var fn = `Math.min(${fn},-Math.min((X/${size})%1-1/3,2/3-(X/${size})%1))`
var fn = `Math.min(${fn},-Math.min(Math.min((Math.pow(3,${d})*X/${size})%1-1/3,2/3-(Math.pow(3,${d})*X/${size})%1),Math.min((Math.pow(3,${d})*Y/${size})%1-1/3,2/3-(Math.pow(3,${d})*Y/${size})%1)))`