原文： https://zetcode.com/tutorials/javagamestutorial/pacman/

在 Java 2D 游戏教程的这一部分中，我们将创建一个简单的 Pacman 游戏克隆。

Pacman 是一款街机游戏，最初由日本公司 Namco 在 1980 年开发。Pacman 成为有史以来最受欢迎的街机游戏之一。

开发

以下代码示例是 Brian Postma 对 Pacman 游戏的翻版，可从 http://www.brianpostma.com 获得。 修改并简化了代码，以便于理解。

游戏的目标是收集迷宫中的所有点并避开鬼魂。 吃豆人的动画制作有两种方式：在迷宫中的位置和身体。 我们根据方向为他的身体制作四幅图像。 该动画用于创建吃豆人张开和闭合嘴巴的幻觉。 迷宫由15x15正方形组成。 迷宫的结构基于简单的整数数组。 吃豆人有三命。 我们还计算分数。

游戏包含两个文件：Board.java和Pacman.java。

Board.java

  1. package com.zetcode;
  3. import java.awt.BasicStroke;
  4. import java.awt.Color;
  5. import java.awt.Dimension;
  6. import java.awt.Event;
  7. import java.awt.Font;
  8. import java.awt.FontMetrics;
  9. import java.awt.Graphics;
  10. import java.awt.Graphics2D;
  11. import java.awt.Image;
  12. import java.awt.Toolkit;
  13. import java.awt.event.ActionEvent;
  14. import java.awt.event.ActionListener;
  15. import java.awt.event.KeyAdapter;
  16. import java.awt.event.KeyEvent;
  18. import javax.swing.ImageIcon;
  19. import javax.swing.JPanel;
  20. import javax.swing.Timer;
  22. public class Board extends JPanel implements ActionListener {
  24.     private Dimension d;
  25.     private final Font smallFont = new Font("Helvetica", Font.BOLD, 14);
  27.     private Image ii;
  28.     private final Color dotColor = new Color(192, 192, 0);
  29.     private Color mazeColor;
  31.     private boolean inGame = false;
  32.     private boolean dying = false;
  34.     private final int BLOCK_SIZE = 24;
  35.     private final int N_BLOCKS = 15;
  36.     private final int SCREEN_SIZE = N_BLOCKS * BLOCK_SIZE;
  37.     private final int PAC_ANIM_DELAY = 2;
  38.     private final int PACMAN_ANIM_COUNT = 4;
  39.     private final int MAX_GHOSTS = 12;
  40.     private final int PACMAN_SPEED = 6;
  42.     private int pacAnimCount = PAC_ANIM_DELAY;
  43.     private int pacAnimDir = 1;
  44.     private int pacmanAnimPos = 0;
  45.     private int N_GHOSTS = 6;
  46.     private int pacsLeft, score;
  47.     private int[] dx, dy;
  48.     private int[] ghost_x, ghost_y, ghost_dx, ghost_dy, ghostSpeed;
  50.     private Image ghost;
  51.     private Image pacman1, pacman2up, pacman2left, pacman2right, pacman2down;
  52.     private Image pacman3up, pacman3down, pacman3left, pacman3right;
  53.     private Image pacman4up, pacman4down, pacman4left, pacman4right;
  55.     private int pacman_x, pacman_y, pacmand_x, pacmand_y;
  56.     private int req_dx, req_dy, view_dx, view_dy;
  58.     private final short levelData[] = {
  59.         19, 26, 26, 26, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 22,
  60.         21, 0, 0, 0, 17, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20,
  61.         21, 0, 0, 0, 17, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20,
  62.         21, 0, 0, 0, 17, 16, 16, 24, 16, 16, 16, 16, 16, 16, 20,
  63.         17, 18, 18, 18, 16, 16, 20, 0, 17, 16, 16, 16, 16, 16, 20,
  64.         17, 16, 16, 16, 16, 16, 20, 0, 17, 16, 16, 16, 16, 24, 20,
  65.         25, 16, 16, 16, 24, 24, 28, 0, 25, 24, 24, 16, 20, 0, 21,
  66.         1, 17, 16, 20, 0, 0, 0, 0, 0, 0, 0, 17, 20, 0, 21,
  67.         1, 17, 16, 16, 18, 18, 22, 0, 19, 18, 18, 16, 20, 0, 21,
  68.         1, 17, 16, 16, 16, 16, 20, 0, 17, 16, 16, 16, 20, 0, 21,
  69.         1, 17, 16, 16, 16, 16, 20, 0, 17, 16, 16, 16, 20, 0, 21,
  70.         1, 17, 16, 16, 16, 16, 16, 18, 16, 16, 16, 16, 20, 0, 21,
  71.         1, 17, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 20, 0, 21,
  72.         1, 25, 24, 24, 24, 24, 24, 24, 24, 24, 16, 16, 16, 18, 20,
  73.         9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 25, 24, 24, 24, 28
  74.     };
  76.     private final int validSpeeds[] = {1, 2, 3, 4, 6, 8};
  77.     private final int maxSpeed = 6;
  79.     private int currentSpeed = 3;
  80.     private short[] screenData;
  81.     private Timer timer;
  83.     public Board() {
  85.         loadImages();
  86.         initVariables();
  87.         initBoard();
  88.     }
  90.     private void initBoard() {
  92.         addKeyListener(new TAdapter());
  94.         setFocusable(true);
  96.         setBackground(Color.black);
  97.     }
  99.     private void initVariables() {
  101.         screenData = new short[N_BLOCKS * N_BLOCKS];
  102.         mazeColor = new Color(5, 100, 5);
