//
  // 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/gallery/slideshow/bronte_s02.jpg",
    "images/gallery/slideshow/bronte_s03.jpg",
    "images/gallery/slideshow/bronte_s04.jpg",
    "images/gallery/slideshow/bronte_s05.jpg",
    "images/gallery/slideshow/bronte_s01.jpg"
    );
  var gblPauseSeconds = 3.25;
  var gblFadeSeconds = .85;
  var gblRotations = 500;

  // 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;
  }