//First, we need to include the required header files#include <windows.h>	//Windows header file#include <math.h>		//Math header file#include <stdio.h>		//Standard file input/output header file#include <gl/gl.h>		// - - v#include <gl/glu.h>		// - - > OpenGL Header Files#include <gl/glaux.h>	// - - ^HGLRC hRC = NULL;			//Rendering ContextHDC hDC = NULL;				//Device ContextHWND hWnd = NULL;			//Window HandleHINSTANCE hInstance = NULL;	//Window Instancebool keys[256];			//Array used for keys which are pressedbool active = true;		//Whether or not the window is activebool fullscreen = true;	//Whether or not the program is in full screenbool lp; //L pressedbool lighting; //Lighting activated/deactivatedconst float piover180 = 0.0174532925f;float heading;float xpos, zpos;GLfloat LightAmbient[]= { 0.5f, 0.5f, 0.5f, 1.0f };GLfloat yrot;GLfloat walkbias=0;GLfloat walkbiasangle=0;GLfloat lookupdown=0.0f;GLfloat z=0.0f;GLuint filter;GLuint texture[3];typedef struct tagVERTEX{	float x, y, z;	float u, v;} VERTEX;typedef struct tagPOLY{	int numvertices;	VERTEX* vertex;} POLY;typedef struct tagLIGHT{	GLfloat LightPosition[4];	GLfloat LightDiffuse[4];} LIGHT;typedef struct tagSECTOR{	int numpollies;	POLY* poly;	int numlights;	LIGHT* light;} SECTOR;SECTOR sector1;LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam); //WndProc prototypevoid readstr(FILE *f, char *string){	do	{		fgets(string, 255, f);	}	while ((string[0] == '/') || (string[0] == '\n'));	return;}void SetupWorld(){	float x, y, z, u, v;	int numpollies;	int numlights;;	FILE *filein;	char oneline[255];	filein = fopen("data/world.txt", "rt");	readstr(filein,oneline);	sscanf(oneline, "NUMPOLLIES %d\n", &numpollies);	sector1.poly = new POLY[numpollies];	sector1.numpollies = numpollies;	for (int loop = 0; loop < numpollies; loop++)	{		readstr(filein, oneline);		if (oneline[0]=='Q')		{			sector1.poly[loop].numvertices=4;		}		else		{			sector1.poly[loop].numvertices=3;		}		sector1.poly[loop].vertex=new VERTEX[sector1.poly[loop].numvertices];		for (int vert = 0; vert < sector1.poly[loop].numvertices; vert++)		{			readstr(filein,oneline);			sscanf(oneline, "%f %f %f %f %f", &x, &y, &z, &u, &v);			sector1.poly[loop].vertex[vert].x = x;			sector1.poly[loop].vertex[vert].y = y;			sector1.poly[loop].vertex[vert].z = z;			sector1.poly[loop].vertex[vert].u = u;			sector1.poly[loop].vertex[vert].v = v;		}	}	readstr(filein, oneline);	sscanf(oneline, "NUMLIGHTS %d\n", &numlights);	sector1.light=new LIGHT[numlights];	sector1.numlights=numlights;	for (loop=0; loop < numlights; loop++)	{		readstr(filein, oneline);		sscanf(oneline, "%f, %f, %f, %f", &x, &y, &z, &u);		static GLfloat LightDiffuse [] = {x, y, z, u};		for (int loop2; loop2<4; loop2++)		{			sector1.light[loop].LightDiffuse[loop2]=LightDiffuse[loop2];		}		readstr(filein, oneline);		sscanf(oneline, "%f, %f, %f, %f", &x, &y, &z, &u);		static GLfloat LightPosition [] = {x, y, z, u};		for (loop2; loop2<4; loop2++)		{			sector1.light[loop].LightPosition[loop2]=LightPosition[loop2];		}	}	fclose(filein);	return;}AUX_RGBImageRec *LoadBMP(char *Filename) //Loads a BMP{	FILE *File=NULL;	if (!Filename)	{		return NULL;	}	File=fopen(Filename,"r");	if (File)	{		fclose(File);		return auxDIBImageLoad(Filename);	}	return NULL;}int LoadGLTextures()								// Load Bitmaps And Convert To Textures{	int Status=FALSE;							// Status Indicator	AUX_RGBImageRec *TextureImage[1];					