#pragma comment(lib, "opengl32.lib")
#pragma comment(lib, "glu32.lib")
#pragma comment(lib, "glaux.lib")

#include "main.h"
#include <math.h>
#include "Camera.h"


// Include Your Header File Here 
// Then Call Function CreateMaterialLib()
//			Don't forget Create<YourObj/s>()
//			in RenderScene() Call glCallList Function to Call your Objects ObjectID

#define		INC	3.0
#define		R_180	3.142857142
#define		R_90	1.571428571

bool  g_bFullScreen = 1;							// Set full screen as default
HWND  g_hWnd;											// This is the handle for the window
RECT  g_rRect;											// This holds the window dimensions
HDC   g_hDC;											// General HDC - (handle to device context)
HGLRC g_hRC;											// General OpenGL_DC - Our Rendering Context for OpenGL
HINSTANCE g_hInstance;									// This holds the global hInstance for UnregisterClass() in DeInit()
float rotationH,rotationV;
Point3 CamPos, CamTar;
float thetha,thethaV=0;
float focullength=2;
float step=5;

GLfloat Vertex[] = {	-75.0000,	-50.0000,	0.0000,
						75.0000,	-50.0000,	0.0000,
						-75.0000,	50.0000,	0.0000,
						75.0000,	50.0000,	0.0000
					};

GLfloat TVertex[] = {	0.0f, 0.0f, 
						1.0f, 0.0f, 
						0.0f, 1.0f, 
						1.0f, 1.0f, 
					};
CCamera	g_Camera;

UINT g_Texture[MAX_TEXTURES];


void Init(HWND hWnd)
{
	g_hWnd = hWnd;										// Assign the window handle to a global window handle
	GetClientRect(g_hWnd, &g_rRect);					// Assign the windows rectangle to a global RECT
	InitializeOpenGL(g_rRect.right, g_rRect.bottom);	// Init OpenGL with the global rect

	// CreateMaterialLib() here and 
	// Object's Create Functions 


	g_Camera.PositionCamera( 10,150,12, 9,150,12, 0,1,0 );
	g_Camera.SetCameraRadius(1);

}


WPARAM MainLoop()
{
	MSG msg;
	while(1)											// Do our infinate loop
	{													// Check if there was a message
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) 
        { 
			if(msg.message == WM_QUIT)					// If the message wasnt to quit
				break;
            TranslateMessage(&msg);						// Find out what the message does
            DispatchMessage(&msg);						// Execute the message
        }
		else											// if there wasn't a message
		{ 
			g_Camera.Update();
			RenderScene();								// Redraw the scene every frame
		}	 
	}

	DeInit();											// Free all the app's memory allocated

	return(msg.wParam);									// Return from the program
}


void RenderScene() 
{
	CamTar.x = CamPos.x+focullength*cos( thetha );
	CamTar.z = CamPos.z+focullength*sin( thetha );
	CamPos.y = 100;
	CamTar.y = 100;

	glVertexPointer( 3, GL_FLOAT, 0, Vertex );
	glTexCoordPointer(2, GL_FLOAT, 0, TVertex );

	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);


	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	g_Camera.Look();
	glPushMatrix();

			// Call Your Object Lists Here by 
			// glCallList()
			// Like glCallList( BOX01 ) if BOX01 is defined.
		
	glPopMatrix();
	
	SwapBuffers(g_hDC);									// Swap the backbuffers to the foreground
}



LRESULT CALLBACK WinProc(HWND hWnd,UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    LONG    lRet = 0; 
    PAINTSTRUCT    ps;
    static int lxPos,lyPos;
    static int xPos, yPos;
	

    POINT mpos;
    switch (uMsg)
	{ 
    case WM_SIZE:										// If the window is resized
		if(!g_bFullScreen)								// Do this only if we are NOT in full screen
		{
			SizeOpenGLScreen(LOWORD(lParam),HIWORD(lParam));// LoWord=Width, HiWord=Height
			GetClientRect(hWnd, &g_rRect);	
						
		}
        break; 
		
	case WM_PAINT:										// If we need to repaint the scene
		BeginPaint(hWnd, &ps);							// Init the paint struct		
		EndPaint(hWnd, &ps);							// EndPaint, Clean up
		break;
    case WM_CLOSE:										// If the window is being closes
        PostQuitMessage(0);								// Send a QUIT Message to the window
        break; 
     
    default:											// Return by default
        lRet = DefWindowProc (hWnd, uMsg, wParam, lParam); 
        break; 
    } 
 
    return lRet;										// Return by default
}
 

#ifndef _3DMATH_H
#define _3DMATH_H

#define PI 3.1415926535897932					// This is our famous PI

#define BEHIND		0
#define INTERSECTS	1
#define FRONT		2


// This is our basic 3D point/vector class
struct CVector3
{
public:
	
	// A default constructor
	CVector3() {}
	CVector3( CVector3 *vPos )
	{
		x = vPos->x;
		y = vPos->y;
		z = vPos->z;
	}
	// This is our constructor that allows us to initialize our data upon creating an instance
	CVector3(float X, float Y, float Z) 
	{ 
		x = X; y = Y; z = Z;
	}

	// Here we overload the + operator so we can add vectors together 
	CVector3 operator+(CVector3 vVector)
	{
		// Return the added vectors result.
		return CVector3(vVector.x + x, vVector.y + y, vVector.z + z);
	}

	// Here we overload the - operator so we can subtract vectors 
	CVector3 operator-(CVector3 vVector)
	{
		// Return the subtracted vectors result
		return CVector3(x - vVector.x, y - vVector.y, z - vVector.z);
	}
	
	// Here we overload the * operator so we can multiply by scalars
	CVector3 operator*(float num)
	{
		// Return the scaled vector
		return CVector3(x * num, y * num, z * num);
	}

	// Here we overload the / operator so we can divide by a scalar
	CVector3 operator/(float num)
	{
		// Return the scale vector
		return CVector3(x / num, y / num, z / num);
	}

	float x, y, z;						
};


// This returns the absolute value of "num"
float Absolute(float num);

//	This returns a perpendicular vector from 2 given vectors by taking the cross product.
CVector3 Cross(CVector3 vVector1, CVector3 vVector2);

//	This returns the magnitude of a normal (or any other vector)
float Magnitude(CVector3 vNormal);

//	This returns a normalize vector (A vector exactly of length 1)
CVector3 Normalize(CVector3 vNormal);

//	This returns the normal of a polygon (The direction the polygon is facing)
CVector3 Normal(CVector3 vPolygon[]);

// This returns the distance between 2 3D points
float Distance(CVector3 vPoint1, CVector3 vPoint2);

// This returns the point on the line segment vA_vB that is closest to point vPoint
CVector3 ClosestPointOnLine(CVector3 vA, CVector3 vB, CVector3 vPoint);

// This returns the distance the plane is from the origin (0, 0, 0)
// It takes the normal to the plane, along with ANY point that lies on the plane (any corner)
float PlaneDistance(CVector3 Normal, CVector3 Point);

// This takes a triangle (plane) and line and returns true if they intersected
bool IntersectedPlane(CVector3 vPoly[], CVector3 vLine[], CVector3 &vNormal, float &originDistance);

