/* A fractals program. */

#include <windows.h>
#include <string.h>

void	ComplexSquare(	double *x, double *y );
void	ComplexAdd(		double x, double y, double cx, double cy, double *xAns, double *yAns );
void 	Mandelbrot(	HDC hdc );
void	Dragon(	HDC hdc );

LRESULT CALLBACK WindowFunc(HWND, UINT, WPARAM, LPARAM);

char	szWinName[]	= "WinFractal";				/* name of window class */
char	str[255]	= "";						/* holds output string */
int		maxX, maxY,								/* screen dimensions */
		xCoordinate, yCoordinate;				/* current position of the pen	*/
int		i				= 0,
		myRefreshFlag	= 0,
		xCounter		= 0,
		whichFractal	= 1,
		oldWhichFractal,
		oldi,
		oldxCounter;

HDC		memdc; 									/* handle of memory DC */
HBITMAP	hbit; 									/* handle of compatible bitmap */
HBRUSH	hbrush, hOldbrush; 						/* handles of brushes */

int WINAPI WinMain(HINSTANCE hThisInst, HINSTANCE hPrevInst, 
                   LPSTR lpszArgs, int nWinMode)
{
 	HWND		hwnd;
 	MSG			msg;
 	WNDCLASSEX	wcl;

  	/* Define a window class. */
  	wcl.cbSize = sizeof(WNDCLASSEX); 

  	wcl.hInstance = hThisInst;					/* handle to this instance */
  	wcl.lpszClassName = szWinName;				/* window class name */
  	wcl.lpfnWndProc = WindowFunc;				/* window function */
  	wcl.style = 0;								/* default style */

  	wcl.hIcon = LoadIcon(NULL, IDI_APPLICATION);/* standard icon */
  	wcl.hIconSm = LoadIcon(NULL, IDI_WINLOGO);	/* small icon */
  	wcl.hCursor = LoadCursor(NULL, IDC_ARROW); 	/* cursor style */
 
  	wcl.lpszMenuName = NULL;					/* no menu */
  	wcl.cbClsExtra = 0;							/* no extra */
  	wcl.cbWndExtra = 0;							/* information needed */

  	/* Make the window white. */
  	wcl.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH); 

  	/* Register the window class. */
  	if(!RegisterClassEx(&wcl)) return 0;

  	/*	Now that a window class has been registered, a window
    	can be created. */
  	hwnd = CreateWindow(
    					szWinName,				/* name of window class */
   						"Fractals",				/* title */
    					WS_OVERLAPPEDWINDOW,	/* window style - normal */
    					CW_USEDEFAULT,			/* X coordinate - let Windows decide */
    					CW_USEDEFAULT,			/* Y coordinate - let Windows decide */
    					CW_USEDEFAULT,			/* width - let Windows decide */
    					CW_USEDEFAULT,			/* height - let Windows decide */
    					HWND_DESKTOP,			/* no parent window */
    					NULL,					/* no menu */
    					hThisInst,				/* handle of this instance of the program */
    					NULL					/* no additional arguments */
  	);

  	/* Display the window. */
 	ShowWindow(hwnd, nWinMode);
  	UpdateWindow(hwnd);


  	/* Create the message loop. */
  	while(TRUE)
  	{
  		if(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
  		{
  			if(msg.message == WM_QUIT)
  				break;
  			
    		TranslateMessage(&msg);					/* translate keyboard messages */
    		DispatchMessage(&msg);					/* return control to Windows 98 */
  		}
  		else
  		{
  			if(i <= maxY)
  			{
  				switch(whichFractal)
  				{
  					case 1:
							Mandelbrot(memdc);
							break;
					case 2:
							Dragon(memdc);
							break;
					default:
							break;
				}
				myRefreshFlag	= 1;
				InvalidateRect(hwnd, NULL, 0); 							/* update screen */
			}
		}
  	}


  	return msg.wParam;
}

/* This function is called by Windows 98 and is passed 
   messages from the message queue.
*/
LRESULT CALLBACK WindowFunc(HWND hwnd, UINT message,
                            WPARAM wParam, LPARAM lParam)
{
	HDC			hdc;
	PAINTSTRUCT	paintstruct;

	switch(message)
	{
		case WM_CREATE:
						/* get screen coordinates */
						maxX = GetSystemMetrics(SM_CXSCREEN);
						maxY = GetSystemMetrics(SM_CYSCREEN);
						
