const canvas = document.querySelector('#canvas'), ctx = canvas.getContext('2d') let dinoY = 140; function initCanvas() { canvas.width = canvas.clientWidth; canvas.height = canvas.clientHeight; ctx.fillStyle = 'lightgray'; ctx.fillRect(0, 0, canvas.width, canvas.height); } initCanvas(); window.onresize = initCanvas; function draw() { ctx.fillStyle = 'green'; ctx.fillRect(50, dinoY, 50, 70); ctx.fillStyle = 'black'; ctx.fillRect(0, 210, canvas.width, 1); requestAnimationFrame(draw); } draw(); function jump() { setInterval(() => { dinoY--; }, 0); } window.onkeydown = (e) => { jump(); };