Checker Room Spin

https://www.dwitter.net/d/20170

with(x)for(fillRect(0,0,w=2e3,i=1080);i--;strokeRect(960-i,540-i,i*2,i*2))setLineDash([i]),strokeStyle=R(lineDashOffset=(w+i*t)%i-w,i,i/3)