// Create Storage Space For The Texture	memset(TextureImage,0,sizeof(void *)*1);	if (TextureImage[0]=LoadBMP("Data/Metal.bmp"))	{		Status=true;		glGenTextures(3, &texture[0]);		glBindTexture(GL_TEXTURE_2D, texture[0]);		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);		glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);			}	if (TextureImage[0])	{		if (TextureImage[0]->data)		{			free(TextureImage[0]->data);		}		free(TextureImage[0]);	}	return Status;}GLvoid ReSizeGLScene(GLsizei width, GLsizei height) //Resizes and initializes the OpenGL Window{	if (height==0)	{		height=1;  //Prevents a divide by zero	}	glViewport(0, 0, width, height); //Resets the current viewport	glMatrixMode(GL_PROJECTION); //Select the projection matrix	glLoadIdentity(); //Reset the projection matrix	gluPerspective(45.0f, (GLfloat)width/(GLfloat)height, 0.1f, 100.0f); //Calculates the aspect ratio of the window	glMatrixMode(GL_MODELVIEW); //Select the modelview matrix	glLoadIdentity(); //Reset the modelview matrix}int InitGL(GLvoid) //Setup for OpenGL{	if (!LoadGLTextures())								// Jump To Texture Loading Routine	{		return FALSE;									// If Texture Didn't Load Return FALSE	}		glEnable(GL_TEXTURE_2D);	glBlendFunc(GL_SRC_ALPHA,GL_ONE);	glShadeModel(GL_SMOOTH); //Enables smooth shading	glClearColor(0.0f, 0.0f, 0.0f, 0.0f); //Black background	glClearDepth(1.0f); //Depth buffer setup	glEnable(GL_DEPTH_TEST); //Enables depth testing	glDepthFunc(GL_LEQUAL); //Type of depth test to do	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); //Good perception calculations		SetupWorld();		for (int loop=0; loop<sector1.numlights; loop++)	{		glLightfv(GL_LIGHT0+loop, GL_AMBIENT, LightAmbient); //Set up the ambient light		glLightfv(GL_LIGHT0+loop, GL_DIFFUSE, sector1.light[loop].LightDiffuse); //Set up the diffuse light		glLightfv(GL_LIGHT0+loop, GL_POSITION,sector1.light[loop].LightPosition); //Position the light		glEnable(GL_LIGHT0+loop);	}	return true;}int DrawGLScene(GLvoid)								// Here's Where We Do All The Drawing{	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	glLoadIdentity();	GLfloat x_m, y_m, z_m, u_m, v_m;	GLfloat xtrans=-xpos;	GLfloat ztrans=-zpos;	GLfloat ytrans=-walkbias-0.25f;	GLfloat sceneroty=360.0f-yrot;	int numpollies;	glRotatef(lookupdown, 1.0f, 0, 0);	glRotatef(sceneroty, 0, 1.0f, 0);	glTranslatef(xtrans, ytrans, ztrans);	glBindTexture(GL_TEXTURE_2D, texture[filter]);	numpollies=sector1.numpollies;	for (int loop_m = 0; loop_m < numpollies; loop_m++)	{		if (sector1.poly[loop_m].numvertices==3)		{			glBegin(GL_TRIANGLES);		}		else		{			glBegin(GL_QUADS);		}			glNormal3f(0.0f, 0.0f, 1.0f);			for (int loop_m2 = 0; loop_m2<sector1.poly[loop_m].numvertices; loop_m2++)			{				x_m=sector1.poly[loop_m].vertex[loop_m2].x;				y_m=sector1.poly[loop_m].vertex[loop_m2].y;				z_m=sector1.poly[loop_m].vertex[loop_m2].z;				u_m=sector1.poly[loop_m].vertex[loop_m2].u;				v_m=sector1.poly[loop_m].vertex[loop_m2].v;				glTexCoord2f(u_m, v_m); glVertex3f(x_m, y_m, z_m);			}		glEnd();	}	return true;}GLvoid KillGLWindow(GLvoid) //Kills the window properly{	if (fullscreen) //If we are in fullscreen mode	{		ChangeDisplaySettings(NULL, 0); //then switch back to desktop		ShowCursor(true); //and display the cursor	}	if (hRC) //If we have a rendering context	{		if (!wglMakeCurrent(NULL, NULL)) //Release the DC and RC contexts		{			MessageBox(NULL, "Release of