svelte-scrolling/dist/shared/smoothScroll.js

Scroll to given elements with smooth animation

const currentPosition = (start, end, elapsed, duration, easing) => {
    if (elapsed > duration)
        return end;
    return start + (end - start) * easing(elapsed / duration);
};
const smoothScroll = async (options, callback) => {
    return new Promise((resolve) => {
        const { start, end, duration, easing } = options;
        const clock = Date.now();
        let step = () => {
            const elapsed = Date.now() - clock;
            const positionX = currentPosition(start.x, end.x, elapsed, duration, easing);
            const positionY = currentPosition(start.y, end.y, elapsed, duration, easing);
            callback({ x: positionX, y: positionY });
            if (elapsed > duration)
                return resolve();
            window.requestAnimationFrame(step);
        };
        window.addEventListener('wheel', function stopAnimation() {
            step = () => { };
            window.removeEventListener('wheel', stopAnimation);
        });
        window.requestAnimationFrame(step);
    });
};
export default smoothScroll;