#include <cmath>#include <deque>#include <fstream>#include <map>#include <string>#include <windows.h>#include <GL/gl.h>#include <GL/glu.h>/* Don't worry about this, it's just a more bullet proof version of NULL */class NullPtr{	public:		template <typename TYPE>		operator const TYPE*() const		{			return 0;		}		operator void*() const		{			return 0;		}		template <typename TYPE, class CLASS>		operator const TYPE CLASS::*() const		{			return 0;		}	private:		void operator&() const;} nullptr;HDC hDC = nullptr;HGLRC hRC = nullptr;HWND hWnd = nullptr;HINSTANCE hInstance = nullptr;bool keys[256];bool active = true;bool fullscreen = true;bool blend;bool bp;bool fp;const float piover180 = 3.14159f / 180;float heading;float xpos;float zpos;GLfloat yrot;GLfloat walkbias = 0;GLfloat walkbiasangle = 0;GLfloat lookupdown = 0.0f;GLfloat z = 0.0f;/* This is C++, so there is no need to typedef the structs */struct Vertex{	float x, y, z;	float u, v;};struct Triangle{	Vertex vertex[3];};/* Why use a raw array when you can use a deque? */struct Sector{	std::deque<Triangle> triangle;};Sector sector1;/* Let's store our textures in a map to make things easier */std::map<std::string, GLuint> textures;LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);/* Prefer std::string to char*.  Also changed the id to a string for ease of use */bool neHeLoadBitmap(std::string fileName, std::string textureName){	HBITMAP bitmapHandle;	BITMAP bitmap;	GLuint textureId;	glGenTextures(1, &textureId);	/* Use proper named casts in C++.  In this case we use static_cast */	bitmapHandle = static_cast<HBITMAP>(LoadImage(GetModuleHandle(nullptr), fileName.c_str(), IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION | LR_LOADFROMFILE));	if (!bitmapHandle)	{		return false;	}	GetObject(bitmapHandle, sizeof(bitmap), &bitmap);	glPixelStorei(GL_UNPACK_ALIGNMENT, 4);	glBindTexture(GL_TEXTURE_2D, textureId);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);	/* Prefer named constant GL_RGB to literal 3 for the second parameter.  Also bitmaps are stored in BGR format */	gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, bitmap.bmWidth, bitmap.bmHeight, GL_BGR_EXT, GL_UNSIGNED_BYTE, bitmap.bmBits);	/* Add the texture id to our list.  It's named so we can retrieve it easily later */	textures.insert(std::pair<std::string, GLuint>(textureName, textureId));	DeleteObject(bitmapHandle);	return true;}/* Read a colour from a file stream */void readFloatColour(std::ifstream& reader, float* colourArray){	reader >> colourArray[0];	reader >> colourArray[1];	reader >> colourArray[2];	reader >> colourArray[3];}/* Read light data */void readLight(std::ifstream& reader){	/* Ignore the '|' identifier */	reader.ignore(1);	float lightColour[4];	readFloatColour(reader, lightColour);	glLightfv(GL_LIGHT1, GL_AMBIENT, lightColour);	readFloatColour(reader, lightColour);	glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColour);	readFloatColour(reader, lightColour);	glLightfv(GL_LIGHT1, GL_POSITION, lightColour);}/* Read a texture from a file stream */void readTexture(std::ifstream& reader){	/* Ignore the 't' identifier */	reader.ignore(1);	/* Read the file name and the name to identify the texture by */	std::string fileName;	std::string textureName;	reader >> fileName;	reader >> textureName;	/* Load the texture.  Throw an exception if the texture was not found */	if (!neHeLoadBitmap(fileName, textureName))	{		throw "Texture not found: " + fileName;	}}/* Read a vertex from a file stream */void readVertex(std::ifstream& reader, Vertex& vertex){	reader >> vertex.x;	reader >> vertex.y;	reader >> vertex.z;	reader >> vertex.u;	reader >> vertex.v;}/* Read a triangle from a file stream */void readTriangle(std::ifstream& reader){	Triangle triangle;	readVertex(reader, triangle.vertex[0]);	readVertex(reader, triangle.vertex[1]);	readVertex(reader, triangle.vertex[2]);	/* We use a deque, so push the triangle onto the back of it */	sector1.triangle.push_back(triangle);}bool setupWorld(){	/* Use streams, not raw file pointers */	std::ifstream reader("data/world.txt");	if (!reader)	{		return false;	}	/* Get the length of the file */	reader.seekg(0, std::ios::end);	int fileSize = reader.tellg();	reader.seekg(0, std::ios::beg);	while (!reader.eof())	{		/* Skip any leading whitespace */		while (reader.peek() == 10 || reader.peek() == 13 || reader.peek() == ' ' || reader.peek() == '\t')		{			reader.ignore(1);		}		/* Does this line contain light