In this article, we are going to see how to set the opacity of a canvas Polyline using FabricJS. The canvas Polyline means the Polyline is movable and can be stretched according to requirements. Further, the Polyline can be customized when it comes to initial stroke color, shape, fill color, or stroke width.
To make it possible we are going to use a JavaScript library called FabricJS. After importing the library, we will create a canvas block in the body tag that will contain the Polyline. After this, we will initialize instances of Canvas and Polyline provided by FabricJS and set the opacity of the Polyline using opacity property, and render the Polyline on the Canvas as given in the example below.
Syntax:
var polyline = new fabric.Polyline(Points, {
opacity: number
});
Parameters: This property accepts a single parameter as mentioned above and described below:
- opacity: It is a number that specifies the opacity of the canvas polygon.
The below example illustrates the opacity property in Fabric.js:
Example:h
HTML
<!DOCTYPE html> <html> <head> <!-- Loading the FabricJS library --> <script src= </script> </head> <body> <div style="text-align: center;width: 600px;"> <h1 style="color: green;"> neveropen </h1> <b> Fabric.js | Polyline opacity Property </b> </div> <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 polyline 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, cornerStyle: 'circle', opacity: 0.5 }); // Render the polyline in canvas canvas.add(polyline); </script> </body> </html> |
Output:
