/*Marat Irner
SID 12952035
cs184-ad
*/ 
surface 
lab7     ( color circlecolor = color "rgb" (1.0, 0.0, 0.0);
	   color bgcolor = color "rgb" (1.0, 1.0, 1.0);
	   float radius = 0.35;
	   float column_count = 10.0;
	   float row_count = 10.0)
{
#define repeat(x,freq)    (mod((x) * (freq), 1.0))
#define blend(a,b,x) ((a) * (1 - (x)) + (b) * (x))
  point center;
  float disk;
  float ss, tt,d;
  color surface_color;
  float fuzz = 0.025;
  
  ss = repeat(s, column_count);
  tt = repeat(t, row_count);
  center = (0.5, 0.5, 0.0);
  d = distance(center, (ss, tt, 0));
  disk = 1 - smoothstep(radius - fuzz, radius, d);
  surface_color = blend(bgcolor, circlecolor, disk);
  Ci = surface_color;
}