Cocos2d-x FlappyBird

 HelloWorldScene.cpp

#include "HelloWorldScene.h"

USING_NS_CC;

CCScene* HelloWorld::scene()
{
    // 'scene' is an autorelease object
    CCScene *scene = CCScene::create();

    // 'layer' is an autorelease object
    HelloWorld *layer = HelloWorld::create();

    //添加一个背景颜色图层
    CCSize s = CCDirector::sharedDirector()->getWinSize();

    CCLayer *colorlayer = CCLayerColor::create(ccc4(0x00, 0xff, 0xff, 0xff), s.width, s.height);

    colorlayer->ignoreAnchorPointForPosition(false);

    colorlayer->setPosition(s.width / 2, s.height / 2);

    scene->addChild(colorlayer, 1, colorlayer->getTag());
    
    // add layer as a child to scene
    //将主图层添加都背景图层中
    colorlayer->addChild(layer);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool HelloWorld::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !CCLayer::init() )
    {
        return false;
    }

    //取得屏幕的大小
    screenSize = CCDirector::sharedDirector()->getVisibleSize();

    //初始化世界
    initWorld();

    //添加小鸟、障碍物容器及地面
    addBird();
    addBarContainer();
    addGround();

    //每隔一秒添加一组障碍物
    scheduleUpdate();
    schedule(schedule_selector(HelloWorld::addBar), 1.0f);

    //设置允许触摸
    setTouchEnabled(true);

    return true;
}

void HelloWorld::initWorld()
{
    //重力加速度：纵向9.8，横向 0
    world = new b2World(b2Vec2(0, -9.8f));
    //添加监视
    world->SetContactListener(this);
}

void HelloWorld::startGame(float dt){
    scheduleUpdate();
    schedule(schedule_selector(HelloWorld::addBar), 1);
}

void HelloWorld::stopGame(){
    unscheduleUpdate();
    unschedule(schedule_selector(HelloWorld::addBar));
}


void HelloWorld::addBird()
{
    bird = B2Sprite::create("bird.png");
    CCSize size = bird->getContentSize();

    //添加小鸟
    b2BodyDef bodyDef;
    bodyDef.type = b2_dynamicBody;
    bodyDef.position = b2Vec2(screenSize.width/2/RATIO, screenSize.height/2/RATIO);
    b2Body * birdBody = world->CreateBody(&bodyDef);

    //设置边界
    b2PolygonShape birdShape;
    birdShape.SetAsBox(size.width/2/RATIO, size.height/2/RATIO);

    //碰撞
    b2FixtureDef birdFixtureDef;
    birdFixtureDef.shape= &birdShape;
    birdBody->CreateFixture(&birdFixtureDef);

    bird->setPTMRatio(RATIO);
    bird->setB2Body(birdBody);
    addChild(bird);
}

void HelloWorld::addBar(float dt)
{
    float offset = -rand()%5;

    //downbar
    B2Sprite *downBar = B2Sprite::create("down_bar.png");
    CCSize downBarSize = downBar->getContentSize();

    b2BodyDef downBarBodyDef;
    downBarBodyDef.type = b2_kinematicBody;
    downBarBodyDef.position = b2Vec2(screenSize.width/RATIO + 2, downBarSize.height/RATIO/2 + offset);
    downBarBodyDef.linearVelocity = b2Vec2(-5.0f, 0);

    b2PolygonShape downBarShape;
    downBarShape.SetAsBox(downBarSize.width/RATIO/2, downBarSize.height/RATIO/2);

    b2FixtureDef downBarFixtureDef;
    downBarFixtureDef.shape = &downBarShape;

    b2Body *downBarBody = world->CreateBody(&downBarBodyDef);
    downBarBody->CreateFixture(&downBarFixtureDef);

    downBar->setB2Body(downBarBody);
    downBar->setPTMRatio(RATIO);

