cocos2dx实例开发之flappybird（入门版）

cocos2dx社区里有个系列博客完整地复制原版flappybird的全部特性。只是那个代码写得比較复杂，新手学习起来有点捉摸不透，这里我写了个简单的版本号。演演示样例如以下：

创建项目

VS2013+cocos2dx 3.2创建win32项目。因为仅仅是学习，所以没有编译为安卓、ios或者WP平台的可运行文件。
终于的项目project结构例如以下：



非常easy，仅仅有三个类，预载入类。游戏主场景类，应用代理类。新手刚入门喜欢将非常多东西都写在尽量少的类里面。

游戏设计

游戏结构例如以下，游戏包括预载入场景和主场景，主场景中包括背景、小鸟、管道和各种UI界面。

开发步骤

1，素材收集
从apk文件中提取出来一些图片和音频，并用TexturePatcher拼成大图，导出plist文件。



2。预载入场景
新建一个LoadingScene，在里面加入一张启动图片，通过异步载入纹理并回调的方式把全部图片素材、小鸟帧动画以及音频文件都加入到缓存，载入完成后跳转到游戏主场景。

//加入载入回调函数，用异步载入纹理
Director::getInstance()->getTextureCache()->addImageAsync("game.png", CC_CALLBACK_1(LoadingScene::loadingCallBack, this));

void LoadingScene::loadingCallBack(Texture2D *texture)
{
//预载入帧缓存纹理
SpriteFrameCache::getInstance()->addSpriteFramesWithFile("game.plist", texture);
//预载入帧动画
auto birdAnimation = Animation::create();
birdAnimation->setDelayPerUnit(0.2f);
birdAnimation->addSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("bird1.png"));
birdAnimation->addSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("bird2.png"));
birdAnimation->addSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("bird3.png"));
AnimationCache::getInstance()->addAnimation(birdAnimation, "birdAnimation"); //将小鸟动画加入到动画缓存
//预载入音效
SimpleAudioEngine::getInstance()->preloadEffect("die.mp3");
SimpleAudioEngine::getInstance()->preloadEffect("hit.mp3");
SimpleAudioEngine::getInstance()->preloadEffect("point.mp3");
SimpleAudioEngine::getInstance()->preloadEffect("swooshing.mp3");
SimpleAudioEngine::getInstance()->preloadEffect("wing.mp3");

//载入完成跳转到游戏场景
auto gameScene = GameScene::createScene();
TransitionScene *transition = TransitionFade::create(0.5f, gameScene);
Director::getInstance()->replaceScene(transition);
}

3，游戏主场景
3.1。背景和logo
用图片精灵就可以

//加入游戏背景
Sprite *backGround = Sprite::createWithSpriteFrameName("bg.png");
backGround->setPosition(visibleOrigin.x + visibleSize.width / 2, visibleOrigin.y + visibleSize.height / 2);
this->addChild(backGround);
//logo
auto gameLogo = Sprite::createWithSpriteFrameName("bird_logo.png");
gameLogo->setPosition(visibleOrigin.x + visibleSize.width / 2, visibleOrigin.y + visibleSize.height / 2+100);
gameLogo->setName("logo");
this->addChild(gameLogo);

logo在游戏開始后要隐藏掉。

3.2。小鸟

//小鸟
birdSprite = Sprite::create();
birdSprite->setPosition(visibleOrigin.x + visibleSize.width / 3, visibleOrigin.y + visibleSize.height / 2);
this->addChild(birdSprite);
auto birdAnim = Animate::create(AnimationCache::getInstance()->animationByName("birdAnimation"));
birdSprite->runAction(RepeatForever::create(birdAnim));  //挥翅动画
auto up = MoveBy::create(0.4f, Point(0, 8));
auto upBack = up->reverse();
if (gameStatus == GAME_READY)
{
swingAction = RepeatForever::create(Sequence::create(up, upBack, NULL));
birdSprite->runAction(swingAction); //上下晃动动画
}

