About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 17 years
old) and has a wealth of features making it an ideal
choice to use for showing charts on your website.
Version 7.01 released
Version 7.01 (released in October 2025) is the
latest version of RGraph and now includes a new tree
structure object. The accompanying Treemenu object can then turn
the object into a fully dynamic tree menu.
You can read the API documentation for the tree on
the main API documentation page
and see an example of the Treemenu
feature by following this link...
New HTML datagrid
In the April 2025 (v6.21) release a new datagrid object
was added.
This makes it easy to add static or dynamic data
tables to your pages. It can be used whether you use the
canvas or SVG libraries or entirely standalone.
Download
Get the latest version of RGraph (version 7.01, 8th October 2025) from
the download page. You can read the changelog here. 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 (£129) commercial license available.The roundRect function
The roundRect function is used to draw a rectangle to the canvas which has rounded corners. Nothing is actually drawn to the canvas until you call either the stroke or fill function.
Arguments to the function
- The x-axis coordinate (of the top left of the rectangle)
- The y-axis coordinate (of the top left of the rectangle)
- The width of the rectangle
- The height of the rectangle
-
Either a number or an array of numbers
controlling the extent of the rounding. This can be:
- A single number. This number is used as the rounding radius for all four corners.
- An array containing a single number. This number is used as the rounding radius for all four corners.
- An array of two numbers. In this case the first number stipulates the rounding radius for the top-left/bottom-right corners and the second number stipulates the rounding radius for the top-right/bottom-left corners.
- An array of three numbers. In this case the first number controls the rounding radius for the top-left corner. The second number controls the radius for the top-right and bottom-left corners. And the third number controls the radius of the bottom-left corner.
- An array of four numbers. In this case each number controls the rounding of each corner - top-left, top-right, bottom-right and bottom-left.
An example
<script>
window.onload = function ()
{
var canvas = document.getElementById("cvs");
var context = canvas.getContext('2d');
context.beginPath();
context.roundRect(50, 50, 100, 100, 10);
context.roundRect(200, 50, 100, 100, [10]);
context.roundRect(350, 50, 100, 100, [10,20]);
context.roundRect(500, 50, 100, 100, [10,20,30]);
context.roundRect(650, 50, 100, 100, [10,20,30,40]);
context.stroke();
}
</script>