information? */		if (reader.peek() == '|')		{			readLight(reader);		}		/* Does this line contain texture information? */		else if (reader.peek() == 't')		{			readTexture(reader);		}		/* Does this line contain a comment or the number of polygons? */		/* Because we use a deque we don't need the number of polygons, so we just ignore it */		else if (reader.peek() == 'N' || reader.peek() == '/')		{			reader.ignore(fileSize, '\n');		}		/* Not anything else, so it must be triangle information */		else		{			readTriangle(reader);		}	}	glEnable(GL_LIGHT1);	glEnable(GL_LIGHTING);	glEnable(GL_COLOR_MATERIAL);	return true;}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{	glEnable(GL_TEXTURE_2D);							// Enable Texture Mapping	glBlendFunc(GL_SRC_ALPHA,GL_ONE);					// Set The Blending Function For Translucency	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);				// This Will Clear The Background Color To Black	glClearDepth(1.0);									// Enables Clearing Of The Depth Buffer	glDepthFunc(GL_LESS);								// The Type Of Depth Test To Do	glEnable(GL_DEPTH_TEST);							// Enables Depth Testing	glShadeModel(GL_SMOOTH);							// Enables Smooth Color Shading	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	// Really Nice Perspective Calculations	setupWorld();	return TRUE;										// Initialization Went OK}int DrawGLScene(GLvoid)									// Here's Where We Do All The Drawing{	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear The Screen And The Depth Buffer	glLoadIdentity();									// Reset The View	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 numtriangles;	glRotatef(lookupdown,1.0f,0,0);	glRotatef(sceneroty,0,1.0f,0);		glTranslatef(xtrans, ytrans, ztrans);	glBindTexture(GL_TEXTURE_2D, textures["1"]);		// Process Each Triangle	for (int loop_m = 0; loop_m < sector1.triangle.size(); loop_m++)	{		glBegin(GL_TRIANGLES);			glNormal3f( 0.0f, 0.0f, 1.0f);			x_m = sector1.triangle[loop_m].vertex[0].x;			y_m = sector1.triangle[loop_m].vertex[0].y;			z_m = sector1.triangle[loop_m].vertex[0].z;			u_m = sector1.triangle[loop_m].vertex[0].u;			v_m = sector1.triangle[loop_m].vertex[0].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);						x_m = sector1.triangle[loop_m].vertex[1].x;			y_m = sector1.triangle[loop_m].vertex[1].y;			z_m = sector1.triangle[loop_m].vertex[1].z;			u_m = sector1.triangle[loop_m].vertex[1].u;			v_m = sector1.triangle[loop_m].vertex[1].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);						x_m = sector1.triangle[loop_m].vertex[2].x;			y_m = sector1.triangle[loop_m].vertex[2].y;			z_m = sector1.triangle[loop_m].vertex[2].z;			u_m = sector1.triangle[loop_m].vertex[2].u;			v_m = sector1.triangle[loop_m].vertex[2].v;			glTexCoord2f(u_m,v_m); glVertex3f(x_m,y_m,z_m);		glEnd();	}	return TRUE;										// Everything Went OK}GLvoid KillGLWindow(GLvoid)								// Properly Kill The Window{	if (fullscreen)										// Are We In Fullscreen Mode?	{		ChangeDisplaySettings(nullptr,0);					// If So Switch Back To The Desktop		ShowCursor(TRUE);								// Show Mouse Pointer	}	if (hRC)											// Do We Have A Rendering Context?	{		if (!wglMakeCurrent(nullptr,nullptr))					// Are We Able To Release The DC And RC Contexts?		{			MessageBox(nullptr,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		}		if (!wglDeleteContext(hRC))						// Are We Able To Delete The RC?		{			MessageBox(nullptr,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		}		hRC=nullptr;										// Set RC To NULL	}	if (hDC && !ReleaseDC(hWnd,hDC))					// Are We Able To Release The DC	{		MessageBox(nullptr,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		hDC=nullptr;										// Set DC To NULL	}	if (hWnd && !DestroyWindow(hWnd))					// Are We Able To Destroy The Window?	{		MessageBox(nullptr,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		hWnd=nullptr;										// Set hWnd To NULL	}	if (!UnregisterClass("OpenGL",hInstance))			// Are We Able To Unregister Class	{		MessageBox(nullptr,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		hInstance=nullptr;									// Set hInstance To NULL	}}/*	This Code Creates Our OpenGL Window.  