在准备界面下除了有扇翅膀的动作，还有上下浮动的动作。

3.3，地板
地板的左移是用两张错位的地板图片循环左移实现的。

须要用到自己定义调度器，注意调节移动速度。

//加入两个land
land1 = Sprite::createWithSpriteFrameName("land.png");
land1->setAnchorPoint(Point::ZERO);
land1->setPosition(Point::ZERO);
this->addChild(land1, 10);  //置于最顶层
land2 = Sprite::createWithSpriteFrameName("land.png");
land2->setAnchorPoint(Point::ZERO);
land2->setPosition(Point::ZERO);
this->addChild(land2, 10);

Size visibleSize = Director::getInstance()->getVisibleSize();
//两个图片循环移动
land1->setPositionX(land1->getPositionX() - 1.0f);
land2->setPositionX(land1->getPositionX() + land1->getContentSize().width - 2.0f);
if (land2->getPositionX() <= 0)
land1->setPosition(Point::ZERO);

3.4，水管
一组水管由上下2半根组成，用Node包起来，弄个vector容器加入两组管道。每次出如今屏幕中的管子仅仅有两组，当一组消失在屏幕范围内则重设置其横坐标，须要提前计算好各种间距或者高度。

//同屏幕出现的仅仅有两根管子。放到容器里面，上下绑定为一根
for (int i = 0; i < 2; i++)
{
auto visibleSize = Director::getInstance()->getVisibleSize();
Sprite *pipeUp = Sprite::createWithSpriteFrameName("pipe_up.png");
Sprite *pipeDown = Sprite::createWithSpriteFrameName("pipe_down.png");
Node *singlePipe = Node::create();
//给上管绑定刚体
auto pipeUpBody = PhysicsBody::createBox(pipeUp->getContentSize());
pipeUpBody->setDynamic(false);
pipeUpBody->setContactTestBitmask(1);
pipeUp->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
pipeUp->setPhysicsBody(pipeUpBody);
//给两个管子分开设置刚体。能够留出中间的空隙使得小鸟通过
//给下管绑定刚体
auto pipeDownBody = PhysicsBody::createBox(pipeDown->getContentSize());
pipeDownBody->setDynamic(false);
pipeDownBody->setContactTestBitmask(1);
pipeDown->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
pipeDown->setPhysicsBody(pipeDownBody);

pipeUp->setPosition(0, PIPE_HEIGHT + PIPE_SPACE);
singlePipe->addChild(pipeUp);
singlePipe->addChild(pipeDown);  //pipeDown默认加到（0,0），上下合并，此时singlePipe以以下的管子中心为锚点
singlePipe->setPosition(i*PIPE_INTERVAL + WAIT_DISTANCE, getRandomHeight() ); //设置初始高度
singlePipe->setName("newPipe");
this->addChild(singlePipe);  //把两个管子都增加到层
pipes.pushBack(singlePipe);  //两个管子先后增加到容器
}

//管子滚动
for (auto &singlePipe : pipes)
{
singlePipe->setPositionX(singlePipe->getPositionX() - 1.0f);
if (singlePipe->getPositionX() < -PIPE_WIDTH/2)
{
singlePipe->setPositionX(visibleSize.width+PIPE_WIDTH/2);
singlePipe->setPositionY(getRandomHeight());
singlePipe->setName("newPipe");  //每次重设一根管子，标为new
}
}

3.5。增加物理世界
cocos2dx 3.0后引入了自带的物理引擎，使用方法和box2D等差点儿相同。
物理世界初始化

gameScene->getPhysicsWorld()->setGravity(Vec2(0, -900)); //设置重力场,重力加速度能够依据手感改小点

gameLayer->setPhysicWorld(gameScene->getPhysicsWorld()); //绑定物理世界

小鸟绑定刚体

//小鸟绑定刚体
auto birdBody = PhysicsBody::createCircle(BIRD_RADIUS); //将小鸟当成一个圆，懒得弄精确的轮廓线了
birdBody->setDynamic(true);   //设置为能够被物理场所作用而动作
birdBody->setContactTestBitmask(1); //必须设置这项为1才干检測到不同的物体碰撞
birdBody->setGravityEnable(false);   //设置是否被重力影响,准备画面中不受重力影响
birdSprite->setPhysicsBody(birdBody); //为小鸟设置刚体

