// JavaScript Document
var nav = document.getElementsByTagName("nav")[0],
 section = document.getElementsByTagName("section")[0],
 slide = document.getElementsByClassName("content"),
 slideCount = document.getElementById("slideCount"),
 slideNumber = 0,
 first,
 next,
 prev,
 popUpPane = document.getElementById("popUpPane"),
 greyOut = document.getElementById("greyOut"),
 popUpPicCanvas = document.getElementById("popUpPicCanvas"),
 popCanvasContext = popUpPicCanvas.getContext("2d");

var hideNav = function(){
	nav.style.opacity = ".2";
};
var fadeIn = function(){
	section.style.opacity = "1";
};
var doSlide= function(order){
	var isSlide = slideNumber;
	if (order=="first"){
		slide[slideNumber].style.display = "inline";
	};
	if (order=="next"){
		slide[isSlide].style.display = "none";
		if (isSlide+1==slide.length){
			slideNumber=0
			}
		else{
			slideNumber = isSlide+1
			}
		slide[slideNumber].style.display = "inline";
	};
	if (order=="prev"){
		slide[isSlide].style.display = "none";
		if (isSlide-1<0){
			slideNumber=slide.length-1
			}
		else{
			slideNumber = isSlide-1
			}
		slide[slideNumber].style.display = "inline";
	};
	slideCount.innerHTML = slideNumber+1+" / "+slide.length;
};
var initSlides = function(){
	for (var i = 0; i < slide.length; ++i)
	slide[i].style.marginLeft = "225px !important",
  	slide[i].style.display = "none";
	slide[0].style.margin="0";
	slide[slide.length-1].style.margin="0";
  	//var firstSlideNumber=Math.floor(Math.random()*(slide.length-1));
	//slideNumber = firstSlideNumber;
	slideNumber = 0;
  	doSlide("first");
};
var nextSlide = function(){
	doSlide('next');
}
var prevSlide = function(){
	doSlide('prev');
}
var doPopUp = function(source,x,y){
	var popUpPic = document.getElementById("pic"+source);
	popCanvasContext.canvas.width = x;
	popCanvasContext.canvas.height = y;
	popCanvasContext.drawImage(popUpPic, 0, 0,x,y);
	popUpPane.style.visibility = "visible";
	greyOut.style.opacity = "0.7";
	popUpPicCanvas.style.opacity = "1";
};
var noPopUp = function(){
	greyOut.style.opacity = "0";
	popUpPicCanvas.style.opacity = "0";
	popUpPane.style.visibility = "hidden";
};