Camera = {
   pos = Point:new(0, 0),
   width = 0,
   height = 0,
   speed = 4,
}

function Camera:followPlayer(player)
	-- make sure we have the Point metatable	self:moveTowards(pos)
	local pos = Point.copy(player.pos)
	local room = player:getCollidingAt(pos.x,pos.y,LoadedObjects.Rooms)

	self:moveTowards(self:confineTo(room, pos))
end

function Camera:confineTo(box, pos)
	if box == nil then
		--frameDebug("not in a room")
		return pos
	end
	--frameDebug("in a room")

	local w = self.width/game.scale
	local h = self.height/game.scale
	local npos = pos - self:centerOffset()

	-- bottom edge
	npos.y = math.min(npos.y+h, box.to.y)-h
	-- right edge
	npos.x = math.min(npos.x+w, box.to.x)-w
	-- top edge
	npos.y = math.max(npos.y, box.from.y)
	-- left edge
	npos.x = math.max(npos.x, box.from.x)
	return npos + self:centerOffset()
end

function Camera:confineToLevel()
	self.pos.x = math.max(0,math.min(self.pos.x,LevelData.Width-self.width/game.scale))
	self.pos.y = math.max(0,math.min(self.pos.y,LevelData.Height-self.height/game.scale))
end

function Camera:moveTowards(pt)
   --local pt = Point:new(x,y)
   local diff = pt - self:center()
   local dist = diff:abs()
   local npos
   if dist < self.speed then
	  npos = pt
   else
	   frameDebug("camera at speed limit")
	   npos = self:center() + diff * (self.speed/dist)
	   frameDebug("dist = "..dist..", npos = "..tostring(npos))
   end
   self:positionCenterAt(npos.x, npos.y)
end

function Camera:size()
	return Point:new(self.width, self.height)
end

function Camera:centerOffset()
	return self:size()/game.scale/2
end

function Camera:center()
	return self.pos + self:centerOffset()
end
function Camera:positionCenterAt(x,y)
	self.pos.x = x-self.width/game.scale/2
	self.pos.y = y-self.height/game.scale/2
	--self:ConfineToLevel()
end

function Camera:positionAt(x,y)
	self.pos.x = math.floor((x/self.width)*self.width)
	self.pos.y = math.floor((y/self.height)*self.height)
end