, 10);
}
void drawStartScreen(Graphics2D g) {
g.setColor(Color.blue);
g.setFont(getFont());
g.drawString("Snake", 240, 190);
g.setColor(Color.orange);
g.setFont(smallFont);
g.drawString("(click to start)", 250, 240);
}
void drawScore(Graphics2D g) {
int h = getHeight();
g.setFont(smallFont);
g.setColor(getForeground());
String s = format("hiscore %d score %d", hiScore, score);
g.drawString(s, 30, h - 30);
g.drawString(format("energy %d", energy), getWidth() - 150, h - 30);
}
@Override
public void paintComponent(Graphics gg) {
super.paintComponent(gg);
Graphics2D g = (Graphics2D) gg;
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
drawGrid(g);
if (gameOver) {
drawStartScreen(g);
} else {
drawSnake(g);
drawTreats(g);
drawScore(g);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setTitle("Snake");
f.setResizable(false);
f.add(new Snake(), BorderLayout.CENTER);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
});
}
}</lang>