#include "rmannotes.sl"

surface greeny(float Ka = 1, Kd = 0.5, Ks = 0.5, roughness = 0.1;
               color specularcolor = 1)
{
   color paper, ink;
   float opac;
   float fuzz = 0.3;
   float tile_s, tile_t;
   float line, circleone, circletwo, circlethree, circlefour;
   float line2, circle5, circle6, circle7, circle8, circle9;

   point Nf, V;

   Nf = faceforward(normalize(N), I);
   V = normalize(-I);  

   paper = color(.462, .933, 0);

   Oi = 1;

   tile_s = repeat(s, 10);
   tile_t = repeat(t, 10);

/*     blue fuzzy line down the middle     */

   line = pulse(tile_s, 0.2, 0.8, fuzz);

   ink = color(.067, .652, .674);   
   opac = line; 
   paper = mix(paper, ink, opac);   

/*          random circle stuff            */

   circleone = pulse(distance((tile_s, tile_t, 0), (0.3, 0.3, 0)), 0.00, 0.2,
                     fuzz = 0.02);
   circletwo = pulse(distance((tile_s, tile_t, 0), (0.45, 0.45, 0)), 0.00, 0.2,
                     fuzz = 0.02);    

   ink = color(0, .545, .270);
   opac =  difference(circleone, circletwo);
   opac *= 0.5;
   paper = mix(paper, ink, opac);

   circlethree = pulse(distance((tile_s, tile_t, 0), (0.7, 0.7, 0)),
                                 0.00, 0.2, fuzz = 0.02);

   ink = color(.462, .933, .270);
   opac = difference(circlethree, line);
   paper = mix(paper, ink, opac);

   circlefour = pulse(distance((tile_s, tile_t, 0), (0.5, 0.5, 0)), 0.2, 0.3,
                      fuzz = 0.02);

   ink = color (0, 1, .519);
   opac = difference (circletwo, circlefour);
   opac *= 0.5;
   paper = mix(paper, ink, opac); 

   circle5 = pulse(distance((tile_s, tile_t, 0), (0.3, 0.7, 0)), 0.0, 0.2,
                   fuzz = 0.02);
   circle6 = pulse(distance((tile_s, tile_t, 0), (0.7, 0.3, 0)), 0.0, 0.2, 
                   fuzz = 0.02); 
   circle7 = pulse(distance((tile_s, tile_t, 0), (0.6, 0.9, 0)), 0.0, 0.2, 
                   fuzz = 0.02); 
   circle8 = pulse(distance((tile_s, tile_t, 0), (0.9, 0.6, 0)), 0.0, 0.2, 
                   fuzz = 0.02);
   circle9 = pulse(distance((tile_s, tile_t, 0), (0.8, 0.8, 0)), 0.0, 0.2, 
                   fuzz = 0.02);


   line = pulse(tile_t, 0.45, 0.55, fuzz);

   rotate2d(tile_s, 2.3*tile_t, 45, 0.17, 0.17, tile_s, tile_t);
   line = pulse(tile_t, 0.45, 0.55, fuzz);
  
   ink = color(0, .237, .437);
   opac = difference(line, circle5);
   opac *= 0.4;
   paper = mix(paper, ink, opac);

   ink = color(.63, .97, 0);
   opac = union(circle5, circle6);
   opac *= 0.4;
   paper = mix(paper, ink, opac);

   tile_s = repeat(s, 10);
   tile_t = repeat(t, 10);

   ink = color(0, .63, .733);
   opac = intersection(circle7, circle9);
   opac *= 0.35;
   paper = mix(paper, ink, opac);

   Ci = Oi * (paper * (Ka * ambient() + Kd * diffuse(Nf)) +
              specularcolor * Ks * specular(Nf, V, roughness)); 
}