DC and RC failed.", "Shutdown Error", MB_OK | MB_ICONINFORMATION);		}		if (!wglDeleteContext(hRC)) //Delete the RC		{			MessageBox(NULL, "Release Render Conext Failed.", "Shutdown Error", MB_OK | MB_ICONINFORMATION);		}		hRC=NULL; //Set RC to NULL	}	if (hDC && !ReleaseDC(hWnd,hDC)) //Release the DC	{		MessageBox(NULL, "Release Device Context Failed.", "Shutdown Error", MB_OK | MB_ICONINFORMATION);		hDC=NULL;	}	if (hWnd && !DestroyWindow(hWnd)) //Destroy the window	{		MessageBox(NULL, "Could not release hWnd.", "Shutdown Error", MB_OK | MB_ICONINFORMATION);		hWnd=NULL;	}	if (!UnregisterClass("OpenGL", hInstance)) //Unregister the class	{		MessageBox(NULL, "Could not unregister class.", "Shutdown Error", MB_OK | MB_ICONINFORMATION);		hInstance=NULL;	}}bool CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag) //Create the OpenGL window{	GLuint PixelFormat; //Holds the result after searching for a match	WNDCLASS wc; //Windows class structure	DWORD dwExStyle; //Window Extended Style	DWORD dwStyle; //Window Style	RECT WindowRect; //Holds upper-left and lower-right values of the window	WindowRect.left=(long)0; //Left is zero	WindowRect.right=(long)width; //Right is the width	WindowRect.top=(long)0; //Top is 0	WindowRect.bottom=(long)height; //Bottom is the height	fullscreen=fullscreenflag; //Fullscreen is as requested	hInstance=GetModuleHandle(NULL); //Gets an instance for the window	//Declares the window class	wc.style=CS_HREDRAW | CS_VREDRAW | CS_OWNDC; //Redraw when moved, and own DC	wc.lpfnWndProc=(WNDPROC)WndProc; //WndProc function handles messages	wc.cbClsExtra=0; //Extra window data	wc.cbWndExtra=0; //Extra window data	wc.hInstance=hInstance; //Set the instance	wc.hIcon=LoadIcon(NULL, IDI_WINLOGO); //Set the icon	wc.hCursor=LoadCursor(NULL, IDC_ARROW); //Set the cursor	wc.hbrBackground=NULL; //Set the background	wc.lpszMenuName=NULL; //Set the menu	wc.lpszClassName="OpenGL"; //Set the name of the class	if (!RegisterClass(&wc)) //Registers the class defined above	{		MessageBox(NULL, "Failed to register the window class.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	if (fullscreen) //If we are in fullscreen mode	{		DEVMODE dmScreenSettings; //Device mode		memset(&dmScreenSettings, 0, sizeof(dmScreenSettings)); //Make sure the memory's cleared		dmScreenSettings.dmSize=sizeof(dmScreenSettings); //Size of the device mode structure		dmScreenSettings.dmPelsWidth=width; //Screen width		dmScreenSettings.dmPelsHeight=height; //Screen height		dmScreenSettings.dmBitsPerPel=bits; //Bits per pixel		dmScreenSettings.dmFields=DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;		if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL) //Changes the display settings		{			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) //Asks if the user would like to switch to windowed mode			{				fullscreen=false;			}			else			{				MessageBox(NULL, "The Program Will Now Quit.", "ERROR", MB_OK | MB_ICONSTOP);				return false;			}		}	}	if (fullscreen)	{		dwExStyle=WS_EX_APPWINDOW; //Window extended style		dwStyle=WS_POPUP; //Window style - WS_POPUP gets rid of all borders around a window		ShowCursor(false); //Hide the cursor	}	else	{		dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; //Window extended style		dwStyle=WS_OVERLAPPEDWINDOW; //Window style - WS_OVERLAPPEDWINDOW gives the window a title bar, sizing border, window menu, and min/max buttons	}	AdjustWindowRectEx(&WindowRect, dwStyle, false, dwExStyle); //Adjust the window to true requested sizes	//Create the window:	if (!