【发布时间】：2019-02-08 20:49:01
【问题描述】：
我正在使用 Swing 用 Java 开发一个简单的 Snake 游戏。 到目前为止，我制作了令我困扰的蛇动画：当蛇移动时，它似乎开始无缘无故地滞后，但当我用箭头键移动它时，它变得平滑。
当它在直线上时，我怎样才能使它移动平滑？ 代码如下：
游戏框架
public class GameFrame extends JFrame {
private GamePanel gamePanel;
private JLabel scoreLabel;
public GameFrame() throws HeadlessException {
this.setTitle("Snake");
this.setBounds(100, 100, 400, 400);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
this.setResizable(false);
getContentPane().setLayout(null);
getContentPane().setBackground(Color.BLACK);
scoreLabel = new JLabel("0000");
scoreLabel.setBounds(0, 0, 70, 20);
scoreLabel.setForeground(Color.WHITE);
getContentPane().add(scoreLabel);
gamePanel = new GamePanel();
gamePanel.setBounds(20, 20, 360, 350);
this.add(gamePanel);
this.setVisible(true);
}
}
游戏面板
public class GamePanel extends JPanel implements KeyListener, ActionListener {
private GameManager gameManager;
private Timer timer;
private final int DELAY = 150;
GamePanel() {
this.setOpaque(true);
this.setBackground(new Color(51, 51, 51));
this.addKeyListener(this);
this.setFocusable(true);
this.requestFocus();
gameManager = new GameManager(this);
timer = new Timer(DELAY, this);
timer.start();
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
gameManager.renderSnake(g);
}
@Override
public void actionPerformed(ActionEvent e) {
gameManager.gameLoop();
}
@Override
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_UP:
gameManager.moveSnakeUp();
break;
case KeyEvent.VK_DOWN:
gameManager.moveSnakeDown();
break;
case KeyEvent.VK_RIGHT:
gameManager.moveSnakeRight();
break;
case KeyEvent.VK_LEFT:
gameManager.moveSnakeLeft();
break;
}
}
@Override
public void keyTyped(KeyEvent e) { }
@Override
public void keyReleased(KeyEvent e) { }
}
游戏管理器
public class GameManager {
private Color snakeColor;
private Snake snake;
private GamePanel gamePanel;
private boolean running;
public GameManager(GamePanel gamePanel) {
this.gamePanel = gamePanel;
snakeColor = Color.GREEN;
snake = new Snake();
running = true;
}
public void gameLoop() {
update();
draw();
}
public void renderSnake(Graphics graphics) {
Graphics2D graphics2D = (Graphics2D) graphics;
graphics2D.setColor(snakeColor);
for (Rectangle tile : snake.getBody())
graphics2D.fillRect(tile.x, tile.y, tile.width, tile.height);
}
public void update() {
snake.move();
}
public boolean isRunning() {
return running;
}
public void draw() {
gamePanel.repaint();
}
public void moveSnakeUp() {
snake.setUpDirection();
}
public void moveSnakeDown() {
snake.setDownDirection();
}
public void moveSnakeRight() {
snake.setRightDirection();
}
public void moveSnakeLeft() {
snake.setLeftDirection();
}
}
蛇
public class Snake {
private final int SNAKE_SPEED = 10;
private final int BODY_WIDTH = 10;
private LinkedList<Rectangle> body;
private Directions direction;
public Snake() {
direction = Directions.RIGHT;
body = new LinkedList<>();
body.add(new Rectangle(50, 20, BODY_WIDTH, BODY_WIDTH));
body.add(new Rectangle(40, 20, BODY_WIDTH, BODY_WIDTH));
body.add(new Rectangle(30, 20, BODY_WIDTH, BODY_WIDTH));
body.add(new Rectangle(20, 20, BODY_WIDTH, BODY_WIDTH));
body.add(new Rectangle(10, 20, BODY_WIDTH, BODY_WIDTH));
}
public LinkedList<Rectangle> getBody() {
return body;
}
public void setUpDirection() {
if (direction != Directions.UP)
direction = Directions.UP;
}
public void setDownDirection() {
if (direction != Directions.DOWN)
direction = Directions.DOWN;
}
public void setRightDirection() {
if (direction != Directions.RIGHT)
direction = Directions.RIGHT;
}
public void setLeftDirection() {
if (direction != Directions.LEFT)
direction = Directions.LEFT;
}
public void move() {
Rectangle newHead = body.removeLast();
newHead.x = body.peek().x;
newHead.y = body.peek().y;
switch (direction) {
case UP:
newHead.y -= SNAKE_SPEED;
break;
case DOWN:
newHead.y += SNAKE_SPEED;
break;
case RIGHT:
newHead.x += SNAKE_SPEED;
break;
case LEFT:
newHead.x -= SNAKE_SPEED;
break;
}
body.addFirst(newHead);
}
}
我尝试过使用Thread 和不同的延迟时间值，但无济于事。如何改进？
非常感谢。
编辑
我找到了一个使用BufferedImage 的解决方案，它确实有很大的不同，简单但有效：
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
BufferedImage bufferedImage = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics bufferedGraphics = bufferedImage.getGraphics();
gameManager.renderSnake(bufferedGraphics);
gameManager.renderFruit(bufferedGraphics);
g.drawImage(bufferedImage, 0, 0, this);
}
编辑 2
即使没有使用来自java.Swing 的Timer，我也终于设法制作了一个不错的动画，而是使用了Thread。对我来说效果很好。
对这里感兴趣的人是code。
【问题讨论】：
-
您似乎只在执行操作后才调用
gameManager.gameLoop();。 -
@kai 这就是代码已经在做的事情。注意使用
Timer来移动蛇。 -
对不起，我删除了我的 cmets
-
尝试通过 javax.swing.SwingUtilities.invokeLater(Runnable) 进行线程同步；用于调用游戏循环的计时器。
-
@kai javax.swing.Timer 已经在 AWT 事件调度线程上调用了它的 ActionListener。事实上，这可以说是它的主要目的。