-- ================
-- Private helpers
-- ================
local setmetatable = setmetatable

-- Internal class constructor
local class = function(...)
  local klass = {}
  klass.__index = klass
  klass.__call = function(_,...) return klass:new(...) end
  function klass:new(...)
    local instance = setmetatable({}, klass)
    klass.__init(instance, ...)
    return instance
  end
  return setmetatable(klass,{__call = klass.__call})
end

local Room = class()
Room.__tostring = function(r) return ('Room  x=%f y=%f w=%d h=%d'):format(r.x, r.y, r.width, r.height) end

function Room:__init(x, y, width, height)
	self.x, self.y, self.width, self.height = x, y, width, height
	self.vx, self.vy = 0,0
end

function Room:intersects(r)
	local a = {
		x=self.x+self.width/2,
		y=self.y+self.height/2,
		wh = self.width/2,
		hh = self.height/2
	}
	local b = {
		x=r.x+r.width/2,
		y=r.y+r.height/2,
		wh = r.width/2+1,
		hh = r.height/2+1
	}
	return not (math.abs(a.x - b.x) > (a.wh + b.wh) or math.abs(a.y - b.y) > (a.hh + b.hh))
end

return Room