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<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<script>
function do_test() {
var canvas = document.getElementById("test");
var ctx = canvas.getContext("2d");
var g = ctx.createLinearGradient(0, 0, canvas.width, canvas.height);
g.addColorStop(0, "red");
g.addColorStop(1, "green");
ctx.fillStyle = g;
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.strokeStyle = "white";
ctx.font = "bold 24px sans-serif";
ctx.strokeText('globalAlpha = 1.0', 20, 40);
ctx.globalAlpha = 0.5;
ctx.strokeText('globalAlpha = 0.5', 20, 80);
ctx.globalAlpha = 0.2;
ctx.strokeText('globalAlpha = 0.2', 20, 120);
};
</script>
</head>
<body onload="do_test()">
<canvas id="test"></canvas>
</body>
</html>
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