//
  // 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.

  function deckSize(imgList) {
    return imgList.length;
  }
  
  function photoShufflerLaunch(selPref) {
    var useThis = selPref;
  	var theimg = document.getElementById(photoShufflerPref[selPref]['photoimg']);
	photoShufflerPref[selPref]['startImg'] = theimg.src; // save away to show as final image

	document.getElementById(photoShufflerPref[selPref]['photodiv']).style.backgroundImage='url(' + photoShufflerPref[selPref]['imgList'][photoShufflerPref[selPref]['onDeck']] + ')';

	setTimeout("photoShufflerFade('" + selPref + "');",photoShufflerPref[selPref]['pauseSeconds']*1000);
  }

  function photoShufflerFade(selPref)
  {
  	var theimg = document.getElementById(photoShufflerPref[selPref]['photoimg']);
	
  	// determine delta based on number of fade seconds
	// the slower the fade the more increments needed
        var fadeDelta = 100 / (30 * photoShufflerPref[selPref]['fadeSeconds']);

	// fade top out to reveal bottom image
	if (photoShufflerPref[selPref]['opacity'] < 2*fadeDelta ) 
	{
	  photoShufflerPref[selPref]['opacity'] = 100;
	  // stop the rotation if we're done
	  if (photoShufflerPref[selPref]['rotations'] < 1) return;
	  photoShufflerShuffle(selPref);
	  // pause before next fade
      setTimeout("photoShufflerFade('" + selPref + "');",photoShufflerPref[selPref]['pauseSeconds']*1000);
	}
	else
	{
	  photoShufflerPref[selPref]['opacity'] -= fadeDelta;
	  setOpacity(theimg,photoShufflerPref[selPref]['opacity']);
	  setTimeout("photoShufflerFade('" + selPref + "');",30);
	}
  }

  function photoShufflerShuffle(selPref)
  {
	var thediv = document.getElementById(photoShufflerPref[selPref]['photodiv']);
	var theimg = document.getElementById(photoShufflerPref[selPref]['photoimg']);
    photoShufflerPref[selPref]['rotations'] = deckSize(photoShufflerPref[selPref]['imgList']) * (photoShufflerPref[selPref]['rotations']+1);
	
	// copy div background-image to img.src
	theimg.src = photoShufflerPref[selPref]['imgList'][photoShufflerPref[selPref]['onDeck']];
	// set img opacity to 100
	setOpacity(theimg,100);

        // shuffle the deck
	photoShufflerPref[selPref]['onDeck'] = ++photoShufflerPref[selPref]['onDeck'] % deckSize(photoShufflerPref[selPref]['imgList']);
	// decrement rotation counter
	if (--photoShufflerPref[selPref]['rotations'] < 1)
	{
	  // insert start/final image if we're done
	  photoShufflerPref[selPref]['imgList'][photoShufflerPref[selPref]['onDeck']] = photoShufflerPref[selPref]['startImg'];
	}

	// slide next image underneath
	thediv.style.backgroundImage='url(' + photoShufflerPref[selPref]['imgList'][photoShufflerPref[selPref]['onDeck']] + ')';
  }

  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;
  }