ParticleBehavior = function(){}
// create a particle behavior function
ParticleBehavior.create = function(method, argumentsObject){
	return ParticleBehavior[method].apply(null, ParticleBehavior.generateArguments(method, argumentsObject));
}
// combine multiple particle behavior functions into one function
ParticleBehavior.multiple = function(){
	var i, a = arguments, n = a.length;
	return function(){
		for(i=0;i<n;i++) a[i].call(this);
	}
}

// private, used in create
ParticleBehavior.generateArguments = function(method, argumentsObject){
	var args = ParticleBehavior[method].defaults;
	var len = args.length;
	var argsList = new Array(len);
	for (var i=0; i<len; i++){
		argsList[i] = (argumentsObject[args[i].param] != undefined) ? argumentsObject[args[i].param] : args[i].value;
	}
	return argsList;
}


/* MOTION FUNCTIONS */
ParticleBehavior.fall = function(g, vy){
	return function(){
		this._y += (vy += g);
	}
}
ParticleBehavior.fall.defaults = [
	{param:"gravity", value:1},
	{param:"yvelocity", value:0}
];

ParticleBehavior.slide = function(vx, vy, cx, cy, fx, fy, g){
	if (g) cy += g;
	return function(){
		this._x += vx = (vx + cx) * fx;
		this._y += vy = (vy + cy) * fy;
	}
}
ParticleBehavior.slide.defaults = [
	{param:"xvelocity", value:0},
	{param:"yvelocity", value:0},
	{param:"xincrease", value:0},
	{param:"yincrease", value:0},
	{param:"xfriction", value:1},
	{param:"yfriction", value:1},
	{param:"gravity", value:0}
];

ParticleBehavior.bounce = function(vx, vy, cx, cy, fx, fy, g, b){
	var l = b.xMin;
	var t = b.yMin;
	var r = b.xMax;
	b = b.yMax;
	if (g) cy += g;
	return function(){
		this._x += vx = (vx + cx) * fx;
		this._y += vy = (vy + cy) * fy;
		if (this._x <= l){
			this._x = l;
			vx = Math.abs(vx);
		}else if (this._x >= r){
			this._x = r;
			vx = -Math.abs(vx);
		}
		if (this._y <= t){
			this._y = t;
			vy = Math.abs(vy);
		}else if (this._y >= b){
			this._y = b;
			vy = -Math.abs(vy);
		}
	}
}
ParticleBehavior.bounce.defaults = [
	{param:"xvelocity", value:0},
	{param:"yvelocity", value:0},
	{param:"xincrease", value:0},
	{param:"yincrease", value:0},
	{param:"xfriction", value:1},
	{param:"yfriction", value:1},
	{param:"gravity", value:0},
	{param:"bounds", value:{xMin: 0, yMin: 0, xMax: Stage.width, yMax: Stage.height}}
];
ParticleBehavior.bounce3D = function(x, y, z, vx, vy, vz, cx, cy, cz, fx, fy, fz, g, b, fl, w){
	var l = b.xMin;
	var r = b.xMax;
	var f = b.zMax;
	var k = b.zMin;
	var t = b.yMax;
	b = b.yMin;
	if (g) cy -= g;
	var s;
	return function(){
		x += vx = (vx + cx) * vx;
		y += vy = (vy + cy) * vy;
		z += vz = (vz + cz) * vz;
		if (x <= l){
			x = l;
			vx = Math.abs(vx);
		}else if (x >= r){
			x = r;
			vx = -Math.abs(vx);
		}
		if (y <= b){
			y = b;
			vy = Math.abs(vy);
		}else if (y >= t){
			y = t;
			vy = -Math.abs(vy);
		}
		if (z <= k){
			z = k;
			vz = Math.abs(vz);
		}else if (z >= f){
			z = f;
			vz = -Math.abs(vz);
		}
		s = fl/(fl + z);
		this._xscale = this._yscale = 100*s;
		this._x = x*s;
		this._y = -y*s;
		if (w) this.swapDepths(Math.round(s*1000));
	}
}
ParticleBehavior.bounce3D.defaults = [
	{param:"x", value:0},
	{param:"y", value:0},
	{param:"z", value:0},
	{param:"xvelocity", value:0},
	{param:"yvelocity", value:0},
	{param:"zvelocity", value:0},
	{param:"xincrease", value:0},
	{param:"yincrease", value:0},
	{param:"zincrease", value:0},
	{param:"xfriction", value:0},
	{param:"yfriction", value:0},
	{param:"zfriction", value:0},
	{param:"gravity", value:0},
	{param:"bounds", value:{
			xMin:Number.NEGATIVE_INFINITY,	yMin:0,						zMin:Number.NEGATIVE_INFINITY,
			xMax:Number.POSITIVE_INFINITY,	yMax:Number.POSITIVE_INFINITY,	zMax:Number.POSITIVE_INFINITY
		}
	},
	{param:"focallength", value:300},
	{param:"swap", value:false}
];

