Mouse over the below area
The Code:
<!DOCTYPE HTML>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
</style>
</head>
<body>
<canvas id="myCanvas" width="640" height="480"></canvas>
<script>
function writeMessage(canvas, message)
{
var context = canvas.getContext('2d');
// Could just clear the canvas, but to see when you leave the area it needs to be more visible
// context.clearRect(0, 0, canvas.width, canvas.height);
context.globalCompositionOperation = "source-over";
context.fillStyle = "cyan";
context.fillRect(0, 0, canvas.width, canvas.height);
context.font = '18pt Calibri';
context.fillStyle = 'black';
context.fillText(message, 10, 25);
}
function getMousePos(canvas, evt)
{
var rect = canvas.getBoundingClientRect();
return {
x: Math.round( (evt.clientX-rect.left)/(rect.right-rect.left)*canvas.width ),
y: Math.round( (evt.clientY-rect.top)/(rect.bottom-rect.top)*canvas.height )
};
}
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
canvas.addEventListener('mousemove', function(evt)
{
var mousePos = getMousePos(canvas, evt);
var message = 'Mouse position: ' + mousePos.x + ',' + mousePos.y;
writeMessage(canvas, message);
}, false);
</script>
</body>
</html>
<html>
<head>
<style>
body {
margin: 0px;
padding: 0px;
}
</style>
</head>
<body>
<canvas id="myCanvas" width="640" height="480"></canvas>
<script>
function writeMessage(canvas, message)
{
var context = canvas.getContext('2d');
// Could just clear the canvas, but to see when you leave the area it needs to be more visible
// context.clearRect(0, 0, canvas.width, canvas.height);
context.globalCompositionOperation = "source-over";
context.fillStyle = "cyan";
context.fillRect(0, 0, canvas.width, canvas.height);
context.font = '18pt Calibri';
context.fillStyle = 'black';
context.fillText(message, 10, 25);
}
function getMousePos(canvas, evt)
{
var rect = canvas.getBoundingClientRect();
return {
x: Math.round( (evt.clientX-rect.left)/(rect.right-rect.left)*canvas.width ),
y: Math.round( (evt.clientY-rect.top)/(rect.bottom-rect.top)*canvas.height )
};
}
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
canvas.addEventListener('mousemove', function(evt)
{
var mousePos = getMousePos(canvas, evt);
var message = 'Mouse position: ' + mousePos.x + ',' + mousePos.y;
writeMessage(canvas, message);
}, false);
</script>
</body>
</html>