/***********************************************
*Julia3DNeg.c
*
*  Generates a RAW format file of a 3D image 
*  of a Julia set (grayscale)
*
*  C source file by Alberto Strumia
*
************************************************/

#include<stdio.h>

/* definition of constants */

#define Radius 10	
#define Cx 0.745429	
#define Cy 0.0		
#define Side 0.8	
#define M 700	
#define Num 100	
#define scale 1		
#define co 1.41			
#define si 1.41		
#define x0 -2.0*Side		
#define y0 Side		

/* main program */
main()
{
	
	int p, q, n, w, r[M+Num/scale];		
	double x, y, xx, yy, Incx, Incy;

	FILE *fp;
	fp = fopen("Julia.raw","w");	

	for (p = 1; p <= M; p++)
	{
		
			printf("%i %%\n", p*100/M);	
		
		for (q = 1; q <= M; q++)
		{
			Incx = x0 - Side + 2*Side*(p*co+q*si)/M;
			Incy = y0 - Side + 2*Side*(-p*si+q*co)/M;
			
		x = Incx;
		y = Incy;
		w = 0;		
		
			for ( n = 1; n <= Num; ++n)
			{
				xx = x*x - y*y - Cx;
				yy = 2*x*y - Cy;
				
				x = xx;
				y = yy;
				
				if ( x*x + y*y > Radius )	
					{
						w = n;
						n = Num;
					}
			}
		
		
		for ( n = 1; n <= w; n++)
			{
				if ( q > n/scale )
					{
						r[q + n/scale] = w;
					}
				
			}
		}

		
		for ( q = 1; q <= M; q++)
			{	
			
		fprintf(fp, "%c", r[q] );
		
		r[q] = 255;	 	
			}
	}
	
	fclose(fp);				
}

/* end of main program */