Fabric.js Circle strokeUniform Property

Last Updated : 25 Jan, 2021

In this article, we are going to see how to set the uniform stroke width of a canvas Circle using FabricJS so that width of the stroke remains the same even when we scale the object to a bigger size. The canvas means 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 size.

Approach:

To make it possible we are going to use a JavaScript HTML5 canvas 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 lock uniform stroke width of the canvas Circle using strokeUniform property and render the Circle on the Canvas as given in the example below.

Syntax:

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

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

radius: It specifies the radius of the circle.
strokeUniform: It specifies whether to lock uniform stroke width.

Example: This example uses FabricJS to lock the uniform stroke width of the canvas Circle.

HTML

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        Fabric.js Circle strokeUniform Property 
    </title> 
  
    <!-- FabricJS CDN -->
    <script src= 
"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js"> 
    </script> 
</head> 
  
<body> 
    <h1 style="color: green;"> 
        GeeksforGeeks 
    </h1> 
  
    <h3> 
        Fabric.js Circle strokeUniform Property 
    </h3> 
  
    <canvas id="canvas" width="600" height="300"
        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: 100, 
            fill: '', 
            stroke: 'green', 
            strokeUniform: true, 
            strokeWidth: 3 
        }); 
  
        // Render the circle in canvas  
        canvas.add(circle); 
        canvas.centerObject(circle); 
    </script> 
</body> 
  
</html>