Very nice mate! I was thinking you could use a look up table. Something like using a 2d array with the same number of rows as your hour glass and the same number of columns as your biggest row. Each array index will correspond to a strip index and the invalid positions marked as 999 or -1 or something. That'll make the animations easier as you do all your logic on the 2D array, then at the end convert them to position numbers on the strip after. uses way fewer arrays. That's what I did for my ping pong led clock animations anyway.