/*
Digital Differential Analyzer (DDA) algorithm for drawing a circle.
Code from Computer Graphics (SPPU - Second Year - Computer Engineering - Content) repository on KSKA Git: https://git.kska.io/sppu-se-comp-codes/CG
*/

// BEGINNING OF CODE
#include <iostream>
#include <graphics.h>
using namespace std;

int main() {
	
	// Taking input for X, Y coordinate and radius of the circle
	int cordx, cordy, rad;
	cout<<"Enter X coordinate for the circle:\t";
	cin>>cordx;
	cout<<"Enter Y coordinate for the circle:\t";
	cin>>cordy;
	cout<<"Enter radius for the circle:\t";
	cin>>rad;
	
	// Logic for octent
	int gd=DETECT,gm;
	initgraph(&gd, &gm, NULL);

	int x,y,p;
	x=0;
	y=rad;
	
	p=3-(2*rad);
	
	do {
		putpixel(cordx+x, cordy-y, WHITE);
		putpixel(cordx-x, cordy-y, GREEN);
		putpixel(cordx+x, cordy+y, YELLOW);
		putpixel(cordx-x, cordy+y, RED);
		putpixel(cordx+y, cordy+x, WHITE);
		putpixel(cordx+y, cordy-x, GREEN);
		putpixel(cordx-y, cordy+x, YELLOW);
		putpixel(cordx-y, cordy-x, RED);
			if (p<0) {
				p=p+(4*x)+6;
			}
			else {
				p=p+(4*(x-y))+10;
				y=y-1;
			}
	x=x+1;	
	} while(x<y);
	
	outtext("Designed and Engineered by KSHITIJ");
	
	delay(50000);
	closegraph();
	return 0;
}
// END OF CODE