Android实战打飞机游戏之无限循环的背景图(2)

public class GameBg { // 游戏背景的图片资源 // 为了循环播放，这里定义两个位图对象， // 其资源引用的是同一张图片 private Bitmap bmpBackGround1; private Bitmap bmpBackGround2; // 游戏背景坐标 private int bg1x, bg1y, bg2x, bg2y; private int speed = 3; public GameBg(Bitmap bmpBackGround) {  this.bmpBackGround1 = bmpBackGround;  this.bmpBackGround2 = bmpBackGround;  // 首先让第一张填满屏幕  bg1y = -Math.abs(bmpBackGround.getHeight() - MySurfaceView.screenH);  bg2y = bg1y - bmpBackGround1.getHeight() +50; } public void draw(Canvas canvas,Paint paint){  canvas.drawBitmap(bmpBackGround1, bg1x, bg1y, paint);  canvas.drawBitmap(bmpBackGround2, bg2x, bg2y, paint); } public void logic(){  bg1y +=speed;  bg2y +=speed;  if(bg1y > MySurfaceView.screenH){   bg1y = bg2y - bmpBackGround1.getHeight() +50;  }  if(bg2y > MySurfaceView.screenH){   bg2y = bg1y - bmpBackGround1.getHeight() +50;  } }}

public class MySurfaceView extends SurfaceView implements Callback, Runnable { private SurfaceHolder sfh; private Paint paint; private Thread th; private boolean flag; private Canvas canvas; // 1 定义游戏状态常量 public static final int GAME_MENU = 0;// 游戏菜单 public static final int GAMEING = 1;// 游戏中 public static final int GAME_WIN = 2;// 游戏胜利 public static final int GAME_LOST = 3;// 游戏失败 public static final int GAME_PAUSE = -1;// 游戏菜单 // 当前游戏状态(默认初始在游戏菜单界面) public static int gameState = GAME_MENU; // 声明一个Resources实例便于加载图片 private Resources res = this.getResources(); // 声明游戏需要用到的图片资源(图片声明) private Bitmap bmpBackGround;// 游戏背景 private Bitmap bmpBoom;// 爆炸效果 private Bitmap bmpBoosBoom;// Boos爆炸效果 private Bitmap bmpButton;// 游戏开始按钮 private Bitmap bmpButtonPress;// 游戏开始按钮被点击 private Bitmap bmpEnemyDuck;// 怪物鸭子 private Bitmap bmpEnemyFly;// 怪物苍蝇 private Bitmap bmpEnemyBoos;// 怪物猪头Boos private Bitmap bmpGameWin;// 游戏胜利背景 private Bitmap bmpGameLost;// 游戏失败背景 private Bitmap bmpPlayer;// 游戏主角飞机 private Bitmap bmpPlayerHp;// 主角飞机血量 private Bitmap bmpMenu;// 菜单背景 public static Bitmap bmpBullet;// 子弹 public static Bitmap bmpEnemyBullet;// 敌机子弹 public static Bitmap bmpBossBullet;// Boss子弹 public static int screenW; public static int screenH; // private GameMenu gameMenu; private GameBg gameBg; /**  * SurfaceView初始化函数  */ public MySurfaceView(Context context) {  super(context);  sfh = this.getHolder();  sfh.addCallback(this);  paint = new Paint();  paint.setColor(Color.WHITE);  paint.setAntiAlias(true);  setFocusable(true); } /**  * SurfaceView视图创建，响应此函数  */ @Override public void surfaceCreated(SurfaceHolder holder) {  screenW = this.getWidth();  screenH = this.getHeight();  initGame();  flag = true;  // 实例线程  th = new Thread(this);  // 启动线程  th.start(); } /**  * 加载游戏资源  */ private void initGame() {  // 加载游戏资源  bmpBackGround = BitmapFactory    .decodeResource(res, R.drawable.background);  bmpBoom = BitmapFactory.decodeResource(res, R.drawable.boom);  bmpBoosBoom = BitmapFactory.decodeResource(res, R.drawable.boos_boom);  bmpButton = BitmapFactory.decodeResource(res, R.drawable.button);  bmpButtonPress = BitmapFactory.decodeResource(res,    R.drawable.button_press);  