地板绑定刚体

//设置地板刚体
Node *groundNode = Node::create();
auto groundBody = PhysicsBody::createBox(Size(visibleSize.width, land1->getContentSize().height));
groundBody->setDynamic(false);
groundBody->setContactTestBitmask(1);
groundNode->setAnchorPoint(Vec2::ANCHOR_MIDDLE); //物理引擎中的刚体仅仅同意结点锚点设置为中心
groundNode->setPhysicsBody(groundBody);
groundNode->setPosition(visibleOrigin.x+visibleSize.width/2,land1->getContentSize().height/2);
this->addChild(groundNode);

管道设置刚体，上下半根分别设置，留出中间的缝隙

//给上管绑定刚体
auto pipeUpBody = PhysicsBody::createBox(pipeUp->getContentSize());
pipeUpBody->setDynamic(false);
pipeUpBody->setContactTestBitmask(1);
pipeUp->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
pipeUp->setPhysicsBody(pipeUpBody);
//给两个管子分开设置刚体，能够留出中间的空隙使得小鸟通过
//给下管绑定刚体
auto pipeDownBody = PhysicsBody::createBox(pipeDown->getContentSize());
pipeDownBody->setDynamic(false);
pipeDownBody->setContactTestBitmask(1);
pipeDown->setAnchorPoint(Vec2::ANCHOR_MIDDLE);
pipeDown->setPhysicsBody(pipeDownBody);

碰撞检測
如今层的init里面的事件分发器中增加碰撞侦听

//加入碰撞监測
auto contactListener = EventListenerPhysicsContact::create();
contactListener->onContactBegin = CC_CALLBACK_1(GameScene::onContactBegin, this);
_eventDispatcher->addEventListenerWithSceneGraphPriority(contactListener, this);

//碰撞监測
bool GameScene::onContactBegin(const PhysicsContact& contact)
{
if (gameStatus == GAME_OVER)  //当游戏结束后不再监控碰撞
return false;

gameOver();
return true;
}

3.6，触摸检測

//触摸监听
bool GameScene::onTouchBegan(Touch *touch, Event *event)

3.7。控制小鸟
由准备模式变到游戏開始模式后，触摸屏幕会给小鸟一个向上的速度。写在触摸检測里面

birdSprite->getPhysicsBody()->setVelocity(Vec2(0, 250)); //给一个向上的初速度

小鸟的旋转角度与纵向速度有关，写在update（）里

//小鸟的旋转
auto curVelocity = birdSprite->getPhysicsBody()->getVelocity();
birdSprite->setRotation(-curVelocity.y*0.1 - 20);  //依据竖直方向的速度算出旋转角度。逆时针为负

3.8，游戏開始
開始后启动各种定时器

//游戏開始
void GameScene::gameStart()
{
gameStatus = GAME_START;
score = 0;//重置分数
scoreLabel->setString(String::createWithFormat("%d", score)->getCString());
this->getChildByName("logo")->setVisible(false); //logo消失
scoreLabel->setVisible(true); //计分開始
this->scheduleUpdate();//启动默认更新
this->schedule(schedule_selector(GameScene::scrollLand), 0.01f); //启动管子和地板滚动
birdSprite->stopAction(swingAction); //游戏開始后停止上下浮动
birdSprite->getPhysicsBody()->setGravityEnable(true); //開始受重力作用
}

