/* Pete Hriso  Assignment #5 part 1 */

#include "rmannotes.sl"

surface proceed1(float Ks=.5, Kd=.5, freq = 6,  fuzz = .05;
		 float   Ka=1, roughness=.1; color specularcolor=1)
     
		

{
  
  color test = color (.787, 0, 0);
  color blue = color (.242, 0, .682);
  color orchid  = color (.545, .278, .537);
  
  color green1  = color (0, 1, 0);
  color green2  = color (0, 1, .348);
  color lavender  = color (.513, 1, .513);
  color lavender2  = color (.124, .575, .124);

  color black = color (.2, .1, .3);
  color idont = color (.764, 0 , .567);
  color paper, ink;
  float paper_opac, ink_opac;
  float ss, tt;
  float row, col;
  point center, Nf, V;
  float radius;
  float d;
  float width;
  float disk, ring;
  color blood = spline(t,test, test, black ,blue, blue);
  color flood = spline(t,lavender, lavender, black, lavender2, lavender2 );
  
   /* paper */
  
  paper =  color (0, 0, 0);
  paper_opac = 1;


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

 

 
  /* layer #1 */
  
  ss = repeat(s, 4);
  tt = repeat(t, 4);
  center = (0.5, 0.5, 0);
  radius = 0.5;
  width = 0.2;
  d = distance(center, (ss, tt, 0));
  ring = pulse(radius - width / 2, radius + width / 2, fuzz, d);
  
  ink = mix(mix(lavender, green1, s),mix(lavender2, green2, s), t);
  ink_opac = ring * .6;
  paper = mix(paper, ink, ink_opac);

/* layer #2 */

  rotate2d(s, t, radians(45), 0.5, 0.5, ss, tt);
  
  ss = repeat(ss, freq);
  tt = repeat(tt, freq);
  col = whichtile(ss, freq);
  row = whichtile(tt, freq);
  if (even(row))
    ss = mod(s * freq + .5 , 1);
  else
    ss = repeat(ss, freq + .5);
   tt = repeat(tt, freq );
  
  ink = spline(t,green1, green1, lavender, green2, green2); 
  ink_opac = pulse(.35, .65, fuzz, ss);
  paper = mix(paper, ink, ink_opac);
 

  /* plastic illum for all layers */

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


  /* output! */
  
  Oi = paper_opac;
  Ci = paper_opac * paper;
  
}