How to add shadow to a canvas circle using Fabric.js ?

Last Updated : 12 May, 2020

In this article, we are going to see how to add shadow to 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 which will contain our circle. After this, we will initialize instances of Canvas and Circle provided by FabricJS and add shadow to the circle using shadow property and render the Circle on the Canvas as given in the example below.

Syntax:

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

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

radius: It specifies the radius.
shadow: It specifies the shadow object.

Example: This example uses FabricJS to add shadow to a canvas circle.

<!DOCTYPE html> 
<html> 
  
<head> 
    <title>  
        How to add shadow to a canvas 
        circle using FabricJS?  
    </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"); 
  
        // Create shadow object 
        var shadow = new fabric.Shadow({ 
            color: 'black', 
            blur: 30 
        }); 
  
        // Initiate a Circle instance 
        var circle = new fabric.Circle({ 
            radius: 50, 
            shadow: shadow 
        }); 
  
        // Render the circle in canvas 
        canvas.add(circle); 
    </script> 
</body> 
  
</html> 