// This returns the dot product between 2 vectors
float Dot(CVector3 vVector1, CVector3 vVector2);

// This returns the angle between 2 vectors
double AngleBetweenVectors(CVector3 Vector1, CVector3 Vector2);

// This returns an intersection point of a polygon and a line (assuming intersects the plane)
CVector3 IntersectionPoint(CVector3 vNormal, CVector3 vLine[], double distance);

// This returns true if the intersection point is inside of the polygon
bool InsidePolygon(CVector3 vIntersection, CVector3 Poly[], long verticeCount);

// Use this function to test collision between a line and polygon
bool IntersectedPolygon(CVector3 vPoly[], CVector3 vLine[], int verticeCount);

// This function classifies a sphere according to a plane. (BEHIND, in FRONT, or INTERSECTS)
int ClassifySphere(CVector3 &vCenter, 
				   CVector3 &vNormal, CVector3 &vPoint, float radius, float &distance);

// This takes in the sphere center, radius, polygon vertices and vertex count.
// This function is only called if the intersection point failed.  The sphere
// could still possibly be intersecting the polygon, but on it's edges.
bool EdgeSphereCollision(CVector3 &vCenter, 
						 CVector3 vPolygon[], int vertexCount, float radius);

// This returns true if the sphere is intersecting with the polygon.
bool SpherePolygonCollision(CVector3 vPolygon[], 
							CVector3 &vCenter, int vertexCount, float radius);

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

// This returns the offset the sphere needs to move in order to not intersect the plane
CVector3 GetCollisionOffset(CVector3 &vNormal, float radius, float distance);

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

#endif 


 

//***********************************************************************//
//																		 //
//		- "Talk to me like I'm a 3 year old!" Programming Lessons -		 //
//                                                                       //
//		$Author:		DigiBen		DigiBen@GameTutorials.com			 //
//																		 //
//		$Program:		BSP Loader										 //
//																		 //
//		$Description:	Loads faces and textures from a Quake3 BSP file  //
//																		 //
//		$Date:			5/9/02											 //
//																		 //
//***********************************************************************//


#include "main.h"
#include "Camera.h"


// We increased the speed a bit from the Camera Strafing Tutorial
// This is how fast our camera moves
#define kSpeed	190.0f									

// Our global float that stores the elapsed time between the current and last frame
float g_FrameInterval = 0.0f;


///////////////////////////////// CALCULATE FRAME RATE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This function calculates the frame rate and time intervals between frames
/////
///////////////////////////////// CALCULATE FRAME RATE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CalculateFrameRate()
{
	static float framesPerSecond    = 0.0f;		// This will store our fps
    static float lastTime			= 0.0f;		// This will hold the time from the last frame
	static char strFrameRate[50] = {0};			// We will store the string here for the window title

	static float frameTime = 0.0f;				// This stores the last frame's time

	// Get the current time in seconds
    float currentTime = timeGetTime() * 0.001f;				

	// Here we store the elapsed time between the current and last frame,
	// then keep the current frame in our static variable for the next frame.
 	g_FrameInterval = currentTime - frameTime;
	frameTime = currentTime;

	// Increase the frame counter
    ++framesPerSecond;

	// Now we want to subtract the current time by the last time that was stored
	// to see if the time elapsed has been over a second, which means we found our FPS.
    if( currentTime - lastTime > 1.0f )
    {
		// Here we set the lastTime to the currentTime
	    lastTime = currentTime;
		
		// Copy the frames per second into a string to display in the window title bar
		sprintf(strFrameRate, "Current Frames Per Second: %d", int(framesPerSecond));

		// Set the window title bar to our string
		SetWindowText(g_hWnd, strFrameRate);

		// Reset the frames per second
        framesPerSecond = 0;
    }
}


///////////////////////////////// CCAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This is the class constructor
/////
///////////////////////////////// CCAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

CCamera::CCamera()
{
	CVector3 vZero = CVector3(0.0, 0.0, 0.0);		// Init a vVector to 0 0 0 for our position
	CVector3 vView = CVector3(0.0, 1.0, 0.5);		// Init a starting view vVector (looking up and out the screen) 
	CVector3 vUp   = CVector3(0.0, 0.0, 1.0);		// Init a standard up vVector (Rarely ever changes)

	m_vPosition	= vZero;					// Init the position to zero
	m_vView		= vView;					// Init the view to a std starting view
	m_vUpVector	= vUp;						// Init the UpVector

	for( int i=0; i<10 ; i++ )
	{
		for( int j=0 ; j<10 ; j++ )
		{
			if( i==0 || j==0 || i==9 || j==9 )
				Map[i][j] = 1;
			else
				Map[i][j] = 0;

		}
	}
}


///////////////////////////////// POSITION CAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This function sets the camera's position and view and up vVector.
/////
///////////////////////////////// POSITION CAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CCamera::PositionCamera(float positionX, float positionY, float positionZ,
				  		     float viewX,     float viewY,     float viewZ,
							 float upVectorX, float upVectorY, float upVectorZ)
{
	CVector3 vPosition	= CVector3(positionX, positionY, positionZ);
	CVector3 vView		= CVector3(viewX, viewY, viewZ);
	CVector3 vUpVector	= CVector3(upVectorX, upVectorY, upVectorZ);

	// The code above just makes it cleaner to set the variables.
	// Otherwise we would have to set each variable x y and z.

	m_vPosition = vPosition;					// Assign the position
	m_vView     = vView;						// Assign the view
	m_vUpVector = vUpVector;					// Assign the up vector
}


///////////////////////////////// SET VIEW BY MOUSE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This allows us to look around using the mouse, like in most first person games.
/////
///////////////////////////////// SET VIEW BY MOUSE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CCamera::SetViewByMouse()
{
	POINT mousePos;									// This is a window structure that holds an X and Y
	int middleX = SCREEN_WIDTH  >> 1;				// This is a binary shift to get half the width
	int middleY = SCREEN_HEIGHT >> 1;				// This is a binary shift to get half the height
	float angleY = 0.0f;							// This is the direction for looking up or down
	float angleZ = 0.0f;							// This will be the value we need to rotate around the Y axis (Left and Right)
	static float currentRotX = 0.0f;
	
	// Get the mouse's current X,Y position
	GetCursorPos(&mousePos);						
	
	// If our cursor is still in the middle, we never moved... so don't update the screen
	if( (mousePos.x == middleX) && (mousePos.y == middleY) ) return;

	// Set the mouse position to the middle of our window
	SetCursorPos(middleX, middleY);							

	// Get the direction the mouse moved in, but bring the number down to a reasonable amount
	angleY = (float)( (middleX - mousePos.x) ) / 500.0f;		
	angleZ = (float)( (middleY - mousePos.y) ) / 500.0f;		

	// Here we keep track of the current rotation (for up and down) so that
	// we can restrict the camera from doing a full 360 loop.
	currentRotX -= angleZ;  

	/* Kapil This is desable because it restricts the viewing angle
	// If the current rotation (in radians) is greater than 1.0, we want to cap it.
	if(currentRotX > 1.0f)
		currentRotX = 1.0f;
	// Check if the rotation is below -1.0, if so we want to make sure it doesn't continue
	else if(currentRotX < -1.0f)
		currentRotX = -1.0f;
	// Otherwise, we can rotate the view around our position
	else
	{*/
		// To find the axis we need to rotate around for up and down
		// movements, we need to get a perpendicular vector from the
		// camera's view vector and up vector.  This will be the axis.
		CVector3 vAxis = Cross(m_vView - m_vPosition, m_vUpVector);
		vAxis = Normalize(vAxis);

