/*move by wooksang 4/29*/
#include "rmannotes.sl"
surface 
crosstile()
{
  color surface_color, layer_color;
  color surface_opac, layer_opac;
  float ss, tt;
  float col, row;
  float fuzz = 0;
  float freq=7;


/*background color*/
  surface_color=(0.9, 0.1, 0.1); /*red*/
  surface_opac=Os;

/*coordinate, making numbers*/
   
  ss=repeat(s,freq);
  tt=repeat(t,freq);
  col=whichtile(t, freq);
  row=whichtile(s, freq);
if (even(row)&&even(col))||(odd(row)&&odd(col))
{
/*verticle*/
  layer_color=(0.2,0.1,0.3);  /*green*/
  surface_color=(0.2,0.1,0.3);
}
Oi=surface_opac;
Ci=surface_color;

}