做这个小游戏,主要是学习一下游戏制作的基本逻辑,加深对面向对象的理解。
游戏引擎:
/*** 大牛程序员写的游戏的公共类 * 使用Game.init()方法初始化游戏* 使用Game.gameOver()方法退出游戏*/
public class Game extends JPanel {private GameEngine engine;private Graphics2D g2d;private static JFrame frame;@Overridepublic void paint(Graphics g) {super.paint(g);g2d = (Graphics2D) g;g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);engine.renderUI(g2d);}/*** 使用游戏引擎初始化游戏的方法* @param title 游戏窗体的标题* @param width 游戏窗体的宽度* @param height 游戏窗体的高度* @param engine 游戏引擎*/public static void init(String title, int width, int height, GameEngine engine){frame = new JFrame(title);Game game = new Game();game.engine = engine;game.addKeyListener(engine.listener);game.setFocusable(true);game.setPreferredSize(new Dimension(width, height));frame.add(game);frame.pack();frame.setVisible(true);frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);while (true) {engine.updateLogic();game.repaint();try {Thread.sleep(Config.SLEEP_TIME);} catch (InterruptedException e) {e.printStackTrace();}}}/*** 显示退出游戏对话框的方法* @param message 对话框提示的消息* @param title 对话框提示的标题*/public static void gameOver(String message,String title) {JOptionPane.showMessageDialog(frame, message, title, JOptionPane.YES_NO_OPTION);System.exit(ABORT);}
}
/*** 由大牛程序员编写的游戏引擎的抽象模板类* 需要调用者实现两个抽象方法, 更新逻辑方法updateLogic* 更新UI方法 renderUI*/
public abstract class GameEngine {KeyListener listener;private int currentPressedKeyCode;/*** 构造方法,创建出游戏引擎*/public GameEngine(){this.listener = new KeyListener() {@Overridepublic void keyTyped(KeyEvent e) {}@Overridepublic void keyPressed(KeyEvent e) {currentPressedKeyCode = e.getKeyCode();}@Overridepublic void keyReleased(KeyEvent e) {currentPressedKeyCode = -1;}};}/*** 获取当前用户的按键代码 按键代码的定义在KeyEvent对象中定义* @return 返回KeyEvent的按键代码*/public int getCurrentPressedKeyCode(){return currentPressedKeyCode;}/*** 根据用户行为或者游戏的时间更新游戏的逻辑*/public abstract void updateLogic();/*** 根据用户需求更新绘制图形化界面的内容* 示例代码,绘制矩形: g2d.fillRect(左上角x的坐标, 左上角y的坐标, 矩形的宽度, 矩形的高度);* 示例代码:绘制椭圆形: g2d.fillOval(椭圆外包裹矩形左上角x的坐标, 椭圆外包裹矩形y的坐标, 要填充椭圆形的宽度, 要填充椭圆形的高度);* @param g2d*/public abstract void renderUI(Graphics2D g2d);
}
分析过程:
其实游戏就是逻辑判断,页面更新的死循环。
我们要做的就是继承GameEngine,实现updateLogic,renderUI方法。
一开始我们可以画上网格线,方便程序的编写。等到完成之后,将网格线去除即可。
面向对象思想(指的是程序的最小单位是对象。对象之间彼此协调,相互调用,构成了程序):
我们需要什么,我们就创建什么类:我们需要一个蛇,于是创建了一个Snake类,然后蛇又是由一个个的节点组成,于是我们又创建了Node类,以此类推,我们又创建了Apple类…
贪吃蛇的具体实现代码:
public class SnakeGameEngine extends GameEngine {Grid grid = new Grid();Snake snake = new Snake();Apple apple = new Apple();@Overridepublic void updateLogic() {boolean flag = snake.headHaveApple(apple);int keyCode = getCurrentPressedKeyCode();if (keyCode == KeyEvent.VK_RIGHT) {snake.moveRight(flag);}if (keyCode == KeyEvent.VK_LEFT) {snake.moveLeft(flag);}if (keyCode == KeyEvent.VK_UP) {snake.moveUp(flag);}if (keyCode == KeyEvent.VK_DOWN) {snake.moveDown(flag);}switch(snake.headDirection) {case Direction.RIGHT:snake.moveRight(flag);break;case Direction.LEFT:snake.moveLeft(flag);break;case Direction.UP:snake.moveUp(flag);break;case Direction.DOWN:snake.moveDown(flag);break;}}@Overridepublic void renderUI(Graphics2D g2d) {grid.draw(g2d);snake.draw(g2d);apple.draw(g2d);}
}
public class SnakeGame {public static void main(String[] args) {Game.init("贪吃蛇", Config.SCREEN_WIDTH, Config.SCREEN_HEIGHT, new SnakeGameEngine());}
