COCOS2DX引擎深入一————调度原理

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里的run()循环调用了导演类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是我们设定的循环间隔，每次前后两个时间的差大于这个间隔，就执行一次主循环director->mainLoop()，小于这个间隔呢，就一直获取当前的时间，直到大于这个间隔。


 

再看mainLoop，

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

 

调用drawScene()方法绘制场景，并弹出自动回收池，使这一帧被放入自动回收池里的对象全部被释放。