Three.js How do I define variables and/or positions after a gsap position change

Basically, what im trying to do is, that I have three cubes, and on each click they switch positions. This works fine when done once. Now, I added 3 Lines in the end of the function called “rotWorld” like this:

var i1 = i3;
var i2 = i1;
var i3 = i2;

but i get errors all the time. How can I define the switches positions as new initial positions, to that the next time I click on the trigger, the objects will move again, making a full circle at 3 clicks?

Heres a fiddle:
https://jsfiddle.net/ung8qapd/1/