gles2.0环境的在windows上的建立

  1 #include <Windows.h>
  2 #include <tchar.h>
  3 #include <EGL/egl.h>
  4 #include <gles2/gl2.h>
  5 
  6 
  7 
  8 class   CELLWinApp
  9 {
 10 public:
 11     /**
 12     *   应用程序实例句柄
 13     */
 14     HINSTANCE           _hInstance;
 15     /**
 16     *   窗口句柄，操作窗口使用
 17     */
 18     HWND                _hWnd;
 19     /**
 20     *   窗口的宽度和高度
 21     */
 22     int                 _winWidth;
 23     int                 _winHeight;
 24     EGLConfig            _config;
 25     EGLSurface             _surface;
 26     EGLContext             _context;
 27     EGLDisplay             _display;
 28 public:
 29     CELLWinApp(HINSTANCE hInstance = 0)
 30     {
 31         _hWnd       =   0;
 32         _winWidth   =   0;
 33         _winHeight  =   0;
 34         _hInstance  =   hInstance;
 35         _config     =   0;
 36         _surface    =   0;
 37         _context    =   0;
 38         _display    =   0;
 39         /**
 40         *   要想创建一个窗口，首先要注册一个窗口类
 41         *   相关内存，可以了解windows变成，这里不做介绍。
 42         */
 43         ::WNDCLASSEX winClass;
 44         winClass.lpszClassName  =   _T("CELLWinApp");
 45         winClass.cbSize         =   sizeof(::WNDCLASSEX);
 46         winClass.style          =   CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
 47         winClass.lpfnWndProc    =   windowProc;
 48         winClass.hInstance      =   hInstance;
 49         winClass.hIcon            =   0;
 50         winClass.hIconSm        =   0;
 51         winClass.hCursor        =   LoadCursor(NULL, IDC_ARROW);
 52         winClass.hbrBackground  =   (HBRUSH)GetStockObject(BLACK_BRUSH);
 53         winClass.lpszMenuName   =   NULL;
 54         winClass.cbClsExtra     =   0;
 55         winClass.cbWndExtra     =   0;
 56         RegisterClassEx(&winClass);
 57     }
 58     virtual ~CELLWinApp()
 59     {
 60     }
 61     /**
 62     *   渲染函数
 63     */
 64     virtual void    render()
 65     {
 66         glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
 67         glViewport(0,0,_winWidth,_winHeight);
 68         {
 69 
 70         }
 71         eglSwapBuffers(_display, _surface);
 72     }
 73 
 74     /**
 75     *   入口函数
 76     *   width :创建窗口宽度
 77     *   height:创建窗口的高度
 78     */
 79     int     start(HWND hWnd,int width,int height)
 80     {
 81         _winWidth   =   width;
 82         _winHeight  =   height;
 83 
 84         /**
 85         *   创建窗口
 86         */
 87         if (hWnd == 0)
 88         {
 89             if (!_createWindow(_winWidth,_winHeight))
 90             {
 91                 return  -1;
 92             }
 93         }
 94         else
 95         {
 96             _hWnd   =   hWnd;
 97         }
 98         /**
 99         *   初始化gles环境。
100         */
101         if (!initDevice())
102         {
103             return  -2;
104         }
105         onInit();
106        
107         if (hWnd)
108         {
109             return  0;
110         }
111         /**
112         *   进入消息循环
113         */
114         MSG msg =   {0};
115         while(msg.message != WM_QUIT)
116         {
117             if (msg.message == WM_DESTROY || 
118                 msg.message == WM_CLOSE)
119             {
120                 break;
121             }
122             /**
123             *   有消息，处理消息，无消息，则进行渲染绘制
124             */
125             if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) )
126             { 
127                 TranslateMessage( &msg );
128                 DispatchMessage( &msg );
129             }
130             else
131             {
132                 render();
133             }
134         }
135         /**
136         *   关闭
137         */
138         shutDownDevice();
139 
140         return  0;
141     }
142     /**
143     *   初始化OpenGL
144     */
145     bool    initDevice()
146     {
147 
148         const EGLint attribs[] =
149         {
150             EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
151             EGL_BLUE_SIZE, 8,
152             EGL_GREEN_SIZE, 8,
153             EGL_RED_SIZE, 8,
154             EGL_DEPTH_SIZE,24,
155             EGL_NONE
156         };
157         EGLint     format(0);
158         EGLint    numConfigs(0);
159         EGLint  major;
160         EGLint  minor;
161 
162         //! 1
163         _display        =    eglGetDisplay(EGL_DEFAULT_DISPLAY);
164 
165         //! 2init
166         eglInitialize(_display, &major, &minor);
167 
168         //! 3
169         eglChooseConfig(_display, attribs, &_config, 1, &numConfigs);
170 
171         eglGetConfigAttrib(_display, _config, EGL_NATIVE_VISUAL_ID, &format);
172         //! 4 
173         _surface        =     eglCreateWindowSurface(_display, _config, _hWnd, NULL);
174 
175         //! 5
176         EGLint attr[]   =   { EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE, EGL_NONE };
177         _context         =     eglCreateContext(_display, _config, 0, attr);
178         //! 6
179         if (eglMakeCurrent(_display, _surface, _surface, _context) == EGL_FALSE)
180         {
181             return false;
182         }
183 
184         eglQuerySurface(_display, _surface, EGL_WIDTH,  &_winWidth);
