www.pudn.com > 20050921094855818.zip > winmain.cpp
/* * Polygon Reduction Demo by Stan Melax (c) 1998 * Permission to use any of this code wherever you want is granted.. * Although, please do acknowledge authorship if appropriate. * * This module contains the window setup code, mouse input, timing * routines, and that sort of stuff. The interesting modules * to see are bunnygut.cpp and progmesh.cpp. * * The windows 95 specific code for this application was taken from * an example of processing mouse events in an OpenGL program using * the Win32 API from the www.opengl.org web site. * * Under Project->Settings, Link Options, General Category * Add: * Opengl32.lib glu32.lib winmm.lib * to the Object/Library Modules * * You will need have OpenGL libs and include files to compile this * Go to the www.opengl.org web site if you need help with this. */ #include/* must include this before GL/gl.h */ #include /* OpenGL header file */ #include /* OpenGL utilities header file */ #include #include #include #include #include "vector.h" #include "font.h" // Functions and Variables from bunny module extern void InitModel(); extern void RenderModel(); extern Vector model_position; // position of bunny extern Quaternion model_orientation; // orientation of bunny // Global Variables float DeltaT = 0.1f; float FPS; int Width = 512; int Height = 512; int MouseX = 0; int MouseY = 0; Vector MouseVector; // 3D direction mouse points Vector OldMouseVector; int MouseState=0; // true iff left button down float ViewAngle=45.0f; HDC hDC; /* device context */ HPALETTE hPalette = 0; /* custom palette (if needed) */ void CalcFPSDeltaT(){ static int timeinit=0; static int start,start2,current,last; static int frame=0, frame2=0; if(!timeinit){ frame=0; start=timeGetTime(); timeinit=1; } frame++; frame2++; current=timeGetTime(); // found in winmm.lib double dif=(double)(current-start)/CLOCKS_PER_SEC; double rv = (dif)? (double)frame/(double)dif:-1.0; if(dif>2.0 && frame >10) { start = start2; frame = frame2; start2 = timeGetTime(); frame2 = 0; } DeltaT = (float)(current-last)/CLOCKS_PER_SEC; if(current==last) { DeltaT = 0.1f / CLOCKS_PER_SEC; // it just cant be 0 } // if(DeltaT>1.0) DeltaT=1.0; FPS = (float)rv; last = current; } void ComputeMouseVector(){ OldMouseVector=MouseVector; float spread = (float)tan(ViewAngle/2*3.14/180); float y = spread * ((Height-MouseY)-Height/2.0f) /(Height/2.0f); float x = spread * (MouseX-Width/2.0f) /(Height/2.0f); Vector v(x ,y,-1); // v=UserOrientation *v; v=normalize(v); MouseVector = v; } Quaternion VirtualTrackBall(Vector cop,Vector cor,Vector dir1,Vector dir2) { // Implement track ball functionality to spin stuf on the screen // cop center of projection // cor center of rotation // dir1 old mouse direction // dir2 new mouse direction // pretend there is a sphere around cor. Then find the points // where dir1 and dir2 intersect that sphere. Find the // rotation that takes the first point to the second. float m; // compute plane Vector nrml = cor - cop; float fudgefactor = 1.0f/(magnitude(nrml) * 0.25f); // since trackball proportional to distance from cop nrml = normalize(nrml); float dist = -(nrml^cor); Vector u= planelineintersection(nrml,dist,cop,cop+dir1); u=u-cor; u=u*fudgefactor; m= magnitude(u); if(m>1) {u=u*1.0f/m;} else { u=u - (nrml * (float)sqrt(1-m*m)); } Vector v= planelineintersection(nrml,dist,cop,cop+dir2); v=v-cor; v=v*fudgefactor; m= magnitude(v); if(m>1) {v=v*1.0f/m;} else { v=v - (nrml * (float)sqrt(1-m*m)); } Vector axis = u*v; float angle; m=magnitude(axis); if(m>1)m=1; // avoid potential floating point error Quaternion q(Vector(1.0f,0.0f,0.0f),0.0f); if(m>0 && (angle=(float)asin(m))>3.14/180) { axis = normalize(axis); q=Quaternion(axis,angle); } return q; } void SpinIt(){ // Change the orientation of the bunny according to mouse drag Quaternion q=VirtualTrackBall(Vector(0,0,0),model_position, OldMouseVector,MouseVector); model_orientation=q*model_orientation; } void Reshape(int width, int height){ // called initially and when the window changes size Width=width; Height=height; glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(ViewAngle, (float)width/height, 0.1, 50.