Introduction

Greeting, today we are going to make a scrolling background effect. This script will move the background of any html tag, either vertically or horizontally. I used this script in one of my project which has a blue sky with clouds and it makes the whole website came alive. I think that's pretty impressive.

In this tutorial, we're not only go through how to make it, we will have it in plugin as well which allow user to customize the speed of the movement and direction (vertically, horizontally and diagonally). Alright, the concept behind this animation is really simple. We will use the background-position attribute to move the background, very easy right?

1. HTML

There is nothing about HTML. Basically we will put the background image in the cloud div and animate the background image.

2. CSS

I think, from all of my tutorial, this would be the shortest and simplest CSS code.

body {
	margin:0;
	padding:0;
	background:#fff; 	
}

.clouds {
	width:300px; 
	height:300px; 
	margin:10px; 
	border:2px solid #ccc;
	background:#3e83c8 url(images/bg_clouds.png) repeat-x 0 bottom; 
}

3. Javascript

Alright, this is the part that makes everything alive! We will make it more configurable. We can adjust the speed and the direction. Of course, to make sure you understand what it does, I have put comments in each line of code.

$(document).ready(function () {
    // speed in milliseconds
	var scrollSpeed = 70;

	// set the direction
	var direction = 'h';

	// set the default position
	var current = 0;

	function bgscroll(){

    	// 1 pixel row at a time
	    current -= 1;
   
	    // move the background with backgrond-position css properties
	    $('div.clouds').css("backgroundPosition", (direction == 'h') ? current+"px 0" : "0 " + current+"px");
   
	}

	//Calls the scrolling function repeatedly
	var init = setInterval("bgscroll()", scrollSpeed);	
});

4. The Plugin

I'm not an expert in creating plugins but thanks to my friend from web developer juice, with his amazing skill, he managed to convert the whole script in a very short time and here is the code. He has got some interesting tutorials and articles as well. Make sure you check out his website. :)

(function() {
	$.fn.bgscroll = $.fn.bgScroll = function( options ) {
		
		if( !this.length ) return this;
		if( !options ) options = {};
		if( !window.scrollElements ) window.scrollElements = {};
		
		for( var i = 0; i < this.length; i++ ) {
			
			var allowedChars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
			var randomId = '';
			for( var l = 0; l < 5; l++ ) randomId += allowedChars.charAt( Math.floor( Math.random() * allowedChars.length ) );
			
				this[ i ].current = 0;
				this[ i ].scrollSpeed = options.scrollSpeed ? options.scrollSpeed : 70;
				this[ i ].direction = options.direction ? options.direction : 'h';
				window.scrollElements[ randomId ] = this[ i ];
				
				eval( 'window[randomId]=function(){var axis=0;var e=window.scrollElements.' + randomId + ';e.current -= 1;if (e.direction == "h") axis = e.current + "px 0";else if (e.direction == "v") axis = "0 " + e.current + "px";else if (e.direction == "d") axis = e.current + "px " + e.current + "px";$( e ).css("background-position", axis);}' );
														 
				setInterval( 'window.' + randomId + '()', options.scrollSpeed ? options.scrollSpeed : 70 );
			}
			
			return this;
		}
})(jQuery);

Usage

So, this is how you use it. Make sure you've included jQuery framework and the bgscroll plugin. It accepts two properties:

• scrollSpeed : speed of the movement
• direction : direction can be either "v", "h" or "d" (vertical, horizontal or diagonal)

$( function() {
	$('.clouds1').bgscroll({scrollSpeed:10 , direction:'h' });
	$('.clouds2').bgscroll({direction:'d'});
});

Conclusion

I hope the tutorial and plugin will be useful for you. If you really like this article and want to support me, please share it with your friends :) Thanks!