						/* initial position of the pen	*/
						xCoordinate	= 0;
						yCoordinate	= 0;

						/* make a compatible memory image device */
						hdc = GetDC(hwnd);
					    memdc = CreateCompatibleDC(hdc);
					    hbit = CreateCompatibleBitmap(hdc, maxX, maxY);
					    SelectObject(memdc, hbit);
					    hbrush = (HBRUSH) GetStockObject(WHITE_BRUSH);
					    SelectObject(memdc, hbrush);
					    PatBlt(memdc, 0, 0, maxX, maxY, PATCOPY);
					
					    ReleaseDC(hwnd, hdc);
					    strcpy(str, "Welcome to Ebo. (Alt-F4 to Quit)");
					    TextOut(memdc, maxX/5, maxY/3, str, strlen(str));
					    break;
		case WM_PAINT: /* process a repaint request */
					    hdc = BeginPaint(hwnd, &paintstruct); 					/* get DC */
					    if(myRefreshFlag == 1)
					    {
					    	BitBlt(hdc, xCounter, 0, 2, maxY, memdc, xCounter, 0, SRCCOPY);
					    	xCounter	+= 2;
					  		myRefreshFlag	= 0;
					  	}
					    else
					    	BitBlt(hdc, paintstruct.rcPaint.left,
					    				paintstruct.rcPaint.top,
					    				paintstruct.rcPaint.right-paintstruct.rcPaint.left,
					    				paintstruct.rcPaint.bottom-paintstruct.rcPaint.top,
					    				memdc,
					    				paintstruct.rcPaint.left,
					    				paintstruct.rcPaint.top,
					    				SRCCOPY);								/* now, copy memory image onto screen */
					    EndPaint(hwnd, &paintstruct); 							/* release DC */
					    break;
		case WM_LBUTTONDOWN:
						oldWhichFractal	= whichFractal;
						oldi			= i;
						oldxCounter		= xCounter;
						whichFractal	= 9;
						break;
		case WM_LBUTTONUP:
						whichFractal	= oldWhichFractal;
						myRefreshFlag	= 1;
						i				= oldi;
						xCounter		= oldxCounter;
						break;
		case WM_CHAR:
						switch((char)wParam)
						{
							case '1':
										whichFractal	= 1;
										myRefreshFlag	= 1;
										i				= 1;
										xCounter		= 0;
										break;
 							case '2':
										whichFractal	= 2;
										myRefreshFlag	= 1;
										i				= 1;
										xCounter		= 0;
										break;
						}
						break;
   	case WM_DESTROY: 														/* terminate the program */
					    DeleteDC(memdc);
						PostQuitMessage(0);
						break;
		default:
						/*	Let Windows 98 process any messages not specified in
							the preceding switch statement. */
						return DefWindowProc(hwnd, message, wParam, lParam);
	}
	return 0;
}


void	ComplexSquare( double *x, double *y )
{
	register double temp1, temp2;
	
	temp1	= *x * *x - *y * *y;
	temp2	= *x * *y + *x * *y;
	
	*x		= temp1;
	*y		= temp2;
	
}

void	ComplexAdd( double x, double y, double cx, double cy, double *xAns, double *yAns )
{
	
	*xAns	= x + cx;
	*yAns	= y + cy;
	
