vec3 erot(vec3 p,vec3 ax,float t){return mix(dot(ax,p)*ax,p,cos(t))+cross(ax,p)*sin(t);}
float rnd = 0.;
float bpm = 0.;
float box3(vec3 p,vec3 b){
    p = abs(p)-b;
    return length(max(vec3(0.),p))+min(0.,max(p.x,max(p.y,p.z)));
}
float box2(vec2 p,vec2 b){
    p = abs(p)-b;
    return length(max(vec2(0.),p))+min(0.,max(p.x,p.y));
}
vec2 sdf(vec3 p){
  vec3 op = p;
  vec2 h;
   p.x +=iTime;

  vec3 hp = p;
  hp.y -=2.;
   float d = 0.;
  for(float i=0.2;i<25.;hp=erot(hp,vec3(0.,1.,0.),i+=i)){

       d += abs(dot(asin(sin(hp*i)),vec3(.4)/i));
       hp=erot(hp,normalize(vec3(.1,.2,.3)),i);
  }    float txt = texture(iChannel0,fract(vec2(.05+floor(hp.x*10.)/100.))).r*.1;
     h.x = abs(p.y+2.)-d*.3-txt;

     h.x = max(abs(p.z-7.)-7.5,h.x);
     h.y = 1.;

     vec2 t;
    vec3 tp=p;

  tp.y +=1.+sin(p.z*.5+bpm+iTime)*.1;
   float q = sign(p.y);
   tp.xz = fract(tp.xz)-.5;
   tp =erot(tp,vec3(0.,1.,0.),sign(q)*.785);
   tp.y = abs(tp.y)-.05;
  t.x =max(abs(p.z)-5.5, min(length(tp.zy),length(tp.xy))-.01);
  t.y = 2.;
  h= t.x < h.x ? t:h;

    tp = p;

   tp.y = abs(tp.y)-1.75;
     tp = erot(tp,vec3(1.,0.,0.),bpm+p.x);
    tp = abs(tp)-.2;

     t.x = box2(tp.yz,vec2(.05));

     t.y = 3.;

    h= t.x < h.x ? t:h;



    tp = op;
    for(float j=0.;j<=8.;j++){
      vec3 ttp= tp;
      ttp.y +=sin(iTime+j+rnd*.01);
    ttp.x += tan(bpm+iTime+j+rnd*.01);
    ttp=erot(ttp,normalize(vec3(.0,.1,.2)),bpm);
     t.x = box3(ttp,vec3(.2));
     t.y = 1.+mod(j,3.);;
    h= t.x < h.x ? t:h;
       }


       tp=p;
       tp.y +=1.5;
       t.x = abs(tp.y)-.1;
       t.y = 4.;;

        h= t.x < h.x ? t:h;

  return h;
}

#define q(s) s*sdf(p+s).x

vec3 norm(vec3 p, float ee){vec2 e =vec2(-ee,ee);return normalize(q(e.xyy)+q(e.yxy)+q(e.yyx)+q(e.xxx));}
vec3 sun(vec2 p){
    float up = max(0.,p.y);
     float d = length(p)-.5;;
     float t = texture(iChannel0,fract(vec2(abs(floor(p.x*100.)/100.)))).r*.1;
     float bar = abs(abs(p.y+cos(p.x*5.+iTime)*.1)-.2-t)-.01;
     d = max(-bar,d);

     float glow = abs(.05/d);
     d = smoothstep(fwidth(d),0.,d);
     vec3 col = mix(vec3(.9,.9,.0),vec3(.9,.0,.9),sqrt(up));
    return col *d * up+glow*up*mix(col,1.-col,sin(atan(p.x,p.y)+iTime));
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = (fragCoord-.5*iResolution.xy)/iResolution.y;

    vec3 col = sun(uv);
  float beat = sqrt(texture(iChannel0,vec2(.3)).r);
     rnd = dot(sin(uv*700.),cos(uv.yx*500.))*.5;
     bpm=iTime;
  bpm = floor(bpm)+pow(fract(bpm),2.);
   vec3 ro = vec3(0.2+sin(bpm),1.,-3.+sin(iTime*.1)*2.),rt = vec3(0.,1.,0.);
  vec3 z = normalize(rt-ro);
  vec3 x = normalize(cross(z,vec3(0.,-1.,0.)));
  vec3 y = cross(z,x);
  vec3 rd = mat3(x,y,z)*normalize(vec3(uv,1.-(.3+floor(sin(bpm+rnd*.05)*5.)*.1)*sqrt(length(uv+rnd*.01))));
  vec3 rp = ro;
  vec3 light = vec3(1.,2.,9.);
  float dd =0.;
  vec3 acc = vec3(0.);
  bool ref= false;
  float dir = 1.;
  float IOR = 2.4;
  float i=0.;
  for(i=0.;i++<108. && dd < 50.;){
      vec2 d = sdf(rp);
    d.x  *=dir;
     if(d.y == 2.){

          acc += vec3(.9,.0,.9)*exp(-abs(d.x))/(60.-beat*40.+rnd);
          d.x = max(.002,abs(d.x));
      }

    dd+=d.x;
      rp+=rd*d.x;

      if(d.x < .001){


           vec3 n = norm(rp,.01);
         vec3 n2 = norm(rp,.03);
           float dif = max(0.,dot(normalize(light-rp),n));
           if(d.y == 3.){
              if(!ref){
                   rd = refract(rp,n,1./IOR);
                   rp+=-n+rd*.1;
                    acc+=dif*.1;
                ref = true;
                dir *=-1.;
              } else {

                vec3 _rd = refract(rp,n,IOR);
                if(dot(_rd,rd) ==0.){
                   rd = reflect(rp,-n);
                   rp+=rd*.1;
                } else {
                  rd=_rd;
                  rp+=n+rd*.1;
                   dir *=-1.;
                }
               }
              continue;

           } else if(d.y == 4.){

             rd = reflect(rd,n+rnd*.01);
              rp+=rd*.1;
             col =vec3(.1,.0,.2);
               continue;
             }
           float spc = pow(max(0.,dot(rd,reflect(normalize(light-rp),n))),32.);
           col = dif * vec3(.5)+ mix(vec3(.1),vec3(.3,.0,.9),spc*5.)*dif*step(.15,length(n-n2))*texture(iChannel0,vec2(.3)).r*1.;
           break;
        }
  }
  if(ref && dd >=50.){
    col = sun(rd.xy);
  }
  col = mix(vec3(.01),col,1.-exp(-i*i));

    // Output to screen
    fragColor = vec4(col+acc,1.0);
}