Canvas Parallax

This class will create a canvas element to draw a parallax background image

Example

Canvas Parallax Example on CodePen

Installation

npm i canvas-parallax

Usage

HTML

<section class="banner">
    <img src="https://example.com/image.png" alt="Banner Image" />
</section>

JavaScript

import CanvasParallaxController from 'canvas-parallax';

const banner = document.querySelector('.banner');
const image = banner.querySelector('img');

const CanvasParallax = new CanvasParallaxController({
    // The depth is the pixel movement of the image - 200 is 100px up and 100px down
    depth: 200,
});

Put the canvas into the document

banner.appendChild(CanvasParallax.canvas.element);

We can load image src URLs from the DOM

// The"50% 50%" is the main focus point of the image, it can be set to 0% 0% for top left hand corner or 100% 100% for bottom right hand corner etc.
CanvasParallax.load(image.src, "50% 50%");

Options

Option	Type	Description	Default
alpha	boolean	Whether or not the canvas needs to be cleared between each render.	false
depth	number	The depth of the parallax effect.	50
preload	boolean	Whether or not the class will pre-calculate all the positions of the parallax	true
throttle	number	The resize calculations throttle time in milliseconds.	100
precision	number	The precision of the parallax effect. (I'd suggest keeping this as low as possible, without seeing a stuttering parallax)	5

Callbacks

CanvasParallax.on('draw', () => {
    // Do something
});

CanvasParallax.on('resize', () => {
    // Do something
});

License

MIT