COCOS2DX引擎深入一————調度原理

main.cpp

 

int APIENTRY _tWinMain(HINSTANCE hInstance,
                       HINSTANCE hPrevInstance,
                       LPTSTR    lpCmdLine,
                       int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // create the application instance
    AppDelegate app;
    return Application::getInstance()->run();
}

Application裏的run()循環調用了導演類Director的mainLoop();

 

 while(!glview->windowShouldClose())
    {
        QueryPerformanceCounter(&nNow);
        if (nNow.QuadPart - nLast.QuadPart > _animationInterval.QuadPart)
        {
            nLast.QuadPart = nNow.QuadPart;
            
            director->mainLoop();
            glview->pollEvents();
        }
        else
        {
            Sleep(0);
        }
    }

_animationInterval是我們設定的循環間隔，每次前後兩個時間的差大於這個間隔，就執行一次主循環director->mainLoop()，小於這個間隔呢，就一直獲取當前的時間，直到大於這個間隔。


 

再看mainLoop，

void DisplayLinkDirector::mainLoop()
{
    if (_purgeDirectorInNextLoop)
    {
        _purgeDirectorInNextLoop = false;
        purgeDirector();
    }
    else if (! _invalid)
    {
        drawScene();
     
        // release the objects
        PoolManager::getInstance()->getCurrentPool()->clear();
    }
}

 

調用drawScene()方法繪製場景，並彈出自動回收池，使這一幀被放入自動回收池裏的對象全部被釋放。