<!DOCTYPE html>
<html>
<head>
<title>Canvas 2D global alpha test</title>
<style type="text/css">
body {
color: #fff;
}
canvas {
border-width: 1px;
border-style: solid;
border-color: #fff;
}
</style>
<script>
document.addEventListener("DOMContentLoaded", function() {
ctx = document.getElementById("foo").getContext("2d");
image = new Image(100, 100);
image.onload = drawImage;
image.src = "car.png";
function drawImage() {
ctx.drawImage(image, 0, 0, 400, 400);
}
var width = 200;
var height = 100;
ctx.globalAlpha = 0.4;
ctx.font = "100px serif";
ctx.fillText("hello friends", 50, 90);
for (var i = 0; i < 2; i++)
{
ctx.globalAlpha = 0.5;
ctx.fillStyle = 'red';
ctx.fillRect(10, 10, width, height);
ctx.globalAlpha = 0.6;
ctx.strokeStyle = 'blue';
ctx.strokeRect(10, 10, width, height);
ctx.scale(0.5, 0.5);
ctx.translate(10 + width * 2, 10 + height * 2);
}
});
</script>
</head>
<body>
<canvas id="foo" width="1000" height="1000"></canvas>
</body>
</html>