(hWnd=CreateWindowEx(	dwExStyle, //Window extended style								"OpenGL", //Window class name, as defined above								title, //Title of the window								WS_CLIPSIBLINGS | //Required								WS_CLIPCHILDREN | //Required								dwStyle, //Window style								0,0, //Window coordinates								WindowRect.right-WindowRect.left, //Window width								WindowRect.bottom-WindowRect.top, //Windot height								NULL, //Parent window								NULL, //Menu								hInstance, //Instance								NULL))) //Passed to WM_CREATE	{		KillGLWindow(); //Destroys the window if window creation fials		MessageBox(NULL, "Window Creation Error.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	static PIXELFORMATDESCRIPTOR pfd= //Tells windows how we want things to be	{		sizeof(PIXELFORMATDESCRIPTOR), //Size of Pixel Format Descriptor		1, //Version number		PFD_DRAW_TO_WINDOW | //Must support window		PFD_SUPPORT_OPENGL | //Must support OpenGL		PFD_DOUBLEBUFFER, //Must support double buffering		PFD_TYPE_RGBA, //RGBA format		bits, //Color depth		0, 0, 0, 0, 0, 0, //Color bits		0, //Alpha buffer		0, //Shift bit		0, //Accumulation buffer		0, 0, 0, 0, //Accumulation bits		16, //16-bit Z-Buffer		0, //Stencil buffer		0, //Auxiliary buffer		PFD_MAIN_PLANE, //Main drawing layer		0, //Reserved		0, 0, 0 //Layer masks	};		if (!(hDC=GetDC(hWnd))) //Get a device context	{		KillGLWindow();		MessageBox(NULL, "Can't Create A GL Device Context.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	if (!(PixelFormat=ChoosePixelFormat(hDC, &pfd))) //Find a matching pixel format	{		KillGLWindow();		MessageBox(NULL, "Can't Find A Suitable PixelFormat.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	if (!SetPixelFormat(hDC, PixelFormat, &pfd)) //Set the pixel format	{		KillGLWindow();		MessageBox(NULL, "Can't Set The PixelFormat.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	if (!(hRC=wglCreateContext(hDC))) //Get a rendering context	{		KillGLWindow();		MessageBox(NULL, "Can't Create A GL Rendering Context.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	if (!wglMakeCurrent(hDC, hRC)) //Activate the rendering context	{		KillGLWindow();		MessageBox(NULL, "Can't Activate the GL Rendering Context.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	ShowWindow(hWnd, SW_SHOW); //Show the window	SetForegroundWindow(hWnd); //Give the window slightly higher priority	SetFocus(hWnd); //Set the focus to the window	ReSizeGLScene(width, height); //Set up our perspective	if (!InitGL()) //Initialize our new GL window	{		KillGLWindow();		MessageBox(NULL, "Initialization Failed.", "ERROR", MB_OK | MB_ICONEXCLAMATION);		return false;	}	return true;}//Handles windows messages:LRESULT CALLBACK WndProc(	HWND hWnd, //Window handle							UINT uMsg, //Message							WPARAM wParam, //Additional message info							LPARAM lParam) //Additional message info{	switch (uMsg) //Check the message	{		case WM_ACTIVATE: //The window has been activated/deactivated		{			if (!HIWORD(wParam))			{				active=true;			}			else			{				active=false;			}			return 0;		}				case WM_SYSCOMMAND: //Windows is trying to start the screens saver, or power down the moniter		{			switch (wParam)			{				case SC_SCREENSAVE:				case SC_MONITORPOWER:				return 0; //Don't let the screensaver start, or the