3.9，计分和数据存储
在默认的update（）函数里对得分进行推断和更新，通过默认xml存储历史分数

//当游戏開始时，推断得分，这个事实上也能够写在其它地方。比方管子滚动的更新函数里面或者触摸监測里面
if (gameStatus == GAME_START)
{
for (auto &pipe : pipes)
{
if (pipe->getName() == "newPipe") //新来一根管子就推断
{
if (pipe->getPositionX() < birdSprite->getPositionX())
{
score++;
scoreLabel->setString(String::createWithFormat("%d", score)->getCString());
SimpleAudioEngine::getInstance()->playEffect("point.mp3");
pipe->setName("passed"); //标记已经过掉的管子
}
}
}
}

4.0。游戏结束

//游戏结束
void GameScene::gameOver()
{
gameStatus = GAME_OVER;
//获取历史数据
bestScore = UserDefault::getInstance()->getIntegerForKey("BEST");
if (score > bestScore)
{
bestScore = score;  //更新最好分数
UserDefault::getInstance()->setIntegerForKey("BEST", bestScore);
}

SimpleAudioEngine::getInstance()->playEffect("hit.mp3");
//游戏结束后停止地板和管道的滚动
this->unschedule(schedule_selector(GameScene::scrollLand));
}

结束后比較当前分数和历史分数。以便更新。
4.1，音频
音效文件已经增加到缓存，在适当的地方加上全局音频控制器播放音效就可以

SimpleAudioEngine::getInstance()->playEffect("hit.mp3");

4.2，记分板
游戏结束后滑入记分板，并显示重玩button。

//加入记分板和重玩菜单
void GameScene::gamePanelAppear()
{
Size size = Director::getInstance()->getVisibleSize();
Vec2 origin = Director::getInstance()->getVisibleOrigin();
//用node将gameoverlogo和记分板绑在一起
Node *gameOverPanelNode = Node::create();
auto gameOverLabel = Sprite::createWithSpriteFrameName("gameover.png");
gameOverPanelNode->addChild(gameOverLabel);
auto panel = Sprite::createWithSpriteFrameName("board.PNG");//注意这里是大写PNG。原图片用什么后缀这里就用什么，区分大写和小写
gameOverLabel->setPositionY(panel->getContentSize().height); //设置一下坐标
gameOverPanelNode->addChild(panel);
//记分板上加入两个分数
auto curScoreTTF = LabelTTF::create(String::createWithFormat("%d", score)->getCString(), "Arial", 20);
curScoreTTF->setPosition(panel->getContentSize().width-40, panel->getContentSize().height-45);
curScoreTTF->setColor(Color3B(255, 0, 0));
panel->addChild(curScoreTTF);
auto bestScoreTTF = LabelTTF::create(String::createWithFormat("%d", bestScore)->getCString(), "Arial", 20);
bestScoreTTF->setPosition(panel->getContentSize().width - 40, panel->getContentSize().height - 90);
bestScoreTTF->setColor(Color3B(0, 255, 0));
panel->addChild(bestScoreTTF);
this->addChild(gameOverPanelNode);
gameOverPanelNode->setPosition(origin.x + size.width / 2, origin.y + size.height );
//滑入动画
gameOverPanelNode->runAction(MoveTo::create(0.5f, Vec2(origin.x + size.width / 2, origin.y + size.height / 2)));
SimpleAudioEngine::getInstance()->playEffect("swooshing.mp3");
//加入菜单
MenuItemImage *restartItem = MenuItemImage::create("start_btn.png", "start_btn_pressed.png", this,menu_selector(GameScene::gameRetart));
auto menu = CCMenu::createWithItem(restartItem);
menu->setPosition(origin.x + size.width / 2, 150);
this->addChild(menu);
}
//游戏又一次開始
void GameScene::gameRetart(Ref *sender)
{
//又一次回到初始画面
auto gameScene = GameScene::createScene();
Director::getInstance()->replaceScene(gameScene); //这里懒得加特效了，直接转场
}

效果图：

源码
csdn下载：MyFlappyBird
github下载：MyFlappyBird

还有非常多要完好的地方，比方没有增加图片数字以及社交分享等等。