NeHe的OpenGl教程 - 前5课总结

NeHe 的 OpenGL 教程浅显易懂，每行都有注释，适合入门学习用。不过，要想让教程中的程序运行在我的电脑上，需要做一些小小的设置

我的电脑的软件配置：Windows XP Professional + Visual C++ 2008 Express

1. “项目属性”的 Configuration Properties 选项卡：Character Set
NeHe 教程用的全是 C-sytle null terminated string。所以我们要根据自己的项目的特点做相应设置。我的程序使用的都是UNICODE字符串，所以设置为 Use UNICODE Character Set

2. “Linker” -> “Input”选项卡：Additional Dependencies 需要添加两行

"$(WindowsSdkDir)Lib\glu32.lib"
"$(WindowsSdkDir)Lib\opengl32.lib"

3. 原教程中的代码：#include <glaux.h> 在网上很难找，于是去掉了。反正只要不用里面的代码就OK

然后就可以让下面的代码运行了：

#include <windows.h> #include <math.h> #include <gl\gl.h> #include <gl\glu.h> // global variable HDC g_hDC = NULL; HGLRC g_hRC = NULL; HWND g_hWnd = NULL; HINSTANCE g_hIns = NULL; BOOL g_pKeys[256] = {0}; BOOL g_bActive = TRUE; BOOL g_bFullScreen = TRUE; GLfloat g_fAngle4Tri = 0.0f; GLfloat g_fAngle4Quad = 0.0f; LPCTSTR g_lpszWndClass = TEXT("OpenGL"); const float kRotateSpeed = 0.001f; const float kRadius = 3.0f; const DWORD kStartTime = GetTickCount(); GLvoid ResizeGLWnd(GLsizei nWidth, GLsizei nHeight) { if(nHeight == 0) { nHeight = 1; } glViewport(0, 0, nWidth, nHeight); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(45.0f, (GLfloat)nWidth/(GLfloat)nHeight, 0.1f, 100.0f); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } GLvoid KillGLWnd() { if(g_bFullScreen) { ChangeDisplaySettings(NULL, 0); ShowCursor(TRUE); } if(g_hRC) { if(!wglMakeCurrent(NULL, 0)) { MessageBox(g_hWnd, TEXT("Desktop cannot be showed properly."), TEXT("SHUTDOWN ERROR"), MB_OK | MB_ICONINFORMATION); } if(!wglDeleteContext(g_hRC)) { MessageBox(g_hWnd, TEXT("OpenGL rendering context cannot be released"), TEXT("SHUTDOWN ERROR"), MB_OK | MB_ICONINFORMATION); } g_hRC = NULL; } if(g_hDC && !ReleaseDC(g_hWnd, g_hDC)) { MessageBox(g_hWnd, TEXT("Windows device context cannot be released"), TEXT("SHUTDOWN ERROR"), MB_OK | MB_ICONINFORMATION); g_hDC = NULL; } if(g_hWnd && !DestroyWindow(g_hWnd)) { MessageBox(g_hWnd, TEXT("Windows cannot be destroyed"), TEXT("SHUTDOWN ERROR"), MB_OK | MB_ICONINFORMATION); g_hWnd = NULL; } if(!UnregisterClass(g_lpszWndClass, g_hIns)) { MessageBox(g_hWnd, TEXT("Windows class unregistering failed"), TEXT("SHUTDOWN ERROR"), MB_OK | MB_ICONINFORMATION); g_hIns = NULL; } } int InitOpenGL() { glShadeModel(GL_SMOOTH); glClearColor(0.0f, 0.0f, 0.0f, 0.0f); glClearDepth(1.0f); glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LEQUAL); glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); return TRUE; } LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); BOOL CreateGLWnd(PTSTR lpTitle, int nWidth, int nHeight, int nBits, bool bFullScreen) { GLuint nPixelFormat; WNDCLASS wc; DWORD dwStyle, dwExStyle; RECT WndRect; WndRect.left = (long)0; WndRect.right = (long)nWidth; WndRect.top = (long)0; WndRect.bottom = (long)nHeight; g_bFullScreen = bFullScreen; g_hIns = GetModuleHandle(NULL); wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; wc.lpfnWndProc = (WNDPROC)WndProc; wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = g_hIns; wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); wc.hCursor = LoadCursor(NULL, IDC_ARROW); wc.hbrBackground = NULL; wc.lpszMenuName = NULL; wc.lpszClassName = g_lpszWndClass; if(!RegisterClass(&wc)) { MessageBox(NULL, TEXT("Register of window class failed"), TEXT("CREATE ERROR"), MB_OK | MB_ICONEXCLAMATION); return FALSE; } if(g_bFullScreen) { DEVMODE dmScreenSettings; memset(&dmScreenSettings, 0, sizeof(dmScreenSettings)); dmScreenSettings.dmSize = sizeof(dmScreenSettings); dmScreenSettings.dmPelsWidth = nWidth; dmScreenSettings.dmPelsHeight = nHeight; dmScreenSettings.dmBitsPerPel = nBits; dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT; if(ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN)) { if (MessageBox(NULL, TEXT("The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?"), TEXT("NeHe GL"), MB_YESNO | MB_ICONEXCLAMATION) == IDYES) { g_bFullScreen = FALSE; // Windowed Mode Selected. Fullscreen = FALSE } else { // Pop Up A Message Box Letting User Know The Program Is Closing. MessageBox(NULL, TEXT("Program Will Now Close."),TEXT("ERROR"), MB_OK | MB_ICONSTOP); return FALSE; // Return FALSE } } } if(g_bFullScreen) { dwExStyle = WS_EX_APPWINDOW; dwStyle = WS_POPUP; ShowCursor(FALSE); } else { dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; dwStyle = WS_OVERLAPPEDWINDOW; } AdjustWindowRectEx(&WndRect, dwStyle, FALSE, dwExStyle); if(!(g_hWnd = CreateWindowEx(dwExStyle, g_lpszWndClass, lpTitle, dwStyle | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, 0, 0, WndRect.right - WndRect.left, WndRect.bottom - WndRect.top, NULL, NULL, g_hIns, NULL))) { KillGLWnd(); MessageBox(NULL, TEXT("Window Creation Error."),TEXT("ERROR"), MB_OK | MB_ICONEXCLAMATION); return FALSE; } static PIXELFORMATDESCRIPTOR pfd = { sizeof(PIXELFORMATDESCRIPTOR), 1, PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER, PFD_TYPE_RGBA, nBits, 0,0,0,0,0,0, 0, 0, 0, 0,0,0,0, 16, 0, 0, PFD_MAIN_PLANE, 0, 0,0,0 }; if(!(g_hDC = GetDC(g_hWnd))) { KillGLWnd(); MessageBox(NULL, TEXT("Can't Create A GL Device Context."), TEXT("ERROR"), MB_OK | MB_ICONEXCLAMATION); return FALSE; } if(!(nPixelFormat = ChoosePixelFormat(g_hDC, &pfd))) { KillGLWnd(); MessageBox(NULL, TEXT("Can't find proper pixel format."), TEXT("ERROR"), MB_OK | MB_ICONEXCLAMATION); return FALSE; } if(!SetPixelFormat(g_hDC, nPixelFormat, &pfd)) { KillGLWnd(); MessageBox(NULL, TEXT("Can't Set The PixelFormat."), TEXT("ERROR"),MB_OK | MB_ICONEXCLAMATION); return FALSE; } if (!(g_hRC = wglCreateContext(g_hDC))) { KillGLWnd(); MessageBox(NULL, TEXT("Can't Create A GL Rendering Context."), TEXT("ERROR"),MB_OK | MB_ICONEXCLAMATION); return FALSE; } if(!wglMakeCurrent(g_hDC, g_hRC)) { KillGLWnd(); MessageBox(NULL, TEXT("Can't Activate The GL Rendering Context."), TEXT("ERROR"),MB_OK | MB_ICONEXCLAMATION); return FALSE; } ShowWindow(g_hWnd, SW_SHOW); SetForegroundWindow(g_hWnd); SetFocus(g_hWnd); ResizeGLWnd(nWidth, nHeight); if(!InitOpenGL()) { KillGLWnd(); MessageBox(NULL, TEXT("Initialization Failed."), TEXT("ERROR"),MB_OK | MB_ICONEXCLAMATION); return FALSE; } } int DrawScene() { const GLfloat kDistanceZ = -15.0f; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); // triangle glTranslatef(0.0f, -2.0f, kDistanceZ); glRotatef(g_fAngle4Tri, 0.0f, 1.0f, 0.0f); glBegin(GL_TRIANGLES); glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(0.0f, 1.0f, 0.0f); glColor3f(0.