We would like to know how to set pixel on Canvas.
<!-- w w w . j a va2s. c o m-->
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.9.1.js'></script>
<style type='text/css'>
canvas {
margin: 1em;
border: 1px solid #dddddd;
}
</style>
<script type='text/javascript'>//<![CDATA[
$(window).load(function(){
var element,
canvas,
width,
height,
red;
black = {
r: 0,
g: 0,
b: 0,
a: 255
};
// init canvas
element = $('#canvas').get(0);
canvas = element.getContext('2d');
width = element.width;
height = element.height;
canvas.fillStyle = '#eeeeee';
canvas.fillRect(0, 0, width, height);
// setpixel
var setPixel = function (x,y,c) {
var p=canvas.createImageData(1,1);
p.data[0]=c.r;
p.data[1]=c.g;
p.data[2]=c.b;
p.data[3]=c.a;
canvas.putImageData(p,x,y);
}
$('#canvas').on('click',
function (e) {
setPixel(e.offsetX, e.offsetY, black);
});
});//]]>
</script>
</head>
<body>
<p>Click to set pixel</p>
<canvas id='canvas' width='128' height='128'></canvas>
</body>
</html>
The code above is rendered as follows: