Rooms.clipper = new function(){
	var base = this

	base.init = function(){
		base.bind()
		base.update()
	}
	
	base.bind = function(){
		map.ui.mouse.tube.on("up", function(){ base.update() })
	}

	base.update = function(){
		base.solve_rects()
		app.tube("clip")
	}
	
	var rooms, regions
	
	// Given a set of overlapping rooms, clip any intersections, then cull any duplicate polygons
	base.solve_rects = function(){
		if (Rooms.list.length == 0) return
		
		base.reset_rects()
		base.clip_rects()
		base.cull_rects()
		
		Rooms.regions = sort_rects_by_position(regions)
	}
	
	// Reset the clipping/culling states of each of the rooms
	base.reset_rects = function(){
		for (var i = 0; i < Rooms.list.length; i++) {
			Rooms.list[i].reset()
		}
	}

	// Compare each room to the rooms it overlaps, and subdivide
	base.clip_rects = function(){
		var rooms = Rooms.sorted_by_position()
		regions = []

		var left, right
		for (var i = 0; i < rooms.length; i++) {
			left = rooms[i]
			for (var j = i+1; j < rooms.length; j++) {
				right = rooms[j]
				if (left.rect.intersects(right.rect)) {
					left.clipTo(right.rect)
					right.clipTo(left.rect)
					left.intersects.push(right)
					right.intersects.push(left)
				}
				if (left.rect.x.b < right.rect.x.a) {
					break
				}
			}
		}
		for (var i = 0; i < rooms.length; i++) {
			rooms[i].regions = rooms[i].regions.filter(function(r){ return !!r })
			regions = regions.concat(rooms[i].regions)
		}
	}
	
	// Find overlapping regions (of the same size) and dedupe
	base.cull_rects = function(){
		regions = sort_rects_by_area( regions )

		var ty = new Tree (regions[0].y.a, [regions[0]])
		var tx = new Tree (regions[0].x.a, ty)
		var ttx, tty
	
		for (var i = 1; i < regions.length; i++) {
			ttx = tx.add (regions[i].x.a, null)
			if (ttx.data) {
				tty = ttx.data.add (regions[i].y.a, null)
				// duplicate polygon?
				if (tty.data) {
					tty.data.forEach(function(yy, ii){
						if (yy.intersects(regions[i])) {
							if (yy.area() > regions[i].area()) {
								regions[i].dupe = true
							}
							else {
								yy.dupe = true
								tty.data[ii] = regions[i]
							}
						}
					})
				}
				else {
					tty.data = [regions[i]]
				}
			}
			else {
				ttx.data = new Tree (regions[i].y.a, [regions[i]])
			}
		}
	}

	return base
}