简单的碰撞检测实践篇（下）源码

      #include "HelloWorldScene.h"
#include "cloud.h"
#include "Missile.h"
#include "Box.h"

using namespace cocos2d;

//天空的颜色
static const ccColor4B SKY_COLOR = {30, 66, 78, 255};
static HelloWorld* layer;
//导弹精灵
static	Missile* MissileSprite;
//天空背景图层
static cocos2d::CCLayerColor* skyLayer;

enum {
	//设定一个父节点的tag
    kTagParentNode = 1,
};

enum {
    Z_PHYSICS_DEBUG = 100,
};

HelloWorld::HelloWorld(){


}

HelloWorld::~HelloWorld()
{
    // manually Free rogue shapes
    for( int i=0;i<4;i++) {
        cpShapeFree( m_pWalls[i] );
    }

    cpSpaceFree( m_pSpace );

}

//调试模式下可以看到为刚体定义的形状，否则形状会不可见
void HelloWorld::toggleDebugCallback(CCObject* pSender)
{
#if CC_ENABLE_CHIPMUNK_INTEGRATION
    m_pDebugLayer->setVisible(! m_pDebugLayer->isVisible());
#endif
}

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

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

        // add layer as a child to scene
        scene->addChild(layer,0,1);


    } while (0);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool HelloWorld::init()
{
    bool bRet = false;
    do 
    {
        //////////////////////////////////////////////////////////////////////////
        // super init first
        //////////////////////////////////////////////////////////////////////////

        CC_BREAK_IF(! CCLayer::init());

        //////////////////////////////////////////////////////////////////////////
        // add your codes below...
        //////////////////////////////////////////////////////////////////////////

        // 1. Add a menu item with "X" image, which is clicked to quit the program.

        // Create a "close" menu item with close icon, it's an auto release object.
        CCMenuItemImage *pCloseItem = CCMenuItemImage::create(
            "CloseNormal.png",
            "CloseSelected.png",
            this,
            menu_selector(HelloWorld::menuCloseCallback));
        CC_BREAK_IF(! pCloseItem);

        // Place the menu item bottom-right conner.
        pCloseItem->setPosition(ccp(CCDirector::sharedDirector()->getWinSize().width - 20, 20));

        // Create a menu with the "close" menu item, it's an auto release object.
        CCMenu* pMenu = CCMenu::create(pCloseItem, NULL);
        pMenu->setPosition(CCPointZero);
        CC_BREAK_IF(! pMenu);

        // Add the menu to HelloWorld layer as a child layer.
        this->addChild(pMenu, 1);

		this->setTouchEnabled(true);
        // Get window size and place the label upper. 
        CCSize size = CCDirector::sharedDirector()->getWinSize();
		//建立天空颜色图层
		CCLayerColor *skyLayer = CCLayerColor::create(SKY_COLOR);
		addChild(skyLayer);

        // 创建地面精灵.
        CCSprite* pSprite = CCSprite::create("Terrain.png");
		pSprite->setScale(0.5f);
        CC_BREAK_IF(! pSprite);

        // Place the sprite on the center of the screen
        pSprite->setPosition(ccp(size.width/2, size.height/2));

        // Add the sprite to HelloWorld layer as a child layer.
        this->addChild(pSprite, 0);

		 //加入箱子的表情纹理
		 		CCTextureCache::sharedTextureCache()->addImage("BoxUpset.png");
				CCTextureCache::sharedTextureCache()->addImage("BoxHappy.png");

		initPhysics();

		//创建并设置自定义的精灵-愤怒的乌云
		cloudSprite=cloud::create("Cloud.png");
		cloudSprite->setScale(0.5f);
		addChild(cloudSprite);
		cloudSprite->setPosition(ccp(240,280));

    // menu for debug layer 设定物理引擎运行的模式用的菜单按钮
    CCMenuItemFont::setFontSize(24);
    CCMenuItemFont *item = CCMenuItemFont::create("Toggle debug", this, menu_selector(HelloWorld::toggleDebugCallback));

    CCMenu *menu = CCMenu::create(item, NULL);
    this->addChild(menu);
    menu->setPosition(ccp(VisibleRect::right().x-100, VisibleRect::top().y-60));

	Box* box=Box::create("BoxHappy.png",ccp(110,100),m_pSpace);
	box->setScale(0.6f);
	addChild(box);
			//调用计时器，此类计时器只认update方法，也就是层里定义的那个
		 scheduleUpdate();



        bRet = true;
    } while (0);

    return bRet;
}

void HelloWorld::ccTouchesBegan(CCSet* touches, CCEvent* event)
{
    //Add a new body/atlas sprite at the touched location
	//根据触屏位置添加刚体精灵
    CCSetIterator it;
    CCTouch* touch;
    for( it = touches->begin(); it != touches->end(); it++) 
    {
        touch = (CCTouch*)(*it);

        if(!touch)
            break;
		
