/* Snowfall jquery plugin Version 1.5 Oct 5th 2011 Added collecting snow! Uses the canvas element to collect snow. In order to initialize snow collection use the following jQuery(document).snowfall({collection : 'element'}); element = any valid jquery selector. The plugin then creates a canvas above every element that matches the selector, and collects the snow. If there are a varrying amount of elements the flakes get assigned a random one on start they will collide. Version 1.4 Dec 8th 2010 Fixed issues (I hope) with scroll bars flickering due to snow going over the edge of the screen. Added round snowflakes via css, will not work for any version of IE. - Thanks to Luke Barker of http://www.infinite-eye.com/ Added shadows as an option via css again will not work with IE. The idea behind shadows, is to show flakes on lighter colored web sites - Thanks Yutt Version 1.3.1 Nov 25th 2010 Updated script that caused flakes not to show at all if plugin was initialized with no options, also added the fixes that Han Bongers suggested Developed by Jason Brown for any bugs or questions email me at loktar69@hotmail info on the plugin is located on Somethinghitme.com values for snow options are flakeCount, flakeColor, flakeIndex, minSize, maxSize, minSpeed, maxSpeed, round, true or false, makes the snowflakes rounded if the browser supports it. shadow true or false, gives the snowflakes a shadow if the browser supports it. Example Usage : jQuery(document).snowfall({flakeCount : 100, maxSpeed : 10}); -or- jQuery('#element').snowfall({flakeCount : 800, maxSpeed : 5, maxSize : 5}); -or with defaults- jQuery(document).snowfall(); - To clear - jQuery('#element').snowfall('clear'); */ (function(jQuery){ jQuery.snowfall = function(element, options){ var defaults = { flakeCount : 35, flakeColor : '#ffffff', flakeIndex: 999999, minSize : 1, maxSize : 2, minSpeed : 1, maxSpeed : 5, round : true, shadow : false, collection : false, collectionHeight : 40 }, options = jQuery.extend(defaults, options), random = function random(min, max){ return Math.round(min + Math.random()*(max-min)); }; jQuery(element).data("snowfall", this); // Snow flake object function Flake(_x, _y, _size, _speed, _id) { // Flake properties this.id = _id; this.x = _x; this.y = _y; this.size = _size; this.speed = _speed; this.step = 0; this.stepSize = random(1,10) / 100; if(options.collection){ this.target = canvasCollection[random(0,canvasCollection.length-1)]; } var flakeMarkup = jQuery(document.createElement("div")).attr({'class': 'snowfall-flakes', 'id' : 'flake-' + this.id}).css({'width' : this.size, 'height' : this.size, 'background' : options.flakeColor, 'position' : 'absolute', 'top' : this.y, 'left' : this.x, 'fontSize' : 0, 'zIndex' : options.flakeIndex}); if(jQuery(element).get(0).tagName === jQuery(document).get(0).tagName){ jQuery('body').append(flakeMarkup); element = jQuery('body'); }else{ jQuery(element).append(flakeMarkup); } this.element = document.getElementById('flake-' + this.id); // Update function, used to update the snow flakes, and checks current snowflake against bounds this.update = function(){ this.y += this.speed; if(this.y > (elHeight) - (this.size + 6)){ this.reset(); } this.element.style.top = this.y + 'px'; this.element.style.left = this.x + 'px'; this.step += this.stepSize; this.x += Math.cos(this.step); // Pileup check if(options.collection){ if(this.x > this.target.x && this.x < this.target.width + this.target.x && this.y > this.target.y && this.y < this.target.height + this.target.y){ var ctx = this.target.element.getContext("2d"), curX = this.x - this.target.x, curY = this.y - this.target.y, colData = this.target.colData; if(colData[parseInt(curX)][parseInt(curY+this.speed+this.size)] !