bmpEnemyDuck = BitmapFactory.decodeResource(res, R.drawable.enemy_duck);  bmpEnemyFly = BitmapFactory.decodeResource(res, R.drawable.enemy_fly);  bmpEnemyBoos = BitmapFactory.decodeResource(res, R.drawable.enemy_pig);  bmpGameWin = BitmapFactory.decodeResource(res, R.drawable.gamewin);  bmpGameLost = BitmapFactory.decodeResource(res, R.drawable.gamelost);  bmpPlayer = BitmapFactory.decodeResource(res, R.drawable.player);  bmpPlayerHp = BitmapFactory.decodeResource(res, R.drawable.hp);  bmpMenu = BitmapFactory.decodeResource(res, R.drawable.menu);  bmpBullet = BitmapFactory.decodeResource(res, R.drawable.bullet);  bmpEnemyBullet = BitmapFactory.decodeResource(res,    R.drawable.bullet_enemy);  bmpBossBullet = BitmapFactory    .decodeResource(res, R.drawable.boosbullet);  //菜单类实例化  gameMenu = new GameMenu(bmpMenu, bmpButton, bmpButtonPress);  gameBg = new GameBg(bmpBackGround); } /**  * 游戏绘图  */ public void myDraw() {  try {   canvas = sfh.lockCanvas();   if (canvas != null) {    canvas.drawColor(Color.WHITE);    // 绘图函数根据游戏状态不同进行不同绘制    switch (gameState) {    case GAME_MENU:     gameMenu.draw(canvas, paint);     break;    case GAMEING:     gameBg.draw(canvas, paint);     break;    case GAME_WIN:     break;    case GAME_LOST:     break;    case GAME_PAUSE:     break;    default:     break;    }   }  } catch (Exception e) {   // TODO: handle exception  } finally {   if (canvas != null)    sfh.unlockCanvasAndPost(canvas);  } } /**  * 触屏事件监听  */ @Override public boolean onTouchEvent(MotionEvent event) {  switch (gameState) {  case GAME_MENU:   gameMenu.onTouchEvent(event);   break;  case GAMEING:   break;  case GAME_WIN:   break;  case GAME_LOST:   break;  case GAME_PAUSE:   break;  }  return true; } /**  * 按键事件监听  */ @Override public boolean onKeyDown(int keyCode, KeyEvent event) {  switch (gameState) {  case GAME_MENU:   break;  case GAMEING:   break;  case GAME_WIN:   break;  case GAME_LOST:   break;  case GAME_PAUSE:   break;  }  return super.onKeyDown(keyCode, event); } @Override public boolean onKeyUp(int keyCode, KeyEvent event) {  switch (gameState) {  case GAME_MENU:   break;  case GAMEING:   break;  case GAME_WIN:   break;  case GAME_LOST:   break;  case GAME_PAUSE:   break;  }  return super.onKeyUp(keyCode, event); } /**  * 游戏逻辑  */ private void logic() {  switch (gameState) {  case GAME_MENU:   break;  case GAMEING:   gameBg.logic();   break;  case GAME_WIN:   break;  case GAME_LOST:   break;  case GAME_PAUSE:   break;  } } @Override public void run() {  while (flag) {   long start = System.currentTimeMillis();   myDraw();   logic();   long end = System.currentTimeMillis();   try {    if (end - start < 50) {     Thread.sleep(50 - (end - start));    }   } catch (InterruptedException e) {    e.printStackTrace();   }  } } /**  * SurfaceView视图状态发生改变，响应此函数  */ @Override public void surfaceChanged(SurfaceHolder holder, int format, int width,   int height) { } /**  * SurfaceView视图消亡时，响应此函数  */ @Override public void surfaceDestroyed(SurfaceHolder holder) {  flag = false; }}