cocos2dx 2.1.4 程序运行脉络解析1— win32版本的相关代码调用流程

我解析的是win32的代码：（比较之前版本的代码，我感觉引擎代码的布局要明确清晰多了，怪不得要换版本哈哈）

程序的入口点：

int APIENTRY _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow){ UNREFERENCED_PARAMETER(hPrevInstance); UNREFERENCED_PARAMETER(lpCmdLine); // create the application instance AppDelegate app; CCEGLView* eglView = CCEGLView::sharedOpenGLView(); eglView->setViewName("HelloCpp"); eglView->setFrameSize(2048, 1536); // The resolution of ipad3 is very large. In general, PC's resolution is smaller than it. // So we need to invoke 'setFrameZoomFactor'(only valid on desktop(win32, mac, linux)) to make the window smaller. eglView->setFrameZoomFactor(0.4f); return CCApplication::sharedApplication()->run();}

程序构造了一个AppDelegate对象，该对象继承自CCApplication，然后构造了CCEGLView对象，然后对CCEGLView进行了一些初始化等设置最后调用run方法进入游戏循环。

int CCApplication::run(){//win32注册表中设置"Software\\Imagination Technologies\\PVRVFRame\\STARTUP\\"是否为真，//具体有什么用，还不清楚 PVRFrameEnableControlWindow(false); // Main message loop: MSG msg; LARGE_INTEGER nFreq; LARGE_INTEGER nLast; LARGE_INTEGER nNow;//win32高精度计时用的API QueryPerformanceFrequency(&nFreq);//1s钟的计数次数（频率） QueryPerformanceCounter(&nLast);//当前的计数量 // Initialize instance and cocos2d. if (!applicationDidFinishLaunching())//应用程序初始化代码放在这个地方 { return 0; } CCEGLView* pMainWnd = CCEGLView::sharedOpenGLView(); pMainWnd->centerWindow(); ShowWindow(pMainWnd->getHWnd(), SW_SHOW);//获取CCEGLView创建的window//进入消息循环 while (1) {//如果windows消息队列为空则执行游戏主循环，否则处理消息 if (! PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {//用此方法来控制FPS // Get current time tick. QueryPerformanceCounter(&nNow); // If it's the time to draw next frame, draw it, else sleep a while. if (nNow.QuadPart - nLast.QuadPart > m_nAnimationInterval.QuadPart) { nLast.QuadPart = nNow.QuadPart; CCDirector::sharedDirector()->mainLoop(); } else { Sleep(0); } continue; } if (WM_QUIT == msg.message) { // Quit message loop. break; } // Deal with windows message. if (! m_hAccelTable || ! TranslateAccelerator(msg.hwnd, m_hAccelTable, &msg)) { TranslateMessage(&msg); DispatchMessage(&msg); } } return (int) msg.wParam;}

下面开始解析cocos2dx的重点类：CCEGLView

根据main函数调用流程 :
    CCEGLView* eglView = CCEGLView::sharedOpenGLView();
    eglView->setViewName("HelloCpp");
    eglView->setFrameSize(2048, 1536);
    // The resolution of ipad3 is very large. In general, PC's resolution is smaller than it.
    // So we need to invoke 'setFrameZoomFactor'(only valid on desktop(win32, mac, linux)) to make the window smaller.
    eglView->setFrameZoomFactor(0.4f);

 CCEGLView::sharedOpenGLView():如果该类没有创建则创建并进行初始化相关操作：

bool CCEGLView::Create(){ bool bRet = false; do {//创建窗口 CC_BREAK_IF(m_hWnd); HINSTANCE hInstance = GetModuleHandle( NULL ); WNDCLASS wc; // Windows Class Structure // Redraw On Size, And Own DC For Window. wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; wc.lpfnWndProc = _WindowProc; // WndProc Handles Messages wc.cbClsExtra = 0; // No Extra Window Data wc.cbWndExtra = 0; // No Extra Window Data wc.hInstance = hInstance; // Set The Instance wc.hIcon = LoadIcon( NULL, IDI_WINLOGO ); // Load The Default Icon wc.hCursor = LoadCursor( NULL, IDC_ARROW ); // Load The Arrow Pointer wc.hbrBackground = NULL; // No Background Required For GL wc.lpszMenuName = m_menu; // wc.lpszClassName = kWindowClassName; // Set The Class Name CC_BREAK_IF(! RegisterClass(&wc) && 1410 != GetLastError()); // center window position RECT rcDesktop; GetWindowRect(GetDesktopWindow(), &rcDesktop); WCHAR wszBuf[50] = {0}; MultiByteToWideChar(CP_UTF8, 0, m_szViewName, -1, wszBuf, sizeof(wszBuf)); // create window m_hWnd = CreateWindowEx( WS_EX_APPWINDOW | WS_EX_WINDOWEDGE, // Extended Style For The Window kWindowClassName, // Class Name wszBuf, // Window Title WS_CAPTION | WS_POPUPWINDOW | WS_MINIMIZEBOX, // Defined Window Style 0, 0, // Window Position //TODO: Initializing width with a large value to avoid getting a wrong client area by 'GetClientRect' function. 1000, // Window Width 1000, // Window Height NULL, // No Parent Window NULL, // No Menu hInstance, // Instance NULL ); CC_BREAK_IF(! m_hWnd);//初始化opengl，绑定到创建的窗口上，如果需要移植到MFC中则需要改写Create与initGL方法 bRet = initGL();if(!bRet) destroyGL(); CC_BREAK_IF(!bRet); s_pMainWindow = this; bRet = true; } while (0);#if(_MSC_VER >= 1600)//检测支持touch m_bSupportTouch = CheckTouchSupport(); if(m_bSupportTouch){ m_bSupportTouch = (s_pfRegisterTouchWindowFunction(m_hWnd, 0) != 0); }#endif /* #if(_MSC_VER >= 1600) */ return bRet;}

