/*
Problem Statement:Write C++ program to draw the following pattern. Use DDA line and Bresenham's
circle drawing algorithm. Apply the concept of encapsulation. 
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>
#include <bits/stdc++.h>
using namespace std;

class algo {
	public:
		void dda_line(float x1, float y1, float x2, float y2);
		void bresneham_cir(int r);
};

void algo::dda_line(float x1, float y1, float x2, float y2) {
	float x,y,dx,dy,step;
	int i;
	//step 2
	dx=abs(x2-x1);
	dy=abs(y2-y1);
	cout<<"dy="<<dy<<"\tdx="<<dx;
	//step 3
	if(dx>=dy)
		step=dx;
	else
		step=dy;
	cout<<"\n"<<step<<endl;
	//step 4
	float xinc=float((x2-x1)/step);
	float yinc=float((y2-y1)/step);
	//step 5
	x=x1;
	y=y1;
	// outtextxy(0,0,"(0,0)");
	//step 6
	i=1;
	while(i<=step) {
		// cout<<endl<<"\t"<<i<<"\t(x,y)=("<<x<<","<<y<<")";
		putpixel(320+x,240-y,4);
		x=x+xinc;
		y=y+yinc;
		i=i+1;
		// delay(10);
	}
}

void algo::bresneham_cir(int r) {
	float x,y,p;
	x=0;
	y=r;
	p=3-(2*r);
	while(x<=y) {
		putpixel(320+x,240+y,1);
		putpixel(320-x,240+y,2);
		putpixel(320+x,240-y,3);
		putpixel(320-x,240-y,5);
		putpixel(320+y,240+x,6);
		putpixel(320+y,240-x,7);
		putpixel(320-y,240+x,8);
		putpixel(320-y,240-x,9);
		x=x+1;
		if(p<0) {
			p=p+4*(x)+6;
		}
		else {
			p=p+4*(x-y)+10;
			y=y-1;
		}
	// delay(20);
	}
}

int main() {
	algo a1;
	int i;
	float r,ang,r1;
	initwindow(630,480);
	cout<<"Enter radius of circle";
	cin>>r;
	a1.bresneham_cir((int)r);
	ang=3.24/180;
	float c=r*cos(30*ang);
	float s=r*sin(30*ang);
	a1.dda_line(0,r,0-c,0-s);
	a1.dda_line(0-c,0-s,0+c,0-s);
	a1.dda_line(0+c,0-s,0,r);
	r1=s;
	a1.bresneham_cir((int)r1);
	getch();
	closegraph();
	return 0;
}
// END OF CODE