/* Shader description goes here */
surface
maya_pattern(float	Kfb = 1,
					inv_circle_size = .03,
					black_circle_size = .01,
					repeats = 7,
					left_right = .5,
					up_down = .5;
			color 	stripe = color(0,0,1),
					background_color = color(1,0,0),
					dot = color(0,0,0))
{
color	surfcolor = .4;
normal n = normalize(N);
normal nf = faceforward(n, I);

/* STEP 1 - set the apparent surface opacity */
Oi = Os;

// Do the lighting (copy is in dropbox). Diff can be called whatever.
color diff = diffuse(nf);

/* Diagonal patterns */
float j;
float swap = 0;
float decr = 1.0/repeats;

for(j = 1; j >= 0; j = j - decr)
	{
	if ( s + j >=  1 - t)
		{
		if(swap == 0) {
			surfcolor = stripe;
			swap = 1;
			}
		else
			{
			surfcolor = background_color;
			swap = 0;
			}
		}
	if ( s - j >=  1 - t)
		{
		if(swap == 0) {
			surfcolor = background_color;
			swap = 1;
			}
		else
			{
			surfcolor = stripe;
			swap = 0;
			}
		}
	}
	

/* First circle set */
if(((s-left_right)*(s-left_right))+((t-up_down)*(t-up_down))<inv_circle_size) 
	surfcolor = background_color;

if(((s-left_right)*(s-left_right))+((t-up_down)*(t-up_down))<black_circle_size) 
	surfcolor = dot;
	

/* Second circle set */
/*if(((s-.5)*(s-.5))+((t-.5)*(t-.5))<inv_circle) */
/*	surfcolor = color(s,0,0);*/

/*if(((s-.5)*(s-.5))+((t-.5)*(t-.5))<black_circle) */
/*	surfcolor = color(0,0,0);*/

	

/* STEP 2 - calculate the apparent surface color */
// OLD Ci = Oi * Cs * surfcolor * Kfb;
Ci = Oi * Cs * surfcolor * Kfb * diff;
}