计算机图形学opengl源码

// Gingerbread Man // // A dot constellation that is generated procedurally by an // Iterated function system (IFS). // // The IFS: // x = R(1 + 2S) - old_y + abs(old_x - SR) // y = old_x // // The pattern is familiar with the chaos theory as it is // a form of a strange attractor #include <windows.h> #include <gl/gl.h> #include <gl/glu.h> HGLRC hRC=NULL; // Permanent Rendering Context HDC hDC=NULL; // Private GDI Device Context HWND hWnd=NULL; // Holds Our Window Handle HINSTANCE hInstance; // Holds The Instance Of The Application bool keys[256]; // Array Used For The Keyboard Routine bool active=TRUE; // Window Active Flag Set To TRUE By Default bool fullscreen=TRUE; // Fullscreen Flag Set To Fullscreen Mode By Default LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); // Declaration For WndProc GLvoid ReSizeGLScene(GLsizei width, GLsizei height) // Resize And Initialize The GL Window { if (height==0) // Prevent A Divide By Zero By { height=1; // Making Height Equal One } glViewport(0, 0, width, height); // Reset The Current Viewport glMatrixMode(GL_PROJECTION); // Select The Projection Matrix glLoadIdentity(); // Reset The Projection Matrix // Calculate The Aspect Ratio Of The Window gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f); glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix glLoadIdentity(); // Reset The Modelview Matrix } int InitGL(GLvoid) // All Setup For OpenGL Goes Here { glShadeModel(GL_SMOOTH); // Enables Smooth Shading glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Black Background glColor3f(1,1,1); // White colour for points glClearDepth(1.0f); // Depth Buffer Setup glEnable(GL_DEPTH_TEST); // Enables Depth Testing glDepthFunc(GL_LEQUAL); // The Type Of Depth Test To Do glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear screen to background colour glPointSize(1.0); // Set the point size to 3 pixels return TRUE; // Initialization Went OK } int DrawGLScene(GLvoid) // Here's Where We Do All The Drawing { // Don't bother clearing screen glLoadIdentity(); glTranslatef(-30,-30,-90); // Translate out a so we can see the image and adjust image to middle of screen glScaled(0.15, 0.15, 0.15); // Fit image on screen float x, y; // x/y of point to draw static float old_x=115, old_y=121; // Previous point static float R=40, S=3; // Constant Values glBegin(GL_POINTS); for (int i=0; i<1000; i++) // Draw 1000 points per render { x = R*(1 + 2*S) - old_y + abs(int(old_x - S*R));// The IFS for x y = old_x; // and for y old_x = x; old_y = y; glVertex2f(x,y); // Output that magic vertex } glEnd(); glFlush(); // Flush the OpenGL pipe return TRUE; // Everything Went OK } GLvoid KillGLWindow(GLvoid) // Properly Kill The Window { if (fullscreen) // Are We In Fullscreen Mode? { ChangeDisplaySettings(NULL,0); // If So Switch Back To The Desktop ShowCursor(TRUE); // Show Mouse Pointer } if (hRC) // Do We Have A Rendering Context? { if (!wglMakeCurrent(NULL,NULL)) // Are We Able To Release The DC And RC Contexts? { MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); } if (!wglDeleteContext(hRC)) // Are We Able To Delete The RC? { MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); } hRC=NULL; // Set RC To NULL } if (hDC && !ReleaseDC(hWnd,hDC)) // Are We Able To Release The DC { MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); hDC=NULL; // Set DC To NULL } if (hWnd && !DestroyWindow(hWnd)) // Are We Able To Destroy The Window? { MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); hWnd=NULL; // Set hWnd To NULL } if (!UnregisterClass("OpenGL",hInstance)) // Are We Able To Unregister Class { MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION); hInstance=NULL; // Set hInstance To NULL } } BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag) { GLuint PixelFormat; // Holds The Results After Searching For A Match WNDCLASS wc; // Windows Class Structure DWORD dwExStyle; // Window Extended Style DWORD dwStyle; // Window Style RECT WindowRect; // Grabs Rectangle Upper Left / Lower Right Values WindowRect.left=(long)0; // Set Left Value To 0 WindowRect.right=(long)width; // Set Right Value To Requested Width WindowRect.top=(long)0; // Set Top Value To 0 WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height fullscreen=fullscreenflag; // Set The Global Fullscreen Flag hInstance = GetModuleHandle(NULL); // Grab An Instance For Our Window wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // Redraw On Move, And Own DC For Window wc.lpfnWndProc = (WNDPROC) WndProc; // 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 = NULL; // We Don't Want A Menu wc.lpszClassName = "OpenGL"; // Set The Class Name if (!RegisterClass(&wc)) // Attempt To Register The Window Class { MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION); return FALSE; // Exit And Return FALSE } if (fullscreen) // Attempt Fullscreen Mode? { DEVMODE dmScreenSettings; // Device Mode memset(&dmScreenSettings,0,sizeof(dmScreenSettings)); // Makes Sure Memory's Cleared dmScreenSettings.dmSize=sizeof(dmScreenSettings); // Size Of The Devmode Structure dmScreenSettings.dmPelsWidth = width; // Selected Screen Width dmScreenSettings.dmPelsHeight = height; // Selected Screen Height dmScreenSettings.dmBitsPerPel = bits; // Selected Bits Per Pixel dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT; // Try To Set Selected Mode And Get Results. NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar. if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL) { // If The Mode Fails, Offer Two Options. Quit Or Run In A Window. if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES) { fullscreen=FALSE; // Select Windowed Mode (Fullscreen=FALSE) } else { // Pop Up A Message Box Letting User Know The Program Is Closing. MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP); return FALSE; // Exit And Return FALSE } } } if (fullscreen) // Are We Still In Fullscreen Mode? { dwExStyle=WS_EX_APPWINDOW; // Window Extended Style dwStyle=WS_POPUP; // Windows Style ShowCursor(FALSE); // Hide Mouse Pointer } else { dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window Extended Style dwStyle=WS_OVERLAPPEDWINDOW; // Windows Style } AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);