//<!--
//# Written by Russell Moffitt, NOAA
//# Modified Oct 2005
//# License: GPL
//-->

// ANIMATION - Smooth Sin Slide (slow>>fast>>slow)
// Modified from cross-browser.com x lib (Mike Foster).

/* x_slide.js
   additional functions can be found in
       x_core.js:	Cross-browser DOM & CSS compatibility functions (REQUIRED!)
       x_dom.js:	DOM traversal and Element searching functions
       x_event.js:	W3C DOM and Microsoft event model compatibility functions
*/

function xSlideTo(e, x, y, uTime) {
	if (!(e=xGetElementById(e))) return;
	if (!e.timeout) e.timeout = 25;
	e.xTarget = x; e.yTarget = y; e.slideTime = uTime; e.stop = false;
	e.yA = e.yTarget - xTop(e); e.xA = e.xTarget - xOffsetLeft(e); // A = distance
	if (e.slideLinear) e.B = 1/e.slideTime;
	else e.B = Math.PI / (2 * e.slideTime); // B = period
	e.yD = xTop(e); e.xD = xOffsetLeft(e); // D = initial position
	var d = new Date(); e.C = d.getTime();
	if (!e.moving) _xSlideTo(e);
}
function _xSlideTo(e) {
	if (!(e=xGetElementById(e))) return;
	var now, s, t, newY, newX;
	now = new Date();
	t = now.getTime() - e.C;
	if (e.stop) { e.moving = false; }
	else if (t < e.slideTime) {
		setTimeout("_xSlideTo('"+e.id+"')", e.timeout);
		if (e.slideLinear) s = e.B * t;
		else s = Math.sin(e.B * t);
		newX = Math.round(e.xA * s + e.xD);
		newY = Math.round(e.yA * s + e.yD);
		xMoveTo(e, newX, newY);
		e.moving = true;
	}
	else {
		xMoveTo(e, e.xTarget, e.yTarget);
		e.moving = false;
	}
}