main.cpp

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{
   float a[3], b[3], result[3];
   float length;

   a[0] = p1[0] - p2[0];
   a[1] = p1[1] - p2[1];
   a[2] = p1[2] - p2[2];

   b[0] = p1[0] - p3[0];
   b[1] = p1[1] - p3[1];
   b[2] = p1[2] - p3[2];

   result[0] = a[1] * b[2] - b[1] * a[2];
   result[1] = b[0] * a[2] - a[0] * b[2];
   result[2] = a[0] * b[1] - b[0] * a[1];

   // calculate the length of the normal
   length = (float)sqrt(result[0]*result[0] + result[1]*result[1] + result[2]*result[2]);

   // normalize and specify the normal
   glNormal3f(result[0]/length, result[1]/length, result[2]/length);
}

// CleanUp()
// desc: frees allocated objects
void CleanUp()
{
	myModel->Unload();
	delete myModel;

	free(groundTexture);
}

// Initialize
// desc: initializes OpenGL
void Initialize()
{
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);			// clear to black

	glShadeModel(GL_SMOOTH);						// use smooth shading
	glEnable(GL_DEPTH_TEST);						// hidden surface removal
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);// Really Nice Perspective Calculations
	glEnable(GL_TEXTURE_2D);

	// allocate memory for model objects
	myModel = new CMD2Model;
	gunModel = new CMD2Model;

	// load models and their textures
	myModel->Load("models\\ogro\\tris.md2", "models\\ogro\\ogrobase.pcx");
	gunModel->Load("models\\ogro\\weapon.md2", "models\\ogro\\weapon.pcx");

	// load ground texture and setup texture for OpenGL
	groundTexture = LoadTexture("ground.bmp");
	SetupGround(groundTexture);
}

// Render
// desc: handles drawing of scene
void Render()
{
	float percent;

	radians =  float(PI*(angle-90.0f)/180.0f);

	// calculate the camera's position
	cameraX = lookX + (float)sin(radians)*mouseY;	// multiplying by mouseY makes the
	cameraZ = lookZ + (float)cos(radians)*mouseY;  // camera get closer/farther away with mouseY
	cameraY = lookY + mouseY / 2.0f;

	// calculate the camera look-at coordinates as the center
	lookX = 0.0f;
	lookY = 2.0f;
	lookZ = 0.0f;

	// set interpolation between keyframes
	percent = 0.07f;

	// clear screen and depth buffer
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);		
	glLoadIdentity();

	// set the camera position
	gluLookAt(cameraX, cameraY, cameraZ, lookX, lookY, lookZ, 0.0, 1.0, 0.0);

	glPushMatrix();
		glRotatef(90.0f, -1.0f, 0.0f, 0.0f);
		glColor3f(1.0, 1.0, 1.0);
		/*
		   Frame#  Action
		   ----------------
		   0-39    idle
		   40-46   running
		   47-60   getting shot but not falling (back bending)
		   61-66   getting shot in shoulder
		   67-73   jumping
		   74-95   idle
		   96-112  getting shot and falling down
		   113-122 idle
		   123-135 idle
		   136-154 crouch
		   155-161 crouch crawl
		   162-169 crouch adjust weapon (idle)
		   170-177 kneeling dying
		   178-185 falling back dying
		   186-190 falling forward dying
		   191-198 falling back slow dying
		*/

		// set current model animation state
		myModel->SetState(modelState);
		gunModel->SetState(modelState);

		// perform animation based on model state
		// NOTE: Not the best way to do this!!!
		switch (myModel->GetState())
		{
		case MODEL_IDLE:
			myModel->Animate(0, 39, percent);
			gunModel->Animate(0, 39, percent);
			break;
		case MODEL_RUN:
			myModel->Animate(40, 46, percent);
			gunModel->Animate(40, 46, percent);
			break;
		case MODEL_CROUCH:
			myModel->Animate(136, 154, percent);
			gunModel->Animate(136, 154, percent);
			break;
		case MODEL_JUMP:
			myModel->Animate(67, 73, percent);
			gunModel->Animate(67, 73, percent);
			break;
		default:
			break;
		}
	glPopMatrix();

