// Bonfire [458] by bµg
// License: CC BY-NC-SA 4.0
#define r(a)*=mat2(cos(a+vec4(0,33,11,0))),
void main(){float i,t,a,n,w,o,d=1.;for(vec3 p,q,k;i++<5e1&&d>.001;o+=d>n?d=abs(n)*.4+.05,1./d:exp(3.-length(k)*.6),t+=d*.5)for(k=normalize(vec3(P+P-R,R.y))*t,d=k.y+=6.,k.z-=15.,w=.0025,a-=a,n=.96*length(k.xz)+.27*d-5.34;a++<9.;w+=w)p=k,p.zx r(a*2.4)q=p,q.y-=a*T,n+=abs(dot(sin(q*.7/w),q-q+w)),p.z-=5.,p.zy r(atan(a*.18))d=min(d,max(abs(p.z+5.)-5.,max(abs(p.x)*.9+p*.5,-p).y-.3));O=vec4(tanh(o*vec3(9,3,1)/5e2),1);}