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); glColor3f(0.0f, 0.0f, 1.0f); glVertex3f(1.0f, -1.0f, 1.0f); glColor3f(1.0f, 0.0f, 0.0f); glVertex3f(0.0f, 1.0f, 0.0f); glColor3f(0.0f, 0.0f, 1.0f); glVertex3f(1.0f, -1.0f, -1.0f); glColor3f(0.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); glColor3f(0.0f, 0.0f, 1.0f); glVertex3f(1.0f, -1.0f, 1.0f); glVertex3f(1.0f, -1.0f, -1.0f); glColor3f(0.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); glColor3f(0.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); glVertex3f(-1.0f, -1.0f, 1.0f); glColor3f(0.0f, 0.0f, 1.0f); glVertex3f(1.0f, -1.0f, 1.0f); glEnd(); glLoadIdentity(); // square DWORD dwDeltaTime = GetTickCount() - kStartTime; GLfloat fNewX = kRadius * cos(dwDeltaTime * kRotateSpeed); GLfloat fNewZ = kRadius * sin(dwDeltaTime * kRotateSpeed); glTranslatef(fNewX, -2.0f, fNewZ + kDistanceZ); glRotatef(g_fAngle4Quad, 0.0f, 1.0f, 0.0f); glBegin(GL_QUADS); glColor3f(0.0f, 1.0f, 0.0f); glVertex3f(1.0f, 1.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 0.0f); glVertex3f(1.0f, -1.0f, 0.0f); glEnd(); g_fAngle4Tri += 2.0f; g_fAngle4Quad += 20.0f; return TRUE; } LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { switch (uMsg) { case WM_ACTIVATE: g_bActive = !HIWORD(wParam) ? TRUE : FALSE; return 0; case WM_SYSCOMMAND: switch (wParam) { case SC_SCREENSAVE: case SC_MONITORPOWER: return 0; } break; case WM_CLOSE: PostQuitMessage(0); return 0; case WM_KEYDOWN: g_pKeys[wParam] = TRUE; return 0; case WM_KEYUP: g_pKeys[wParam] = FALSE; return 0; case WM_SIZE: ResizeGLWnd(LOWORD(lParam), HIWORD(lParam)); return 0; } return DefWindowProc(hWnd, uMsg, wParam, lParam); } int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrev, LPSTR lpCmdLine, int nCmdShow) { MSG msg; BOOL bDone = FALSE; // Ask The User Which Screen Mode They Prefer if (MessageBox(NULL, TEXT("Would You Like To Run In Fullscreen Mode?"), TEXT("Start FullScreen?"), MB_YESNO | MB_ICONQUESTION) == IDNO) { g_bFullScreen = FALSE; } if (!CreateGLWnd(TEXT("NeHe's Rotation Tutorial"), 640, 480, 16, g_bFullScreen)) { return 0; } while(!bDone) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { if (msg.message == WM_QUIT) { bDone = TRUE; } else { TranslateMessage(&msg); DispatchMessage(&msg); } } else { if ((g_bActive && !DrawScene()) || g_pKeys[VK_ESCAPE]) { bDone = TRUE; } else { SwapBuffers(g_hDC); } if (g_pKeys[VK_F1]) { g_pKeys[VK_F1] = FALSE; KillGLWnd(); g_bFullScreen = !g_bFullScreen; if (!CreateGLWnd(TEXT("NeHe's Rotation Tutorial"), 640, 480, 16, g_bFullScreen)) { return 0; } } } } KillGLWnd(); return (msg.wParam); }

显示效果如下图：