cocos2d学习（02）——CCApplication类中的run方法分析

CCApplication类中的run方法分析

   1: int CCApplication::run()

   2: {

   3:     PVRFrameEnableControlWindow(false);    //windows相关的，不理会

   4:  

   5:     // Main message loop:    message消息loop循环

   6:     MSG msg;

   7:     LARGE_INTEGER nFreq;

   8:     LARGE_INTEGER nLast;

   9:     LARGE_INTEGER nNow;

  10:     //WinBase.h中声明的两个函数，不用理会

  11:     QueryPerformanceFrequency(&nFreq);

  12:     QueryPerformanceCounter(&nLast);

  13:  

  14:     //初始化cocos2d应用实例

  15:     // Initialize instance and cocos2d.

  16:     if (!applicationDidFinishLaunching())

  17:     {

  18:         //applicationDidFinishLaunching()函数在AppDelegate中实现

  19:         return 0;

  20:     }

  21:     //下面都是和windows窗口显示相关的，暂时不理会

  22:     CCEGLView* pMainWnd = CCEGLView::sharedOpenGLView();

  23:     pMainWnd->centerWindow();

  24:     ShowWindow(pMainWnd->getHWnd(), SW_SHOW);

  25:     //死循环，程序

  26:     while (1)

  27:     {

  28:         if (! PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))

  29:         {

  30:             // Get current time tick.获取当前时间标记

  31:             QueryPerformanceCounter(&nNow);

  32:             //获取到的时间是绘制下一个帧的时间，就绘制。否则继续while循环

  33:             // If it's the time to draw next frame, draw it, else sleep a while.

  34:             if (nNow.QuadPart - nLast.QuadPart > m_nAnimationInterval.QuadPart)

  35:             {

  36:                 nLast.QuadPart = nNow.QuadPart;

  37:                 CCDirector::sharedDirector()->mainLoop();

  38:             }

  39:             else

  40:             {

  41:                 Sleep(0);

  42:             }

  43:             continue;

  44:         }

  45:  

  46:         if (WM_QUIT == msg.message)

  47:         {

  48:             // Quit message loop.

  49:             break;

  50:         }

  51:  

  52:         // Deal with windows message.

  53:         if (! m_hAccelTable || ! TranslateAccelerator(msg.hwnd, m_hAccelTable, &msg))

  54:         {

  55:             TranslateMessage(&msg);

  56:             DispatchMessage(&msg);

  57:         }

  58:     }

  59:  

  60:     return (int) msg.wParam;

  61: }