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } void PrintStats(){ char buf[1024];buf[0]='\0'; sprintf(buf,"FPS: %5.2f ",FPS); PostString(buf,0,-1,0); } void Display(){ // main drawing routine - called every frame glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); glLoadIdentity(); // camera at default (zero) position and orientation RenderModel(); PrintStats(); glLoadIdentity(); RenderStrings(); glPopMatrix(); glFlush(); SwapBuffers(hDC); /* nop if singlebuffered */ } LONG WINAPI WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { static PAINTSTRUCT ps; static GLboolean left = GL_FALSE; /* left button currently down? */ static GLboolean right = GL_FALSE; /* right button currently down? */ static int omx, omy, mx, my; switch(uMsg) { case WM_PAINT: BeginPaint(hWnd, &ps); EndPaint(hWnd, &ps); return 0; case WM_SIZE: Reshape(LOWORD(lParam), HIWORD(lParam)); PostMessage(hWnd, WM_PAINT, 0, 0); return 0; case WM_CHAR: switch (wParam) { case 27: /* ESC key */ PostQuitMessage(0); break; } return 0; case WM_LBUTTONDOWN: /* if we don't set the capture we won't get mouse move messages when the mouse moves outside the window. */ SetCapture(hWnd); MouseX = LOWORD(lParam); MouseY = HIWORD(lParam); ComputeMouseVector(); MouseState = 1; return 0; case WM_LBUTTONUP: MouseX = LOWORD(lParam); MouseY = HIWORD(lParam); if(MouseX & 1 << 15) MouseX -= (1 << 16); if(MouseY & 1 << 15) MouseY -= (1 << 16); ComputeMouseVector(); if(MouseState) SpinIt(); MouseState=0; /* remember to release the capture when we are finished. */ ReleaseCapture(); return 0; case WM_MOUSEMOVE: MouseX = LOWORD(lParam); MouseY = HIWORD(lParam); /* Win32 is pretty braindead about the x, y position that it returns when the mouse is off the left or top edge of the window (due to them being unsigned). therefore, roll the Win32's 0..2^16 pointer co-ord range to the more amenable (and useful) 0..+/-2^15. */ if(MouseX & 1 << 15) MouseX -= (1 << 16); if(MouseY & 1 << 15) MouseY -= (1 << 16); ComputeMouseVector(); if(MouseState) SpinIt(); return 0; case WM_PALETTECHANGED: if (hWnd == (HWND)wParam) break; /* fall through to WM_QUERYNEWPALETTE */ case WM_QUERYNEWPALETTE: if (hPalette) { UnrealizeObject(hPalette); SelectPalette(hDC, hPalette, FALSE); RealizePalette(hDC); return TRUE; } return FALSE; case WM_CLOSE: PostQuitMessage(0); return 0; } return DefWindowProc(hWnd, uMsg, wParam, lParam); } HWND CreateOpenGLWindow(char* title) { // make a double-buffered, rgba, opengl window int n, pf; HWND hWnd; WNDCLASS wc; LOGPALETTE* lpPal; PIXELFORMATDESCRIPTOR pfd; static HINSTANCE hInstance = 0; /* only register the window class once - use hInstance as a flag. */ if (!hInstance) { hInstance = GetModuleHandle(NULL); wc.style = CS_OWNDC; wc.lpfnWndProc = (WNDPROC)WindowProc; wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = hInstance; wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); wc.hCursor = LoadCursor(NULL, IDC_ARROW); wc.hbrBackground = NULL; wc.lpszMenuName = NULL; wc.lpszClassName = "OpenGL"; if (!RegisterClass(&wc)) { MessageBox(NULL, "RegisterClass() failed: " "Cannot register window class.", "Error", MB_OK); return NULL; } } hWnd = CreateWindow("OpenGL", title, WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, 0,0,Width,Height, NULL, NULL, hInstance, NULL); if (hWnd == NULL) { MessageBox(NULL, "CreateWindow() failed: Cannot create a window.", "Error", MB_OK); return NULL; } hDC = GetDC(hWnd); /* there is no guarantee that the contents of the stack that become the pfd are zeroed, therefore _make sure_ to clear these bits. */ memset(&pfd, 0, sizeof(pfd)); pfd.nSize = sizeof(pfd); pfd.nVersion = 1; pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER; pfd.iPixelType = PFD_TYPE_RGBA; pfd.cDepthBits = 32; pfd.cColorBits = 32; pf = ChoosePixelFormat(hDC, &pfd); if (pf == 0) { MessageBox(NULL, "ChoosePixelFormat() failed: " "Cannot find a suitable pixel format.", "Error", MB_OK); return 0; } if (SetPixelFormat(hDC, pf, &pfd) == FALSE) { MessageBox(NULL, "SetPixelFormat() failed: " "Cannot set format specified.", "Error", MB_OK); return 0; } DescribePixelFormat(hDC, pf, sizeof(PIXELFORMATDESCRIPTOR), &pfd); if (pfd.dwFlags & PFD_NEED_PALETTE || pfd.iPixelType == PFD_TYPE_COLORINDEX) { n = 1 << pfd.cColorBits; if (n > 256) n = 256; lpPal = (LOGPALETTE*)malloc(sizeof(LOGPALETTE) + sizeof(PALETTEENTRY) * n); memset(lpPal, 0, sizeof(LOGPALETTE) + sizeof(PALETTEENTRY) * n); lpPal->palVersion = 0x300; lpPal->palNumEntries = n; GetSystemPaletteEntries(hDC, 0, n, &lpPal->palPalEntry[0]); /* if the pixel type is RGBA, then we want to make an RGB ramp, otherwise (color index) set individual colors. */ if (pfd.iPixelType == PFD_TYPE_RGBA) { int redMask = (1 << pfd.cRedBits) - 1; int greenMask = (1 << pfd.cGreenBits) - 1; int blueMask = (1 << pfd.cBlueBits) - 1; int i; /* fill in the entries with an RGB color ramp. */ for (i = 0; i < n; ++i) { lpPal->palPalEntry[i].peRed = (((i >> pfd.cRedShift) & redMask) * 255) / redMask; lpPal->palPalEntry[i].peGreen = (((i >> pfd.cGreenShift) & greenMask) * 255) / greenMask; lpPal->palPalEntry[i].peBlue = (((i >> pfd.cBlueShift) & blueMask) * 255) / blueMask; lpPal->palPalEntry[i].peFlags = 0; } } else { lpPal->palPalEntry[0].peRed = 0; lpPal->palPalEntry[0].peGreen = 0; lpPal->palPalEntry[0].peBlue = 0; lpPal->palPalEntry[0].peFlags = PC_NOCOLLAPSE; lpPal->palPalEntry[1].peRed = 255; lpPal->palPalEntry[1].peGreen = 0; lpPal->palPalEntry[1].peBlue = 0; lpPal->palPalEntry[1].peFlags = PC_NOCOLLAPSE; lpPal->palPalEntry[2].peRed = 0; lpPal->palPalEntry[2].peGreen = 255; lpPal->palPalEntry[2].peBlue = 0; lpPal->palPalEntry[2].peFlags = PC_NOCOLLAPSE; lpPal->palPalEntry[3].peRed = 0; lpPal->palPalEntry[3].peGreen = 0; lpPal->palPalEntry[3].peBlue = 255; lpPal->palPalEntry[3].peFlags = PC_NOCOLLAPSE; } hPalette = CreatePalette(lpPal); if (hPalette) { SelectPalette(hDC, hPalette, FALSE); RealizePalette(hDC); } free(lpPal); } ReleaseDC(hDC, hWnd); return hWnd; } int APIENTRY WinMain(HINSTANCE hCurrentInst, HINSTANCE hPreviousInst, LPSTR lpszCmdLine, int nCmdShow) { HGLRC hRC; /* opengl context */ HWND hWnd; /* window */ MSG msg; /* message */ // InitModel() initializes some data structures and // does the progressive mesh polygon reduction algorithm // on the model. CalcFPSDeltaT(); // to time the algorithm InitModel(); CalcFPSDeltaT(); hWnd = CreateOpenGLWindow("bunnylod by Stan Melax"); if (hWnd == NULL) exit(1); hDC = GetDC(hWnd); hRC = wglCreateContext(hDC); wglMakeCurrent(hDC, hRC); ShowWindow(hWnd, nCmdShow); glEnable(GL_DEPTH_TEST); PostString("Demo by Stan Melax (c)1998",5,-5,20); PostString("Model by Viewpoint Datalabs (c)1996",5,-4,20); char buf[128]; PostString("Mesh Reduction Algorithm (non-optimized)",1,0,5); sprintf(buf,"was executed in %5.3f seconds",DeltaT); PostString(buf,2,1,6); while (1) { while(PeekMessage(&msg, hWnd, 0, 0, PM_NOREMOVE)) { if(GetMessage(&msg, hWnd, 0, 0)) { TranslateMessage(&msg); DispatchMessage(&msg); } else { goto quit; // This 'goto' was in the sample code } } CalcFPSDeltaT(); Display(); } quit: wglMakeCurrent(NULL, NULL); ReleaseDC(hDC, hWnd); wglDeleteContext(hRC); DestroyWindow(hWnd); if (hPalette) DeleteObject(hPalette); return msg.wParam; }