}
public class Snake {LinkedList<Node> snake;int headDirection = Direction.RIGHT;public Snake() {snake = new LinkedList<Node>();snake.add(new Node(6, 4));snake.addLast(new Node(5, 4));snake.addLast(new Node(4, 4));snake.addLast(new Node(3, 4));}public void moveRight(boolean flag) {if (headDirection == Direction.LEFT) {return;}headDirection = Direction.RIGHT;Node node = new Node(snake.getFirst().x + 1, snake.getFirst().y);snake.addFirst(node);if (flag == true) {} else {snake.removeLast();}}public void moveLeft(boolean flag) {if (headDirection == Direction.RIGHT) {return;}headDirection = Direction.LEFT;Node node = new Node(snake.getFirst().x - 1, snake.getFirst().y);snake.addFirst(node);if (flag == true) {} else {snake.removeLast();}}public void moveUp(boolean flag) {if (headDirection == Direction.DOWN) {return;}headDirection = Direction.UP;Node node = new Node(snake.getFirst().x, snake.getFirst().y - 1);snake.addFirst(node);if (flag == true) {} else {snake.removeLast();}}public void moveDown(boolean flag) {if (headDirection == Direction.UP) {return;}headDirection = Direction.DOWN;Node node = new Node(snake.getFirst().x, snake.getFirst().y + 1);snake.addFirst(node);if (flag == true) {} else {snake.removeLast();}}public boolean headHaveApple(Apple apple) {if ((snake.getFirst().x == apple.getX()) && (snake.getFirst().y == apple.getY())) {apple.generateNext();return true;} else {return false;}}public void draw(Graphics2D g2d) {
// for (Node node : snake) {
// node.draw(g2d);
// }g2d.drawString("蛇的长度:" + snake.size(), 50, 50);for (int i = 0; i < snake.size(); i ++ ) {if (i == 0) {g2d.setColor(Color.GREEN);} else {g2d.setColor(Color.BLACK);}snake.get(i).draw(g2d);}}
}
public class Config {public static final boolean DEBUG_FLAG = false;public static final int SCREEN_WIDTH = 1000;public static final int SCREEN_HEIGHT = 900;public static final int GRID_SiZE = 20;public static final int COLOUM = SCREEN_WIDTH / GRID_SiZE;public static final int ROW = SCREEN_HEIGHT / GRID_SiZE;public static final int SLEEP_TIME = 50;
}
apublic class Grid {int x1;int y1;int x2;int y2;public void draw(Graphics2D g2d) {if (Config.DEBUG_FLAG == true) {for (int i = 0; i < Config.ROW; i ++ ) {g2d.drawLine(0, Config.GRID_SiZE * i, Config.SCREEN_WIDTH, Config.GRID_SiZE * i);}for (int i = 0; i < Config.COLOUM; i ++ ) {g2d.drawLine(Config.GRID_SiZE * i, 0, Config.GRID_SiZE * i,Config.SCREEN_HEIGHT);}}}
}
public class Node {int x;int y;public Node(int x, int y) {this.x = x;this.y = y;}public void draw(Graphics2D g2d) {g2d.fillRect(x * Config.GRID_SiZE, y * Config.GRID_SiZE, Config.GRID_SiZE,Config.GRID_SiZE);}
}
public class Direction {public static final int UP = 1;public static final int DOWN = 2;public static final int LEFT = 3;public static final int RIGHT = 4;
}
public class Apple {Random random = new Random();Node apple;public Apple() {apple = new Node(random.nextInt(Config.COLOUM), random.nextInt(Config.ROW));}public int getX() {return apple.x;}public int getY() {return apple.y;}public void draw(Graphics2D g2d) {g2d.setColor(Color.RED);apple.draw(g2d);g2d.setColor(Color.BLACK);}public void generateNext() {apple = new Node(random.nextInt(Config.COLOUM), random.nextInt(Config.ROW));}
}
最终效果:
做的很简易,还有很多不足:
蛇不能超过屏幕的范围
地图添加障碍物
添加游戏关卡,蛇移动的速度越来越快
等等…