  103.         d = new Dimension(400, 400);
  104.         ghost_x = new int[MAX_GHOSTS];
  105.         ghost_dx = new int[MAX_GHOSTS];
  106.         ghost_y = new int[MAX_GHOSTS];
  107.         ghost_dy = new int[MAX_GHOSTS];
  108.         ghostSpeed = new int[MAX_GHOSTS];
  109.         dx = new int[4];
  110.         dy = new int[4];
  112.         timer = new Timer(40, this);
  113.         timer.start();
  114.     }
  116.     @Override
  117.     public void addNotify() {
  118.         super.addNotify();
  120.         initGame();
  121.     }
  123.     private void doAnim() {
  125.         pacAnimCount--;
  127.         if (pacAnimCount <= 0) {
  128.             pacAnimCount = PAC_ANIM_DELAY;
  129.             pacmanAnimPos = pacmanAnimPos + pacAnimDir;
  131.             if (pacmanAnimPos == (PACMAN_ANIM_COUNT - 1) || pacmanAnimPos == 0) {
  132.                 pacAnimDir = -pacAnimDir;
  133.             }
  134.         }
  135.     }
  137.     private void playGame(Graphics2D g2d) {
  139.         if (dying) {
  141.             death();
  143.         } else {
  145.             movePacman();
  146.             drawPacman(g2d);
  147.             moveGhosts(g2d);
  148.             checkMaze();
  149.         }
  150.     }
  152.     private void showIntroScreen(Graphics2D g2d) {
  154.         g2d.setColor(new Color(0, 32, 48));
  155.         g2d.fillRect(50, SCREEN_SIZE / 2 - 30, SCREEN_SIZE - 100, 50);
  156.         g2d.setColor(Color.white);
  157.         g2d.drawRect(50, SCREEN_SIZE / 2 - 30, SCREEN_SIZE - 100, 50);
  159.         String s = "Press s to start.";
  160.         Font small = new Font("Helvetica", Font.BOLD, 14);
  161.         FontMetrics metr = this.getFontMetrics(small);
  163.         g2d.setColor(Color.white);
  164.         g2d.setFont(small);
  165.         g2d.drawString(s, (SCREEN_SIZE - metr.stringWidth(s)) / 2, SCREEN_SIZE / 2);
  166.     }
  168.     private void drawScore(Graphics2D g) {
  170.         int i;
  171.         String s;
  173.         g.setFont(smallFont);
  174.         g.setColor(new Color(96, 128, 255));
  175.         s = "Score: " + score;
  176.         g.drawString(s, SCREEN_SIZE / 2 + 96, SCREEN_SIZE + 16);
  178.         for (i = 0; i < pacsLeft; i++) {
  179.             g.drawImage(pacman3left, i * 28 + 8, SCREEN_SIZE + 1, this);
  180.         }
  181.     }
  183.     private void checkMaze() {
  185.         short i = 0;
  186.         boolean finished = true;
  188.         while (i < N_BLOCKS * N_BLOCKS && finished) {
  190.             if ((screenData[i] & 48) != 0) {
  191.                 finished = false;
  192.             }
  194.             i++;
  195.         }
  197.         if (finished) {
  199.             score += 50;
  201.             if (N_GHOSTS < MAX_GHOSTS) {
  202.                 N_GHOSTS++;
  203.             }
  205.             if (currentSpeed < maxSpeed) {
  206.                 currentSpeed++;
  207.             }
  209.             initLevel();
  210.         }
  211.     }
  213.     private void death() {
  215.         pacsLeft--;
  217.         if (pacsLeft == 0) {
  218.             inGame = false;
  219.         }
  221.         continueLevel();
  222.     }
  224.     private void moveGhosts(Graphics2D g2d) {
  226.         short i;
  227.         int pos;
  228.         int count;
  230.         for (i = 0; i < N_GHOSTS; i++) {
  231.             if (ghost_x[i] % BLOCK_SIZE == 0 && ghost_y[i] % BLOCK_SIZE == 0) {
  232.                 pos = ghost_x[i] / BLOCK_SIZE + N_BLOCKS * (int) (ghost_y[i] / BLOCK_SIZE);
  234.                 count = 0;
  236.                 if ((screenData[pos] & 1) == 0 && ghost_dx[i] != 1) {
  237.                     dx[count] = -1;
  238.                     dy[count] = 0;
  239.                     count++;
  240.                 }
  242.                 if ((screenData[pos] & 2) == 0 && ghost_dy[i] != 1) {
  243.                     dx[count] = 0;
  244.                     dy[count] = -1;
  245.                     count++;
  246.                 }
  248.                 if ((screenData[pos] & 4) == 0 && ghost_dx[i] != -1) {
  249.                     dx[count] = 1;
  250.                     dy[count] = 0;
  251.                     count++;
  252.                 }
  254.                 if ((screenData[pos] & 8) == 0 && ghost_dy[i] != -1) {