185         eglQuerySurface(_display, _surface, EGL_HEIGHT, &_winHeight);
186 
187         //! windows api
188         SendMessage(_hWnd,WM_SIZE,0,0);
189         return  true;
190     }
191     /**
192     *   关闭
193     */
194     void    shutDownDevice()
195     {
196        
197          onDestroy();
198          if (_display != EGL_NO_DISPLAY)
199          {
200              eglMakeCurrent(_display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
201              if (_context != EGL_NO_CONTEXT) 
202              {
203                  eglDestroyContext(_display, _context);
204              }
205              if (_surface != EGL_NO_SURFACE) 
206              {
207                  eglDestroySurface(_display, _surface);
208              }
209              eglTerminate(_display);
210          }
211          _display    =   EGL_NO_DISPLAY;
212          _context    =   EGL_NO_CONTEXT;
213          _surface    =   EGL_NO_SURFACE;
214 
215         UnregisterClass( _T("CELLWinApp"), _hInstance );
216     }
217     /**
218     *   事件
219     */
220     virtual int     events(unsigned msg, unsigned wParam, unsigned lParam)
221     {
222     #ifndef GET_X_LPARAM
223         #define GET_X_LPARAM(lp)                        ((int)(short)LOWORD(lp))
224     #endif
225 
226     #ifndef GET_Y_LPARAM
227         #define GET_Y_LPARAM(lp)                        ((int)(short)HIWORD(lp))
228     #endif
229 
230     #ifndef GET_WHEEL_DELTA_WPARAM
231         #define GET_WHEEL_DELTA_WPARAM(wParam)          (int)((short)HIWORD(wParam))
232     #endif
233 
234         switch( msg )
235         {
236         case WM_SIZE:
237             {
238                 RECT    rt;
239                 GetClientRect(_hWnd,&rt);
240                 _winWidth   =   rt.right - rt.left;
241                 _winHeight  =   rt.bottom - rt.top;
242             }
243             break;
244         case WM_LBUTTONDOWN:
245             {
246             }
247             break;
248         case WM_LBUTTONUP:
249             {
250             }
251             break;
252         case WM_RBUTTONDOWN:
253             {
254             }
255             break;
256         case WM_RBUTTONUP:
257             {
258             }
259             break;
260         case WM_MOUSEMOVE:
261             {
262             }
263             break;
264 
265         case WM_MOUSEWHEEL:
266             {
267             }
268             break;
269         case WM_CHAR:
270             {
271             }
272             break;
273         case WM_KEYDOWN:
274             {
275             }
276             break;
277         case WM_CLOSE:
278         case WM_DESTROY:
279             {
280                 ::PostQuitMessage(0);
281             }
282             break;
283         default:
284             return DefWindowProc(_hWnd, msg, wParam, lParam );
285         }
286         return  0;
287     }
288 public:
289     /**
290     *   增加一个初始化OpenGL的函数,第二课中增加
291     *   调用该函数完成对OpenGL的基本状态的初始化
292     *   在进入消息循环之前的一次通知,只调用一次
293     */
294     virtual void    onInit()
295     {
296         /**
297         *   清空窗口为黑色
298         */
299         glClearColor(0,0,0,1);
300         /**
301         *   设置OpenGL视口的位置和大小。
302         */
303         glViewport( 0, 0, (GLint) _winWidth, (GLint) _winHeight );
304     }
305     virtual void        onDestroy()
306     {
307     }
308 protected:
309     /**
310     *   创建窗口函数
311     */
312     bool    _createWindow(int width,int height)
313     {
314         _hWnd   =   CreateWindowEx(
315                                     NULL,
316                                     _T("CELLWinApp"),
317                                     _T("CELLWinApp"),
318                                     WS_OVERLAPPEDWINDOW,
319                                     CW_USEDEFAULT,
320                                     CW_USEDEFAULT,
321                                     width,
322                                     height, 
323                                     NULL, 
324                                     NULL,
325                                     _hInstance, 
326                                     this    //! 这里注意，将当前类的指针作为参数，传递,参见 windowProc函数.
327                                     );
328        
329         if( _hWnd == 0 )
330         {
331             return  false;
332         }
333         ShowWindow( _hWnd, SW_SHOW );
334         UpdateWindow( _hWnd );
335         return  true;
336     }
337     /**
338     *   Windows消息过程处理函数
339     */
340     static  LRESULT CALLBACK    windowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
341     {
342 #define GWL_USERDATA (-21)
343         /**
344         *   使用this数据，将全局函数，转化为类的成员函数调用
345         */
346         CELLWinApp*  pThis   =   (CELLWinApp*)GetWindowLong(hWnd,GWL_USERDATA);
347         if (pThis)
348         {
349             return  pThis->events(msg,wParam,lParam);
350         }
351         if (WM_CREATE == msg)
352         {
353             CREATESTRUCT*   pCreate =   (CREATESTRUCT*)lParam;
354             SetWindowLong(hWnd,GWL_USERDATA,(DWORD_PTR)pCreate->lpCreateParams);
355         }
356         return  DefWindowProc( hWnd, msg, wParam, lParam );
357     }
358 };