    //upbar
    B2Sprite *upBar = B2Sprite::create("up_bar.png");
    CCSize upBarSize = upBar->getContentSize();

    b2BodyDef upBarBodyDef;
    upBarBodyDef.type = b2_kinematicBody;
    upBarBodyDef.position = b2Vec2(screenSize.width/RATIO + 2, upBarSize.height/RATIO/2 + offset + downBarSize.height/RATIO + 2.5f);
    upBarBodyDef.linearVelocity = b2Vec2(-5, 0);

    b2PolygonShape upBarShape;
    upBarShape.SetAsBox(upBarSize.width/RATIO/2, upBarSize.height/RATIO/2);

    b2FixtureDef upBarFixtureDef;
    upBarFixtureDef.shape = &upBarShape;

    b2Body *upBarBody = world->CreateBody(&upBarBodyDef);
    upBarBody->CreateFixture(&upBarFixtureDef);

    upBar->setB2Body(upBarBody);
    upBar->setPTMRatio(RATIO);

    barContainer->addChild(upBar);
    barContainer->addChild(downBar);
}

void HelloWorld::addBarContainer()
{
    //将所有的障碍物包裹在一个容器中
    barContainer = CCSprite::create();
    addChild(barContainer);
}

void HelloWorld::addGround()
{
    B2Sprite *ground = B2Sprite::create("ground.png");
    CCSize size = ground->getContentSize();

    b2BodyDef bDef;
    bDef.type = b2_staticBody;
    bDef.position = b2Vec2(size.width/2/RATIO, size.height/2/RATIO);
    b2Body *groundBody = world->CreateBody(&bDef);

    b2PolygonShape groundShape;
    groundShape.SetAsBox(size.width/2/RATIO, size.height/2/RATIO);

    b2FixtureDef groundFixtureDef;
    groundFixtureDef.shape = &groundShape;
    groundBody->CreateFixture(&groundFixtureDef);

    ground->setPTMRatio(RATIO);
    ground->setB2Body(groundBody);
    addChild(ground);
}

void HelloWorld::update(float dt)
{
    world->Step(dt, 8, 3);

    CCSprite *sprite;

    //取得世界中的所有的body
    b2Body *node = world->GetBodyList();

    //遍历世界中的body
    while(node)
    {
        b2Body *body = node;
        node = node->GetNext();
        sprite = (CCSprite*)body->GetUserData();

        //超出屏幕左边界，销毁
        if (body->GetPosition().x < -1)
        {
            if (sprite != NULL)
            {
                //在屏幕上清除
                sprite->removeFromParent();
            }
            //在内存中销毁
            world->DestroyBody(body);
        }
    }
}

void HelloWorld::BeginContact(b2Contact *contact){
    //碰撞检测，有一个为鸟游戏就结束
    if (contact->GetFixtureA()->GetBody()->GetUserData()==bird || contact->GetFixtureB()->GetBody()->GetUserData()==bird)
    {
        //游戏结束，弹出dialog
        stopGame();
        CCMessageBox("Game Over", "Alert");
    }
}

void HelloWorld::ccTouchesBegan(CCSet *pTouches, CCEvent *pEvent)
{
    //触碰屏幕时，小鸟向上运动，重力加速度：纵向 5，横向 0
    bird->getB2Body()->SetLinearVelocity(b2Vec2(0, 5.0f));
}


void HelloWorld::menuCloseCallback(CCObject* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT) || (CC_TARGET_PLATFORM == CC_PLATFORM_WP8)
    CCMessageBox("You pressed the close button. Windows Store Apps do not implement a close button.","Alert");
#else
    CCDirector::sharedDirector()->end();
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
    exit(0);
#endif
#endif
}

HelloWorldScene.h

#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__

#include "cocos2d.h"
#include "Box2DBox2D.h"
#include "B2Sprite.h"

#define RATIO 72.0f

class HelloWorld : public cocos2d::CCLayer,public b2ContactListener
{
public:
    // Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone
    virtual bool init();  

    // there's no 'id' in cpp, so we recommend returning the class instance pointer
    static cocos2d::CCScene* scene();
    
    // a selector callback
    void menuCloseCallback(CCObject* pSender);
    
    // implement the "static node()" method manually
    CREATE_FUNC(HelloWorld);

    virtual void ccTouchesBegan(CCSet *pTouches, CCEvent *pEvent);
    virtual void BeginContact(b2Contact* contact);

    virtual void update(float dt);

    b2World *world;
    B2Sprite *bird;

    CCSize screenSize;

    CCSprite *barContainer;

private:
    void addBird();
    void addGround();
    void initWorld();
    void addBar(float dt);
    void addBarContainer();
    void startGame(float dt);
    void stopGame();
};

#endif // __HELLOWORLD_SCENE_H__