#include "svg.h"

#define SQRT3_6 0.28867513459481288225457439025098

void koch(int n, double x0, double y0, double x4, double y4) {
    if (n==0) {
        line(x0, y0, x4, y4);
        return;
    }  else {
        double x1 = x0*2/3+x4/3, y1 = y0*2/3+y4/3;
        double x2 = (x0+x4)/2 + (y4-y0) * SQRT3_6 , y2 = (y0+y4)/2 - (x4-x0) * SQRT3_6;
        double x3 = x0/3+x4*2/3, y3 = y0/3+y4*2/3;
        koch(n-1, x0, y0, x1, y1);
        koch(n-1, x1, y1, x2, y2);
        koch(n-1, x2, y2, x3, y3);
        koch(n-1, x3, y3, x4, y4);
    }
}

int main(void) {
    start();
    stroke(0x008000);
    strokeWeight(0.5);
    koch(6, 40, 180, 254, 180);
    finish();
    return 0;
}