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Moved old functions into object

This commit is contained in:
Jake Howard 2015-08-13 14:04:18 +01:00
parent 30bd06d867
commit 7f6239e987
1 changed files with 26 additions and 7 deletions
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33
parallax.js
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@ -1,20 +1,39 @@
var Parallax = {
initialise: function() {
initialise: function(createEvents) {
$(this.ident).each(function(){
// Calculate Offset
inset = $(this).attr('parallax-inset');
image_height = $(this).height();
range = image_height / inset;
$(this).attr('parallax-offset', range / 2);
});
console.log("Parallax Initialised.");
if (createEvents) {this.createEvents();}
this.calculate();
},
calculate: function() {
window_top = $(window).scrollTop();
window_bottom = window_top + $(window).height();
$(this.ident).each(function(){
if (!is_on_screen(this) || !$(this).attr('parallax-offset') != false) { return; }
element = $(this);
center_pos = (element.offset().top - $(window).scrollTop()) + (element.height() / 2);
perc = -(0.5 - ((window_top - center_pos) / window_bottom));
pos = Math.round((perc * element.attr('parallax-offset')) * 100) / 100;
element.css('background-position',"0px " + pos + "px");
});
},
events: function() {
createEvents: function() {
$(window).scroll(function() { Parallax.calculate(); });
$(window).resize(function() { Parallax.initialise(); })
},
ident: '.parallax'
}
function is_on_screen(elm) {
var vpH = $(window).height(), // Viewport Height
st = $(window).scrollTop(), // Scroll Top
var vpH = $(window).height(),
st = $(window).scrollTop(),
y = $(elm).offset().top,
elementHeight = $(elm).height();
return ((y < (vpH + st)) && (y > (st - elementHeight)));