Back property
Implementation
static Map<ETTypes,num Function(num,[num?])> Back = {
ETTypes.In:(amount,[power]) {
var s = 1.70158;
return amount == 1 ? 1 : amount * amount * ((s + 1) * amount - s);
},
ETTypes.Out:(amount,[power]) {
var s = 1.70158;
return amount == 0 ? 0 : --amount * amount * ((s + 1) * amount + s) + 1;
},
ETTypes.InOut:(amount,[power]) {
var s = 1.70158 * 1.525;
if ((amount *= 2) < 1) {
return 0.5 * (amount * amount * ((s + 1) * amount - s));
}
return 0.5 * ((amount -= 2) * amount * ((s + 1) * amount + s) + 2);
},
};