		// Rotate around our perpendicular axis and along the y-axis
		RotateView(angleZ, vAxis.x, vAxis.y, vAxis.z);
		RotateView(angleY, 0, 1, 0);
	//}
}


///////////////////////////////// ROTATE VIEW \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This rotates the view around the position using an axis-angle rotation
/////
///////////////////////////////// ROTATE VIEW \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CCamera::RotateView(float angle, float x, float y, float z)
{
	CVector3 vNewView;

	// Get the view vector (The direction we are facing)
	CVector3 vView = m_vView - m_vPosition;		

	// Calculate the sine and cosine of the angle once
	float cosTheta = (float)cos(angle);
	float sinTheta = (float)sin(angle);

	// Find the new x position for the new rotated point
	vNewView.x  = (cosTheta + (1 - cosTheta) * x * x)		* vView.x;
	vNewView.x += ((1 - cosTheta) * x * y - z * sinTheta)	* vView.y;
	vNewView.x += ((1 - cosTheta) * x * z + y * sinTheta)	* vView.z;

	// Find the new y position for the new rotated point
	vNewView.y  = ((1 - cosTheta) * x * y + z * sinTheta)	* vView.x;
	vNewView.y += (cosTheta + (1 - cosTheta) * y * y)		* vView.y;
	vNewView.y += ((1 - cosTheta) * y * z - x * sinTheta)	* vView.z;

	// Find the new z position for the new rotated point
	vNewView.z  = ((1 - cosTheta) * x * z - y * sinTheta)	* vView.x;
	vNewView.z += ((1 - cosTheta) * y * z + x * sinTheta)	* vView.y;
	vNewView.z += (cosTheta + (1 - cosTheta) * z * z)		* vView.z;

	// Now we just add the newly rotated vector to our position to set
	// our new rotated view of our camera.
	m_vView = m_vPosition + vNewView;
}


///////////////////////////////// STRAFE CAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This strafes the camera left and right depending on the speed (-/+)
/////
///////////////////////////////// STRAFE CAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CCamera::StrafeCamera(float speed)
{	
	// Add the strafe vector to our position
	CVector3 m_vPosition1 ( &m_vPosition ),m_vView1( &m_vView );
	m_vPosition1.x += m_vStrafe.x * speed;
	m_vPosition1.z += m_vStrafe.z * speed;

	// Add the strafe vector to our view
	m_vView1.x += m_vStrafe.x * speed;
	m_vView1.z += m_vStrafe.z * speed;
	if( m_vPosition1.x > -800 && m_vPosition1.x < 230 
		&& m_vPosition1.z > -190 && m_vPosition1.z < 770 )
	{
		m_vPosition.x = m_vPosition1.x;
		m_vPosition.z = m_vPosition1.z;

		m_vView.x = m_vView1.x;
		m_vView.z = m_vView1.z;
	}
}


///////////////////////////////// MOVE CAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This will move the camera forward or backward depending on the speed
/////
///////////////////////////////// MOVE CAMERA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CCamera::MoveCamera(float speed)
{
	// Get the current view vector (the direction we are looking)
	CVector3 m_vPosition1 ( &m_vPosition ),m_vView1( &m_vView );
	CVector3 vVector = m_vView - m_vPosition;
	
	vVector = Normalize(vVector);
	m_vPosition1.x += vVector.x * speed;		// Add our acceleration to our position's X
	m_vPosition1.y += vVector.y * speed;		// Add our acceleration to our position's Y
	m_vPosition1.z += vVector.z * speed;		// Add our acceleration to our position's Z

	m_vView1.x += vVector.x * speed;			// Add our acceleration to our view's X
	m_vView1.y += vVector.y * speed;			// Add our acceleration to our view's Y
	m_vView1.z += vVector.z * speed;			// Add our acceleration to our view's Z

	// Here should be the collision testing condition.....
	if( m_vPosition1.x > -800 && m_vPosition1.x < 230 
		&& m_vPosition1.z > -190 && m_vPosition1.z < 770 )
	{
		m_vPosition.x = m_vPosition1.x;
		m_vPosition.y = m_vPosition1.y;
		m_vPosition.z = m_vPosition1.z;

		m_vView.x = m_vView1.x;
		m_vView.y = m_vView1.y;
		m_vView.z = m_vView1.z;
	}
}


//////////// *** NEW *** ////////// *** NEW *** ///////////// *** NEW *** ////////////////////

///////////////////////////////// CHECK CAMERA COLLISION \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This checks all the polygons in our list and offsets the camera if collided
/////
///////////////////////////////// CHECK CAMERA COLLISION \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

void CCamera::CheckCameraCollision(CVector3 *pVertices, int numOfVerts)
{	
	for(int i = 0; i < numOfVerts; i += 3)
	{

		CVector3 vTriangle[3] = { pVertices[i], pVertices[i+1], pVertices[i+2] };
		CVector3 vNormal = Normal(vTriangle);
		float distance = 0.0f;
		int classification = ClassifySphere(m_vPosition, vNormal, vTriangle[0], m_radius, distance);
		if(classification == INTERSECTS) 
		{

			CVector3 vOffset = vNormal * distance;
			CVector3 vIntersection = m_vPosition - vOffset;
			if(InsidePolygon(vIntersection, vTriangle, 3) ||
			   EdgeSphereCollision(m_vPosition, vTriangle, 3, m_radius / 2))
			{
				vOffset = GetCollisionOffset(vNormal, m_radius, distance);
				m_vPosition = m_vPosition + vOffset;
				m_vView = m_vView + vOffset;
			}
		}
	}
}


void CCamera::CheckForMovement()
{	
	float speed = kSpeed * g_FrameInterval;

	
	x = (m_vView.x + 750 )/100;
	y = (m_vView.z + 180 )/100;
	if(GetKeyState(VK_UP) & 0x80 || GetKeyState('W') & 0x80) 
	{				

			MoveCamera(speed);				
	}

	if(GetKeyState(VK_DOWN) & 0x80 || GetKeyState('S') & 0x80) 
	{			
		MoveCamera(-speed);				
	}


	if(GetKeyState(VK_LEFT) & 0x80 || GetKeyState('A') & 0x80) 
	{			
		StrafeCamera(-speed);
	}

	// Check if we hit the Right arrow or the 'd' key
	if(GetKeyState(VK_RIGHT) & 0x80 || GetKeyState('D') & 0x80) {			

		// Strafe the camera right
		StrafeCamera(speed);
	}	
}


void CCamera::Update() 
{
	// Initialize a variable for the cross product result
	CVector3 vCross = Cross(m_vView - m_vPosition, m_vUpVector);

	// Normalize the strafe vector
	m_vStrafe = Normalize(vCross);

	// Move the camera's view by the mouse
	SetViewByMouse();

	// This checks to see if the keyboard was pressed
	CheckForMovement();
	
