About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 15 years
old) and has a wealth of features making it an ideal
choice to show charts on your website.
Download
Get the latest version of RGraph (version 6.17) from
the download page. There's also older versions available,
minified files and links to cdnjs.com hosted libraries.
License
RGraph can be used for free under the GPL or if
that doesn't suit your situation there's an
inexpensive (£99) commercial license available.The shadowBlur property
This sets the amount of blurring that the shadow has. In conjunction with the
clip
function and setting the offset X/Y values
to zero you can achieve inner shadows:
- Draw a shape
- Clip the
canvas
to that shape - Draw an outline of that shape just outside the clipped area with shadow enabled
- Set the shadow X/Y offsets to 0
- Half the shadow will fall inside the clipped area and will thus be drawn on your
canvas
An example
<script>
window.onload = function ()
{
var canvas = document.getElementById("cvs");
var context = canvas.getContext('2d');
var x = 50;
var y = 50;
var width = 100;
var height = 100;
context.shadowColor = '#ccc';
context.shadowOffsetX = 3;
context.shadowOffsetY = 3;
context.shadowBlur = 25;
context.fillStyle = 'red';
context.fillRect(x, y, width, height);
}
</script>