#define S 83.0
#define D 68.0
#define C 67.0
#define T 84.0
#define Y 89.0
#define F 70.0

#define SDCTYF (S+D+C+T+Y+F)
#define PI 3.14159265359

#define jitter ((tan(iTime)+iTime*10.0)/10.0)
//#define iTime ((tan(iTime)+iTime*10.0)/10.0)
#define iTime iTime*.5
vec3 mod289(vec3 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 mod289(vec4 x) {
  return x - floor(x * (1.0 / 289.0)) * 289.0;
}

vec4 permute(vec4 x) {
     return mod289(((x*34.0)+1.0)*x);
}

vec4 taylorInvSqrt(vec4 r)
{
  return 1.79284291400159 - 0.85373472095314 * r;
}

float snoise(vec3 v)
  {
  const vec2  c = vec2(1.0/6.0, 1.0/3.0) ;
  const vec4  d = vec4(0.0, 0.5, 1.0, 2.0);

// First corner
  vec3 i  = floor(v + dot(v, c.yyy) );
  vec3 x0 =   v - i + dot(i, c.xxx) ;

// Other corners
  vec3 g = step(x0.yzx, x0.xyz);
  vec3 l = 1.0 - g;
  vec3 i1 = min( g.xyz, l.zxy );
  vec3 i2 = max( g.xyz, l.zxy );

  //   x0 = x0 - 0.0 + 0.0 * C.xxx;
  //   x1 = x0 - i1  + 1.0 * C.xxx;
  //   x2 = x0 - i2  + 2.0 * C.xxx;
  //   x3 = x0 - 1.0 + 3.0 * C.xxx;
  vec3 x1 = x0 - i1 + c.xxx;
  vec3 x2 = x0 - i2 + c.yyy; // 2.0*C.x = 1/3 = C.y
  vec3 x3 = x0 - d.yyy;      // -1.0+3.0*C.x = -0.5 = -D.y

// Permutations
  i = mod289(i);
  vec4 p = permute( permute( permute(
             i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
           + i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
           + i.x + vec4(0.0, i1.x, i2.x, 1.0 ));

// Gradients: 7x7 points over a square, mapped onto an octahedron.
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
  float n_ = 0.142857142857; // 1.0/7.0
  vec3  ns = n_ * d.wyz - d.xzx;

  vec4 j = p - 49.0 * floor(p * ns.z * ns.z);  //  mod(p,7*7)

  vec4 x_ = floor(j * ns.z);
  vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)

  vec4 x = x_ *ns.x + ns.yyyy;
  vec4 y = y_ *ns.x + ns.yyyy;
  vec4 h = 1.0 - abs(x) - abs(y);

  vec4 b0 = vec4( x.xy, y.xy );
  vec4 b1 = vec4( x.zw, y.zw );

  //vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
  //vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
  vec4 s0 = floor(b0)*2.0 + 1.0;
  vec4 s1 = floor(b1)*2.0 + 1.0;
  vec4 sh = -step(h, vec4(0.0));

  vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
  vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;

  vec3 p0 = vec3(a0.xy,h.x);
  vec3 p1 = vec3(a0.zw,h.y);
  vec3 p2 = vec3(a1.xy,h.z);
  vec3 p3 = vec3(a1.zw,h.w);

//Normalise gradients
  vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
  p0 *= norm.x;
  p1 *= norm.y;
  p2 *= norm.z;
  p3 *= norm.w;

// Mix final noise value
  vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
  m = m * m;
  return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1),
                                dot(p2,x2), dot(p3,x3) ) );
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
	vec2 uv = fragCoord.xy / iResolution.xy*2.0-1.0;
    uv.x *= iResolution.x/iResolution.y;

    float count = 7.0+cos(iTime)*5.0;

	float sum = 0.;

    for(float i = 0.0; i < 100.0; i+=1.0)
    {
        if(i > count)
            break;

        float theta = float(i)/float(count)*PI*2.0+iTime;
        vec2 p1 = vec2(cos(theta), sin(theta))*.75;

        float radialCount = 7.0+cos(iTime/PI)*5.0;

        for(float j = 0.0; j < 100.0; j+=1.0)
        {
        	float theta2 = float(j)/float(radialCount)*PI*2.0-iTime*2.0;
            vec2 p2 = p1+vec2(cos(theta2), sin(theta2));

            if(j > radialCount)
                break;

            float d =
                    (p2.y-p1.y)*uv.x-
                    (p2.x-p1.x)*uv.y+
                    p2.x*p1.y-p2.y*p1.x/
                    length(p2-p1);
            float maxd = 10./max(iResolution.x,iResolution.y);

            if(abs(d) < maxd)
            {
                sum += (cos(d/maxd*PI/2.0));
            }
        }
    }
    fragColor = vec4((cos(iTime*PI+length(uv.xy)*PI+sum*PI/2.+vec3(0., 4.*PI/3.,2.*PI/3.))*.5+.5)*clamp(sum,0., PI), 1.0);
}