	// Calculate our frame rate and set our frame interval for time based movement
	CalculateFrameRate();
}


void CCamera::Look()
{

	gluLookAt(m_vPosition.x, m_vPosition.y, m_vPosition.z,	
			  m_vView.x,	 m_vView.y,     m_vView.z,	
			  m_vUpVector.x, m_vUpVector.y, m_vUpVector.z);
}


/////////////////////////////////////////////////////////////////////////////////
//
// * QUICK NOTES * 
//
//
//
// Ben Humphrey (DigiBen)
// Game Programmer
// DigiBen@GameTutorials.com
// Co-Web Host of www.GameTutorials.com
//
//
 

#ifndef _CAMERA_H
#define _CAMERA_H

#include <mmsystem.h>

class CCamera {

public:
	int x, y;
	int Map[10][10];
		

	// Our camera constructor
	CCamera();	

	// These are are data access functions for our camera's private data
	CVector3 Position() 
	{	
		return m_vPosition;		
	}
	CVector3 View()		{	return m_vView;			}
	CVector3 UpVector() {	return m_vUpVector;		}
	CVector3 Strafe()	{	return m_vStrafe;		}
	

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

	// This intializes the camera's sphere radius
	void SetCameraRadius(float radius) {	m_radius = radius;	};

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *


	// This changes the position, view, and up vector of the camera.
	// This is primarily used for initialization
	void PositionCamera(float positionX, float positionY, float positionZ,
			 		    float viewX,     float viewY,     float viewZ,
						float upVectorX, float upVectorY, float upVectorZ);

	// This rotates the camera's view around the position depending on the values passed in.
	void RotateView(float angle, float X, float Y, float Z);

	// This moves the camera's view by the mouse movements (First person view)
	void SetViewByMouse(); 

	// This rotates the camera around a point (I.E. your character).
	void RotateAroundPoint(CVector3 vCenter, float X, float Y, float Z);

	// This strafes the camera left or right depending on the speed (+/-) 
	void StrafeCamera(float speed);

	// This will move the camera forward or backward depending on the speed
	void MoveCamera(float speed);

	// This checks for keyboard movement
	void CheckForMovement();


/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

	// This takes a list of vertices and the vertex count to determine if the camera's
	// shere has collided with them.
	void CheckCameraCollision(CVector3 *pVertices, int numOfVerts);

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *


	// This updates the camera's view and other data (Should be called each frame)
	void Update();

	// This uses gluLookAt() to tell OpenGL where to look
	void Look();

private:

	// The camera's position
	CVector3 m_vPosition;					

	// The camera's view
	CVector3 m_vView;						

	// The camera's up vector
	CVector3 m_vUpVector;		
	
	// The camera's strafe vector
	CVector3 m_vStrafe;						


/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *
	
	// The camera's collision radius
	float m_radius;										

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

};

#endif


 

#include "main.h"


void CreateTexture(UINT textureArray[], LPSTR strFileName, int textureID)
{
	AUX_RGBImageRec *pBitmap = NULL;
	
	if(!strFileName)
		return;
	
	pBitmap = auxDIBImageLoad( strFileName );

	if(pBitmap == NULL)	
		exit(0);

	glGenTextures(1, &textureArray[textureID]);
	glBindTexture(GL_TEXTURE_2D, textureArray[textureID]);

	gluBuild2DMipmaps(GL_TEXTURE_2D, 3, 
		pBitmap->sizeX, pBitmap->sizeY, 
		GL_RGB, GL_UNSIGNED_BYTE, pBitmap->data);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);//GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR_MIPMAP_LINEAR);//GL_NEAREST);
	//GL_NEAREST
	if (pBitmap)										// If we loaded the bitmap
	{
		if (pBitmap->data)								// If there is texture data
		{
			free(pBitmap->data);						// Free the texture data, we don't need it anymore
		}

		free(pBitmap);									// Free the bitmap structure
	}
}


void ChangeToFullScreen()
{
	DEVMODE dmSettings;									// Device Mode variable

	memset(&dmSettings,0,sizeof(dmSettings));			// Makes Sure Memory's Cleared

	if(!EnumDisplaySettings(NULL,ENUM_CURRENT_SETTINGS,&dmSettings))
	{
		MessageBox(NULL, "Could No t Enum Display Settings", "Error", MB_OK);
		return;
	}

	dmSettings.dmPelsWidth	= SCREEN_WIDTH;				// Selected Screen Width
	dmSettings.dmPelsHeight	= SCREEN_HEIGHT;			// Selected Screen Height

	int result = ChangeDisplaySettings(&dmSettings,CDS_FULLSCREEN);	

	if(result != DISP_CHANGE_SUCCESSFUL)
	{
		MessageBox(NULL, "Display Mode Not Compatible", "Error", MB_OK);
		PostQuitMessage(0);
	}
}


HWND CreateMyWindow(LPSTR strWindowName, int width, int height, DWORD dwStyle, bool bFullScreen, HINSTANCE hInstance)
{
	HWND hWnd;
	WNDCLASS wndclass;
	
	memset(&wndclass, 0, sizeof(WNDCLASS));				// Init the size of the class
	wndclass.style = CS_HREDRAW | CS_VREDRAW;			// Regular drawing capabilities
	wndclass.lpfnWndProc = WinProc;						// Pass our function pointer as the window procedure
	wndclass.hInstance = hInstance;						// Assign our hInstance
	wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);	// General icon
	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);		// An arrow for the cursor
	wndclass.hbrBackground = (HBRUSH) (COLOR_WINDOW+1);	// A white window
	wndclass.lpszClassName = "GameTutorials";			// Assign the class name

	RegisterClass(&wndclass);							// Register the class
	
	if(bFullScreen && !dwStyle) 						// Check if we wanted full screen mode
	{													// Set the window properties for full screen mode
		dwStyle = WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN;
		ChangeToFullScreen();							// Go to full screen
		ShowCursor(FALSE);								// Hide the cursor
	}
	else if(!dwStyle)									// Assign styles to the window depending on the choice
		dwStyle = WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN;
	
	g_hInstance = hInstance;							// Assign our global hInstance to the window's hInstance

	RECT rWindow;
	rWindow.left	= 0;								// Set Left Value To 0
	rWindow.right	= width;							// Set Right Value To Requested Width
	rWindow.top	    = 0;								// Set Top Value To 0
	rWindow.bottom	= height;							// Set Bottom Value To Requested Height

	AdjustWindowRect( &rWindow, dwStyle, false);		// Adjust Window To True Requested Size

														// Create the window
	hWnd = CreateWindow("GameTutorials", strWindowName, dwStyle, 0, 0,
						rWindow.right  - rWindow.left, rWindow.bottom - rWindow.top, 
						NULL, NULL, hInstance, NULL);

	if(!hWnd) return NULL;								// If we could get a handle, return NULL

	ShowWindow(hWnd, SW_SHOWNORMAL);					// Show the window
	UpdateWindow(hWnd);									// Draw the window