  255.                     dx[count] = 0;
  256.                     dy[count] = 1;
  257.                     count++;
  258.                 }
  260.                 if (count == 0) {
  262.                     if ((screenData[pos] & 15) == 15) {
  263.                         ghost_dx[i] = 0;
  264.                         ghost_dy[i] = 0;
  265.                     } else {
  266.                         ghost_dx[i] = -ghost_dx[i];
  267.                         ghost_dy[i] = -ghost_dy[i];
  268.                     }
  270.                 } else {
  272.                     count = (int) (Math.random() * count);
  274.                     if (count > 3) {
  275.                         count = 3;
  276.                     }
  278.                     ghost_dx[i] = dx[count];
  279.                     ghost_dy[i] = dy[count];
  280.                 }
  282.             }
  284.             ghost_x[i] = ghost_x[i] + (ghost_dx[i] * ghostSpeed[i]);
  285.             ghost_y[i] = ghost_y[i] + (ghost_dy[i] * ghostSpeed[i]);
  286.             drawGhost(g2d, ghost_x[i] + 1, ghost_y[i] + 1);
  288.             if (pacman_x > (ghost_x[i] - 12) && pacman_x < (ghost_x[i] + 12)
  289.                     && pacman_y > (ghost_y[i] - 12) && pacman_y < (ghost_y[i] + 12)
  290.                     && inGame) {
  292.                 dying = true;
  293.             }
  294.         }
  295.     }
  297.     private void drawGhost(Graphics2D g2d, int x, int y) {
  299.         g2d.drawImage(ghost, x, y, this);
  300.     }
  302.     private void movePacman() {
  304.         int pos;
  305.         short ch;
  307.         if (req_dx == -pacmand_x && req_dy == -pacmand_y) {
  308.             pacmand_x = req_dx;
  309.             pacmand_y = req_dy;
  310.             view_dx = pacmand_x;
  311.             view_dy = pacmand_y;
  312.         }
  314.         if (pacman_x % BLOCK_SIZE == 0 && pacman_y % BLOCK_SIZE == 0) {
  315.             pos = pacman_x / BLOCK_SIZE + N_BLOCKS * (int) (pacman_y / BLOCK_SIZE);
  316.             ch = screenData[pos];
  318.             if ((ch & 16) != 0) {
  319.                 screenData[pos] = (short) (ch & 15);
  320.                 score++;
  321.             }
  323.             if (req_dx != 0 || req_dy != 0) {
  324.                 if (!((req_dx == -1 && req_dy == 0 && (ch & 1) != 0)
  325.                         || (req_dx == 1 && req_dy == 0 && (ch & 4) != 0)
  326.                         || (req_dx == 0 && req_dy == -1 && (ch & 2) != 0)
  327.                         || (req_dx == 0 && req_dy == 1 && (ch & 8) != 0))) {
  328.                     pacmand_x = req_dx;
  329.                     pacmand_y = req_dy;
  330.                     view_dx = pacmand_x;
  331.                     view_dy = pacmand_y;
  332.                 }
  333.             }
  335.             // Check for standstill
  336.             if ((pacmand_x == -1 && pacmand_y == 0 && (ch & 1) != 0)
  337.                     || (pacmand_x == 1 && pacmand_y == 0 && (ch & 4) != 0)
  338.                     || (pacmand_x == 0 && pacmand_y == -1 && (ch & 2) != 0)
  339.                     || (pacmand_x == 0 && pacmand_y == 1 && (ch & 8) != 0)) {
  340.                 pacmand_x = 0;
  341.                 pacmand_y = 0;
  342.             }
  343.         }
  344.         pacman_x = pacman_x + PACMAN_SPEED * pacmand_x;
  345.         pacman_y = pacman_y + PACMAN_SPEED * pacmand_y;
  346.     }
  348.     private void drawPacman(Graphics2D g2d) {
  350.         if (view_dx == -1) {
  351.             drawPacnanLeft(g2d);
  352.         } else if (view_dx == 1) {
  353.             drawPacmanRight(g2d);
  354.         } else if (view_dy == -1) {
  355.             drawPacmanUp(g2d);
  356.         } else {
  357.             drawPacmanDown(g2d);
  358.         }
  359.     }
  361.     private void drawPacmanUp(Graphics2D g2d) {
  363.         switch (pacmanAnimPos) {
  364.             case 1:
  365.                 g2d.drawImage(pacman2up, pacman_x + 1, pacman_y + 1, this);
  366.                 break;
  367.             case 2:
  368.                 g2d.drawImage(pacman3up, pacman_x + 1, pacman_y + 1, this);
  369.                 break;
  370.             case 3:
  371.                 g2d.drawImage(pacman4up, pacman_x + 1, pacman_y + 1, this);
