motion/dist/utils/stagger.es.js

The Motion library for the web

import { getEasingFunction } from '../targets/js/easing/get-function.es.js';

function stagger(duration = 0.1, { start = 0, from = 0, easing } = {}) {
    return (i, total) => {
        const fromIndex = typeof from === "number" ? from : getFromIndex(from, total);
        const distance = Math.abs(fromIndex - i);
        let delay = duration * distance;
        if (easing) {
            const maxDelay = total * i;
            const easingFunction = getEasingFunction(easing);
            delay = easingFunction(delay / maxDelay) * maxDelay;
        }
        return start + delay;
    };
}
function getFromIndex(from, total) {
    if (from === "first") {
        return 0;
    }
    else {
        const lastIndex = total - 1;
        return from === "last" ? lastIndex : lastIndex / 2;
    }
}
function resolveOption(option, i, total) {
    return typeof option === "function"
        ? option(i, total)
        : option;
}

export { getFromIndex, resolveOption, stagger };