export function animate(func, duration) {
	console.assert(typeof func === "function", func);
	console.assert(duration > 0, duration);

	let start = NaN;
	function frame(timestamp) {
		if (isNaN(start))
			start = timestamp;
		else if (timestamp - start >= duration)
			return;

		func(timestamp - start);
		requestAnimationFrame(frame);
	}
	requestAnimationFrame(frame);
}



import {
	easeInOutQuad,
} from "js/Number.js";

export function smoothScroll(targetY, duration) {
	console.assert(!isNaN(targetY), targetY);
	console.assert(arguments.length < 2 || duration >= 0, duration);

	duration = duration || 0;

	let startY = window.scrollY();
	animate((progress) => {
		let y = easeInOutQuad(progress.value, startY, targetY - startY, duration);
		window.scroll(0, Math.round(y));
	}, duration);
}