//
//  parralax.js
//
//  Author:
//       Paul Schneider <paul@pschneider.fr>
//
//  Copyright (c) 2015 GNU GPL
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.


$(document).ready(function($){
	var $window = $(window); 
	var $stwidth = $(window).width();
	var $stheight = $(window).height();

	var onPos = function (bgobj,ax,ay) {
	  	var speed = bgobj.data('speed');
		var dx=($window.scrollLeft()+ax-$stwidth/2)/speed;
		var dy=($window.scrollTop()+ay-$stheight/2)/speed;
		var xPos = bgobj.attr('orgbgpx') - Math.round( dx );
		var yPos = bgobj.attr('orgbgpy') - Math.round( dy );
		// Put together our final background position
		var coords = '' + xPos + bgobj.attr('orgbgpxu') + yPos + bgobj.attr('orgbgpyu');
		// Move the background
		bgobj.css({ backgroundPosition: coords });
	};
	 var tiltLR=0;
	 var titleFB=0;

	$('[data-type="background"]').each(function(){
		var $bgobj = $(this); // assigning the object
		// get the initial background position, assumes a "X% Yem" ?
		var orgpos = $bgobj.css('backgroundPosition');
		var bgpos = orgpos.split(" ");

		var bgposx = bgpos[0];
		var bgposy = bgpos[1];
		if (/%$/.test(bgposx)){ 
			bgposx = bgposx.substr(0,bgposx.length-1);
			$bgobj.attr('orgbgpxu','% ');
		}
		else if (/em$/.test(bgposx)){
			bgposx = bgposx.substr(0,bgposx.length-2);
			$bgobj.attr('orgbgpxu','em ');
		}
		else if (/px$/.test(bgposx)){
			bgposx = bgposx.substr(0,bgposx.length-2);
			$bgobj.attr('orgbgpxu','px ');
		}
		else { $bgobj.attr('orgbgpxu','px '); } 

		if (/%$/.test(bgposy)){ 
			bgposy = bgposy.substr(0,bgposy.length-1);
			$bgobj.attr('orgbgpyu','% ');
		}
		else if (/em$/.test(bgposy)){
			bgposy = bgposy.substr(0,bgposy.length-2);
			$bgobj.attr('orgbgpyu','em ');
		}
		else if (/px$/.test(bgposy)){
			bgposy = bgposy.substr(0,bgposy.length-2);
			$bgobj.attr('orgbgpyu','px ');
		}
		else { $bgobj.attr('orgbgpyu','px '); } 
		$bgobj.attr('orgbgpx',parseInt(bgposx));
		$bgobj.attr('orgbgpy',parseInt(bgposy));
		    
		$(window).scroll(function() {
		  onPos($bgobj,tiltLR,titleFB);
		});
		if (window.DeviceOrientationEvent) {
		if ($stwidth>320 && $stheight>320) {
		  window.addEventListener('deviceorientation', function(event) {
		  tiltLR = $stwidth*Math.sin(event.gamma*Math.PI/180);
		  	titleFB = $stheight*Math.sin(event.beta*Math.PI/90);
			onPos($bgobj,tiltLR,titleFB);
		  },false); }
		  $(window).mousemove(function(e) {
		  	tiltLR = e.pageX;
		  	titleFB = e.pageY;
			onPos($bgobj,e.pageX,e.pageY);
			});
		}  
	});
}(jQuery));