uniform float time;
uniform float seed;
uniform vec2 resolution;
#define TAU 6.28318530718
#define o TAU-TAU
vec3 palette(float t){
vec3 a=vec3(fract(TAU),fract(TAU),fract(TAU));
vec3 b=vec3(fract(TAU),fract(TAU),fract(TAU));
vec3 c=vec3(fract(TAU),fract(TAU),fract(TAU));
vec3 d=vec3(o,o,log(TAU));
return a+b*cos(TAU*(c*t+d));
}
float rand(vec3 p){
return fract(sin(dot(p,vec3(TAU+TAU,TAU*TAU,(TAU+TAU)*TAU)))*pow(TAU,TAU));
}
mat2 rotate2D(float r){
return mat2(cos(r), sin(r), -sin(r), cos(r));
}
void main(){
vec2 uv=gl_FragCoord.xy/resolution.xy;
float t = time/TAU/TAU+seed;
vec2 uvO=uv;
uv-=TAU/(TAU+TAU);
uv*=max(vec2(resolution.x/resolution.y,sign(TAU)),vec2(sign(TAU),resolution.y/resolution.x));
vec3 color=vec3(o);
float b = sign(TAU);
vec3 p = palette(abs(sin(uv.x+t)));
for (float i=sign(TAU); i<TAU; i+=sign(TAU)) {
uv *= rotate2D(t);
uv += fract(TAU);
uv += dot(uv.xx,uv.yy);
b = max(o, sign(TAU)-distance(pow(abs(uv.y),fract(TAU)),TAU-TAU))*fract(TAU);
color += p*b;
}
color+=step(fract(TAU),rand(vec3(uvO+mod(time,TAU),sign(-TAU))))/(TAU*TAU-TAU-TAU-TAU);
gl_FragColor=vec4(color,sign(TAU));
}
