//
// 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 = "slideshow_div";
var gblPhotoShufflerImgId = "slideshow_img";
//var gblImg = new Array(
//"http://static.flickr.com/53/149047107_78ebdaf8bc.jpg?v=0",
//"http://static.flickr.com/48/149048049_3523869ba4.jpg?v=0",
//"http://static.flickr.com/56/149047438_fabcf2f7ce.jpg?v=0"
//);
var gblPauseSeconds = 3;
var gblFadeSeconds = .85;
var gblRotations = 3;

// End Customization section

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

window.load = 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;
}