(function(){
	var vec2, Rect, sort
	if ('window' in this) {
		vec2 = window.vec2
		Rect = window.Rect
		sort = window.sort
	}
	else {
		vec2 = require('./vec2')
		Rect = require('./rect')
		UidGenerator = require('../util/uid')
		Rooms = { uid: new UidGenerator({}) }
		sort = require('../util/sort')
		FRONT = 0x1, BACK = 0x2, LEFT = 0x4, RIGHT = 0x8, FLOOR = 0x10, CEILING = 0x20
		TOP = CEILING, BOTTOM = FLOOR
		FRONT_BACK = FRONT | BACK
		LEFT_RIGHT = LEFT | RIGHT
		function sidesToString(sides){
			var s = ""
			if (sides & FRONT) s += "front "
			if (sides & BACK)  s += "back "
			if (sides & LEFT)  s += "left "
			if (sides & RIGHT) s += "right "
			if (sides & TOP)  s += "top "
			if (sides & BOTTOM) s += "bottom "
			return s
		}
	}

	var Room = function(opt){
		this.id = opt.id || Rooms.uid("room_")
		this.rect = opt.rect
		this.regions = []

		this.height = opt.height || 200
		this.focused = false

		this.mx_walls = []
		this.mx_floor = []
		this.mx_ceiling = []
	}
	
	Room.prototype.copy = function(){
	  return {
	    id: this.id,
	    rect: this.rect.clone(),
	    height: this.height,
	  }
	}
	
	Room.prototype.toString = function(){
		return this.rect.toString()
	}
	
	Room.prototype.serialize = function(){
		return {
			id: this.id,
			rect: this.rect.serialize(),
			height: ~~this.height,
		}
	}
	
	Room.prototype.reset = function(){
		var copy = this.rect.clone()
		copy.id = this.id
		copy.sides = FRONT | BACK | LEFT | RIGHT
		this.regions = [ copy ]

		this.intersects = []
		this.constructed = false
		
		this.mx_walls = []
		this.mx_floor = []
		this.mx_ceiling = []
	}

	Room.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
	}
	
	Room.prototype.collides = function(x,y){
		var collision = 0, wall_collision, contains_x, contains_y
		this.regions.forEach(function(r){
			if (! r.sides) return
			
			wall_collision = 0

			if ((r.sides & FRONT) && y < r.y.a) {
				wall_collision |= FRONT
			}
			if ((r.sides & BACK) && r.y.b < y) {
				wall_collision |= BACK
			}
			if ((r.sides & LEFT) && x < r.x.a) {
				wall_collision |= LEFT
			}
			if ((r.sides & RIGHT) && r.x.b < x) {
				wall_collision |= RIGHT
			}
			if (! wall_collision) return

			contains_y = r.y.contains(y)
			contains_x = r.x.contains(x)
			
			if (contains_x) {
				collision |= wall_collision & FRONT_BACK
			}
			else if (contains_y) {
				collision |= wall_collision & LEFT_RIGHT
			}
			else if (bitcount(wall_collision) > 1) {
 				collision |= wall_collision
			}
		})
		return collision
	}

	Room.prototype.collidesDisc = function(src, dest, radius){
	  var x = dest.x, y = dest.z
		var collision = 0, wall_collision, contains_x, contains_y
		this.regions.forEach(function(r){
			if (! r.sides) return
			
			wall_collision = 0

			if ((r.sides & FRONT) && y-radius < r.y.a) {
				wall_collision |= FRONT
			}
			if ((r.sides & BACK) && r.y.b < y+radius) {
				wall_collision |= BACK
			}
			if ((r.sides & LEFT) && x-radius < r.x.a) {
				wall_collision |= LEFT
			}
			if ((r.sides & RIGHT) && r.x.b < x+radius) {
				wall_collision |= RIGHT
			}
			if (! wall_collision) return

			contains_x = r.x.contains(x, radius)
			contains_y = r.y.contains(y, radius)

			if (contains_x) {
				collision |= wall_collision & FRONT_BACK
			}
			if (contains_y) {
				collision |= wall_collision & LEFT_RIGHT
			}
		})
		return collision
	}
	
	if ('window' in this) {
		window.Room = Room
	}
	else {
		module.exports = Room
	}

})()