//Koch Curve 
void setup(){ 
  size(800,600); 
  smooth(); 
  background(0); 
  noLoop(); 
} 
void draw(){ 
  koch(0,0,800, 600, 4); 
} 
void koch(int x1, int y1,int x2,int y2,int iterations){ 
  //line(x1,y1,x2,y2); 
 
  strokeWeight(0.5); 
  stroke(255,150); 
  noFill(); 
  rectMode(CORNERS); 
  if(iterations==0){ 
  line(x1,y1,(x2-x1)/3+x1,(y2-y1)/3+y1); 
  line((x2-x1)/3+x1,(y2-y1)/3+y1,(x2-x1)/2+x1+(y2-y1)/3,(y2-y1)/2+y1-(x2-x1)/3); 
  line((x2-x1)/2+x1+(y2-y1)/3,(y2-y1)/2+y1-(x2-x1)/3,(x2-x1)/3*2+x1,(y2-y1)/3*2+y1); 
  line((x2-x1)/3*2+x1,(y2-y1)/3*2+y1,x2,y2); 
  } 
 
  if(iterations>0){ 
    koch(x1,y1,(x2-x1)/3+x1,(y2-y1)/3+y1,iterations-1); 
    koch((x2-x1)/3+x1,(y2-y1)/3+y1,(x2-x1)/2+x1+(y2-y1)/3,(y2-y1)/2+y1-(x2-x1)/3,iterations-1); 
    koch((x2-x1)/2+x1+(y2-y1)/3,(y2-y1)/2+y1-(x2-x1)/3,(x2-x1)/3*2+x1,(y2-y1)/3*2+y1,iterations-1); 
    koch((x2-x1)/3*2+x1,(y2-y1)/3*2+y1,x2,y2,iterations-1); 
      stroke(0); 
  }  
  iterations--; 
}