/* ==== slider nameSpace ==== */

var slider = function() {

	/* ==== private methods ==== */

	function getElementsByClass(object, tag, className) {

		var o = object.getElementsByTagName(tag);

		for ( var i = 0, n = o.length, ret = []; i < n; i++) {

			if (o[i].className == className) ret.push(o[i]);

		}

		if (ret.length == 1) ret = ret[0];

		return ret;

	}

	function setOpacity (obj,o) {

		if (obj.filters) obj.filters.alpha.opacity = Math.round(o);

		else obj.style.opacity = o / 100;

	}

	/* ==== Slider Constructor ==== */

	function Slider(oCont, speed, iW, iH, oP) {

		this.slides = [];

		this.over   = false;

		this.S      = this.S0 = speed;

		this.iW     = iW;

		this.iH     = iH;

		this.oP     = oP;

		this.oc     = document.getElementById(oCont);

		this.frm    = getElementsByClass(this.oc, 'div', 'slide');

		this.NF     = this.frm.length;

		this.resize();

		for (var i = 0; i < this.NF; i++) {

			this.slides[i] = new Slide(this, i);

		}

		this.oc.parent = this;

		this.view      = this.slides[0];

		this.Z         = this.mx;

		/* ==== on mouse out event ==== */

		this.oc.onmouseout = function () {

			this.parent.mouseout();

			return false;

		}

	}

	Slider.prototype = {

		/* ==== animation loop ==== */

		run : function () {

			this.Z += this.over ? (this.mn - this.Z) * .5 : (this.mx - this.Z) * .5;

			this.view.calc();

			var i = this.NF;

			while (i--) this.slides[i].move();

		},

		/* ==== resize  ==== */

		resize : function () {

			this.wh = this.oc.clientWidth;

			this.ht = this.oc.clientHeight;

			this.wr = this.wh * this.iW;

			this.r  = this.ht / this.wr;

			this.mx = this.wh / this.NF;

			this.mn = (this.wh * (1 - this.iW)) / (this.NF - 1);

		},

		/* ==== rest  ==== */

		mouseout : function () {

			this.over      = false;

			setOpacity(this.view.img, this.oP);

		}

	}

	/* ==== Slide Constructor ==== */

	Slide = function (parent, N) {

		this.parent = parent;

		this.N      = N;

		this.x0     = this.x1 = N * parent.mx;

		this.v      = 0;

		this.loaded = false;

		this.cpt    = 0;

		this.start  = new Date();

		this.obj    = parent.frm[N];

		this.txt    = getElementsByClass(this.obj, 'div', 'text');

		this.img    = getElementsByClass(this.obj, 'img', 'diapo');

		this.bkg    = document.createElement('div');

		this.bkg.className = 'backgroundText';

		this.obj.insertBefore(this.bkg, this.txt);

		if (N == 0) this.obj.style.borderLeft = 'none';

		this.obj.style.left = Math.floor(this.x0) + 'px';

		setOpacity(this.img, parent.oP);

		/* ==== mouse events ==== */

		this.obj.parent = this;

		this.obj.onmouseover = function() {

			this.parent.over();

			return false;

		}

	}

	Slide.prototype = {

		/* ==== target positions ==== */

		calc : function() {

			var that = this.parent;

			// left slides

			for (var i = 0; i <= this.N; i++) {

				that.slides[i].x1 = i * that.Z;

			}

			// right slides

			for (var i = this.N + 1; i < that.NF; i++) {

				that.slides[i].x1 = that.wh - (that.NF - i) * that.Z;

			}

		},

		/* ==== HTML animation : move slides ==== */

		move : function() {

			var that = this.parent;

			var s = (this.x1 - this.x0) / that.S;

			/* ==== lateral slide ==== */

			if (this.N && Math.abs(s) > .5) {

				this.obj.style.left = Math.floor(this.x0 += s) + 'px';

			}

			/* ==== vertical text ==== */

			var v = (this.N < that.NF - 1) ? that.slides[this.N + 1].x0 - this.x0 : that.wh - this.x0;

			if (Math.abs(v - this.v) > .5) {

				this.bkg.style.top = this.txt.style.top = Math.floor(2 + that.ht - (v - that.Z) * that.iH * that.r) + 'px';

				this.v = v;

				this.cpt++;

			} else {

				if (!this.pro) {

					/* ==== adjust speed ==== */

					this.pro = true;

					var tps = new Date() - this.start;

					if(this.cpt > 1) {

						that.S = Math.max(2, (28 / (tps / this.cpt)) * that.S0);

					}

				}

			}

			if (!this.loaded) {

				if (this.img.complete) {

					this.img.style.visibility = 'visible';

					this.loaded = true;

				}

			}

		},

		/* ==== light ==== */

		over : function () {

			this.parent.resize();

			this.parent.over = true;

			setOpacity(this.parent.view.img, this.parent.oP);

			this.parent.view = this;

			this.start = new Date();

			this.cpt = 0;

			this.pro = false;

			this.calc();

			setOpacity(this.img, 100);

		}

	}

	/* ==== public method - script initialization ==== */

	return {

		init : function() {

			// create instances of sliders here

			// parameters : HTMLcontainer name, speed (2 fast - 20 slow), Horizontal ratio, vertical text ratio, opacity

			this.s1 = new Slider("slider", 12, 370/957, 3.5/10, 70);

			setInterval("slider.s1.run();", 16);

		}

	}

}();