11_KochCurve.cpp

//
// Created by piyush on 4/2/19.
//
#include <graphics.h>
#include<bits/stdc++.h>
using namespace std;

#define callInitgraph int gd=DETECT,gm; initgraph(&gd,&gm,NULL);

void kochCurve(int x1, int y1, int x2, int y2, int it)
{
    float angle = 60*3.14/180;
    int x3 = (2*x1+x2)/3;
    int y3 = (2*y1+y2)/3;

    int x4 = (x1+2*x2)/3;
    int y4 = (y1+2*y2)/3;

    int x = x3 + (x4-x3)*cos(angle)+(y4-y3)*sin(angle);
    int y = y3 - (x4-x3)*sin(angle)+(y4-y3)*cos(angle);

    if(it > 0)
    {
        kochCurve(x1, y1, x3, y3, it - 1);
        kochCurve(x3, y3, x, y, it - 1);
        kochCurve(x, y, x4, y4, it - 1);
        kochCurve(x4, y4, x2, y2, it - 1);
    }
    else
    {
        setcolor(5);
        line(x1, y1, x3, y3);
        line(x3, y3, x, y);
        line(x, y, x4, y4);
        line(x4, y4, x2, y2);
        delay(1000);
    }
}

int main()
{
    callInitgraph;
    int x1 = 100, y1 = 300, x2 = 500, y2 = 300;
    kochCurve(x1, y1, x2, y2, 4);
    getch();
    return 0;
}