JS dibuja cuadrado a lienzo
// canvas context.fillRect(x, y, height, width);
ctx.fillRect(20, 20, 150, 100);
Glamorous Goldfinch
// canvas context.fillRect(x, y, height, width);
ctx.fillRect(20, 20, 150, 100);// canvas context.fillRect(x, y, width, height);
ctx.fillRect(20, 20, 150, 100);It is open sorce javascript library for building UI<html>
<head>
<meta charset="UTF-8">
<title>Pong</title>
<script language="Javascript" type="text/Javascript" src="libraries/p5.js"></script>
<script language="Javascript" type="text/Javascript" src="pong.js" defer></script>
<style> body {padding: 0; margin: 0;} </style>
</head>
<body>
<canvas id="pong" width="600" height="400"></canvas>
</body>
</html>