/* Paul Badger */


surface bub(float tile_no = 8)
{
float d, opac, rand, per, blend, sd;
float tile_s, tile_t, tileX, tileY;
color paper, ink,  color1, color2, color3, color4, layer1, layer2;
float fuzz = .02;

tile_s = mod( s * tile_no, 1);
tile_t = mod( t * tile_no, 1);
tileX = floor(s * tile_no);
tileY = floor(t * tile_no);

color1 = color(1.0, 1, 1);      /* yel */
color2 = color(0, 0, 0);  /* brown */ 
color3 = color(.04, .65, 1.0);  /* blue */
color4 = color(.35, .19, .6);  /* grape */
paper = color1;
ink = color2;
fuzz= .05;

per = mod(tileX, tile_no/5);
blend = tile_no/20;
sd = tile_no/10 +tile_no/20;

rand =(noise(tileX+.21, tileY + .37) * mod(tileX, tile_no/2)) 
      + ( 1 - mod(tileX * tileY, tile_no/2 ));  
    
/* mod( 3 * noise((tileX +.31),(tileY+.27)) * (tileX/tile_no), 1) ;*/
/* mod((sin(tile_no * tileX * 6.18/360) + 17*  noise(tileY + .27)), 5)/4 */
/* mod(tileX + 5 * sin(tileX*6.18/360)+7*tileY+17* noise(tileY+.27), 29)/28; */
/*   mod((tileX) + (tileY*5), 28)); */
/*  noise((tileX+.371)/2 , (tileY+.271) /2); */
/* mod (tileY*tileY + tileX * tileX, 40) / 39; */
/*  noise((tileX+.371)/2 , (tileY+.271) /2);  get values off integers) */

if (mod(tileX + tileY, 2) == 0)
  {
    if (rand  > 0.5)
      { 	
	paper = color2;
	ink = color1; 
 	opac = smoothstep(.5-fuzz, .5+fuzz , distance((tile_s, tile_t, 0), (0, 1, 0)) );  /* a  code */
	paper = mix(ink, paper,  opac);
	opac = smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 0, 0)) );
	paper = mix ( ink, paper, opac);
      }
    else	
      {
	opac = smoothstep(.5-fuzz, .5+fuzz,   distance((tile_s, tile_t, 0), (0, 0, 0)) );  /* b code */
	paper = mix(ink, paper,  opac);
	opac = smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 1, 0)) );
	paper = mix(ink, paper,  opac);
      }
  }
  else
    {
      if (rand > .5)
	{
	  opac =1-smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (0,1, 0)) );   /* c code */
	  paper = mix(paper, ink, opac);
	  opac =1-smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 0, 0)) );
	  paper = mix(paper, ink, opac);
      }
      else
	{
	  paper = color2;
	  ink = color1; 
 	  opac =1 -smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (0,0, 0)) );  /* d  code */
	  paper = mix(paper, ink,  opac);
	  opac =1 -smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 1, 0)) );
	  paper = mix(paper, ink,  opac);
	}	   
    }

layer1 = paper;

tileX *= 2;
tileY *= 2;

rand =  noise((tileX+.371)/2 , (tileY+.271) /2); /* layer2 */
       

ink = color3;
paper = color4;
fuzz = .3;

if (mod(tileX + tileY, 2) == 0)
  {
    if (rand  > 0.5)
      { 	
	paper = color3;
	ink = color4; 
 	opac = smoothstep(.5-fuzz, .5+fuzz , distance((tile_s, tile_t, 0), (0, 1, 0)) );  /* a  code */
	paper = mix(ink, paper,  opac);
	opac = smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 0, 0)) );
	paper = mix ( ink, paper, opac);
      }
    else	
      {
	opac = smoothstep(.5-fuzz, .5+fuzz,   distance((tile_s, tile_t, 0), (0, 0, 0)) );  /* b code */
	paper = mix(ink, paper,  opac);
	opac = smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 1, 0)) );
	paper = mix(ink, paper,  opac);
      }
  }
  else
    {
      if (rand > .5)
	{
	  opac =1-smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (0,1, 0)) );   /* c code */
	  paper = mix(paper, ink, opac);
	  opac =1-smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 0, 0)) );
	  paper = mix(paper, ink, opac);
      }
      else
	{
	  paper = color3;
	  ink = color4;
	  opac =1 -smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (0,0, 0)) );  /* d  code */
	  paper = mix(paper, ink,  opac);
	  opac =1 -smoothstep(.5-fuzz, .5+fuzz,  distance((tile_s, tile_t, 0), (1, 1, 0)) );
	  paper = mix(paper, ink,  opac);
	}	   
    }
layer2 = paper;
Ci = mix(layer1, layer2, .5);


}