	SetFocus(hWnd);										// Sets Keyboard Focus To The Window	

	return hWnd;
}


bool bSetupPixelFormat(HDC hdc) 
{ 
    PIXELFORMATDESCRIPTOR pfd; 
    int pixelformat; 
 
    pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);			// Set the size of the structure
    pfd.nVersion = 1;									// Always set this to 1
														// Pass in the appropriate OpenGL flags
    pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER; 
    pfd.dwLayerMask = PFD_MAIN_PLANE;					// We want the standard mask (this is ignored anyway)
    pfd.iPixelType = PFD_TYPE_RGBA;						// We want RGB and Alpha pixel type
    pfd.cColorBits = SCREEN_DEPTH;						// Here we use our #define for the color bits
    pfd.cDepthBits = SCREEN_DEPTH;						// Depthbits is ignored for RGBA, but we do it anyway
    pfd.cAccumBits = 0;									// No special bitplanes needed
    pfd.cStencilBits = 0;								// We desire no stencil bits
 
    if ( (pixelformat = ChoosePixelFormat(hdc, &pfd)) == FALSE ) 
    { 
        MessageBox(NULL, "ChoosePixelFormat failed", "Error", MB_OK); 
        return FALSE; 
    } 
 
    if (SetPixelFormat(hdc, pixelformat, &pfd) == FALSE) 
    { 
        MessageBox(NULL, "SetPixelFormat failed", "Error", MB_OK); 
        return FALSE; 
    } 
 
    return TRUE;										// Return a success!
}

void SizeOpenGLScreen(int width, int height)			// Initialize The GL Window
{
	if (height==0)										// Prevent A Divide By Zero error
	{
		height=1;										// Make the Height Equal One
	}

	glClearIndex( 0.0f );
	glClearDepth( 1.0f );
	glEnable( GL_DEPTH_TEST );
	

	glViewport(0,0,width,height);						// Make our viewport the whole window
	glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix

	glLoadIdentity();									// Reset The Projection Matrix

	gluPerspective(45.0f,(GLfloat)width/(GLfloat)height, 10.0f ,2000.0f);

	glMatrixMode(GL_MODELVIEW);							// Select The Modelview Matrix
	glLoadIdentity();									// Reset The Modelview Matrix
	glEnable( GL_LIGHTING );
	glEnable( GL_LIGHT0 );

}


void InitializeOpenGL(int width, int height) 
{  
    g_hDC = GetDC(g_hWnd);								// This sets our global HDC
														// We don't free this hdc until the end of our program
    if (!bSetupPixelFormat(g_hDC))						// This sets our pixel format/information
        PostQuitMessage (0);							// If there's an error, quit

    g_hRC = wglCreateContext(g_hDC);					// This creates a rendering context from our hdc
    wglMakeCurrent(g_hDC, g_hRC);						// This makes the rendering context we just created the one we want to use

	glEnable(GL_TEXTURE_2D);
	glCullFace( GL_FRONT );
	glEnable( GL_CULL_FACE );
	GLfloat Amb[] ={ 2,2,2,1 };
	glLightModelfv( GL_LIGHT_MODEL_AMBIENT, Amb );
	
	SizeOpenGLScreen(width, height);					// Setup the screen translations and viewport
}



void DeInit()
{
	if (g_hRC)											
	{
		wglMakeCurrent(NULL, NULL);						// This frees our rendering memory and sets everything back to normal
		wglDeleteContext(g_hRC);						// Delete our OpenGL Rendering Context	
	}
	
	if (g_hDC) 
		ReleaseDC(g_hWnd, g_hDC);						// Release our HDC from memory
		
	if(g_bFullScreen)									// If we were in full screen
	{
		ChangeDisplaySettings(NULL,0);					// If So Switch Back To The Desktop
		ShowCursor(TRUE);								// Show Mouse Pointer
	}

	UnregisterClass("GameTutorials", g_hInstance);		// Free the window class

	PostQuitMessage (0);								// Post a QUIT message to the window
}



int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hprev, PSTR cmdline, int ishow)
{	
	HWND hWnd;

	hWnd = CreateMyWindow("Hotel", SCREEN_WIDTH, SCREEN_HEIGHT, 0, g_bFullScreen, hInstance);


	// If we never got a valid window handle, quit the program
	if(hWnd == NULL) return TRUE;

	// INIT OpenGL
	Init(hWnd);													

	// Run our message loop and after it's done, return the result
	return MainLoop();						
}


 

//***********************************************************************//
//																		 //
//		- "Talk to me like I'm a 3 year old!" Programming Lessons -		 //
//                                                                       //
//		$Author:		DigiBen		digiben@gametutorials.com			 //
//																		 //
//		$Program:		CameraWorldCollision							 //
//																		 //
//		$Description:	Shows how to check if camera and world collide	 //
//																		 //
//		$Date:			1/23/02											 //
//																		 //
//***********************************************************************//

#include "main.h"
#include <math.h>	// We include math.h so we can use the sqrt() function
#include <float.h>	// This is so we can use _isnan() for acos()

/////////////////////////////////////// ABSOLUTE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the absolute value of the number passed in
/////
/////////////////////////////////////// ABSOLUTE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

float Absolute(float num)
{
	// If num is less than zero, we want to return the absolute value of num.
	// This is simple, either we times num by -1 or subtract it from 0.
	if(num < 0)
		return (0 - num);

	// Return the original number because it was already positive
	return num;
}


/////////////////////////////////////// CROSS \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns a perpendicular vector from 2 given vectors by taking the cross product.
/////
/////////////////////////////////////// CROSS \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
												
CVector3 Cross(CVector3 vVector1, CVector3 vVector2)
{
	CVector3 vNormal;									// The vector to hold the cross product

	// The X value for the vector is:  (V1.y * V2.z) - (V1.z * V2.y)													// Get the X value
	vNormal.x = ((vVector1.y * vVector2.z) - (vVector1.z * vVector2.y));
														
	// The Y value for the vector is:  (V1.z * V2.x) - (V1.x * V2.z)
	vNormal.y = ((vVector1.z * vVector2.x) - (vVector1.x * vVector2.z));
														
	// The Z value for the vector is:  (V1.x * V2.y) - (V1.y * V2.x)
	vNormal.z = ((vVector1.x * vVector2.y) - (vVector1.y * vVector2.x));

	return vNormal;										// Return the cross product (Direction the polygon is facing - Normal)
}


/////////////////////////////////////// MAGNITUDE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the magnitude of a normal (or any other vector)
/////
/////////////////////////////////////// MAGNITUDE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

float Magnitude(CVector3 vNormal)
{
	// This will give us the magnitude or "Norm" as some say, of our normal.
	// Here is the equation:  magnitude = sqrt(V.x^2 + V.y^2 + V.z^2)  Where V is the vector

	return (float)sqrt( (vNormal.x * vNormal.x) + (vNormal.y * vNormal.y) + (vNormal.z * vNormal.z) );
}


/////////////////////////////////////// NORMALIZE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns a normalize vector (A vector exactly of length 1)
/////
/////////////////////////////////////// NORMALIZE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

CVector3 Normalize(CVector3 vNormal)
{
	float magnitude = Magnitude(vNormal);				// Get the magnitude of our normal

	// Now that we have the magnitude, we can divide our normal by that magnitude.
	// That will make our normal a total length of 1.  This makes it easier to work with too.

	vNormal.x /= magnitude;								// Divide the X value of our normal by it's magnitude
	vNormal.y /= magnitude;								// Divide the Y value of our normal by it's magnitude
	vNormal.z /= magnitude;								// Divide the Z value of our normal by it's magnitude

