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How to draw a hexagon with Polygon using FabricJS?
We can create a Polygon object by creating an instance of fabric.Polygon. A polygon object can be characterized by any closed shape consisting of a set of connected straight line segments. Since it is one of the basic elements of FabricJS, we can also easily customize it by applying properties like angle, opacity etc.
Syntax
new fabric.Polygon( points: Array, options: Object )
Parameters
points ? This parameter accepts an Array which denotes the array of points that make up the polygon object.
options (optional) ? This parameter is an Object which provides additional customizations to our object. Using this parameter origin, stroke width and a lot of other properties can be changed related to the Polygon object.
Example 1: Default Appearance of Polygon Object
Let's see a code example of how we can draw any general polygon object. We need to specify an array of points where each point is an object with x and y. Specifying the array of points is crucial without which our polygon object would not be rendered onto the canvas. We can also customize the polygon object by using various properties. Here, we have customized our polygon object by assigning fill colour, stroke colour and setting the strokeWidth to 2.
<!DOCTYPE html>
<html>
<head>
<!-- Adding the Fabric JS Library-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
<h2>Default appearance of polygon object</h2>
<p>You can see that a polygon object has been added to the canvas</p>
<canvas id="canvas"></canvas>
<script>
// Initiate a canvas instance
var canvas = new fabric.Canvas("canvas");
canvas.setWidth(document.body.scrollWidth);
canvas.setHeight(250);
// Initiate a polygon instance
var polygon = new fabric.Polygon(
[
{ x: 500, y: 20 },
{ x: 550, y: 60 },
{ x: 550, y: 200 },
{ x: 350, y: 200 },
{ x: 350, y: 60 },
{ x: 500, y: 20 },
],
{
fill: "black",
stroke: "blue",
strokeWidth: 2,
}
);
// Adding it to the canvas
canvas.add(polygon);
</script>
</body>
</html>
Example 2: Drawing a Hexagon using Polygon
Let's see a code example to see how we draw a hexagon using polygon. We can draw many types of hexagons, however, in this example we will demonstrate the procedure to draw a regular hexagon. We know that a regular hexagon has six equal sides and all interior angles are 120 degrees.
<!DOCTYPE html>
<html>
<head>
<!-- Adding the Fabric JS Library-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
<h2>Drawing a Hexagon using Polygon</h2>
<p>You can see a hexagon object has been added to the canvas</p>
<canvas id="canvas"></canvas>
<script>
// Initiate a canvas instance
var canvas = new fabric.Canvas("canvas");
canvas.setWidth(document.body.scrollWidth);
canvas.setHeight(250);
// Initiate a polygon object
var hexagon = new fabric.Polygon(
[
{ x: 50, y: 0 },
{ x: 25, y: 43.30},
{ x: -25, y: 43.301 },
{ x: -50, y: 0},
{ x: -25, y: -43.301},
{ x: 25, y: -43.301 },
],
{
fill: "red",
left: 140,
top: 10,
}
);
// Adding it to the canvas
canvas.add(hexagon);
</script>
</body>
</html>
Understanding Hexagon Coordinates
The hexagon coordinates are calculated using trigonometry. For a regular hexagon with radius 50, each vertex is positioned at 60-degree intervals around a center point. The y-coordinates use the value 43.301 which is approximately 50 * sin(60°) = 50 * ?3/2.
Customization Options
You can customize your hexagon using various FabricJS properties:
- fill - Background color of the polygon
- stroke - Border color
- strokeWidth - Border thickness
- left/top - Position on canvas
- angle - Rotation angle
- opacity - Transparency level
Conclusion
Creating a hexagon with FabricJS Polygon requires defining six coordinate points that form the hexagon's vertices. The key is calculating the proper coordinates using trigonometry for a regular hexagon, then customizing appearance with fill, stroke, and positioning properties.
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