// preload splash images

var splashImgCount = 27;

if (document.images) {
	imgInSplashArr            = new Array(4);
	imgOutSplashArr           = new Array(4);
	imgInSplashArr[1]         = new Image();
	imgInSplashArr[1].src     = "./images/distributors-splash-small_in.jpg";
	imgOutSplashArr[1]        = new Image();
	imgOutSplashArr[1].src    = "./images/distributors-splash-small_out.jpg";
	imgInSplashArr[2]         = new Image();
	imgInSplashArr[2].src     = "./images/truck-splash-small_in.jpg";
	imgOutSplashArr[2]        = new Image();
	imgOutSplashArr[2].src    = "./images/truck-splash-small_out.jpg";
	imgInSplashArr[3]         = new Image();
	imgInSplashArr[3].src     = "./images/calendar-splash-small_in.jpg";
	imgOutSplashArr[3]        = new Image();
	imgOutSplashArr[3].src    = "./images/calendar-splash-small_out.jpg";
}

// Copyright note: 
// Shuttle bus image taken from commons.wikipedia.org, copyright author Arnold C (user Buchanan-Hermit)

usedArr = new Array(splashImgCount + 1);
for ( i = 1; i <= splashImgCount; i ++ )  usedArr[i] = 0;

function jsInSplash(imgNum)   { 
	document.getElementById("splash" + imgNum).src = imgInSplashArr[imgNum].src;
	document.getElementById("splashtext" + imgNum).style.display = "block";
}
	
function jsOutSplash(imgNum)  {
	document.getElementById("splash" + imgNum).src = imgOutSplashArr[imgNum].src;
	document.getElementById("splashtext" + imgNum).style.display = "none";
}

function pickNewImage( )
{
	var r = 1 + Math.floor( splashImgCount * Math.random( ) );
	var i;
	for ( i = 1; i <= splashImgCount; i ++ )   
		if ( usedArr[( r + i - 1 ) % splashImgCount + 1] == 0 ) break;
	r = ( r + i - 1 ) % splashImgCount + 1;
	return r;
}

function pickCell( )
{
	var r = 1 + Math.floor( 2 * Math.random( ) );
	var c = 1 + Math.floor( 3 * Math.random( ) );
	return "" + r + c;
}

function switchImage( )
{
	var cell = pickCell();
	var img = pickNewImage();
	fadePicture(cell, img, 100);
	window.setTimeout("switchImage()", 4000);
}

function fadePicture(cell, img, opacity)
{
	var oa = document.getElementById( "c" + cell + "a" );
	var ob = document.getElementById( "c" + cell + "b" );
	if ( opacity == 100 )   {
		for ( var i = 1; i <= splashImgCount; i ++ )   {
			if ( usedArr[i] == cell )   {
				usedArr[i] = 0;
				usedArr[img] = cell;
				break;
			}
		}
		//oa.src = "images/mainsplash_" + img + ".jpg";
		ob.src = "images/mainsplash_" + img + ".jpg";
	}
	setOpacity(oa, opacity);
	setOpacity(ob, 100 - opacity);
	if ( opacity > 0 )   {
		opacity -= 10;
		window.setTimeout("fadePicture('" + cell + "', " + img + ", " + opacity + ");", 66);
	}
	else   {
		oa.src = "images/mainsplash_" + img + ".jpg";
		setOpacity(oa, 100);
	}
}

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, new Firefox
	obj.style.MozOpacity = opacity/100;

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

}