Parameters Are:					* *	title			- Title To Appear At The Top Of The Window				* *	width			- Width Of The GL Window Or Fullscreen Mode				* *	height			- Height Of The GL Window Or Fullscreen Mode			* *	bits			- Number Of Bits To Use For Color (8/16/24/32)			* *	fullscreenflag	- Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE)	*/ 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(nullptr);				// Grab An Instance For Our Window	wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;	// Redraw On Size, 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(nullptr, IDI_WINLOGO);			// Load The Default Icon	wc.hCursor			= LoadCursor(nullptr, IDC_ARROW);			// Load The Arrow Pointer	wc.hbrBackground	= nullptr;									// No Background Required For GL	wc.lpszMenuName		= nullptr;									// We Don't Want A Menu	wc.lpszClassName	= "OpenGL";								// Set The Class Name	if (!RegisterClass(&wc))									// Attempt To Register The Window Class	{		MessageBox(nullptr,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;											// 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 Use Windowed Mode.			if (MessageBox(nullptr,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)			{				fullscreen=FALSE;		// Windowed Mode Selected.  Fullscreen = FALSE			}			else			{				// Pop Up A Message Box Letting User Know The Program Is Closing.				MessageBox(nullptr,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);				return FALSE;									// 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);		// Adjust Window To True Requested Size	// Create The Window	if (!(hWnd=CreateWindowEx(	dwExStyle,							// Extended Style For The Window								"OpenGL",							// Class Name								title,								// Window Title								dwStyle |							// Defined Window Style								WS_CLIPSIBLINGS |					// Required Window Style								WS_CLIPCHILDREN,					// Required Window Style								0, 0,								// Window Position								WindowRect.right-WindowRect.left,	// Calculate Window Width								WindowRect.bottom-WindowRect.top,	// Calculate Window Height								nullptr,								// No Parent Window								nullptr,								// No Menu								hInstance,							// Instance								nullptr)))								// Dont Pass Anything To WM_CREATE	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	static	PIXELFORMATDESCRIPTOR pfd=				// pfd Tells Windows How We Want Things To Be	{		sizeof(PIXELFORMATDESCRIPTOR),				// Size Of This Pixel Format Descriptor		1,											// Version Number		PFD_DRAW_TO_WINDOW |						// Format Must Support Window		PFD_SUPPORT_OPENGL |						// Format Must Support OpenGL		PFD_DOUBLEBUFFER,							// Must Support Double Buffering		PFD_TYPE_RGBA,								// Request An RGBA Format		bits,										// Select Our Color Depth		0, 0, 0, 0, 0, 0,							// Color Bits Ignored		0,											// No Alpha Buffer		0,											// Shift Bit Ignored		0,											// No Accumulation Buffer		0, 0, 0, 0,									// Accumulation Bits Ignored		16,											// 16Bit Z-Buffer (Depth Buffer)  		0,											// No Stencil Buffer		0,											// No Auxiliary Buffer		PFD_MAIN_PLANE,								// Main Drawing Layer		0,											// Reserved		0, 0, 0										// Layer Masks Ignored	};		if (!(hDC=GetDC(hWnd)))							// Did We Get A Device Context?	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))	// Did Windows Find A Matching Pixel Format?	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	if(!SetPixelFormat(hDC,PixelFormat,&pfd))		// Are We Able To Set The Pixel Format?	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	if (!(hRC=wglCreateContext(hDC)))				// Are We Able To Get A Rendering Context?	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	if(!wglMakeCurrent(hDC,hRC))					// Try To Activate The Rendering Context	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	ShowWindow(hWnd,SW_SHOW);						// Show The Window	SetForegroundWindow(hWnd);						// Slightly Higher Priority	SetFocus(hWnd);									// Sets Keyboard Focus To The Window	ReSizeGLScene(width, height);					// Set Up Our Perspective GL Screen	if (!InitGL())									// Initialize Our Newly Created GL Window	{		KillGLWindow();								// Reset The Display		MessageBox(nullptr,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;								// Return FALSE	}	return TRUE;									// Success}LRESULT CALLBACK WndProc(	HWND	hWnd,			// Handle For This Window							UINT	uMsg,			// Message For This Window							WPARAM	wParam,			// Additional Message Information							LPARAM	lParam)			// Additional Message Information{	switch (uMsg)									// Check For Windows Messages	{		case WM_ACTIVATE:							// Watch For Window Activate Message		{			if (!HIWORD(wParam))					// Check Minimization State			{				active=TRUE;						// Program Is Active			}			else			{				active=FALSE;						// Program Is No Longer Active			}			return 0;								// Return To The Message Loop		}		case WM_SYSCOMMAND:							// Intercept System Commands		{			switch (wParam)							// Check System Calls			{				case SC_SCREENSAVE:					// Screensaver Trying To Start?				