  372.                 break;
  373.             default:
  374.                 g2d.drawImage(pacman1, pacman_x + 1, pacman_y + 1, this);
  375.                 break;
  376.         }
  377.     }
  379.     private void drawPacmanDown(Graphics2D g2d) {
  381.         switch (pacmanAnimPos) {
  382.             case 1:
  383.                 g2d.drawImage(pacman2down, pacman_x + 1, pacman_y + 1, this);
  384.                 break;
  385.             case 2:
  386.                 g2d.drawImage(pacman3down, pacman_x + 1, pacman_y + 1, this);
  387.                 break;
  388.             case 3:
  389.                 g2d.drawImage(pacman4down, pacman_x + 1, pacman_y + 1, this);
  390.                 break;
  391.             default:
  392.                 g2d.drawImage(pacman1, pacman_x + 1, pacman_y + 1, this);
  393.                 break;
  394.         }
  395.     }
  397.     private void drawPacnanLeft(Graphics2D g2d) {
  399.         switch (pacmanAnimPos) {
  400.             case 1:
  401.                 g2d.drawImage(pacman2left, pacman_x + 1, pacman_y + 1, this);
  402.                 break;
  403.             case 2:
  404.                 g2d.drawImage(pacman3left, pacman_x + 1, pacman_y + 1, this);
  405.                 break;
  406.             case 3:
  407.                 g2d.drawImage(pacman4left, pacman_x + 1, pacman_y + 1, this);
  408.                 break;
  409.             default:
  410.                 g2d.drawImage(pacman1, pacman_x + 1, pacman_y + 1, this);
  411.                 break;
  412.         }
  413.     }
  415.     private void drawPacmanRight(Graphics2D g2d) {
  417.         switch (pacmanAnimPos) {
  418.             case 1:
  419.                 g2d.drawImage(pacman2right, pacman_x + 1, pacman_y + 1, this);
  420.                 break;
  421.             case 2:
  422.                 g2d.drawImage(pacman3right, pacman_x + 1, pacman_y + 1, this);
  423.                 break;
  424.             case 3:
  425.                 g2d.drawImage(pacman4right, pacman_x + 1, pacman_y + 1, this);
  426.                 break;
  427.             default:
  428.                 g2d.drawImage(pacman1, pacman_x + 1, pacman_y + 1, this);
  429.                 break;
  430.         }
  431.     }
  433.     private void drawMaze(Graphics2D g2d) {
  435.         short i = 0;
  436.         int x, y;
  438.         for (y = 0; y < SCREEN_SIZE; y += BLOCK_SIZE) {
  439.             for (x = 0; x < SCREEN_SIZE; x += BLOCK_SIZE) {
  441.                 g2d.setColor(mazeColor);
  442.                 g2d.setStroke(new BasicStroke(2));
  444.                 if ((screenData[i] & 1) != 0) { 
  445.                     g2d.drawLine(x, y, x, y + BLOCK_SIZE - 1);
  446.                 }
  448.                 if ((screenData[i] & 2) != 0) { 
  449.                     g2d.drawLine(x, y, x + BLOCK_SIZE - 1, y);
  450.                 }
  452.                 if ((screenData[i] & 4) != 0) { 
  453.                     g2d.drawLine(x + BLOCK_SIZE - 1, y, x + BLOCK_SIZE - 1,
  454.                             y + BLOCK_SIZE - 1);
  455.                 }
  457.                 if ((screenData[i] & 8) != 0) { 
  458.                     g2d.drawLine(x, y + BLOCK_SIZE - 1, x + BLOCK_SIZE - 1,
  459.                             y + BLOCK_SIZE - 1);
  460.                 }
  462.                 if ((screenData[i] & 16) != 0) { 
  463.                     g2d.setColor(dotColor);
  464.                     g2d.fillRect(x + 11, y + 11, 2, 2);
  465.                 }
  467.                 i++;
  468.             }
  469.         }
  470.     }
  472.     private void initGame() {
  474.         pacsLeft = 3;
  475.         score = 0;
  476.         initLevel();
  477.         N_GHOSTS = 6;
  478.         currentSpeed = 3;
  479.     }
  481.     private void initLevel() {
  483.         int i;
  484.         for (i = 0; i < N_BLOCKS * N_BLOCKS; i++) {
  485.             screenData[i] = levelData[i];
  486.         }
  488.         continueLevel();
  489.     }
  491.     private void continueLevel() {
  493.         short i;
  494.         int dx = 1;
  495.         int random;
  497.         for (i = 0; i < N_GHOSTS; i++) {
  499.             ghost_y[i] = 4 * BLOCK_SIZE;
  500.             ghost_x[i] = 4 * BLOCK_SIZE;
