Script to make a flickering with increasing frequency (think tak ...... tak .... tak ... tak .. tak . takkkkk ). Useful for when a timing is ending. I used this algorithm in combination with a shader for our GMTK Game Jam 2021 Game "Cursed Leash" (https://st-phan.itch.io/cursed-leash)

index.html

<script>
	let counter = 0;
	setInterval(function(){
		counter += 0.03/8;
		counter = Math.min(1, counter);

		var y = Math.sin(counter * counter * counter * 80);
		var bool = true;
		if (y < 0) {
			document.body.style.background = "grey";
			bool = false;
		}else{
			document.body.style.background = "white";
		}

		console.log(counter, y);
	}, 30)
</script>