/***********************************************
* Julia3DlanGen3.c
*
*  Generates a RAW format file of a 3D image 
*  of a Julia set (grayscale)
*
*  C source file by Alberto Strumia
*
************************************************/


#include<stdio.h>			

/* defintion of constants */
#define Radius 10		
#define Side 2.0			
#define Cx  0.912365		
#define Cy  0.194280
#define M 700			
#define Num 255				
#define height Num/8		

/* main program */
main()
{
	
	int p, q, n, w, r[M+height];				
	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 = - Side + 4*Side*(p+q/2)/M/3;
			Incy = - Side + 2*Side*q/M;
			
		x = Incx;
		y = Incy;
		w = 100;		
		
			for ( n = 1; n <= Num; ++n)
			{
				xx = (x*x - y*y)*(x*x - y*y) - 4*x*x*y*y - Cx;
				yy = 4*x*y*(x*x - y*y) - Cy;
				
				x = xx;
				y = yy;
				
				if ( x*x + y*y > Radius )		
					{
						w = n;
						n = Num;
					}
			}
				
						r[q + height/w] = w;
				
		}

		
		for ( q = 1; q <= M; q++)
			{	
			
		fprintf(fp, "%c", r[q] );	
		
		r[q] = 100;			
			}
	}
	
	fclose(fp);			
}

/* end of main program */