#include "library.h"  

const double pi = acos(-1.0); 
const double ninety = pi/2, degrees = pi/180;  

void block1(double p1x, double p1y, double p2x, double p2y, double len, double beta, double end, int level) {    
      double base = sqrt((p1x-p2x)*(p1x-p2x) + (p1y-p2y)*(p1y-p2y));   
      double alpha = atan2(p2x-p1x,p1y-p2y) - ninety;  
 
      if (sin(beta)>2*len/base || end < 0.3) { 	
            if (random_in_range(0,500)==500) { 			
                  set_pen_color(color::red); 		
                  set_pen_width(20); 		
                  draw_point(); 	
            } 	
            else { 	
                  set_pen_color_int(10,random_in_range(100,200),10);
                  set_pen_width(10); 		
                  draw_point(); 	
            } 	
            return;   
      }   

      double p3x = (p1x + p2x) * 0.5;   
      double p3y = (p1y + p2y) * 0.5;   
      double p4x = p3x + len * sin(alpha+beta);   
      double p4y = p3y - len * cos(alpha+beta);   
      double dx = 0.5 * end * sin(ninety-alpha-beta);   
      double dy = 0.5 * end * cos(ninety-alpha-beta);   
      double p5x = p4x - dx;   
      double p5y = p4y - dy;   
      double p6x = p4x + dx;   
      double p6y = p4y + dy;    

      set_pen_color(color::black);   
      set_pen_width(1);   
      start_shape();   
      move_to(p1x, p1y);   
      note_position();   
      draw_to(p2x, p2y);  
      note_position();   
      draw_to(p6x, p6y);   
      note_position();   
      draw_to(p5x, p5y);   
      note_position();   
      draw_to(p1x, p1y);   
      note_position();   
      set_pen_color(color::brown);   
      fill_shape();   
      if (level<100) { 	
            set_pen_color(color::black); 	
            move_to(p1x, p1y); 	
            draw_to(p2x, p2y); 	
            draw_to(p6x, p6y); 	
            draw_to(p5x, p5y); 	
            draw_to(p1x, p1y);   
      }    

      block1(p5x,p5y,p6x,p6y,len/1.4,beta+20*degrees,end/2,level+1);
      block1(p5x,p5y,p6x,p6y,len/1.5,beta-20*degrees,end/2,level+1);
      block1(p5x,p5y,p6x,p6y,len/1.3,beta-10*degrees,end/2,level+1);   
      if (random_in_range(0,1)==1)
            block1(p5x,p5y,p6x,p6y,len/1.2,beta+10*degrees,end/2,level+1);  
}  

void main() {   
      int width = 800;   
      int height = 800;   
      make_window(width, height);   
      fill_rectangle(0,0,width,height-height/6,color::light_blue);
      fill_rectangle(0,height-height/6,width,height,color::dark_green);
      set_pen_color(color::yellow);   
      set_pen_width(width/10);   
      draw_point(width/10,height/10);   
      block1(width*0.5-width/20, height, width*0.5+width/20, height, height/5, 0, width/10, 0); 
}