text-measure-ref.html
<html>
<script>
function load() {
var ctx = document.getElementById("canvas").getContext("2d");
ctx.font = "bold 12px sans-serif";
ctx.scale(4, 4);
var str = "HeHeHeHe";
ctx.fillText(str, 0, 15);
}
</script>
<body onload="load();">
<canvas id="canvas" width="400" height="200"></canvas>
</body>
</html>
