YogeshChauhan . com

How to create bouncing balls using HTML canvas and JavaScript?

in HTML & JavaScript on May 2, 2021

HTML canvas is easy to use when creating some basic games. You can use it for different types of drawings for e.g. draw a linedraw a circle or even draw a text image.

Recently I was playing with canvas and wanted to make the bouncing balls effect using canvas and JavaScript Class. This was my goal.

HTML

Just one HTML canvas tag.

JavaScript

Just some basic code to get the canvas tag using ID. Also, setting the window’s border as the canvas borders using innerWidth and innerHeight methods. pos variable to set position of canvas and you can set the number of balls you want.

randomcolor function is just to get a random color and randomPos for setting the initial position of the balls randomly.

Here’s the code so far:

Creating a Class

Let’s create the JavaScript class to create number of objects later on. We’ll add a class with a constructor and creating and updating methods.

To draw the circle, we can use different HTML canvas methods.

Here’s a great tutorial on MDN to understand the bounce off the walls.

Creating an array

Now, let’s add an empty array and fill it with the number of balls specified in the numberOfBalls variable.

As, you can see the balls are printed on the canvas. We just need to create the animation.

Change the position of the balls

Using setInterval, we can call the update method for each ball in the array to update the position.

We need to use clearRect method to remove the older drawing from the canvas. What if you don’t? Try and see what happens.

Here’s the working demo and final code:

dreamhost

Most Read

#1 How to check if radio button is checked or not using JavaScript? #2 Solution to “TypeError: ‘x’ is not iterable” in Angular 9 #3 How to uninstall Cocoapods from the Mac OS? #4 How to add Read More Read Less Button using JavaScript? #5 How to Use SQL MAX() Function with Dates? #6 PHP Login System using PDO Part 1: Create User Registration Page

Recently Posted

May 5 Use inline if to make a shorter conditional syntax in React May 4 What is Conditional Rendering in React? May 3 How does @extend rule work in SCSS (Sass)? May 2 How different is Handling Events in React vs HTML DOM? May 2 How to create bouncing balls using HTML canvas and JavaScript? Apr 30 HTML canvas methods

You might also like these

What is Prototypal Inheritance in JavaScript?JavaScriptThe difference between Class declarations and Class expressions in JavaScriptJavaScriptA Quick Guide to Object-Oriented Programming in PHPPHPHow to add CurrencyPipe in TypeScript file in Angular 9 Project?AngularUnderstand Inheritance in PHP in this Basic Example (For Beginners)PHPHow to use PHPMailer to send an Email via Gmail SMTP Server?PHP