Program:
#include <iostream>
#include <GL/glut.h>
#include <GL/freeglut.h>
#include <math.h>
using namespace std;
#define RADIAN (3.14 / 180)
#define XMAX 1400
#define YMAX 900
void Initialize();
void draw();
void draw_koch(float, float, float, float, int);
void Initialize()
{
glClear(GL_COLOR_BUFFER_BIT);
glClearColor(0.0, 0.0, 0.0, 0.0);
glColor3f(1.0, 1.0, 1.0);
gluOrtho2D(0.0, XMAX, 0.0, YMAX);
}
void draw(int n)
{
glBegin(GL_LINES);
draw_koch(600, 100, 800,
400, n);
draw_koch(800, 400, 400,
400, n);
draw_koch(400, 400, 600,
100, n);
glEnd();
glFlush();
}
void draw_koch(float xa, float ya, float xb, float yb, int n)
{
float xc, xd, yc, yd, midx, midy;
xc = (2 * xa + xb) / 3;
yc = (2 * ya + yb) / 3;
xd = (2 * xb + xa) / 3;
yd = (2 * yb + ya) / 3;
midx = xc + ((xd - xc) * cos(60 * RADIAN)) + ((yd - yc) * sin(60 * RADIAN));
midy = yc - ((xd - xc) * sin(60 * RADIAN)) + ((yd - yc) * cos(60 * RADIAN));
if (n > 0)
{
draw_koch(xa, ya, xc, yc, n - 1);
draw_koch(xc, yc, midx, midy, n - 1);
draw_koch(midx, midy, xd, yd, n - 1);
draw_koch(xd, yd, xb, yb, n - 1);
}
else
{
glVertex2f(xa, ya);
glVertex2f(xc, yc);
glVertex2f(xc, yc);
glVertex2f(midx, midy);
glVertex2f(midx, midy);
glVertex2f(xd, yd);
glVertex2f(xd, yd);
glVertex2f(xb, yb);
}
}
int main(int argc, char **argv)
{
int n;
cout << "\n Enter For How Many Iterations You Want to Draw ?::";
cin >> n;
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(XMAX, YMAX);
glutInitWindowPosition(0, 0);
glutCreateWindow("KOCH CURVE");
Initialize();
draw(n);
glutMainLoop();
return 0;
}
Output:
