<!-- Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ --> <!doctype html> <html> <head> <meta charset="utf-8"/> <title>Canvas inspector test page</title> </head> <body> <canvas width="128" height="128"></canvas> <script type="text/javascript;version=1.8"> "use strict"; var ctx = document.querySelector("canvas").getContext("2d"); function drawRect(fill, size) { ctx.fillStyle = fill; ctx.fillRect(size[0], size[1], size[2], size[3]); } function drawScene() { ctx.clearRect(0, 0, 128, 128); drawRect("rgb(192, 192, 192)", [0, 0, 128, 128]); drawRect("rgba(0, 0, 192, 0.5)", [30, 30, 55, 50]); drawRect("rgba(192, 0, 0, 0.5)", [10, 10, 55, 50]); window.setTimeout(drawScene, 50); } drawScene(); </script> </body> </html>