		//根据触屏点创建一个导弹
		MissileSprite=Missile::create("Missile.png",cloudSprite->getPosition(),cpv(this->getParent()->convertTouchToNodeSpace(touch).x,this->convertTouchToNodeSpace(touch).y),m_pSpace);
		MissileSprite->setScale(0.5f);
		addChild(MissileSprite);
		
		//更新乌云眼神的角度
		cloudSprite->lookAt=touch->getLocation();
	}
}

	//触摸移动时的回调函数，用于引导导弹
void HelloWorld::ccTouchesMoved(CCSet* touches, CCEvent* event){
    CCSetIterator it;
    CCTouch* touch;
	    for( it = touches->begin(); it != touches->end(); it++) 
    {

	touch = (CCTouch*)(*it);
	        if(!touch)
            break;

		}

		if(MissileSprite){
		//开启导弹追踪属性并设置重力矢量点到当前触屏移动到的位置
			MissileSprite->isTracking=true;
			MissileSprite->target=cpv(this->getParent()->convertTouchToNodeSpace(touch).x,this->convertTouchToNodeSpace(touch).y);
		}
		//更新乌云眼神的角度
		cloudSprite->lookAt=touch->getLocation();
}

//触摸结束时的回调
void HelloWorld::ccTouchesEnded(CCSet* touches, CCEvent* event){
	//去除导弹的跟踪属性
	if(MissileSprite){
	MissileSprite->isTracking=false;
	}
}

//物理系统初始化
void HelloWorld::initPhysics()
{
#if CC_ENABLE_CHIPMUNK_INTEGRATION    
    // init chipmunk
    //cpInitChipmunk();
	//创建一个物理空间
    m_pSpace = cpSpaceNew();
	//设定空间的重力点
    m_pSpace->gravity = cpv(0, -100);
	
    //
    // rogue shapes
    // We have to free them manually
    //这里创建了四个形状用于创建一个矩形的墙体，其对应的刚体是静态刚体，也就是保持静止不动的刚体
	//cpSegmentShapeNew用来建立一个段状形状，其它定义请看源码
    // bottom
    m_pWalls[0] = cpSegmentShapeNew( m_pSpace->staticBody,
        cpv(VisibleRect::leftBottom().x,VisibleRect::leftBottom().y),
        cpv(VisibleRect::rightBottom().x, VisibleRect::rightBottom().y), 9.0f);

    // top
    m_pWalls[1] = cpSegmentShapeNew( m_pSpace->staticBody, 
        cpv(VisibleRect::leftTop().x, VisibleRect::leftTop().y),
        cpv(VisibleRect::rightTop().x, VisibleRect::rightTop().y), 0.0f);

    // left
    m_pWalls[2] = cpSegmentShapeNew( m_pSpace->staticBody,
        cpv(VisibleRect::leftBottom().x,VisibleRect::leftBottom().y),
        cpv(VisibleRect::leftTop().x,VisibleRect::leftTop().y), 0.0f);

    // right
    m_pWalls[3] = cpSegmentShapeNew( m_pSpace->staticBody, 
        cpv(VisibleRect::rightBottom().x, VisibleRect::rightBottom().y),
        cpv(VisibleRect::rightTop().x, VisibleRect::rightTop().y), 0.0f);

	//为形状设定弹性及摩擦系数并加入到物理空间
    for( int i=0;i<4;i++) {
        m_pWalls[i]->e = 1.0f;
        m_pWalls[i]->u = 1.0f;
		//设定碰撞类型标识
		m_pWalls[i]->collision_type=i;
		//添加墙体到物理空间
        cpSpaceAddStaticShape(m_pSpace, m_pWalls[i] );
		//设定碰撞的回调函数，5是导弹的碰撞类型标识
		cpSpaceAddCollisionHandler(m_pSpace,5,i,beginCollision,NULL,NULL,NULL,NULL);
    }

    // Physics debug layer
    m_pDebugLayer = CCPhysicsDebugNode::create(m_pSpace);
    this->addChild(m_pDebugLayer, Z_PHYSICS_DEBUG);
#endif
}

void HelloWorld::update(float delta)
{
    // Should use a fixed size step based on the animation interval.
    int steps = 2;
    flo