== undefined || curY+this.speed+this.size > this.target.height){ if(curY+this.speed+this.size > this.target.height){ while(curY+this.speed+this.size > this.target.height && this.speed > 0){ this.speed *= .5; } ctx.fillStyle = "#fff"; if(colData[parseInt(curX)][parseInt(curY+this.speed+this.size)] == undefined){ colData[parseInt(curX)][parseInt(curY+this.speed+this.size)] = 1; ctx.fillRect(curX, (curY)+this.speed+this.size, this.size, this.size); }else{ colData[parseInt(curX)][parseInt(curY+this.speed)] = 1; ctx.fillRect(curX, curY+this.speed, this.size, this.size); } this.reset(); }else{ // flow to the sides this.speed = 1; this.stepSize = 0; if(parseInt(curX)+1 < this.target.width && colData[parseInt(curX)+1][parseInt(curY)+1] == undefined ){ // go left this.x++; }else if(parseInt(curX)-1 > 0 && colData[parseInt(curX)-1][parseInt(curY)+1] == undefined ){ // go right this.x--; }else{ //stop ctx.fillStyle = "#fff"; ctx.fillRect(curX, curY, this.size, this.size); colData[parseInt(curX)][parseInt(curY)] = 1; this.reset(); } } } } } if(this.x > (elWidth) - widthOffset || this.x < widthOffset){ this.reset(); } } // Resets the snowflake once it reaches one of the bounds set this.reset = function(){ this.y = 0; this.x = random(widthOffset, elWidth - widthOffset); this.stepSize = random(1,10) / 100; this.size = random((options.minSize * 100), (options.maxSize * 100)) / 100; this.speed = random(options.minSpeed, options.maxSpeed); } } // Private vars var flakes = [], flakeId = 0, i = 0, elHeight = jQuery(element).height(), elWidth = jQuery(element).width(), widthOffset = 0, snowTimeout = 0; // Collection Piece ****************************** if(options.collection !== false){ var testElem = document.createElement('canvas'); if(!!(testElem.getContext && testElem.getContext('2d'))){ var canvasCollection = [], elements = jQuery(options.collection), collectionHeight = options.collectionHeight; for(var i =0; i < elements.length; i++){ var bounds = elements[i].getBoundingClientRect(), canvas = document.createElement('canvas'), collisionData = []; if(bounds.top-collectionHeight > 0){ document.body.appendChild(canvas); canvas.style.position = 'absolute'; canvas.height = collectionHeight; canvas.width = bounds.width; canvas.style.left = bounds.left; canvas.style.top = bounds.top-collectionHeight; for(var w = 0; w < bounds.width/options.minSize; w+=options.minSize){ collisionData[w] = []; } canvasCollection.push({element :canvas, x : bounds.left, y : bounds.top-collectionHeight, width : bounds.width, height: collectionHeight, colData : collisionData}); } } }else{ // Canvas element isnt supported options.collection = false; } } // ************************************************ // This will reduce the horizontal scroll bar from displaying, when the effect is applied to the whole page if(jQuery(element).get(0).tagName === jQuery(document).get(0).tagName){ widthOffset = 25; } // Bind the window resize event so we can get the innerHeight again jQuery(window).bind("resize", function(){ elHeight = jQuery(element).height(); elWidth = jQuery(element).width(); }); // initialize the flakes for(i = 0; i < options.flakeCount; i+=1){ flakeId = flakes.length; flakes.push(new Flake(random(widthOffset,elWidth - widthOffset), random(0, elHeight), random((options.minSize * 100), (options.maxSize * 100)) / 100, random(options.minSpeed, options.maxSpeed), flakeId)); } // This adds the style to make the snowflakes round via border radius property if(options.round){ jQuery('.snowfall-flakes').css({'-moz-border-radius' : options.maxSize, '-webkit-border-radius' : options.maxSize, 'border-radius' : options.maxSize}); } // This adds shadows just below the snowflake so they pop a bit on lighter colored web pages if(options.shadow){ jQuery('.snowfall-flakes').css({'-moz-box-shadow' : '1px 1px 1px #555', '-webkit-box-shadow' : '1px 1px 1px #555', 'box-shadow' : '1px 1px 1px #555'}); } // this controls flow of the updating snow function snow(){ for( i = 0; i < flakes.length; i += 1){ flakes[i].update(); } snowTimeout = setTimeout(function(){snow()}, 30); } snow(); // Public Methods // clears the snowflakes this.clear = function(){ jQuery(element).children('.snowfall-flakes').remove(); flakes = []; clearTimeout(snowTimeout); }; }; // Initialize the options and the plugin jQuery.fn.snowfall = function(options){ if(typeof(options) == "object" || options == undefined){ return this.each(function(i){ (new jQuery.snowfall(this, options)); }); }else if (typeof(options) == "string") { return this.each(function(i){ var snow = jQuery(this).data('snowfall'); if(snow){ snow.clear(); } }); } }; })(jQuery);