  501.             ghost_dy[i] = 0;
  502.             ghost_dx[i] = dx;
  503.             dx = -dx;
  504.             random = (int) (Math.random() * (currentSpeed + 1));
  506.             if (random > currentSpeed) {
  507.                 random = currentSpeed;
  508.             }
  510.             ghostSpeed[i] = validSpeeds[random];
  511.         }
  513.         pacman_x = 7 * BLOCK_SIZE;
  514.         pacman_y = 11 * BLOCK_SIZE;
  515.         pacmand_x = 0;
  516.         pacmand_y = 0;
  517.         req_dx = 0;
  518.         req_dy = 0;
  519.         view_dx = -1;
  520.         view_dy = 0;
  521.         dying = false;
  522.     }
  524.     private void loadImages() {
  526.         ghost = new ImageIcon("images/ghost.png").getImage();
  527.         pacman1 = new ImageIcon("images/pacman.png").getImage();
  528.         pacman2up = new ImageIcon("images/up1.png").getImage();
  529.         pacman3up = new ImageIcon("images/up2.png").getImage();
  530.         pacman4up = new ImageIcon("images/up3.png").getImage();
  531.         pacman2down = new ImageIcon("images/down1.png").getImage();
  532.         pacman3down = new ImageIcon("images/down2.png").getImage();
  533.         pacman4down = new ImageIcon("images/down3.png").getImage();
  534.         pacman2left = new ImageIcon("images/left1.png").getImage();
  535.         pacman3left = new ImageIcon("images/left2.png").getImage();
  536.         pacman4left = new ImageIcon("images/left3.png").getImage();
  537.         pacman2right = new ImageIcon("images/right1.png").getImage();
  538.         pacman3right = new ImageIcon("images/right2.png").getImage();
  539.         pacman4right = new ImageIcon("images/right3.png").getImage();
  541.     }
  543.     @Override
  544.     public void paintComponent(Graphics g) {
  545.         super.paintComponent(g);
  547.         doDrawing(g);
  548.     }
  550.     private void doDrawing(Graphics g) {
  552.         Graphics2D g2d = (Graphics2D) g;
  554.         g2d.setColor(Color.black);
  555.         g2d.fillRect(0, 0, d.width, d.height);
  557.         drawMaze(g2d);
  558.         drawScore(g2d);
  559.         doAnim();
  561.         if (inGame) {
  562.             playGame(g2d);
  563.         } else {
  564.             showIntroScreen(g2d);
  565.         }
  567.         g2d.drawImage(ii, 5, 5, this);
  568.         Toolkit.getDefaultToolkit().sync();
  569.         g2d.dispose();
  570.     }
  572.     class TAdapter extends KeyAdapter {
  574.         @Override
  575.         public void keyPressed(KeyEvent e) {
  577.             int key = e.getKeyCode();
  579.             if (inGame) {
  580.                 if (key == KeyEvent.VK_LEFT) {
  581.                     req_dx = -1;
  582.                     req_dy = 0;
  583.                 } else if (key == KeyEvent.VK_RIGHT) {
  584.                     req_dx = 1;
  585.                     req_dy = 0;
  586.                 } else if (key == KeyEvent.VK_UP) {
  587.                     req_dx = 0;
  588.                     req_dy = -1;
  589.                 } else if (key == KeyEvent.VK_DOWN) {
  590.                     req_dx = 0;
  591.                     req_dy = 1;
  592.                 } else if (key == KeyEvent.VK_ESCAPE && timer.isRunning()) {
  593.                     inGame = false;
  594.                 } else if (key == KeyEvent.VK_PAUSE) {
  595.                     if (timer.isRunning()) {
  596.                         timer.stop();
  597.                     } else {
  598.                         timer.start();
  599.                     }
  600.                 }
  601.             } else {
  602.                 if (key == 's' || key == 'S') {
  603.                     inGame = true;
  604.                     initGame();
  605.                 }
  606.             }
  607.         }
  609.         @Override
  610.         public void keyReleased(KeyEvent e) {
  612.             int key = e.getKeyCode();
  614.             if (key == Event.LEFT || key == Event.RIGHT
  615.                     || key == Event.UP || key == Event.DOWN) {
  616.                 req_dx = 0;
  617.                 req_dy = 0;
  618.             }
  619.         }
  620.     }
  622.     @Override
  623.     public void actionPerformed(ActionEvent e) {
  625.         repaint();
  626.     }
  627. }