moniter power down			}			break;		}		case WM_CLOSE: //The window is closing		{			PostQuitMessage(0);			return 0;		}		case WM_KEYDOWN: //A key on the keyboard is down		{			keys[wParam]=true;			return 0;		}		case WM_KEYUP: //A key on the keyboard has been released		{			keys[wParam]=false;			return 0;		}		case WM_SIZE: //The window has been resized		{			ReSizeGLScene(LOWORD(lParam), HIWORD(lParam));			return 0;		}	}		return DefWindowProc(hWnd, uMsg, wParam, lParam);}int WINAPI WinMain(	HINSTANCE hInstance, //Instance of the window					HINSTANCE hPrevInstance, //Previous instance of the window					LPSTR lpCmdLine, //command line parameters					int nCmdShow) //Window show state{	MSG msg; //Windows message structure	bool done=false; //Variable to exit loop	//Asks the user if they would like to run in fullscreen mode	if (MessageBox(NULL, "Would You Like To Run In Fullscreen Mode?", "Start Fullscreen?", MB_YESNO | MB_ICONQUESTION)==IDNO)	{		fullscreen=false;	}	if (!CreateGLWindow("Lionel Brits & NeHe's 3D World Tutorial", 640, 480, 16, fullscreen)) //Create the window	{		return 0;	}	//Main loop	while (!done)	{		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) //Checks for messages		{			if (msg.message==WM_QUIT) //The program is closing			{				done=true;			}			else			{				TranslateMessage(&msg); //Translate the message				DispatchMessage(&msg); //Dispatch the message			}		}		else		{			if (active)			{				if (keys[VK_ESCAPE]) //If the escape key was pressed				{					done=true; //Allow the loop to end				}				else				{					DrawGLScene();					SwapBuffers(hDC);					if (keys[VK_RIGHT])					{						heading-=1.0f;						yrot=heading;					}					if (keys[VK_LEFT])					{						heading+=1.0f;						yrot=heading;					}										if (keys[VK_UP])					{						xpos-=(float)sin(heading*piover180)*0.05f;						zpos-=(float)cos(heading*piover180)*0.05f;						if (walkbiasangle>=359.0f)						{							walkbiasangle=0.0f;						}						else						{							walkbiasangle+=10;						}						walkbias=(float)sin(walkbiasangle*piover180)/20.0f;					}					if (keys[VK_DOWN])					{						xpos+=(float)sin(heading*piover180)*0.05f;						zpos+=(float)cos(heading*piover180)*0.05f;						if (walkbiasangle<1.0f)						{							walkbiasangle=359.0f;						}						else						{							walkbiasangle-=10;						}						walkbias=(float)sin(walkbiasangle*piover180)*0.05f;					}					if (keys['L'] && !lp)					{						lp=true;						lighting=!lighting;						if (!lighting)						{							glDisable(GL_LIGHTING);						}						else						{							glEnable(GL_LIGHTING);						}					}					if (!keys['L'])					{						lp=false;					}				}			}			if (keys[VK_F1]) //If the F1 key was pressed, then switch between windowed mode and fullscreen mode			{				keys[VK_F1]=false;				KillGLWindow();				fullscreen=!fullscreen;				if (!CreateGLWindow("Lionel Brits & NeHe's 3D World Tutorial", 640, 480, 16, fullscreen))				{					return 0;				}			}		}	}	KillGLWindow(); //Kill the window	return (msg.wParam);}

for (int loop=0; loop<sector1.numlights; loop++){	glLightfv(GL_LIGHT0+loop, GL_AMBIENT, LightAmbient); //Set up the ambient light	glLightfv(GL_LIGHT0+loop, GL_DIFFUSE, sector1.light[loop].LightDiffuse); //Set up the diffuse light	glLightfv(GL_LIGHT0+loop, GL_POSITION,sector1.light[loop].LightPosition); //Position the light	glEnable(GL_LIGHT0+loop);}

sscanf(oneline, "%f, %f, %f, %f", &x, &y, &z, &u);

sscanf(oneline, "%f %f %f %f", &x, &y, &z, &u);