mandelbrot.pc

#include <stdio>
#include <math>
#include <stdlib>
#include <conio>

const int ITERATIONS = 100;
const int LIN = 70, COL = 150;

void main(){
	int plane[LIN][COL];
	double r = 0, im = 0;
	double y, x;
	int k;
	double x1 = -2.5, x2 = 2.5, y1 = -1, y2 = 1;
	char c;
	double dx, dy;
	int i;
	
	do
{
	puts("mandelbrot set grapher");
	puts("enter the coordinates for a rectangle, x1 = left, x2 = right, y1 = bottom, y2 = top");
	puts("the mandelbrot set goes from x in [-2.5, 2.5] and y in [-1, 1]");	

	printf("x1= ");
	scanf("%lf", &x1);
	printf("x2= ");
	scanf("%lf", &x2);
	printf("y1= ");
	scanf("%lf", &y1);
	printf("y2= ");
	scanf("%lf", &y2);

	puts("calculating...");

	dx = (x2 - x1) / COL;
	dy = (y2 - y1) / LIN;

	for(y = 0; y < LIN; y++){
		for(x = 0; x < COL; x++){
			for(k = 0; k <= ITERATIONS; k++){
				mandelbrot(r, im,  x1 + dx * x, y1 + dy * y, &r, &im);
				if(absc(r, im) > 2) break;				
			}
			if(absc(r, im) > 2) plane[y][x] = ' ';
			else plane[y][x] = 'o';
			r = 0;
			im = 0;
		}
	}

	for(y = 0; y < LIN; y++){
		printf("%9.6f", y2 - y * dy);
		for(x = 0; x < COL; x++){
			putchar(plane[y][x]);
		}
		putchar('\n');
	}

	
	for(i = 0; i < 7; i++) putchar(' ');

	for(i = 0; i < COL; i++)
		if(i % 10 == 0) printf("%10.6f", x1 + dx * i);

	printf("\npress e to exit or any other key to try again\n");
	c = getch();

} while( c != 'e');
	
}

void multiply(double r1, double im1, double r2, double im2, double *r3, double *im3){
	*r3 = r1*r2 - im1*im2;
	*im3 = r1*im2 + r2*im1;
}

double absc(double r, double im){
	return sqrt(r * r + im * im);
}

void mandelbrot(double r, double im, double cr, double cim, double *rr, double *rim){
	*rr = r * r - im * im + cr;
	*rim = 2 * r * im + cim;
}