koch_curve.cpp

#include<iostream>
#include<graphics.h> 
#include<math.h> 
using namespace std; 

void snow(int x1, int y1, int x2, int y2, int it) 
{ 
 float angle = 60*M_PI/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) 
 { 
  snow(x1, y1, x3, y3, it-1); 
  snow(x3, y3, x, y, it-1); 
  snow(x, y, x4, y4, it-1); 
  snow(x4, y4, x2, y2, it-1); 
 } 
 else 
 { 

  line(x1, y1, x3, y3); 
  line(x3, y3, x, y); 
  line(x, y, x4, y4); 
  line(x4, y4, x2, y2); 
 } 
} 

int main() 
{ 
 int gd = DETECT,gm; 
 initgraph(&gd, &gm, NULL); 
 int x1 = 150, y1 = 100, x2 = 350, y2 = 100; 
 snow(x1, y1, x2, y2,2); 
snow(250,350,150,100,2); 
snow(350,100,250,350,2); 
 getch(); 
 return 0; 
}