cocos2dx-cpptest的结构

画的不是太清楚，这里详细描述下：

AppDelegate是一个单例类。表示该应用的。入口为：main.cpp

#include "main.h"
#include "AppDelegate.h"
USING_NS_CC;   //#define USING_NS_CC   using namespace cocos2d  
int APIENTRY _tWinMain(HINSTANCE hInstance,
                       HINSTANCE hPrevInstance,
                       LPTSTR    lpCmdLine,
                       int       nCmdShow)
{
   //UNREFERENCED_PARAMETER用于在VC编译器下告知编译器，不必检测改变量是否使用的警告。
    UNREFERENCED_PARAMETER(hPrevInstance); 
    UNREFERENCED_PARAMETER(lpCmdLine);
    //创建一个cocos2dx单例类
    AppDelegate app;
    return Application::getInstance()->run();
}

当run方法执行后，经过一系列的处理，系统会调用AppDelegate的applicationDidFinishLaunching方法。这里有必要讲下AppDelegate中的3个方法：

applicationDidFinishLaunching应用启动会执行该方法。

applicationDidEnterBackground 应用暂停会执行该方法.

applicationWillEnterForeground当应用恢复运行会执行该方法。

进入applicationDidFinishLaunching，看下这里做了什么初始化的操作

    // As an example, load config file
    // XXX: This should be loaded before the Director is initialized,
    // XXX: but at this point, the director is already initialized
    Configuration::getInstance()->loadConfigFile("configs/config-example.plist");
    // initialize director
    auto director = Director::getInstance();
    auto glview = director->getOpenGLView();
    if(!glview) {
        glview = GLView::create("Cpp Tests");
        director->setOpenGLView(glview);
    }
    director->setDisplayStats(true);
    director->setAnimationInterval(1.0 / 60);
    auto screenSize = glview->getFrameSize();
    auto designSize = Size(480, 320);
    auto fileUtils = FileUtils::getInstance();
    std::vector<std::string> searchPaths;
    
    if (screenSize.height > 320)
    {
        auto resourceSize = Size(960, 640);
        searchPaths.push_back("hd");
        searchPaths.push_back("ccs-res/hd");
        searchPaths.push_back("ccs-res/hd/scenetest");
        searchPaths.push_back("ccs-res/hd/scenetest/ArmatureComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/AttributeComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/BackgroundComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/EffectComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/LoadSceneEdtiorFileTest");
        searchPaths.push_back("ccs-res/hd/scenetest/ParticleComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/SpriteComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/TmxMapComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/UIComponentTest");
        searchPaths.push_back("ccs-res/hd/scenetest/TriggerTest");
        searchPaths.push_back("ccs-res");
        director->setContentScaleFactor(resourceSize.height/designSize.height);
    }
    else
    {
        searchPaths.push_back("ccs-res");
        searchPaths.push_back("ccs-res/scenetest/ArmatureComponentTest");
        searchPaths.push_back("ccs-res/scenetest/AttributeComponentTest");
        searchPaths.push_back("ccs-res/scenetest/BackgroundComponentTest");
        searchPaths.push_back("ccs-res/scenetest/EffectComponentTest");
        searchPaths.push_back("ccs-res/scenetest/LoadSceneEdtiorFileTest");
        searchPaths.push_back("ccs-res/scenetest/ParticleComponentTest");
        searchPaths.push_back("ccs-res/scenetest/SpriteComponentTest");
        searchPaths.push_back("ccs-res/scenetest/TmxMapComponentTest");
        searchPaths.push_back("ccs-res/scenetest/UIComponentTest");
        searchPaths.push_back("ccs-res/scenetest/TriggerTest");
    }
    
    fileUtils->setSearchPaths(searchPaths);
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT)
    // a bug in DirectX 11 level9-x on the device prevents ResolutionPolicy::NO_BORDER from working correctly
    glview->setDesignResolutionSize(designSize.width, designSize.height, ResolutionPolicy::SHOW_ALL);
#else
    glview->setDesignResolutionSize(designSize.width, designSize.height, ResolutionPolicy::NO_BORDER);
#endif
    auto scene = Scene::create();
    auto layer = new TestController();
#if (CC_TARGET_PLATFORM != CC_PLATFORM_WP8) && (CC_TARGET_PLATFORM != CC_PLATFORM_WINRT)
    layer->addConsoleAutoTest();
#endif
    layer->autorelease();
    layer->addConsoleAutoTest();
    scene->addChild(layer);
    director->runWithScene(scene);
    // Enable Remote Console
#if (CC_TARGET_PLATFORM != CC_PLATFORM_WINRT)
    auto console = director->getConsole();
    console->listenOnTCP(5678);
    Configuration *conf = Configuration::getInstance();
    bool isAutoRun = conf->getValue("cocos2d.x.testcpp.autorun", Value(false)).asBool();
    if(isAutoRun)
    {
        layer->startAutoRun();
    }
#endif
    
    return true;

这里做了那些操作：

1：初始化Configuration配置对象，并加载配置文件。这一定要在Director对象初始化之前完成

2：初始化Director对象 ，并初始化OpenGLView对象，设置到Director里面。

3：做屏幕适配。 resourceSize通过setContentScaleFactor适配到designSize,如果只有一套资源，那么resouceSize和designSize相同，

designSize通过setDesignResolutionSize适配到screenSize。我们后面使用的position都是相对designSize而言的。

4：然后就是初始化layer,scene，然后运行这个scene. 注意  director->runWithScene(scene);会使得scene和layer的引用计数加1。 layer->autorelease();

5：剩下的是Console，没仔细了解。

现在程序进入TestController::TestController()，在这里初始化menu. 学习了c++11的function和匿名函数的用法。还有事件处理的方法。看下菜单项的事件处理：

void TestController::menuCallback(Ref * sender)
{
	Director::getInstance()->purgeCachedData();
    // get the userdata, it's the index of the menu item clicked
    auto menuItem = static_cast<MenuItem *>(sender);
    int idx = menuItem->getLocalZOrder() - 10000;
    // create the test scene and run it
    auto scene = g_aTestNames[idx].callback();
    if (scene)
    {
        scene->runThisTest();
        scene->release();
    }
}

Director::getInstance()->purgeCachedData();清除缓存的数据。然后执行这个Scene的方法runThisTest()方法。看下ActionsTestScene的runThisScene方法把：

void ActionsTestScene::runThisTest()
 { 
sceneIdx = -1; 
addChild(nextAction()); 
Director::getInstance()->replaceScene(this); 
}

replaceScene之后要执行这个scene对象的release方法。