	// Finally, return our normalized normal.

	return vNormal;										// Return the new normal of length 1.
}


/////////////////////////////////////// NORMAL \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the normal of a polygon (The direction the polygon is facing)
/////
/////////////////////////////////////// NORMAL \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

CVector3 Normal(CVector3 vPolygon[])					
{														// Get 2 vectors from the polygon (2 sides), Remember the order!
	CVector3 vVector1 = vPolygon[2] - vPolygon[0];
	CVector3 vVector2 = vPolygon[1] - vPolygon[0];

	CVector3 vNormal = Cross(vVector1, vVector2);		// Take the cross product of our 2 vectors to get a perpendicular vector

	// Now we have a normal, but it's at a strange length, so let's make it length 1.

	vNormal = Normalize(vNormal);						// Use our function we created to normalize the normal (Makes it a length of one)

	return vNormal;										// Return our normal at our desired length
}


/////////////////////////////////// DISTANCE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the distance between 2 3D points
/////
/////////////////////////////////// DISTANCE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

float Distance(CVector3 vPoint1, CVector3 vPoint2)
{
	// This is the classic formula used in beginning algebra to return the
	// distance between 2 points.  Since it's 3D, we just add the z dimension:
	// 
	// Distance = sqrt(  (P2.x - P1.x)^2 + (P2.y - P1.y)^2 + (P2.z - P1.z)^2 )
	//
	double distance = sqrt( (vPoint2.x - vPoint1.x) * (vPoint2.x - vPoint1.x) +
						    (vPoint2.y - vPoint1.y) * (vPoint2.y - vPoint1.y) +
						    (vPoint2.z - vPoint1.z) * (vPoint2.z - vPoint1.z) );

	// Return the distance between the 2 points
	return (float)distance;
}


////////////////////////////// CLOSEST POINT ON LINE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the point on the line vA_vB that is closest to the point vPoint
/////
////////////////////////////// CLOSEST POINT ON LINE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

CVector3 ClosestPointOnLine(CVector3 vA, CVector3 vB, CVector3 vPoint)
{
	// Create the vector from end point vA to our point vPoint.
	CVector3 vVector1 = vPoint - vA;

	// Create a normalized direction vector from end point vA to end point vB
    CVector3 vVector2 = Normalize(vB - vA);

	// Use the distance formula to find the distance of the line segment (or magnitude)
    float d = Distance(vA, vB);

	// Using the dot product, we project the vVector1 onto the vector vVector2.
	// This essentially gives us the distance from our projected vector from vA.
    float t = Dot(vVector2, vVector1);

	// If our projected distance from vA, "t", is less than or equal to 0, it must
	// be closest to the end point vA.  We want to return this end point.
    if (t <= 0) 
		return vA;

	// If our projected distance from vA, "t", is greater than or equal to the magnitude
	// or distance of the line segment, it must be closest to the end point vB.  So, return vB.
    if (t >= d) 
		return vB;
 
	// Here we create a vector that is of length t and in the direction of vVector2
    CVector3 vVector3 = vVector2 * t;

	// To find the closest point on the line segment, we just add vVector3 to the original
	// end point vA.  
    CVector3 vClosestPoint = vA + vVector3;

	// Return the closest point on the line segment
	return vClosestPoint;
}


/////////////////////////////////// PLANE DISTANCE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the distance between a plane and the origin
/////
/////////////////////////////////// PLANE DISTANCE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
									
float PlaneDistance(CVector3 Normal, CVector3 Point)
{	
	float distance = 0;									// This variable holds the distance from the plane tot he origin

	// Use the plane equation to find the distance (Ax + By + Cz + D = 0)  We want to find D.
	// So, we come up with D = -(Ax + By + Cz)
														// Basically, the negated dot product of the normal of the plane and the point. (More about the dot product in another tutorial)
	distance = - ((Normal.x * Point.x) + (Normal.y * Point.y) + (Normal.z * Point.z));

	return distance;									// Return the distance
}


/////////////////////////////////// INTERSECTED PLANE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This checks to see if a line intersects a plane
/////
/////////////////////////////////// INTERSECTED PLANE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
											
bool IntersectedPlane(CVector3 vPoly[], CVector3 vLine[], CVector3 &vNormal, float &originDistance)
{
	float distance1=0, distance2=0;						// The distances from the 2 points of the line from the plane
			
	vNormal = Normal(vPoly);							// We need to get the normal of our plane to go any further

	// Let's find the distance our plane is from the origin.  We can find this value
	// from the normal to the plane (polygon) and any point that lies on that plane (Any vertex)
	originDistance = PlaneDistance(vNormal, vPoly[0]);

	// Get the distance from point1 from the plane using: Ax + By + Cz + D = (The distance from the plane)

	distance1 = ((vNormal.x * vLine[0].x)  +					// Ax +
		         (vNormal.y * vLine[0].y)  +					// Bx +
				 (vNormal.z * vLine[0].z)) + originDistance;	// Cz + D
	
	// Get the distance from point2 from the plane using Ax + By + Cz + D = (The distance from the plane)
	
	distance2 = ((vNormal.x * vLine[1].x)  +					// Ax +
		         (vNormal.y * vLine[1].y)  +					// Bx +
				 (vNormal.z * vLine[1].z)) + originDistance;	// Cz + D

	// Now that we have 2 distances from the plane, if we times them together we either
	// get a positive or negative number.  If it's a negative number, that means we collided!
	// This is because the 2 points must be on either side of the plane (IE. -1 * 1 = -1).

	if(distance1 * distance2 >= 0)			// Check to see if both point's distances are both negative or both positive
	   return false;						// Return false if each point has the same sign.  -1 and 1 would mean each point is on either side of the plane.  -1 -2 or 3 4 wouldn't...
					
	return true;							// The line intersected the plane, Return TRUE
}


/////////////////////////////////// DOT \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This computers the dot product of 2 vectors
/////
/////////////////////////////////// DOT \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

float Dot(CVector3 vVector1, CVector3 vVector2) 
{
	// The dot product is this equation: V1.V2 = (V1.x * V2.x  +  V1.y * V2.y  +  V1.z * V2.z)
	// In math terms, it looks like this:  V1.V2 = ||V1|| ||V2|| cos(theta)
	
			 //    (V1.x * V2.x        +        V1.y * V2.y        +        V1.z * V2.z)
	return ( (vVector1.x * vVector2.x) + (vVector1.y * vVector2.y) + (vVector1.z * vVector2.z) );
}


/////////////////////////////////// ANGLE BETWEEN VECTORS \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This checks to see if a point is inside the ranges of a polygon
/////
/////////////////////////////////// ANGLE BETWEEN VECTORS \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

double AngleBetweenVectors(CVector3 Vector1, CVector3 Vector2)
{							
	// Get the dot product of the vectors
	float dotProduct = Dot(Vector1, Vector2);				

	// Get the product of both of the vectors magnitudes
	float vectorsMagnitude = Magnitude(Vector1) * Magnitude(Vector2) ;

	// Get the angle in radians between the 2 vectors
	double angle = acos( dotProduct / vectorsMagnitude );

	// Here we make sure that the angle is not a -1.#IND0000000 number, which means indefinate
	if(_isnan(angle))
		return 0;
	
