Canvas animation using Date.now()

by sungsoonz

HTML

<canvas id="canvas"></canvas>

CSS

#canvas {
  background: #999;
}

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

let startTime = Date.now();


function draw() {
	ctx.clearRect(0,0,canvas.width, canvas.height);
	let nowTime = (Date.now() - startTime) / 1000;
  let s = Math.sin(nowTime);
  let x = s * 100;
  
	ctx.beginPath();
  ctx.rect(x,0,40,40);
 	ctx.fill();
 
  requestAnimationFrame(draw);
}

draw();