// DynLayer Glide Methods
// alternative DynLayer animation methods with an acceleration effect

// Copyright (C) 1999 Dan Steinman
// Distributed under the terms of the GNU Library General Public License
// Available at http://www.dansteinman.com/dynapi/

//Modifications for NS6
//Eduardo G. Lafuente - treelogic  2001

function DynLayerGlideTo(startSpeed,endSpeed,endx,endy,angleinc,speed,fn)
	{
		if (endx==null) endx = this.x
		if (endy==null) endy = this.y
		var distx = endx-this.x
		var disty = endy-this.y
		this.glideStart(startSpeed,endSpeed,endx,endy,distx,disty,angleinc,speed,fn)
	}
function DynLayerGlideBy(startSpeed,endSpeed,distx,disty,angleinc,speed,fn) {
	var endx = this.x + distx
	var endy = this.y + disty
	this.glideStart(startSpeed,endSpeed,endx,endy,distx,disty,angleinc,speed,fn)
}
function DynLayerGlideStart(startSpeed,endSpeed,endx,endy,distx,disty,angleinc,speed,fn)
	{
		if (this.glideActive) return

		if (endx==this.x)
			var slantangle = 90
		else if (endy==this.y)
			var slantangle = 0
		else
			var slantangle = Math.abs(Math.atan(disty/distx)*180/Math.PI)

		if (endx>=this.x)
			{if (endy>this.y) slantangle = 360-slantangle}
		else
			{
				if (endy>this.y) slantangle = 180+slantangle
				else slantangle = 180-slantangle
			}
		slantangle *= Math.PI/180
		var amplitude = Math.sqrt(Math.pow(distx,2) + Math.pow(disty,2))
		if (!fn) fn = null
			this.glideActive = true
		if (startSpeed == "fast")
			{
				if (endSpeed=="fast")
					this.glide(1,amplitude/2,0,90,this.x,this.y,slantangle,endx,endy,distx,disty,angleinc,speed,fn)
				else
					this.glide(0,amplitude,0,90,this.x,this.y,slantangle,endx,endy,distx,disty,angleinc,speed,fn)
			}
		else
			{
				if (endSpeed=="fast")
					this.glide(0,amplitude,-90,0,this.x+distx,this.y+disty,slantangle,endx,endy,distx,disty,angleinc,speed,fn)
				else
					this.glide(0,amplitude/2,-90,90,this.x+distx/2,this.y+disty/2,slantangle,endx,endy,distx,disty,angleinc,speed,fn)
			}
	}
	
function DynLayerGlide(type,amplitude,angle,endangle,centerX,centerY,slantangle,endx,endy,distx,disty,angleinc,speed,fn)
	{
		if (angle < endangle && this.glideActive)
			{
				angle += angleinc
				var u = amplitude*Math.sin(angle*Math.PI/180)
				var x = centerX + u*Math.cos(slantangle)
				var y = centerY - u*Math.sin(slantangle)
				this.moveTo(x,y)
				this.onGlide()
				if (this.glideActive)
					setTimeout(this.obj+'.glide('+type+','+amplitude+','+angle+','+endangle+','+centerX+','+centerY+','+slantangle+','+endx+','+endy+','+distx+','+disty+','+angleinc+','+speed+',\''+fn+'\')',speed)
				else
					this.onGlideEnd()
			}
		else
			{
				if (type==1)
					this.glide(0,amplitude,-90,0,this.x+distx/2,this.y+disty/2,slantangle,endx,endy,distx,disty,angleinc,speed,fn)
				else
					{
						this.glideActive = false
						this.moveTo(endx,endy)
						this.onGlide()
						this.onGlideEnd()
						eval(fn)
					}
			}
	}

DynLayerGlideInit = new Function()
DynLayer.prototype.glideInit = new Function()
DynLayer.prototype.glideTo = DynLayerGlideTo
DynLayer.prototype.glideBy = DynLayerGlideBy
DynLayer.prototype.glideStart = DynLayerGlideStart
DynLayer.prototype.glide = DynLayerGlide
DynLayer.prototype.onGlide = new Function()
DynLayer.prototype.onGlideEnd = new Function()