	// Return the angle in radians
	return( angle );
}


/////////////////////////////////// INTERSECTION POINT \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the intersection point of the line that intersects the plane
/////
/////////////////////////////////// INTERSECTION POINT \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
											
CVector3 IntersectionPoint(CVector3 vNormal, CVector3 vLine[], double distance)
{
	CVector3 vPoint, vLineDir;					// Variables to hold the point and the line's direction
	double Numerator = 0.0, Denominator = 0.0, dist = 0.0;

	// 1)  First we need to get the vector of our line, Then normalize it so it's a length of 1
	vLineDir = vLine[1] - vLine[0];		// Get the Vector of the line
	vLineDir = Normalize(vLineDir);				// Normalize the lines vector


	// 2) Use the plane equation (distance = Ax + By + Cz + D) to find the 
	// distance from one of our points to the plane.
	Numerator = - (vNormal.x * vLine[0].x +		// Use the plane equation with the normal and the line
				   vNormal.y * vLine[0].y +
				   vNormal.z * vLine[0].z + distance);

	// 3) If we take the dot product between our line vector and the normal of the polygon,
	Denominator = Dot(vNormal, vLineDir);		// Get the dot product of the line's vector and the normal of the plane
				  
	// Since we are using division, we need to make sure we don't get a divide by zero error
	// If we do get a 0, that means that there are INFINATE points because the the line is
	// on the plane (the normal is perpendicular to the line - (Normal.Vector = 0)).  
	// In this case, we should just return any point on the line.

	if( Denominator == 0.0)						// Check so we don't divide by zero
		return vLine[0];						// Return an arbitrary point on the line

	dist = Numerator / Denominator;				// Divide to get the multiplying (percentage) factor
	
	// Now, like we said above, we times the dist by the vector, then add our arbitrary point.
	vPoint.x = (float)(vLine[0].x + (vLineDir.x * dist));
	vPoint.y = (float)(vLine[0].y + (vLineDir.y * dist));
	vPoint.z = (float)(vLine[0].z + (vLineDir.z * dist));

	return vPoint;								// Return the intersection point
}


/////////////////////////////////// INSIDE POLYGON \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This checks to see if a point is inside the ranges of a polygon
/////
/////////////////////////////////// INSIDE POLYGON \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

bool InsidePolygon(CVector3 vIntersection, CVector3 Poly[], long verticeCount)
{
	const double MATCH_FACTOR = 0.99;		// Used to cover up the error in floating point
	double Angle = 0.0;						// Initialize the angle
	CVector3 vA, vB;						// Create temp vectors
	
	for (int i = 0; i < verticeCount; i++)		// Go in a circle to each vertex and get the angle between
	{	
		vA = Poly[i] - vIntersection;			// Subtract the intersection point from the current vertex
												// Subtract the point from the next vertex
		vB = Poly[(i + 1) % verticeCount] - vIntersection;
												
		Angle += AngleBetweenVectors(vA, vB);	// Find the angle between the 2 vectors and add them all up as we go along
	}
											
	if(Angle >= (MATCH_FACTOR * (2.0 * PI)) )	// If the angle is greater than 2 PI, (360 degrees)
		return true;							// The point is inside of the polygon
		
	return false;								// If you get here, it obviously wasn't inside the polygon, so Return FALSE
}


/////////////////////////////////// INTERSECTED POLYGON \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This checks if a line is intersecting a polygon
/////
/////////////////////////////////// INTERSECTED POLYGON \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

bool IntersectedPolygon(CVector3 vPoly[], CVector3 vLine[], int verticeCount)
{
	CVector3 vNormal;
	float originDistance = 0;

	// First, make sure our line intersects the plane
									 // Reference   // Reference
	if(!IntersectedPlane(vPoly, vLine,   vNormal,   originDistance))
		return false;

	// Now that we have our normal and distance passed back from IntersectedPlane(), 
	// we can use it to calculate the intersection point.  
	CVector3 vIntersection = IntersectionPoint(vNormal, vLine, originDistance);

	// Now that we have the intersection point, we need to test if it's inside the polygon.
	if(InsidePolygon(vIntersection, vPoly, verticeCount))
		return true;							// We collided!	  Return success

	return false;								// There was no collision, so return false
}


///////////////////////////////// CLASSIFY SPHERE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This tells if a sphere is BEHIND, in FRONT, or INTERSECTS a plane, also it's distance
/////
///////////////////////////////// CLASSIFY SPHERE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

int ClassifySphere(CVector3 &vCenter, 
				   CVector3 &vNormal, CVector3 &vPoint, float radius, float &distance)
{
	// First we need to find the distance our polygon plane is from the origin.
	float d = (float)PlaneDistance(vNormal, vPoint);

	// Here we use the famous distance formula to find the distance the center point
	// of the sphere is from the polygon's plane.  
	distance = (vNormal.x * vCenter.x + vNormal.y * vCenter.y + vNormal.z * vCenter.z + d);

	// If the absolute value of the distance we just found is less than the radius, 
	// the sphere intersected the plane.
	if(Absolute(distance) < radius)
		return INTERSECTS;
	// Else, if the distance is greater than or equal to the radius, the sphere is
	// completely in FRONT of the plane.
	else if(distance >= radius)
		return FRONT;
	
	// If the sphere isn't intersecting or in FRONT of the plane, it must be BEHIND
	return BEHIND;
}


///////////////////////////////// EDGE SPHERE COLLSIION \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns true if the sphere is intersecting any of the edges of the polygon
/////
///////////////////////////////// EDGE SPHERE COLLSIION \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

bool EdgeSphereCollision(CVector3 &vCenter, 
						 CVector3 vPolygon[], int vertexCount, float radius)
{
	CVector3 vPoint;

	// This function takes in the sphere's center, the polygon's vertices, the vertex count
	// and the radius of the sphere.  We will return true from this function if the sphere
	// is intersecting any of the edges of the polygon.  

	// Go through all of the vertices in the polygon
	for(int i = 0; i < vertexCount; i++)
	{
		// This returns the closest point on the current edge to the center of the sphere.
		vPoint = ClosestPointOnLine(vPolygon[i], vPolygon[(i + 1) % vertexCount], vCenter);
		
		// Now, we want to calculate the distance between the closest point and the center
		float distance = Distance(vPoint, vCenter);

		// If the distance is less than the radius, there must be a collision so return true
		if(distance < radius)
			return true;
	}

	// The was no intersection of the sphere and the edges of the polygon
	return false;
}


////////////////////////////// SPHERE POLYGON COLLISION \\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns true if our sphere collides with the polygon passed in
/////
////////////////////////////// SPHERE POLYGON COLLISION \\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

bool SpherePolygonCollision(CVector3 vPolygon[], 
							CVector3 &vCenter, int vertexCount, float radius)
{
	// 1) STEP ONE - Finding the sphere's classification
	
	// Let's use our Normal() function to return us the normal to this polygon
	CVector3 vNormal = Normal(vPolygon);

	// This will store the distance our sphere is from the plane
	float distance = 0.0f;

	// This is where we determine if the sphere is in FRONT, BEHIND, or INTERSECTS the plane
	int classification = ClassifySphere(vCenter, vNormal, vPolygon[0], radius, distance);

