window.rect = (function(){
	var FRONT = 0x1, BACK = 0x2, LEFT = 0x4, RIGHT = 0x8

	var rect = function (x0,y0,x1,y1){
		if (x0 instanceof vec2) {
			this.x = x0
			this.y = y0
		}
		else if (x1 === undefined) {
			this.x = new vec2(x0,x0)
			this.y = new vec2(y0,y0)
		}
		else {
			this.x = new vec2(x0,x1)
			this.y = new vec2(y0,y1)
		}
		this.translation = new vec2(0,0)
		this.sides = FRONT | BACK | LEFT | RIGHT
		this.focused = false
		this.id = 0
	}
	rect.prototype.clone = function(){
		return new rect( this.x.clone(), this.y.clone() )
	}
	rect.prototype.center = function(){
		return new vec2(this.x.midpoint(), this.y.midpoint())
	}
	rect.prototype.area = function(){
		return this.x.length() * this.y.length()
	}
	rect.prototype.normalize = function(){
		this.x.abs().add(this.translation.a)
		this.y.abs().add(this.translation.b)
		this.translation.a = this.translation.b = 0
		return this
	}
	rect.prototype.contains = function(x,y){
		return this.x.contains(x) && this.y.contains(y)
	}
	rect.prototype.intersects = function(r){
		return this.x.intersects(r.x) && this.y.intersects(r.y)
	}
	rect.prototype.width = function(){ return this.x.length() }
	rect.prototype.height = function(){ return this.y.length() }
	rect.prototype.fill = function(){
	// 	if (! this.sides) return this
		ctx.fillRect(this.x.a + this.translation.a, this.y.a + this.translation.b, this.x.length(), this.y.length())
		return this
	}
	rect.prototype.stroke_sides = function(){
		if (this.sides & FRONT) line(this.x.a, this.y.a, this.x.b, this.y.a)
		if (this.sides &  BACK) line(this.x.a, this.y.b, this.x.b, this.y.b)
		if (this.sides &  LEFT) line(this.x.a, this.y.a, this.x.a, this.y.b)
		if (this.sides & RIGHT) line(this.x.b, this.y.a, this.x.b, this.y.b)

		function line(a,b,c,d){
			ctx.beginPath()
			ctx.moveTo(a,b)
			ctx.lineTo(c,d)
			ctx.stroke()
		}
		return this
	}
	rect.prototype.stroke = function(){
		ctx.beginPath()
		ctx.moveTo(this.x.a, this.y.a)
		ctx.lineTo(this.x.b, this.y.b)
		ctx.stroke()
		return this
	}
	rect.prototype.perimeter = function(){
		line( this.x.a, this.y.a, this.x.b, this.y.a, this.translation )
		line( this.x.a, this.y.b, this.x.b, this.y.b, this.translation )
		line( this.x.a, this.y.a, this.x.a, this.y.b, this.translation )
		line( this.x.b, this.y.a, this.x.b, this.y.b, this.translation )
	}
	rect.prototype.toString = function(){
		var sides = ""
		if (this.sides & FRONT) sides += "front "
		if (this.sides & BACK)  sides += "back "
		if (this.sides & LEFT)  sides += "left "
		if (this.sides & RIGHT) sides += "right "
		var s = this.id + " " + "[" + this.x.toString() + " " + this.y.toString() + "] " + sides
		if (this.focused) return "<b>" + s + "</b>"
		return s
	}
	rect.prototype.quantize = function(n){
		this.x.quantize(n)
		this.y.quantize(n)
	}
	rect.prototype.reset = function(){
		var copy = this.clone()
		copy.sides = FRONT | BACK | LEFT | RIGHT
		copy.focused = this.focused
		copy.id = this.id
		this.regions = [ copy ]
	}
	rect.prototype.clipTo = function(r){
		// for each of this rect's regions split the region if necessary
		var regions = this.regions
		var splits

		for (var i = 0, len = regions.length; i < len; i++) {
			if (regions[i] && regions[i].intersects(r)) {
				splits = regions[i].split(r)
				regions = regions.concat(splits)
				regions[i] = null
			}
		}
		this.regions = regions
	}
	rect.prototype.split = function(r){
		var rz = this
		var splits = []
		var split_contains = 0
		var x_intervals = [], y_intervals = []
		var sides = this.sides

		// Split vertically
		if (this.x.contains(r.x.a) && r.x.contains(this.x.b)) {
			x_intervals.push([ new vec2( this.x.a,    r.x.a ), LEFT  ])
			x_intervals.push([ new vec2(    r.x.a, this.x.b ), RIGHT ])
			split_contains |= RIGHT
		}

		else if (r.x.contains(this.x.a) && this.x.contains(r.x.b)) {
			x_intervals.push([ new vec2( this.x.a,    r.x.b ), LEFT  ])
			x_intervals.push([ new vec2(    r.x.b, this.x.b ), RIGHT ])
			split_contains |= LEFT
		}
	
		else if (this.x.contains(r.x.a) && this.x.contains(r.x.b)) {
			x_intervals.push([ new vec2( this.x.a,    r.x.a ), LEFT  ])
			x_intervals.push([ new vec2(    r.x.a, 	  r.x.b ), 0     ])
			x_intervals.push([ new vec2(    r.x.b, this.x.b ), RIGHT ])
			split_contains |= LEFT | RIGHT
		}

		else { // if (r.x.contains(this.x.a) && r.x.contains(r.x.b)) {
			x_intervals.push([ new vec2( this.x.a, this.x.b ), LEFT | RIGHT ])
			split_contains |= LEFT | RIGHT
		}

		// Split horizontally
		if (this.y.contains(r.y.a) && r.y.contains(this.y.b)) {
			y_intervals.push([ new vec2( this.y.a,    r.y.a ), FRONT ])
			y_intervals.push([ new vec2(    r.y.a, this.y.b ), BACK  ])
			split_contains |= BACK
		}

		else if (r.y.contains(this.y.a) && this.y.contains(r.y.b)) {
			y_intervals.push([ new vec2( this.y.a,    r.y.b ), FRONT ])
			y_intervals.push([ new vec2(    r.y.b, this.y.b ), BACK  ])
			split_contains |= FRONT
		}
	
		else if (this.y.contains(r.y.a) && this.y.contains(r.y.b)) {
			y_intervals.push([ new vec2( this.y.a,    r.y.a ), FRONT ])
			y_intervals.push([ new vec2(    r.y.a, 	  r.y.b ), 0     ])
			y_intervals.push([ new vec2(    r.y.b, this.y.b ), BACK  ])
			split_contains |= FRONT | BACK
		}

		else { // if (r.y.contains(this.y.a) && this.y.contains(r.y.b)) {
			y_intervals.push([ new vec2( this.y.a, this.y.b ), FRONT | BACK ])
			split_contains |= FRONT | BACK
		}

		x_intervals.forEach(function(x){
			y_intervals.forEach(function(y){
				var rn = new rect(x[0], y[0])
				rn.id = rz.id
				rn.sides = ((x[1] | y[1]) & sides)
				if (r.intersects(rn)) {
					rn.sides = 0
				}
				rn.focused = rz.focused
				splits.push(rn)
			})
		})
		return splits
	}
	
	return rect

})()