fbpx

C++: Fibonacci Word Fractals

Bjarne-stroustrup
 

The Fibonacci word may be represented as a fractal as described here:

For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0

Turn left if n is even
Turn right if n is odd
next n and iterate until end of F_word

For this task create and display a fractal similar to Fig 1.

#include <windows.h>
#include <string>
using namespace std;

class myBitmap
{
public:
	myBitmap() : pen( NULL ) {}
	~myBitmap()
	{
		DeleteObject( pen );
		DeleteDC( hdc );
		DeleteObject( bmp );
	}

	bool create( int w, int h )
	{
		BITMAPINFO	bi;
		ZeroMemory( &bi, sizeof( bi ) );
		bi.bmiHeader.biSize        = sizeof( bi.bmiHeader );
		bi.bmiHeader.biBitCount	   = sizeof( DWORD ) * 8;
		bi.bmiHeader.biCompression = BI_RGB;
		bi.bmiHeader.biPlanes	   = 1;
		bi.bmiHeader.biWidth	   =  w;
		bi.bmiHeader.biHeight	   = -h;
		HDC dc = GetDC( GetConsoleWindow() );
		bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 );
		if( !bmp ) return false;
		hdc = CreateCompatibleDC( dc );
		SelectObject( hdc, bmp );
		ReleaseDC( GetConsoleWindow(), dc ); 
		width = w; height = h;
		clear();
		return true;
	}

	void clear()
	{
		ZeroMemory( pBits, width * height * sizeof( DWORD ) );
	}

	void setPenColor( DWORD clr )
	{
		if( pen ) DeleteObject( pen );
		pen = CreatePen( PS_SOLID, 1, clr );
		SelectObject( hdc, pen );
	}

	void saveBitmap( string path )
	{
		BITMAPFILEHEADER fileheader;
		BITMAPINFO	 infoheader;
		BITMAP		 bitmap;
		DWORD*		 dwpBits;
		DWORD		 wb;
		HANDLE		 file;

		GetObject( bmp, sizeof( bitmap ), &bitmap );
		dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight];
		ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) );
		ZeroMemory( &infoheader, sizeof( BITMAPINFO ) );
		ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) );

		infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8;
		infoheader.bmiHeader.biCompression = BI_RGB;
		infoheader.bmiHeader.biPlanes = 1;
		infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader );
		infoheader.bmiHeader.biHeight = bitmap.bmHeight;
		infoheader.bmiHeader.biWidth = bitmap.bmWidth;
		infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD );

		fileheader.bfType    = 0x4D42;
		fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER );
		fileheader.bfSize    = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage;

		GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS );

		file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL );
		WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL );
		WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL );
		WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL );
		CloseHandle( file );

		delete [] dwpBits;
	}

	HDC getDC()     { return hdc; }
	int getWidth()  { return width; }
	int getHeight() { return height; }

private:
	HBITMAP bmp;
	HDC	    hdc;
	HPEN    pen;
	void    *pBits;
	int	    width, height;
};
class fiboFractal
{
public:
	fiboFractal( int l )
	{
		bmp.create( 600, 440 );
		bmp.setPenColor( 0x00ff00 );
		createWord( l ); createFractal();
		bmp.saveBitmap( "path_to_save_bitmap" );
	}
private:
	void createWord( int l )
	{
		string a = "1", b = "0", c;
		l -= 2;
		while( l-- )
		{ c = b + a; a = b; b = c; }
		fWord = c;
	}

	void createFractal()
	{
		int n = 1, px = 10, dir, 
		py = 420, len = 1, 
		x = 0, y = -len, goingTo = 0;

		HDC dc = bmp.getDC();
		MoveToEx( dc, px, py, NULL );
		for( string::iterator si = fWord.begin(); si != fWord.end(); si++ )
		{
			px += x; py += y;
			LineTo( dc, px, py );
			if( !( *si - 48 ) )
			{	// odd
				if( n & 1 ) dir = 1;	// right
				else dir = 0;			// left
				switch( goingTo )
				{
				case 0: // up
					y = 0;
					if( dir ){ x = len; goingTo = 1; }
					else { x = -len; goingTo = 3; }
					break;
				case 1: // right
					x = 0;
					if( dir ) { y = len; goingTo = 2; }
					else { y = -len; goingTo = 0; }
					break;
				case 2: // down
					y = 0;
					if( dir ) { x = -len; goingTo = 3; }
					else { x = len; goingTo = 1; }
					break;
				case 3: // left
					x = 0;
					if( dir ) { y = -len; goingTo = 0; }
					else { y = len; goingTo = 2; }
				}
			}
			n++;
		}
	}

	string fWord;
	myBitmap bmp;
};
int main( int argc, char* argv[] )
{
	fiboFractal ff( 23 );
	return system( "pause" );
}

SOURCE

Content is available under GNU Free Documentation License 1.2.