opengl试验代码总结-1

opengl试验代码总结-1

这两天终于把网上下载的opengl实验代码的框架敲完了 。代码不算多，才不到400行 。编译链接了一下，解决了一些问题，在此总结 一下 。

 

编辑器 ：Emacs

编译器 ：cl.exe

连接器 ：link.exe

工程构建 ：Nant

编程语言 ：C

其他:opengl+win32 api

 

由于所有东西都是重头开始学习，再加上时间抓得也不紧，造成了需要解决的问题很多，进度也很缓慢，希望通过努力能改变这种情况。

 

首先贴出框架代码

//headers #include <windows.h> #include <gl/gl.h> #include <gl/glu.h> //constant #define WM_TOGGLEFULLSCREEN (WM_USER+1) #define TIMER1 101 #define TITLE "5DG" #define CLASSNAME "5DG_OPENGL" #define WIDTH 640 #define HEIGHT 480 #define BPP 16 //#pragma #pragma comment(lib,"user32.lib") #pragma comment(lib,"kernel32.lib") #pragma comment(lib,"gdi32.lib") #pragma comment(lib,"opengl32.lib") #pragma comment(lib,"glu32.lib") //struct "Keys" typedef struct{ BOOL keyDown[256]; }Keys; //struct "Application" typedef struct{ HINSTANCE hInstance; const char* className; }Application; //struct "GL_WindowInit" typedef struct{ Application* application; char* title; int width; int height; int bitsPerPixel; BOOL isFullScreen; }GL_WindowInit; //struct "GL_Window" typedef struct{ Keys* keys; HWND hWnd; HDC hDC; HGLRC hRC; GL_WindowInit init; }GL_Window; //functions declare BOOL Initialize (GL_Window* window,Keys* keys); void DrawSceneGL(void); void Update(); void DeInitialize(void); //global variable GL_Window* OGL_window; Keys* OGL_keys; // void ResizeWindowGL(int width,int height) { glViewport(0,0,(GLsizei)(width),(GLsizei)(height)); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(45,(float)width/(float)height,0.1,100); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } BOOL ChangeScreenResolution(int width, int height, int bitsPerPixel) { DEVMODE dmScreenSettings; ZeroMemory(&dmScreenSettings,sizeof(DEVMODE)); dmScreenSettings.dmSize=sizeof(DEVMODE); dmScreenSettings.dmPelsWidth=width; dmScreenSettings.dmPelsHeight=height; dmScreenSettings.dmBitsPerPel=bitsPerPixel; dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT; if(ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL) {return FALSE;} else {return TRUE;} } BOOL CreateWindowGL(GL_Window* window) { DWORD windowStyle=WS_OVERLAPPEDWINDOW; DWORD windowExtendedStyle=WS_EX_APPWINDOW; PIXELFORMATDESCRIPTOR pfd= {sizeof(PIXELFORMATDESCRIPTOR), 1, PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER, PFD_TYPE_RGBA, window->init.bitsPerPixel, 0,0,0,0,0,0, 0, 0, 0, 0,0,0,0, 16, 0, 0, PFD_MAIN_PLANE, 0, 0,0,0 }; RECT windowRect={0,0,window->init.width,window->init.height}; GLuint PixelFormat; if(window->init.isFullScreen==TRUE) { if(ChangeScreenResolution(window->init.width,window->init.height,window->init.bitsPerPixel)==FALSE) { MessageBox(HWND_DESKTOP,"can`t fullscreen","ERROR",MB_OK|MB_ICONEXCLAMATION); window->init.isFullScreen=FALSE; } else {ShowCursor(FALSE); windowStyle=WS_POPUP; windowExtendedStyle|=WS_EX_TOPMOST; } } else { AdjustWindowRectEx(&windowRect,windowStyle,0,windowExtendedStyle); } window->hWnd=CreateWindowEx(windowExtendedStyle, window->init.application->className, window->init.title, windowStyle, 0, 0, windowRect.right-windowRect.left, windowRect.bottom-windowRect.top, HWND_DESKTOP, 0, window->init.application->hInstance, window); if(window->hWnd==0) {return FALSE;} window->hDC=GetDC(window->hWnd); if(window->hDC==0) { DestroyWindow(window->hWnd); window->hWnd=0; return FALSE; } PixelFormat=ChoosePixelFormat(window->hDC,&pfd); if(PixelFormat==0) { ReleaseDC(window->hWnd,window->hDC); window->hDC=0; DestroyWindow(window->hWnd); window->hWnd=0; return FALSE; } if(SetPixelFormat(window->hDC,PixelFormat,&pfd)==FALSE) { ReleaseDC(window->hWnd,window->hDC); window->hDC=0; DestroyWindow(window->hWnd); window->hWnd=0; return FALSE; } ShowWindow(window->hWnd,SW_NORMAL); ResizeWindowGL(window->init.width,window->init.height); ZeroMemory(window->keys,sizeof(Keys)); return TRUE; } BOOL DestroyWindowGL(GL_Window* window) { if (window->hWnd!