ParticleBehavior.size = function(xs, ys, c){
	c = (c != "percent");
	var r;
	return function(){
		if (c){
			if (r = this._rotation) this._rotation = 0;
			this._width += xs;
			this._height += ys;
			if (r) this._rotation = r;
		}else{
			this._xscale += xs;
			this._yscale += ys;
		}
	}
}
ParticleBehavior.size.defaults = [
	{param:"xincrease", value:0},
	{param:"yincrease", value:0},
	{param:"use", value:"percent"} /* "percent" or "value", "value" implied if not "percent" */
];

ParticleBehavior.transparency = function(t){
	var a;
	return function(){
		if (a == undefined) a = this._alpha;
		this._alpha = a += t;
	}
}
ParticleBehavior.transparency.defaults = [
	{param:"increase", value:0}
];

ParticleBehavior.repel = function (x, y, o, r, a, f) {
	var d,dx,dy,vx,vy,v;
	return function(){
		if (x == undefined) x = this._x;
		if (y == undefined) y = this._y;
		if (o == Mouse){
			dx = this._parent._xmouse - this._x;
			dy = this._parent._ymouse - this._y;
		}else{
			dx = o._x - this._x;
			dy = o._y - this._y;
		}
		d = Math.sqrt(dx*dx + dy*dy);
		if (d < r) {
			var v = d*r*a;
			if (v != 0){
				vx -= dx/v;
				vy -= dy/v;
			}
		}
		this._x += (vx = (vx + (x - this._x)*a)*f);
		this._y += (vy = (vy + (y - this._y)*a)*f);
	}
}
ParticleBehavior.repel.defaults = [
	{param:"x", value:undefined},
	{param:"y", value:undefined},
	{param:"repeller", value:Mouse},
	{param:"range", value:100},
	{param:"acceleration", value:.03},
	{param:"friction", value:.9}
];

ParticleBehavior.avoid = function(o, r, v, a, f){
	var d,dx,dy,vx=0,vy=0,t,tv=0;
	return function(){
		if (o == Mouse){
			dx = this._parent._xmouse - this._x;
			dy = this._parent._ymouse - this._y;
		}else{
			dx = o._x - this._x;
			dy = o._y - this._y;
		}
		d = Math.sqrt(dx*dx + dy*dy);
		if (d < r) {
			if (a && d) tv = Math.min(v, a*r/d);
			else tv = v;
			if (f) tv *= f;
			t = Math.atan2(dy, dx);
			vx = Math.cos(t);
			vy = Math.sin(t);
		}else if (f) tv *= f;
		else tv = 0;
		if (tv){
			this._x -= vx*tv;
			this._y -= vy*tv;
		}
	}
}
ParticleBehavior.avoid.defaults = [
	{param:"avoid", value:Mouse},
	{param:"range", value:100},
	{param:"velocity", value:1},
	{param:"acceleration", value:0},
	{param:"friction", value:0}
];

ParticleBehavior.constrain = function(b, c){
	var l = b.xMin;
	var t = b.yMin;
	var r = b.xMax;
	b = b.yMax;
	c = (c != "bounds");
	var pb;
	return function(){
		if (c){
			if (this._x < l) this._x = l;
			else if (this._x > r) this._x = r;
			if (this._y < t) this._y = t;
			else if (this._y > b) this._y = b;
		}else{
			pb = this.getBounds(this._parent);
			if (pb.xMin < l) this._x = l - (pb.xMin - this._x);
			else if (pb.xMax > r) this._x = r - (pb.xMax - this._x);
			if (pb.yMin < t) this._y = t - (pb.yMin - this._y);
			else if (pb.yMax > b) this._y = b - (pb.yMax - this._y);
		}
	}
}
ParticleBehavior.constrain.defaults = [
	{param:"bounds", value:{xMin: 0, yMin: 0, xMax: Stage.width, yMax: Stage.height}},
	{param:"check", value:"bounds"} /* "bounds" or "center", "center" implied if not "bounds" */
];


