I was trying to put a canvas in a container. I wanted the canvas to have the same size as the container. To do this I used JQuery, however, this turned out to scale my canvas. This was not my intention, especially because I draw after resizing. Doing seemingly the same thing in good old fashion JavaScript gives me the expected result.
I personally did not expect the JQuery result and it took some time before I figured out the problem. Does anybody know why they opted for this implementation and why it gives a different result? I hope by sharing this I can save some people a lot of time!
Thanks for anybody willing to research this further of fix this!
Here is some example code:
<html>
<head>
<title>Canvas resizing</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<style type="text/css">
#container1{
background-color: green;
width: 100px;
height: 100px;
margin: 50px auto;
}
#container2{
background-color: red;
width: 100px;
height: 100px;
margin: 50px auto;
}
</style>
</head>
<body>
<div id="container1">
<canvas></canvas>
</div>
<div id="container2">
<canvas></canvas>
</div>
<script type="text/javascript">
function draw (canvas) {
var context=canvas.getContext("2d");
context.lineWidth = 5;
context.rect(25,25,50,50);
context.stroke();
}
$(document).ready(function () {
//javascript
var container = document.getElementById('container1');
var canvas = container.childNodes[1];
canvas.width = 100;
canvas.height = 100;
draw(canvas);
//jquery
var container = $('#container2');
var canvas = container.children()[0];
$(canvas).width(100);
$(canvas).height(100);
draw(canvas);
});
</script>
</body>
</html>
