precision highp float;
uniform vec2 resolution;
uniform vec2 mouse;
uniform float time;
uniform sampler2D backbuffer;
out vec4 outColor;
/*
classic (300 es)
20秒
Mouse 🈶
*/
mat2 rot(float a){float c=cos(a),s=sin(a);return mat2(c,-s,s,c);}
void main()
{ 
   vec2 r=resolution,uv=(gl_FragCoord.xy*2.-r)/min(r.x,r.y)+(mouse-.5);
    vec3 col = vec3(0.);
    float aa=0.,rnd;
        vec3 p,d=normalize(vec3(uv,1.-(.8-tanh(.5*sin(time+.1*dot(sin(floor(uv*9.5)),cos(floor(uv.yx*7.))))*25.+uv.x))*.8*sqrt(length(uv*.8))));
        float g=0.;
        float bpm = floor(time)+pow(fract(time),.7-.1*fract(542.4*sin(dot(uv,vec2(243.4,578.4525)))));
        bpm*=5.;
      
        for(float i=0.,e;i++<20.;){for(aa=0.;aa++<3.;){
            vec3 p = d*g;
            vec3 oop=p;
            p.z +=time;
            float path =(1.-tanh(1.-abs(p.x-sin(p.z*.5)*2.1+cos(p.z*.3)*.37)));
            vec3 op=p;
            p.y = -(abs(p.y)+(.5+asin(sin(p.z))*.25))+path;
            p.y -= -2.5;
             float qq=sign(p.y);
               p.y = abs(p.y)-1.05;
               if(qq < 0.)p.xz *=rot(.785);
            vec2 id = floor(p.xz);
            p.xz = fract(p.xz)-.5;
            float h =min(length(p.yz),length(p.xy))-.012;
            g+=e=max(.001,abs(h)*.6);
            float q = e<=.021 ?length(asin(sin((mod(time,6.28*2.)>6.28 ? length(id):0.)+oop.xz*.25+vec2(asin(sin(bpm*.5))-path,bpm*1.)+rnd)))*2. :.5;
            col+=max(vec3(0.),vec3(1.)*.75/exp(.25*i*i*e+q));
        }
      }
      col = mix(col/aa,vec3(.1,.1,.25),.75-exp2(-g));
  outColor=vec4(col,1.0);
}