//
  // CSS Photo Shuffler v1.0 by
  //   Carl Camera
  //   http://iamacamera.org 
  //
  // SetOpacity Function and inpiration from Photo Fade by
  //   Richard Rutter
  //   http://clagnut.com
  //
  // License: Creative Commons Attribution 2.5  License
  //   http://creativecommons.org/licenses/by/2.5/
  //

  // Customize your photo shuffle settings
  // 
  // * Surround the target <img /> with a <div>. specify id= in both
  // * set background-repeat:no-repeat in CSS for the div
  // * The first and final photo displayed is in the html <img> tag
  // * The array contains paths to photos you want in the rotation. 
  //   If you want the first photo in the rotation, then it's best to
  //   put it as the final array image.  All photos must be same dimension
  // * The rotations variable specifies how many times to repeat array.
  //   images. zero is a valid rotation value.

  var gblPhotoShufflerDivId = "photodiv";
  var gblPhotoShufflerImgId = "photoimg"; 
  var gblImg = new Array(
    "/images/randomImages/060804-0038-4.jpg",
    "/images/randomImages/060804-0064-1.jpg",
    "/images/randomImages/41.jpg",
	"/images/randomImages/AERIAL VIEW 2.jpg",
	"/images/randomImages/IMG_0138.jpg",
	"/images/randomImages/mcgill 1.jpg"
    );
  var gblPauseSeconds = 7.25;
  var gblFadeSeconds = .85;
  var gblRotations = 100;

  // End Customization section
  
  var gblDeckSize = gblImg.length;
  var gblOpacity = 100;
  var gblOnDeck = 0;
  var gblStartImg;
  var gblImageRotations = gblDeckSize * (gblRotations+1);

  window.onload = photoShufflerLaunch;
  
  function photoShufflerLaunch()
  {
  	var theimg = document.getElementById(gblPhotoShufflerImgId);
        gblStartImg = theimg.src; // save away to show as final image

	document.getElementById(gblPhotoShufflerDivId).style.backgroundImage='url(' + gblImg[gblOnDeck] + ')';
	setTimeout("photoShufflerFade()",gblPauseSeconds*1000);
  }

  function photoShufflerFade()
  {
	  var theimg = document.getElementById(gblPhotoShufflerImgId);
		
	  // determine delta based on number of fade seconds
	  // the slower the fade the more increments needed
	  var fadeDelta = 100 / (30 * gblFadeSeconds);
	
	  // fade top out to reveal bottom image
	  if (gblOpacity < 2*fadeDelta ) 
	  {
	    gblOpacity = 100;
	    // stop the rotation if we're done
	    if (gblImageRotations < 1) return;
	
	    photoShufflerShuffle();
	    // pause before next fade
	    setTimeout("photoShufflerFade()",gblPauseSeconds*1000);
	
	  } else  {
	
	    gblOpacity -= fadeDelta;
	    setOpacity(theimg,gblOpacity);
	    setTimeout("photoShufflerFade()",30);  // 1/30th of a second
	
	  }
  }


  function photoShufflerShuffle()
  {
	var thediv = document.getElementById(gblPhotoShufflerDivId);
	var theimg = document.getElementById(gblPhotoShufflerImgId);
	
	// copy div background-image to img.src
	theimg.src = gblImg[gblOnDeck];
	// set img opacity to 100
	setOpacity(theimg,100);

        // shuffle the deck
	gblOnDeck = ++gblOnDeck % gblDeckSize;
	// decrement rotation counter
	if (--gblImageRotations < 1)
	{
	  // insert start/final image if we're done
	  gblImg[gblOnDeck] = gblStartImg;
	}

	// slide next image underneath
	thediv.style.backgroundImage='url(' + gblImg[gblOnDeck] + ')';
  }

  function setOpacity(obj, opacity) {
    opacity = (opacity == 100)?99.999:opacity;
    
    // IE/Win
    obj.style.filter = "alpha(opacity:"+opacity+")";
    
    // Safari<1.2, Konqueror
    obj.style.KHTMLOpacity = opacity/100;

    // Older Mozilla and Firefox
    obj.style.MozOpacity = opacity/100;

    // Safari 1.2, newer Firefox and Mozilla, CSS3
    obj.style.opacity = opacity/100;
  }