用光标键控制吃豆人。 Esc 键完成游戏，暂停键暂停游戏。

private int pacman_x, pacman_y, pacmand_x, pacmand_y;

前两个变量存储吃豆子精灵的 x 和 y 坐标。 最后两个变量是水平和垂直方向的增量变化。

private final short levelData[] = {
    19, 26, 26, 26, 18, 18, 18, 18, ...
};

这些数字组成了迷宫。 它们提供了信息，我们可以据此创建角点。 1 号是左上角。 数字 2、4 和 8 分别代表顶角，右角和底角。 16 号是重点。 可以添加这些数字，例如左上角的数字 19 表示正方形将具有顶部和左侧边框以及一个点（16 + 2 + 1）。

private void doAnim() {

    pacAnimCount--;

    if (pacAnimCount <= 0) {
        pacAnimCount = PAC_ANIM_DELAY;
        pacmanAnimPos = pacmanAnimPos + pacAnimDir;

        if (pacmanAnimPos == (PACMAN_ANIM_COUNT - 1) || pacmanAnimPos == 0) {
            pacAnimDir = -pacAnimDir;
        }
    }
}

doAnim()对pacmanAnimPos变量进行计数，该变量确定绘制哪种吃豆子图像。 有四个吃豆人图像。 还有一个PAC_ANIM_DELAY常数，它会使动画变慢。 否则，吃豆人会太快张开嘴。

boolean finished = true;

while (i < N_BLOCKS * N_BLOCKS && finished) {

    if ((screenData[i] & 48) != 0) {
        finished = false;
    }

    i++;
}

此代码是checkMaze()方法的一部分。 它检查吃豆人是否还有剩余的食物要吃。 数字 16 代表一个点。 如果所有积分都被消耗掉了，我们将进入下一个层次。 （在我们的例子中，我们只是重新启动游戏。）

