Fabric.js | Ellipse rotatingPointOffset Property

Last Updated : 25 Jun, 2020

In this article, we are going to see how to set the rotating point offset of a canvas ellipse using FabricJS so that the aspect ratio of the object is maintained. The canvas means ellipse is movable and can be stretched according to requirement. Further, the ellipse can be customized when it comes to initial stroke color, fill color, stroke width, or radius.

To make it possible we are going to use a JavaScript library called FabricJS. After importing the library using CDN, we will create a canvas block in the body tag which will contain our ellipse. After this, we will initialize instances of Canvas and Ellipse provided by FabricJS and set the rotating point offset of the canvas ellipse using rotatingPointOffset property and render the Ellipse on the Canvas as given in the example below.

Syntax:

fabric.Ellipse({
    rx: number,
    ry: number,
    rotatingPointOffset: number
});

Parameters: This function accepts three parameters as mentioned above and described below:

rx: It specifies the horizontal radius.
ry: It specifies the vertical radius.
rotatingPointOffset: This parameter specifies the rotating point offset.

Example: This example uses FabricJS to set rotating point offset of a canvas ellipse.

<!DOCTYPE html> 
<html> 
  
<head> 
    <title>  
        Fabric.js | Ellipse rotatingPointOffset Property 
    </title> 
  
    <!-- FabricJS CDN -->
    <script src= 
"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js"> 
    </script> 
</head> 
  
<body> 
    <div style="text-align: center;width: 600px;"> 
        <h1 style="color: green;"> 
            GeeksforGeeks 
        </h1> 
        <b> 
            Fabric.js | Ellipse rotatingPointOffset Property 
        </b> 
    </div> 
  
    <div style="text-align: center;"> 
    <canvas id="canvas" width="600" height="200" 
            style="border:1px solid #000000;"> 
    </canvas> 
    </div> 
  
    <script> 
        // Initiate a Canvas instance 
        var canvas = new fabric.Canvas("canvas"); 
  
        // Initiate a Ellipse instance 
        var ellipse = new fabric.Ellipse({ 
            rx: 80, 
            ry: 40, 
            rotatingPointOffset: 100 
        }); 
  
        // Render the Ellipse in canvas 
        canvas.add(ellipse); 
    </script> 
</body> 
  
</html>                    