Fabric.js | Circle cornerSize Property

Last Updated : 19 Jun, 2020

In this article, we are going to see how to scale the controlling corners of a canvas circle using FabricJS. The canvas means the circle is movable and can be stretched according to requirement. Further, the circle can be customized when it comes to initial stroke color, fill color, stroke width, or radius.

Approach: 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 that will contain our circle. After that, we will initialize instances of Canvas and Circle provided by FabricJS and scale controlling corners of the circle using cornerSize property and render the Circle on the Canvas as given in the example below.

Syntax:

fabric.Circle({
    radius: number,
    cornerSize: number
});

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

radius: It specifies the radius of circle.
cornerSize: It specifies the size of the controlling corners.

Example: This example uses FabricJS to scale controlling corners of a canvas circle. Note that you have to click on the object to see the corners.

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        Fabric.js | Circle cornerSize Property 
    </title> 
  
    <!-- FabricJS CDN -->
    <script src= 
"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js"> 
    </script> 
</head> 
  
<body> 
    <canvas id="canvas" width="600" height="200"
        style="border:1px solid #000000"> 
    </canvas> 
  
    <script> 
  
        // Initiate a Canvas instance 
        var canvas = new fabric.Canvas("canvas"); 
  
        // Initiate a Circle instance 
        var circle = new fabric.Circle({ 
            radius: 50, 
            cornerSize: 35 
        }); 
  
        // Render the circle in canvas 
        canvas.add(circle); 
    </script> 
</body> 
  
</body> 