=0) { if(window->hDC!=0) { wglMakeCurrent(window->hDC,0); if(window->hRC!=0) { wglDeleteContext(window->hRC); window->hRC=0; } ReleaseDC(window->hWnd,window->hDC); window->hDC=0; } DestroyWindow(window->hWnd); window->hWnd=0; } if(window->init.isFullScreen) { ChangeDisplaySettings(NULL,0); ShowCursor(TRUE); } return TRUE; } LRESULT CALLBACK WindowProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam) { GL_Window* window=(GL_Window*)(GetWindowLong(hWnd,GWL_USERDATA)); CREATESTRUCT *creation=(CREATESTRUCT*)(lParam); switch(uMsg) { case WM_SYSCOMMAND: switch(wParam) { case SC_SCREENSAVE: case SC_MONITORPOWER: return 0; } break; case WM_CREATE: window=(GL_Window*)(creation->lpCreateParams); SetWindowLong(hWnd,GWL_USERDATA,(LONG)(window)); return 0; case WM_TIMER: InvalidateRect(window->hWnd,NULL,FALSE); break; case WM_PAINT: DrawSceneGL(); SwapBuffers(window->hDC); ValidateRect(window->hWnd,NULL); break; case WM_CLOSE: PostMessage(window->hWnd,WM_QUIT,0,0); return 0; case WM_SIZE: ResizeWindowGL(LOWORD(lParam),HIWORD(lParam)); return 0; case WM_KEYDOWN: if((wParam>=0)&&(wParam<=255)) { window->keys->keyDown[wParam]=TRUE; return 0; } case WM_KEYUP: if((wParam>=0)&&(wParam<=255)) { window->keys->keyDown[wParam]=FALSE; return 0; } case WM_TOGGLEFULLSCREEN: DeInitialize(); DestroyWindowGL(window); window->init.isFullScreen=!window->init.isFullScreen; CreateWindowGL(window); Initialize(window,window->keys); break; default: break; } return DefWindowProc(hWnd,uMsg,wParam,lParam); } BOOL RegisterWindowClass(Application* application) { WNDCLASSEX windowClass; ZeroMemory(&windowClass,sizeof(WNDCLASSEX)); windowClass.cbSize=sizeof(WNDCLASSEX); windowClass.style=CS_HREDRAW|CS_VREDRAW|CS_OWNDC; windowClass.lpfnWndProc=(WNDPROC)(WindowProc); windowClass.hInstance=application->hInstance; windowClass.hbrBackground=(HBRUSH)(COLOR_APPWORKSPACE); windowClass.hCursor=LoadCursor(NULL,IDC_ARROW); windowClass.lpszClassName=application->className; if(RegisterClassEx(&windowClass)==0) { MessageBox(HWND_DESKTOP,"NEED Windows NT","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; } return TRUE; } int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShwo) { Application application; GL_Window window; Keys keys; MSG msg; BOOL bRet; application.className="OpenGL"; application.hInstance=hInstance; ZeroMemory(&window,sizeof(GL_Window)); window.keys=&keys; window.init.application=&application; window.init.title=TITLE; window.init.width=WIDTH; window.init.height=HEIGHT; window.init.bitsPerPixel=BPP; window.init.isFullScreen=FALSE; ZeroMemory(&keys,sizeof(Keys)); if(RegisterWindowClass(&application)==FALSE) { MessageBox(HWND_DESKTOP,"regist class error","ERROR",MB_OK|MB_ICONEXCLAMATION); return -1; } if(CreateWindowGL(&window)==TRUE) { if(Initialize(&window,&keys)==FALSE) { PostMessage(window.hWnd,WM_QUIT,0,0); } } else { return 0; } while((bRet=GetMessage(&msg,NULL,0,0)!=0)) { if(bRet!=-1) { Update(); TranslateMessage(&msg); DispatchMessage(&msg); } else { break; } } DeInitialize(); DestroyWindowGL(&window); UnregisterClass(application.className,application.hInstance); return 0; } BOOL Initialize(GL_Window* window, Keys* keys) { OGL_window=window; OGL_keys=keys; SetTimer(window->hWnd,TIMER1,33,NULL); //Initialize opengl glClearColor(0.0f,0.0f,0.0f,0.5f); glClearDepth(1.0f); glDepthFunc(GL_LEQUAL); glEnable(GL_DEPTH_TEST); glShadeModel(GL_SMOOTH); glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST); return TRUE; } void DrawSceneGL(void) { glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); glLoadIdentity(); // glFlush(); } void Update() { if (OGL_keys->keyDown[VK_ESCAPE]==TRUE) { PostMessage(OGL_window->hWnd,WM_QUIT,0,0); } if(OGL_keys->keyDown[VK_F1]==TRUE) { PostMessage(OGL_window->hWnd,WM_TOGGLEFULLSCREEN,0,0); } } void DeInitialize(void) { KillTimer(OGL_window->hWnd,TIMER1); }

