<!DOCTYPE html>
<html>
<body>
This is a test should draw a fine filtered checkerboard pattern with no flickering. <br>
This is a regression test for https://bugs.webkit.org/show_bug.cgi?id=64321. <br>
<canvas id="c" width="300" height="300" style="width : 600px; height : 600px"></canvas>
<script type="text/javascript">
var canvas = document.getElementById('c');
var ctx = canvas.getContext('2d');

for (var x = 0; x < canvas.width; x++) {
    for (var y = 0; y < canvas.height; y++) {
        ctx.fillStyle = ((x + y) % 2) ? 'black' : 'white';
        ctx.fillRect(x, y, 1, 1);
    }
}

var imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);

function draw() {
    ctx.putImageData(imageData, 0, 0);
    window.setTimeout(draw, 0);
}

draw();
</script>
</body>
</html>