/* REMOVAL FUNCTIONS */
ParticleBehavior.boundsRemove = function(b, c){
	var l = b.xMin;
	var t = b.yMin;
	var r = b.xMax;
	b = b.yMax;
	c = (c != "bounds");
	var pb;
	return function(){
		if (c){
			if (this._x < l || this._x > r || this._y < t || this._y > b) this.removeMovieClip();
		}else{
			pb = this.getBounds(this._parent);
			if (pb.xMax < l || pb.xMin > r || pb.yMax < t || pb.yMin > b) this.removeMovieClip();
		}
	}
}
ParticleBehavior.boundsRemove.defaults = [
	{param:"bounds", value:{xMin: 0, yMin: 0, xMax: Stage.width, yMax: Stage.height}},
	{param:"check", value:"bounds"} /* "bounds" or "center", "center" implied if not "bounds" */
];

ParticleBehavior.timedRemove = function(t){
	var s = getTimer();
	return function(){
		if ((getTimer()-s) >= t) this.removeMovieClip();
	}
}
ParticleBehavior.timedRemove.defaults = [
	{param:"time", value:1000}  
];

ParticleBehavior.framesRemove = function(f){
	var e = 0;
	return function(){
		if ((++e) >= f) this.removeMovieClip();
	}
}
ParticleBehavior.framesRemove.defaults = [
	{param:"frames", value:100}  
];

ParticleBehavior.changeInPositionRemove = function(d, c){
	var d = d*d;
	var x,y,dx,dy;
	c = (c != "greater");
	return function(){
		if (x != undefined){
			dx = x - this._x;
			dy = y - this._y;
			if (c){
				if (d >= (dx*dx + dy*dy)) this.removeMovieClip();
			}else{
				if (d <= (dx*dx + dy*dy)) this.removeMovieClip();
			}
		}
		x = this._x;
		y = this._y;
	}
}
ParticleBehavior.changeInPositionRemove.defaults = [
	{param:"distance", value:10},
	{param:"check", value:"greater"} /* "greater" or "less", "less" implied if not "greater" */
];

ParticleBehavior.distanceRemove = function(x, y, d){
	var d = d*d;
	var dx,dy;
	return function(){
		if (x == undefined) x = this._x;
		if (y == undefined) y = this._y;
		dx = x - this._x;
		dy = y - this._y;
		if (d >= (dx*dx + dy*dy)) this.removeMovieClip();
	}
}
ParticleBehavior.distanceRemove.defaults = [
	{param:"x", value:undefined},
	{param:"y", value:undefined},
	{param:"distance", value:100}
];
ParticleBehavior.distanceTraveledRemove = function(d){
	var d = d*d;
	var x,y,dx,dy,dt=0;
	return function(){
		if (x != undefined){
			dx = x - this._x;
			dy = y - this._y;
			dt += (dx*dx + dy*dy);
			if (d >= dt) this.removeMovieClip();
		}
		x = this._x;
		y = this._y;
	}
}
ParticleBehavior.distanceTraveledRemove.defaults = [
	{param:"distance", value:100}  
];

ParticleBehavior.sizeRemove = function(nw, nh, xw, xh, c){
	c = (c != "both");
	var r;
	return function(){
		if (r = this._rotation) this._rotation = 0;
		if (c){
			if (nw && nw > this._width) this.removeMovieClip();
			if (nh && nh > this._height) this.removeMovieClip();
			if (xw && xw < this._width) this.removeMovieClip();
			if (xh && xh < this._height) this.removeMovieClip();
		}else{
			if (nw && nh && nw > this._width && nh > this._height) this.removeMovieClip();
			if (xw && xh && xw < this._width && xh < this._height) this.removeMovieClip();
		}
		if (r) this._rotation = r;
	}
}
ParticleBehavior.sizeRemove.defaults = [
	{param:"minwidth", value:1},
	{param:"minheight", value:1},
	{param:"maxwidth", value:undefined},
	{param:"maxheight", value:undefined},
	{param:"check", value:"both"} /* "both" or "single", "single" implied if not "both" */
];