original post: https://redd.it/12pdskb
vec3 p,q=vec3(0,0,6),a,s=(FC.rgb*2.-r.xyx)/r.x;float w,d,i=0.;for(;i<80.;i++,q+=s*d)for(d=w=6.+t;w>t;w-=1.3){p=q;p.xz*=rotate2D(w);p.xy*=rotate2D(1.);for(a=abs(p);a.z<a.x||a.z<a.y;p=p.zxy,a=a.zxy);d=min(d,length(p.xz-vec2(p.y,1)*a.z/p.z)*.7-.07);}o.rgb=fw
tinycode by flockaroo
vec3 q=vec3(0,0,99),p,u,v;for(float w,d,i=0.;i++<80.;v=u,u=q,q+=(FC.rgb*2.-r.xyx)/r.x*d+vec3(sin(i),cos(i),0))for(d=w=6.;--w>0.;p=q,p.xz*=rotate2D(t+w/.8),p.xy*=rotate2D(1.),d=min(d,dot(p+sin(p)*.3,sign(p)*.3)-9.));o+=sign(.5-cross(q-u,q-v).y-fract(FC.x/9