	// draw the textured ground
	DrawGround(groundTexture, 0.0, -24.0, 0.0);

	glFlush();
	SwapBuffers(g_HDC);			// bring backbuffer to foreground
}

// function to set the pixel format for the device context
void SetupPixelFormat(HDC hDC)
{
	int nPixelFormat;					// our pixel format index

	static PIXELFORMATDESCRIPTOR pfd = {
		sizeof(PIXELFORMATDESCRIPTOR),	// size of structure
		1,								// default version
		PFD_DRAW_TO_WINDOW |			// window drawing support
		PFD_SUPPORT_OPENGL |			// OpenGL support
		PFD_DOUBLEBUFFER,				// double buffering support
		PFD_TYPE_RGBA,					// RGBA color mode
		16,								// 32 bit color mode
		0, 0, 0, 0, 0, 0,				// ignore color bits, non-palettized mode
		0,								// no alpha buffer
		0,								// ignore shift bit
		0,								// no accumulation buffer
		0, 0, 0, 0,						// ignore accumulation bits
		16,								// 16 bit z-buffer size
		0,								// no stencil buffer
		0,								// no auxiliary buffer
		PFD_MAIN_PLANE,					// main drawing plane
		0,								// reserved
		0, 0, 0 };						// layer masks ignored

	nPixelFormat = ChoosePixelFormat(hDC, &pfd);	// choose best matching pixel format

	SetPixelFormat(hDC, nPixelFormat, &pfd);		// set pixel format to device context
}

// the Windows Procedure event handler
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static HGLRC hRC;					// rendering context
	static HDC hDC;						// device context
	int width, height;					// window width and height
	int oldMouseX, oldMouseY;

	switch(message)
	{
		case WM_CREATE:					// window is being created

			hDC = GetDC(hwnd);			// get current window's device context
			g_HDC = hDC;
			SetupPixelFormat(hDC);		// call our pixel format setup function

			// create rendering context and make it current
			hRC = wglCreateContext(hDC);
			wglMakeCurrent(hDC, hRC);

			return 0;
			break;

		case WM_CLOSE:					// windows is closing

			// deselect rendering context and delete it
			wglMakeCurrent(hDC, NULL);
			wglDeleteContext(hRC);

			// send WM_QUIT to message queue
			PostQuitMessage(0);

			return 0;
			break;

		case WM_SIZE:
			height = HIWORD(lParam);		// retrieve width and height
			width = LOWORD(lParam);

			if (height==0)					// don't want a divide by zero
			{
				height=1;					
			}

			glViewport(0, 0, width, height);	// reset the viewport to new dimensions
			glMatrixMode(GL_PROJECTION);		// set projection matrix current matrix
			glLoadIdentity();					// reset projection matrix

			// calculate aspect ratio of window
			gluPerspective(54.0f,(GLfloat)width/(GLfloat)height,1.0f,1000.0f);

			glMatrixMode(GL_MODELVIEW);			// set modelview matrix
			glLoadIdentity();					// reset modelview matrix

			return 0;
			break;

		case WM_KEYDOWN:					// is a key pressed?
			keyPressed[wParam] = true;
			return 0;
			break;

		case WM_KEYUP:
			keyPressed[wParam] = false;
			return 0;
			break;

		case WM_MOUSEMOVE:
			// save old mouse coordinates
			oldMouseX = mouseX;
			oldMouseY = mouseY;

			// get mouse coordinates from Windows
			mouseX = LOWORD(lParam);
			mouseY = HIWORD(lParam);