	// If the sphere intersects the polygon's plane, then we need to check further
	if(classification == INTERSECTS) 
	{
		// 2) STEP TWO - Finding the psuedo intersection point on the plane

		// Now we want to project the sphere's center onto the polygon's plane
		CVector3 vOffset = vNormal * distance;

		// Once we have the offset to the plane, we just subtract it from the center
		// of the sphere.  "vPosition" now a point that lies on the plane of the polygon.
		CVector3 vPosition = vCenter - vOffset;

		// 3) STEP THREE - Check if the intersection point is inside the polygons perimeter

		// If the intersection point is inside the perimeter of the polygon, it returns true.
		// We pass in the intersection point, the list of vertices and vertex count of the poly.
		if(InsidePolygon(vPosition, vPolygon, 3))
			return true;	// We collided!
		else
		{
			// 4) STEP FOUR - Check the sphere intersects any of the polygon's edges

			// If we get here, we didn't find an intersection point in the perimeter.
			// We now need to check collision against the edges of the polygon.
			if(EdgeSphereCollision(vCenter, vPolygon, vertexCount, radius))
			{
				return true;	// We collided!
			}
		}
	}

	// If we get here, there is obviously no collision
	return false;
}


/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

///////////////////////////////// GET COLLISION OFFSET \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*
/////
/////	This returns the offset to move the center of the sphere off the collided polygon
/////
///////////////////////////////// GET COLLISION OFFSET \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*

CVector3 GetCollisionOffset(CVector3 &vNormal, float radius, float distance)
{
	CVector3 vOffset = CVector3(0, 0, 0);

	// Once we find if a collision has taken place, we need make sure the sphere
	// doesn't move into the wall.  In our app, the position will actually move into
	// the wall, but we check our collision detection before we render the scene, which
	// eliminates the bounce back effect it would cause.  The question is, how do we
	// know which direction to move the sphere back?  In our collision detection, we
	// account for collisions on both sides of the polygon.  Usually, you just need
	// to worry about the side with the normal vector and positive distance.  If 
	// you don't want to back face cull and have 2 sided planes, I check for both sides.
	//
	// Let me explain the math that is going on here.  First, we have the normal to
	// the plane, the radius of the sphere, as well as the distance the center of the
	// sphere is from the plane.  In the case of the sphere colliding in the front of
	// the polygon, we can just subtract the distance from the radius, then multiply
	// that new distance by the normal of the plane.  This projects that leftover
	// distance along the normal vector.  For instance, say we have these values:
	//
	//	vNormal = (1, 0, 0)		radius = 5		distance = 3
	//
	// If we subtract the distance from the radius we get: (5 - 3 = 2)
	// The number 2 tells us that our sphere is over the plane by a distance of 2.
	// So basically, we need to move the sphere back 2 units.  How do we know which
	// direction though?  This part is easy, we have a normal vector that tells us the
	// direction of the plane.  
	// If we multiply the normal by the left over distance we get:  (2, 0, 0)
	// This new offset vectors tells us which direction and how much to move back.
	// We then subtract this offset from the sphere's position, giving is the new
	// position that is lying right on top of the plane.  Ba da bing!
	// If we are colliding from behind the polygon (not usual), we do the opposite
	// signs as seen below:
	
	// If our distance is greater than zero, we are in front of the polygon
	if(distance > 0)
	{
		// Find the distance that our sphere is overlapping the plane, then
		// find the direction vector to move our sphere.
		float distanceOver = radius - distance;
		vOffset = vNormal * distanceOver;
	}
	else // Else colliding from behind the polygon
	{
		// Find the distance that our sphere is overlapping the plane, then
		// find the direction vector to move our sphere.
		float distanceOver = radius + distance;
		vOffset = vNormal * -distanceOver;
	}

	// There is one problem with check for collisions behind the polygon, and that
	// is if you are moving really fast and your center goes past the front of the
	// polygon, it will then assume you were colliding from behind and not let
	// you back in.  Most likely you will take out the if / else check, but I
	// figured I would show both ways in case someone didn't want to back face cull.

	// Return the offset we need to move back to not be intersecting the polygon.
	return vOffset;
}
 

#ifndef _MAIN_H
#define _MAIN_H

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <gl\gl.h>										// Header File For The OpenGL32 Library
#include <gl\glu.h>										// Header File For The GLu32 Library
#include <gl\glaux.h>

#include <float.h>
#include <math.h>
#include "3DMath.h"
#include "Camera.h"



#define SCREEN_WIDTH  640								// We want our screen width 800 pixels
#define SCREEN_HEIGHT 480							// We want our screen height 600 pixels
#define SCREEN_DEPTH 8							// We want 16 bits per pixel

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

#define MAX_TEXTURES 1									// This says how many texture we will be using

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

extern bool  g_bFullScreen;									// Set full screen as default
extern HWND  g_hWnd;										// This is the handle for the window
extern RECT  g_rRect;										// This holds the window dimensions
extern HDC   g_hDC;											// General HDC - (handle to device context)
extern HGLRC g_hRC;											// General OpenGL_DC - Our Rendering Context for OpenGL
extern HINSTANCE g_hInstance;	

struct Point3
{
	float x;
	float y;
	float z;
};

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

extern UINT g_Texture[MAX_TEXTURES];					// This is our texture data array

/////// * /////////// * /////////// * NEW * /////// * /////////// * /////////// *

// This is our MAIN() for windows
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hprev, PSTR cmdline, int ishow);

// The window proc which handles all of window's messages.
LRESULT CALLBACK WinProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);

// This controls our main program loop
WPARAM MainLoop();

// This loads a texture into openGL from a file (IE, "bitmap.bmp")
void CreateTexture(UINT textureArray[], LPSTR strFileName, int textureID);

// This changes the screen to full screen mode
void ChangeToFullScreen();

// This is our own function that makes creating a window modular and easy
HWND CreateMyWindow(LPSTR strWindowName, int width, int height, DWORD dwStyle, bool bFullScreen, HINSTANCE hInstance);

// This allows us to configure our window for OpenGL and backbuffered
bool bSetupPixelFormat(HDC hdc);

// This inits our screen translations and projections
void SizeOpenGLScreen(int width, int height);

// This sets up OpenGL
void InitializeOpenGL(int width, int height);

// This initializes the whole program
void Init(HWND hWnd);

// This draws everything to the screen
void RenderScene();

// This frees all our memory in our program
void DeInit();


#endif 


/////////////////////////////////////////////////////////////////////////////////
//
// * QUICK NOTES * 
//
// We added MAX_TEXTURES to this header file.  This define is the size of the g_Texture[]
// array, which we also extern here so init.cpp can free it's data.
// 
//
// Ben Humphrey (DigiBen)
// Game Programmer
// DigiBen@GameTutorials.com
// Co-Web Host of www.GameTutorials.com
//
// 

//{{NO_DEPENDENCIES}}
// Microsoft Developer Studio generated include file.
// Used by Script1.rc
//
#define IDB_BITMAP1                     101

// Next default values for new objects
// 
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE        102
#define _APS_NEXT_COMMAND_VALUE         40001
#define _APS_NEXT_CONTROL_VALUE         1000
#define _APS_NEXT_SYMED_VALUE           101
#endif
#endif