接下来，我们将研究moveGhosts()方法。 鬼魂移动一个正方形，然后决定是否改变方向。

if (ghost_x[i] % BLOCK_SIZE == 0 && ghost_y[i] % BLOCK_SIZE == 0) {

我们仅在完成移动一个正方形后才继续。

pos = pacman_x / BLOCK_SIZE + N_BLOCKS * (int) (pacman_y / BLOCK_SIZE);

这条线确定了幻影的位置； 在哪个位置/正方形。 有 225 个理论职位。 （鬼不能在墙上移动。）

if ((screenData[pos] & 1) == 0 && ghost_dx[i] != 1) {
    dx[count] = -1;
    dy[count] = 0;
    count++;
}

如果左侧没有障碍物并且幻影尚未向右移动，则幻影将向左移动。 该代码的真正含义是什么？ 如果幽灵进入隧道，他将朝着同一方向继续前进，直到他离开隧道。 鬼影的移动部分是随机的。 我们不会在长隧道中应用这种随机性，因为幽灵可能会卡在那里。

if (pacman_x > (ghost_x[i] - 12) && pacman_x < (ghost_x[i] + 12)
        && pacman_y > (ghost_y[i] - 12) && pacman_y < (ghost_y[i] + 12)
        && inGame) {

    dying = true;
}

如果幽灵和吃豆人之间发生碰撞，吃豆人会死。

接下来，我们将研究movePacman()方法。 req_dx和req_dy变量在TAdapter内部类中确定。 这些变量由光标键控制。

if ((ch & 16) != 0) {
    screenData[pos] = (short) (ch & 15);
    score++;
}

如果吃豆人移动到带点的位置，我们将其从迷宫中移出并增加得分值。

if ((pacmand_x == -1 && pacmand_y == 0 && (ch & 1) != 0)
        || (pacmand_x == 1 && pacmand_y == 0 && (ch & 4) != 0)
        || (pacmand_x == 0 && pacmand_y == -1 && (ch & 2) != 0)
        || (pacmand_x == 0 && pacmand_y == 1 && (ch & 8) != 0)) {
    pacmand_x = 0;
    pacmand_y = 0;
}

如果吃豆子无法按当前方向继续前进，则会停下来。

private void drawPacman(Graphics2D g2d) {

    if (view_dx == -1) {
        drawPacnanLeft(g2d);
    } else if (view_dx == 1) {
        drawPacmanRight(g2d);
    } else if (view_dy == -1) {
        drawPacmanUp(g2d);
    } else {
        drawPacmanDown(g2d);
    }
}

吃豆人有四个可能的方向。 所有方向都有四个图像。 这些图像用于为吃豆人张嘴和闭嘴动画。

drawMaze()方法从screenData数组中的数字中提取迷宫。 数字 1 是左侧边框，2 是顶部边框，4 是右侧边框，8 是底部边框，16 是点。 我们只需在迷宫中浏览所有 225 平方。 例如，在screenData数组中有 9 个。 我们设置了第一位（1）和第四位（8）。 因此，我们在此特定正方形上绘制了底部和左侧边框。

if ((screenData[i] & 1) != 0) { 
    g2d.drawLine(x, y, x, y + BLOCK_SIZE - 1);
}

如果设置了数字的第一位，我们将绘制左边框。

Pacman.java

package com.zetcode;

import java.awt.EventQueue;
import javax.swing.JFrame;

public class Pacman extends JFrame {

    public Pacman() {

        initUI();
    }

    private void initUI() {

        add(new Board());

        setTitle("Pacman");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(380, 420);
        setLocationRelativeTo(null);
    }

    public static void main(String[] args) {

        EventQueue.invokeLater(() -> {
            Pacman ex = new Pacman();
            ex.setVisible(true);
        });
    }
}

这是带有main方法的 Pacman 文件。

Java 吃豆人 - 图1

图：吃豆人

这是吃豆子游戏。