下面是我根据功能划分分析的CCEGLView：

/****************************************************************************Copyright (c) 2010 cocos2d-x.orghttp://www.cocos2d-x.orgPermission is hereby granted, free of charge, to any person obtaining a copyof this software and associated documentation files (the "Software"), to dealin the Software without restriction, including without limitation the rightsto use, copy, modify, merge, publish, distribute, sublicense, and/or sellcopies of the Software, and to permit persons to whom the Software isfurnished to do so, subject to the following conditions:The above copyright notice and this permission notice shall be included inall copies or substantial portions of the Software.THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS ORIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THEAUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHERLIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS INTHE SOFTWARE.****************************************************************************/#ifndef __CC_EGLVIEW_WIN32_H__#define __CC_EGLVIEW_WIN32_H__#include "CCStdC.h"#include "platform/CCCommon.h"#include "cocoa/CCGeometry.h"#include "platform/CCEGLViewProtocol.h"NS_CC_BEGINtypedef LRESULT (*CUSTOM_WND_PROC)(UINT message, WPARAM wParam, LPARAM lParam, BOOL* pProcessed);class CCEGL;class CC_DLL CCEGLView : public CCEGLViewProtocol{public: CCEGLView(); virtual ~CCEGLView(); /* override CCEGLViewProtocol functions */ virtual bool isOpenGLReady(); virtual void end(); virtual void swapBuffers();virtual void setIMEKeyboardState(bool bOpen); virtual void setFrameSize(float width, float height);virtual void setViewPortInPoints(float x , float y , float w , float h);virtual void setScissorInPoints(float x , float y , float w , float h);////////////////////win32平台相关//设置菜单 void setMenuResource(LPCWSTR menu);//设置窗口回调（如果自带的回调没有处理的事件则交给该proc处理） void setWndProc(CUSTOM_WND_PROC proc);// win32 platform functionHWND getHWnd();//重设窗口大小(并将m_szViewName, frameSize.width, frameSize.height, m_fFrameZoomFactor作为窗口内容输出)void resize(int width, int height);//窗口位置中void centerWindow();//窗口回调，模拟cocoos2dx的touch事件、输入事件、keypress事件、退出屏幕、进入屏幕事件virtual LRESULT WindowProc(UINT message, WPARAM wParam, LPARAM lParam);typedef void (*LPFN_ACCELEROMETER_KEYHOOK)( UINT message,WPARAM wParam, LPARAM lParam );void setAccelerometerKeyHook( LPFN_ACCELEROMETER_KEYHOOK lpfnAccelerometerKeyHook );private://创建窗口并初始化opengl与其关联的窗口 virtual bool Create(); bool initGL(); void destroyGL();public: /* * Set zoom factor for frame. This method is for debugging big resolution (e.g.new ipad) app on desktop. */ void setFrameZoomFactor(float fZoomFactor);float getFrameZoomFactor(); // static function /** @brief get the shared main open gl window */ static CCEGLView* sharedOpenGLView();protected:private: bool m_bCaptured; HWND m_hWnd; HDC m_hDC; HGLRC m_hRC; LPFN_ACCELEROMETER_KEYHOOK m_lpfnAccelerometerKeyHook; bool m_bSupportTouch; LPCWSTR m_menu; CUSTOM_WND_PROC m_wndproc; float m_fFrameZoomFactor;};NS_CC_END#endif // end of __CC_EGLVIEW_WIN32_H__

其中的setFrameZoomFactor函数实现需要重设投影矩阵，这一点暂时不明白，等到分析到那时再见知晓

void CCEGLView::setFrameZoomFactor(float fZoomFactor)
{
    m_fFrameZoomFactor = fZoomFactor;
    resize(m_obScreenSize.width * fZoomFactor, m_obScreenSize.height * fZoomFactor);
    centerWindow();

//运行机制已经分析完毕，重新设置投影是为了正确的将逻辑像素坐标的像素映射到屏幕中去，请参考第三节
//重新设置投影
    CCDirector::sharedDirector()->setProjection(CCDirector::sharedDirector()->getProjection());
}

CCEGLView win32 相对 CCEGLViewProtocol 多了一个 m_fFrameZoomFactor 属性是由于：（2dx的解释）

// The resolution of ipad3 is very large. In general, PC's resolution is smaller than it.
// So we need to invoke 'setFrameZoomFactor'(only valid on desktop(win32, mac, linux)) to make the window smaller.