//************************  vonKoch.h  ***************************
//     	                Visual C++ program
//     	A header file in a project of type MFC Application.

#define _USE_MATH_DEFINES
#include <cmath>

class vonKoch {
public:
    vonKoch(int,int,CDC*);
    void snowflake();
    void cross();
private:
    double side, angle;
    int level;
    CPoint currPt, pt;
    CDC *pen;
    void right(double x) {
         angle += x;
    }
    void left (double x) {
         angle -= x;
    }
    void drawFourLines(double side, int level);
    void drawCrossSide(double side, int level);
};

vonKoch::vonKoch(int s, int lvl, CDC *pDC) {
    pen = pDC;
    currPt.x = 200;
    currPt.y = 100;
    pen->MoveTo(currPt);
    angle = 0.0;
    side = s;
    level = lvl;
}

void vonKoch::drawFourLines(double side, int level) { 
    // arguments to sin() and cos() are angles
    // specified in radians, i.e., the coefficient
    // PI/180 is necessary;
    if (level == 0) {
       	 pt.x = int(cos(angle*M_PI/180)*side) + currPt.x; 
         pt.y = int(sin(angle*M_PI/180)*side) + currPt.y;
         pen->LineTo(pt);
         currPt.x = pt.x;
       	 currPt.y = pt.y;
	}
    else {                                        
         drawFourLines(side/3,level-1);
         left (60);
         drawFourLines(side/3,level-1);
         right(120);
         drawFourLines(side/3,level-1);
         left (60);
         drawFourLines(side/3,level-1);
    }
}

void vonKoch::snowflake() {
    for (int i = 1; i <= 3; i++) {
        drawFourLines(side,level);
            right(120);
    }
}