}

void Mandelbrot(HDC hdc)
{
	static double	zoom	= 2.0,
					escape	= 4.0;
	
	register double	scale,
					magnitude,
					cx, cy;
					
	double			x, y;
					
	register int	j,
					iter,
					color,
					offsetY	= 120;
					
			

	scale	= 2.0*zoom/maxY;
	
	while( i++ <= maxY )
	{
		for(j=0; j <= maxY; j++ )
		{
			x			= 0;
			y			= 0;
			cx			= scale * i - zoom;
			cy			= zoom - scale * j;
			magnitude	= 0;
			iter		= 0;
			
			while ( (iter < 32) && (magnitude < escape) )
			{
				ComplexSquare( &x, &y );
				ComplexAdd( x, y, cx, cy, &x, &y );
				magnitude	= x*x + y*y;
				iter++;
			}
			
			if ( magnitude > escape)
			{
				color	= iter / 6;
				
				switch (color)
				{
					case	0	:
									SetPixel(hdc, i, j-offsetY, RGB(0,0,0));		// Black
									break;
					case	1	:	
									SetPixel(hdc, i, j-offsetY, RGB(255,0,0));		// Red
									break;
					case	2	:	
									SetPixel(hdc, i, j-offsetY, RGB(0,0,255));		// Blue
									break;
					case	3	:	
									SetPixel(hdc, i, j-offsetY, RGB(0, 255, 0));	// Green
									break;
					case	4	:	
									SetPixel(hdc, i, j-offsetY, RGB(255, 0, 255));	// Purple
									break;
					case	5	:	
									SetPixel(hdc, i, j-offsetY, RGB(0, 255, 255));	// Magenta
									break;
					default		:
									SetPixel(hdc, i, j-offsetY, RGB(0, 0, 0));		// Black
									break;
				}
			}
			else
				SetPixel(hdc, i, j-offsetY, RGB(255, 255, 0));	// Yellow
	}
		if(i%2)
			break;
	}
}


void Dragon(HDC hdc)
{
	static double		zoom	= 2.0,
						attract	= .0001;
						
	register double		scale,
						magnitude;
						
	double				x, y;
	
	register int		 j,
						iter,
						color,
						offsetY	= 120;
	BOOL				goAhead;
			

	scale	= 2.0*zoom/maxY;
	
	while( i++ <= maxY )
	{
		
		for( j = 0; j <= maxY; j++ )
		{
			x			= scale * i - zoom;
			y			= zoom - scale * j;
			goAhead		= TRUE;
			magnitude	= 0;
			iter		= 0;
			
			while ( goAhead == TRUE )
			{
				ComplexSquare( &x, &y );
				ComplexAdd( x, y, .360284, .100376, &x, &y );
				magnitude	= x*x + y*y;
			
				if ( magnitude < attract)
					goAhead	= FALSE;
				else
				{
					if ( (magnitude < 100) && (iter < 32) )
						iter++;
					else
					{
						color	= iter / 4;
				
						switch (color)
						{
							case	0	:	
											SetPixel(hdc, i, j-offsetY, RGB(128,128,128));	// Black
											break;
							case	1	:	
											SetPixel(hdc, i, j-offsetY, RGB(255,0,0));		// Red
											break;
							case	2	:	
											SetPixel(hdc, i, j-offsetY, RGB(0,0,255));		// Blue
											break;
							case	3	:	
											SetPixel(hdc, i, j-offsetY, RGB(0, 255, 0));	// Green
											break;
							case	4	:	
											SetPixel(hdc, i, j-offsetY, RGB(255, 0, 255));	// Purple
											break;
							case	5	:	
											SetPixel(hdc, i, j-offsetY, RGB(0, 255, 255));	// Magenta
											break;
							default		:	
											SetPixel(hdc, i, j-offsetY, RGB(128, 10, 128));	// Black
											break;
						}
						goAhead	= FALSE;
					}
				}
			}
		}
		if(i%2)
			break;
	}
}