Fabric.js Polyline strokeUniform Property

Last Updated : 08 Feb, 2021

In this article, we are going to see how to lock the uniform stroke width of a canvas Polyline using FabricJS so that width of the stroke remains the same even when we scale the object to a bigger size. The canvas means the Polyline is movable and can be stretched according to the requirement. Further, the Polyline can be customized when it comes to initial stroke color, fill color, stroke width, or size.

The FabricJS JavaScript library is used for the above. After importing the library using CDN, we will create a canvas block in the body tag which will contain our Polyline. After this, we will initialize instances of Canvas and Polyline provided by FabricJS and lock the uniform stroke width of the canvas Polyline using strokeUniform property and render the Polyline on the canvas as given in the example below.

Syntax:

var polyline = new fabric.Polyline(Points, {  
   strokeUniform: string
 });

Parameters: This property accepts a single parameter as mentioned above and described below:

strokeUniform: When “false“, the stoke width will scale with the object. When “true”, the stroke will always match the exact pixel size entered for stroke width. The default value is “false”.

The below example illustrates the strokeUniform property in Fabric.js:

Example:

HTML

<!DOCTYPE html>  
<html>  
  <head>  
    <!-- Loading the FabricJS library -->
    <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 | Polyline strokeUniform Property  
      </b>  
    </div>  
    <canvas id="canvas"
            width="600"
            height="200"
            style="border:1px solid #000000;">  
    </canvas>  
  
    <script>  
  
      // Initiate a Canvas instance  
            var polyline = new fabric.Polyline([  
        {x: 200, y: 10 }, {x: 250, y: 50},  
        {x: 250, y: 180}, {x: 150, y: 180},  
        {x: 150, y: 50 }, {x: 200, y: 10 }],  
      {  
        stroke: 'green',   
        strokeWidth: 3,   
        fill: 'yellow', 
        strokeUniform: false,   
      });  
  
      // Render the polyline in canvas  
      canvas.add(polyline);  
    </script>  
  </body>  
</html>