 

总结：

       1.Emacs：Emacs的使用还处于初级阶段。目前熟练掌握的快捷键如下：

                       C-x C-f：打开文件

                       C-x C-s：保存文件

                       C-x b   ：在minibuffer中列出所有的buffer

                       C-x C-b：在新窗口中列出所有buffer

                       M-x speedbar：打开speedbar，在编辑C语言时可以做为函数列表

                       C-x o：在窗口见跳转

                       C-x 1：最大化光标所在窗口

                       C-x 2：横向建立新的窗口

                       C-x 3：纵向建立新的窗口

                       C-x h：全选

                       C-x n：光标下移

                       C-x p：光标上移

                       C-x f： 光标前移

                       C-x b：光标后移

                       C-M-/：代码格式化

                       M-/：补全单词，被我修改为C-Return，具体修改方法为：

                                C-h k：查看某一个热键绑定在哪个命令上，得到命令的名称。

                                M-x global-set-key:点击C-Return，再输入刚才查找得到的命令。

                                C-x esc esc：现在刚才的命令，将这个命令放入init.el中即可。

                       C-s：向后查找单词，查找下一个，继续C-s，前一个：C-r

                       C-r：向前查找单词

                       以上是脑子里能想起来的了，感觉是Emacs的的确好用，前提是你得学一阵子。

       2.编译和链接的问题：

                       由于使用了c+win32 api+opengl+Emacs+Nant的组合，造成了单词的自动补

                       全没有VS的好，编译的大部分错误都是单词的拼写错误，期间只有一个错误费

                       了一些时间，该错误出现在WindowProc函数的

                        CREATESTRUCT * creation=（CREATESTRUCT*)(lParam);

                        此语句单独拿出来没有问题，但是原书中将该语句放入了case WM_CREATE:

                        当中，造成了莫名其妙的“illegal use of this type as expression"的错误，

                        开始以为是结构体的错误，还复习了下结构体的知识，后来发现，把此语句提

                        前到该函数的最前段声明，问题就解决了，是C语言强制声明必须放在前面所

                        至。链接的问题：链接的时候出现了无法解析的符号，结果基本上是名字写错

                        另：要使用glu的函数，必须链接glu32.lib。

 

此篇先总结这么多，代码的详细分析见opengl试验代码总结-2。

万事开头难，加油吧。