			// these lines limit the camera's range
			if (mouseY < 60)
				mouseY = 60;
			if (mouseY > 450)
				mouseY = 450;

			if ((mouseX - oldMouseX) > 0)		// mouse moved to the right
				angle += 3.0f;
			else if ((mouseX - oldMouseX) < 0)	// mouse moved to the left
				angle -= 3.0f;

			return 0;
			break;
		default:
			break;
	}

	return (DefWindowProc(hwnd, message, wParam, lParam));
}

// the main windows entry point
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
	WNDCLASSEX windowClass;		// window class
	HWND	   hwnd;			// window handle
	MSG		   msg;				// message
	bool	   done;			// flag saying when our app is complete
	DWORD	   dwExStyle;		// Window Extended Style
	DWORD	   dwStyle;			// Window Style
	RECT	   windowRect;

	// temp var's
	int width = 800;
	int height = 600;
	int bits = 32;

	//fullScreen = TRUE;

	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

	// fill out the window class structure
	windowClass.cbSize			= sizeof(WNDCLASSEX);
	windowClass.style			= CS_HREDRAW | CS_VREDRAW;
	windowClass.lpfnWndProc		= WndProc;
	windowClass.cbClsExtra		= 0;
	windowClass.cbWndExtra		= 0;
	windowClass.hInstance		= hInstance;
	windowClass.hIcon			= LoadIcon(NULL, IDI_APPLICATION);	// default icon
	windowClass.hCursor			= LoadCursor(NULL, IDC_ARROW);		// default arrow
	windowClass.hbrBackground	= NULL;								// don't need background
	windowClass.lpszMenuName	= NULL;								// no menu
	windowClass.lpszClassName	= "MyClass";
	windowClass.hIconSm			= LoadIcon(NULL, IDI_WINLOGO);		// windows logo small icon

	// register the windows class
	if (!RegisterClassEx(&windowClass))
		return 0;

	if (fullScreen)								// fullscreen?
	{
		DEVMODE dmScreenSettings;					// device mode
		memset(&dmScreenSettings,0,sizeof(dmScreenSettings));
		dmScreenSettings.dmSize = sizeof(dmScreenSettings);	
		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)
		{
			// setting display mode failed, switch to windowed
			MessageBox(NULL, "Display mode failed", NULL, MB_OK);
			fullScreen=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

	// class registered, so now create our window
	hwnd = CreateWindowEx(NULL,									// extended style
						  "MyClass",							// class name
						  "3D Model Loading Example X: Loading MD2 Files",		// app name
						  dwStyle | WS_CLIPCHILDREN |
						  WS_CLIPSIBLINGS,
						  0, 0,									// x,y coordinate
						  windowRect.right - windowRect.left,
						  windowRect.bottom - windowRect.top,	// width, height
						  NULL,									// handle to parent
						  NULL,									// handle to menu
						  hInstance,							// application instance
						  NULL);								// no extra params

	// check if window creation failed (hwnd would equal NULL)
	if (!hwnd)
		return 0;

	ShowWindow(hwnd, SW_SHOW);			// display the window
	UpdateWindow(hwnd);					// update the window

	done = false;						// intialize the loop condition variable
	Initialize();						// initialize OpenGL

	// main message loop
	while (!done)
	{
		PeekMessage(&msg, hwnd, NULL, NULL, PM_REMOVE);

		if (msg.message == WM_QUIT)		// do we receive a WM_QUIT message?
		{
			done = true;				// if so, time to quit the application
		}
		else
		{
			if (keyPressed[VK_ESCAPE])
				done = true;
			else
			{					
				if (keyPressed[VK_UP])
					modelState = MODEL_RUN;
				else if (keyPressed[VK_CONTROL])
					modelState = MODEL_CROUCH;
				else if (keyPressed[VK_SHIFT])
					modelState = MODEL_JUMP;
				else
					modelState = MODEL_IDLE;

				Render();

				TranslateMessage(&msg);		// translate and dispatch to event queue
				DispatchMessage(&msg);
			}
		}
	}

	CleanUp();

	if (fullScreen)
	{
		ChangeDisplaySettings(NULL,0);		// If So Switch Back To The Desktop
		ShowCursor(TRUE);					// Show Mouse Pointer
	}

	return msg.wParam;
}