// ================================================================
// script by Gerard Ferrandez - Ge-1-doot - January 2006
// http://www.dhteumeuleu.com
// ================================================================
// images by Juergen Eilts http://www.shiftedreality.com
// ================================================================
// Haiku by their respective authors
// http://www.toyomasu.com/haiku/
// http://www.stevewhite.org/stuff/CthulhuHaiku.html
// http://www.virtualfrog.net/archives/2005/10/
// http://www.dgp.utoronto.ca/~jade/poetry.html
// ================================================================

var xm = 0;
var ym = 0;

function findPosX(obj){
    var x = obj.offsetLeft || 0;
    while (obj = obj.offsetParent) {
        x += obj.offsetLeft
    }
    return x;
}

function findPosY(obj){
    var y = obj.offsetTop || 0;
    while (obj = obj.offsetParent) {
        y += obj.offsetTop	
    }
    return y;
}
	/* RGB code */
rgb = function(color, R, G, B) {
	color = Math.min(255,Math.max(0,color));
	return "RGB("+Math.round(color*R)+","+Math.round(color*G)+","+Math.round(color*B)+")";
}

/* isolate script */
function gf(){
	/* source images */
	this.images = document.getElementById('images').getElementsByTagName('img');
	/* id hash table */
	this.id = [];
	var items = document.getElementById('center').getElementsByTagName('*');
	for(var i in items)if(items[i].id)this.id[items[i].id]=items[i];
	/* variables */
	this.K      = 0;
	this.w2     = 0;
	this.h2     = 0;
	this.over   = false;
	this.origin = 0;
	this.oL     = 0;
	this.oT     = 0;
	this.xm     = 0;
	this.ym     = 0;
	/* functions */
	this.fade = function(o, c){
		with(o.getElementsByTagName('div')){
			item(0).style.color  = rgb(c,1,1,1);
			item(1).style.color  = rgb(255-c,1,1,1);
			item(0).style.zIndex = c;
			item(1).style.zIndex = 255-c;
		}
	}
	this.text = function(o, t){
		with(o.getElementsByTagName('div')){
			item(1).innerHTML = item(0).innerHTML;
			item(0).innerHTML = t;
		}
	}
	this.move = function(x,y,w,h){
		/* lafelixe recalcul */
		x = x + gf.w2;
		y = y + gf.h2;
		/* position image */
		with(gf.id.d2.style){
			left   = Math.round(x)+"px";
			top    = Math.round(y)+"px";
			width  = Math.max(0,Math.round(w))+"px";
			height = Math.max(0,Math.round(h))+"px";
		}
		with(gf.id.i2.style){
			//left = -(x+gf.w2)+"px";
			//top  = -(y+gf.h2)+"px";
			left = gf.w2-(x+gf.w2)+"px";
			top  = gf.h2-(y+gf.h2)+"px";
		}
		/* transition complete */
		if(gf.origin>0 && w>=gf.w2*2 && h>=gf.h2*2){
			gf.K = ++gf.K % gf.images.length;
			with(gf.id){
				i1.src = i2.src;
				i2.src = gf.images[gf.K].src;
				gf.text(title, gf.images[gf.K].title);
				gf.text(legend, gf.images[gf.K].alt);
			}
			gf.origin = 0;
			gf.over = false;
			w = 0;
			h = 0;
			gf.move(0,0,0,0);
		}
		/* text fade in/out */
		var c = Math.round(((h*w)/(gf.h2*2*gf.w2*2))*255);
		gf.fade(gf.id.title, c);
		gf.fade(gf.id.legend, c);
	}
	/* on load */
	this.init = function(){
		resize();
		with(gf.id){
			i1.src = gf.images[gf.K].src;
			gf.text(title, gf.images[gf.K].title);
			gf.text(legend, gf.images[gf.K].alt);
			i1.style.visibility = i2.style.visibility = "visible";
			i2.src = gf.images[++gf.K].src;
			gf.text(title, gf.images[gf.K].title);
			gf.text(legend, gf.images[gf.K].alt);
			gf.fade(title, 0);
			gf.fade(legend, 0);
		}
	}
	/* mouse move */
	this.movemouse = function(e){
		/* source/target of the event */
		var o = (e.target)?e.target:((e.srcElement)?e.srcElement:null);
		/* over is image */
		var mydiapo = document.getElementById('center');
		var mydebug = document.getElementById('debug');
		var gfxm = findPosX(mydiapo);
		var gfym = findPosY(mydiapo);
		//mydebug.innerHTML = findPosX(mydiapo) + "/" + xm;
		if(o == gf.id.i1){
			/* offset calculation */
			var o2 = o.offsetParent;
			gf.oL  = o.offsetLeft+o2.offsetLeft+o2.offsetParent.offsetLeft;
			gf.oT  = o.offsetTop+o2.offsetTop+o2.offsetParent.offsetTop;
			//gf.xm  = xm-gf.oL;			
			//gf.ym  = ym-gf.oT;
			gf.xm  = xm - gfxm;
			gf.ym  = ym - gfym;
			//gf.xm  = xm-605;
			//gf.ym  = ym-26;

			/* determine origin */
			if(!gf.over){
				if(gf.xm<gf.w2){
					if(gf.ym<gf.h2)gf.origin=1; else gf.origin=2;
				} else {
					if(gf.ym<gf.h2)gf.origin=4; else gf.origin=3;
				}
				gf.over=true;
			}
		} else {
			/* mouse is out */
			//gf.xm = xm-gf.oL;
			//gf.ym = ym-gf.oT;
			gf.xm  = xm - gfxm;
			gf.ym  = ym - gfym;
			//gf.xm = xm-605;
			//gf.ym = ym-26;
		}
		/* move image */
		if (gf.over)
		{
		switch(gf.origin) {
			case 1:
				gf.move(-gf.w2,-gf.h2,gf.xm,gf.ym);
				break;
			case 2:
				gf.move(-gf.w2,Math.max(-gf.h2,-gf.h2+gf.ym),gf.xm,gf.h2*2-gf.ym);
				break;
			case 3:
				gf.move(Math.max(-gf.w2,-gf.w2+gf.xm),Math.max(-gf.h2,-gf.h2+gf.ym),gf.w2*2-gf.xm,gf.h2*2-gf.ym);
				break;
			case 4:
				gf.move(Math.max(-gf.w2,-gf.w2+gf.xm),-gf.h2,gf.w2*2-gf.xm,gf.ym);
				break;
		}
		}
	}
}

function resize(){
	gf.w2 = gf.id.i1.offsetParent.offsetWidth/2;
	gf.h2 = gf.id.i1.offsetParent.offsetHeight/2;
	gf.id.i1.style.width  = gf.id.i2.style.width  = (gf.w2*2)+"px";
	gf.id.i1.style.height = gf.id.i2.style.height = (gf.h2*2)+"px";
}
onresize = resize;