case SC_MONITORPOWER:				// Monitor Trying To Enter Powersave?				return 0;							// Prevent From Happening			}			break;									// Exit		}		case WM_CLOSE:								// Did We Receive A Close Message?		{			PostQuitMessage(0);						// Send A Quit Message			return 0;								// Jump Back		}		case WM_KEYDOWN:							// Is A Key Being Held Down?		{			keys[wParam] = TRUE;					// If So, Mark It As TRUE			return 0;								// Jump Back		}		case WM_KEYUP:								// Has A Key Been Released?		{			keys[wParam] = FALSE;					// If So, Mark It As FALSE			return 0;								// Jump Back		}		case WM_SIZE:								// Resize The OpenGL Window		{			ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  // LoWord=Width, HiWord=Height			return 0;								// Jump Back		}	}	// Pass All Unhandled Messages To DefWindowProc	return DefWindowProc(hWnd,uMsg,wParam,lParam);}int WINAPI WinMain(	HINSTANCE	hInstance,			// Instance					HINSTANCE	hPrevInstance,		// Previous Instance					LPSTR		lpCmdLine,			// Command Line Parameters					int			nCmdShow)			// Window Show State{	MSG		msg;									// Windows Message Structure	BOOL	done=FALSE;								// Bool Variable To Exit Loop	// Ask The User Which Screen Mode They Prefer	if (MessageBox(nullptr,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO)	{		fullscreen=FALSE;							// Windowed Mode	}	// Create Our OpenGL Window	if (!CreateGLWindow("Lionel Brits & NeHe's 3D World Tutorial",640,480,16,fullscreen))	{		return 0;									// Quit If Window Was Not Created	}	while(!done)									// Loop That Runs While done=FALSE	{		if (PeekMessage(&msg,nullptr,0,0,PM_REMOVE))	// Is There A Message Waiting?		{			if (msg.message==WM_QUIT)				// Have We Received A Quit Message?			{				done=TRUE;							// If So done=TRUE			}			else									// If Not, Deal With Window Messages			{				TranslateMessage(&msg);				// Translate The Message				DispatchMessage(&msg);				// Dispatch The Message			}		}		else										// If There Are No Messages		{			// Draw The Scene.  Watch For ESC Key And Quit Messages From DrawGLScene()			if ((active && !DrawGLScene()) || keys[VK_ESCAPE])	// Active?  Was There A Quit Received?			{				done=TRUE;							// ESC or DrawGLScene Signalled A Quit			}			else									// Not Time To Quit, Update Screen			{				SwapBuffers(hDC);					// Swap Buffers (Double Buffering)				if (keys['B'] && !bp)				{					bp=TRUE;					blend=!blend;					if (!blend)					{						glDisable(GL_BLEND);						glEnable(GL_DEPTH_TEST);					}					else					{						glEnable(GL_BLEND);						glDisable(GL_DEPTH_TEST);					}				}				if (!keys['B'])				{					bp=FALSE;				}				if (keys['F'] && !fp)				{					fp=TRUE;				}				if (!keys['F'])				{					fp=FALSE;				}				if (keys[VK_PRIOR])				{					z-=0.02f;				}				if (keys[VK_NEXT])				{					z+=0.02f;				}				if (keys[VK_UP])				{					xpos -= (float)std::sin(heading*piover180) * 0.05f;					zpos -= (float)std::cos(heading*piover180) * 0.05f;					if (walkbiasangle >= 359.0f)					{						walkbiasangle = 0.0f;					}					else					{						walkbiasangle+= 10;					}					walkbias = (float)std::sin(walkbiasangle * piover180)/20.0f;				}				if (keys[VK_DOWN])				{					xpos += (float)std::sin(heading*piover180) * 0.05f;					zpos += (float)std::cos(heading*piover180) * 0.05f;					if (walkbiasangle <= 1.0f)					{						walkbiasangle = 359.0f;					}					else					{						walkbiasangle-= 10;					}					walkbias = (float)std::sin(walkbiasangle * piover180)/20.0f;				}				if (keys[VK_RIGHT])				{					heading -= 1.0f;					yrot = heading;				}				if (keys[VK_LEFT])				{					heading += 1.0f;						yrot = heading;				}				if (keys[VK_PRIOR])				{					lookupdown-= 1.0f;				}				if (keys[VK_NEXT])				{					lookupdown+= 1.0f;				}				if (keys[VK_F1])						// Is F1 Being Pressed?				{					keys[VK_F1]=FALSE;					// If So Make Key FALSE					KillGLWindow();						// Kill Our Current Window					fullscreen=!fullscreen;				// Toggle Fullscreen / Windowed Mode					// Recreate Our OpenGL Window					if (!CreateGLWindow("Lionel Brits & NeHe's 3D World Tutorial",640,480,16,fullscreen))					{						return 0;						// Quit If Window Was Not Created					}				}			}		}	}	// Shutdown	KillGLWindow();										// Kill The Window	return (msg.wParam);								// Exit The Program}