-- Giant Book Overlay by the AlphaBirth team
function getScreenCenterPosition()
local room = Game():GetRoom()
local centerOffset = (room:GetCenterPos()) - room:GetTopLeftPos()
local pos = room:GetCenterPos()
if centerOffset.X > 260 then
  pos.X = pos.X - 260
end
if centerOffset.Y > 140 then
	pos.Y = pos.Y - 140
end
return Isaac.WorldToRenderPosition(pos, false)
end

local playGiantbookOverlay
do
	local sprite
	local anim
	playGiantbookOverlay = function(filename, shake)
		filename = "gfx/ui/giantbook/"..filename
		sprite = Sprite()
		sprite:Load("gfx/ui/giantbook/animation_giantbook.anm2", true)
		sprite:ReplaceSpritesheet(0, filename)
		sprite:LoadGraphics()
		if shake then
			anim = "Shake"
		else
			anim = "Appear"
		end
		sprite:Play(anim, true)
	end
	local function render()
		if not sprite then return end
		local pos = getScreenCenterPosition()
		sprite:Render(pos, Vector(0, 0), Vector(0, 0))
	end
	Cards:AddCallback(ModCallbacks.MC_POST_RENDER, render) -- Change the "Cards" to whatever you want
	local function update()
		if not sprite then return end
		sprite:Update()
		if sprite:IsFinished(anim) then
			sprite = nil
		end
	end
	Cards:AddCallback(ModCallbacks.MC_POST_UPDATE, update) -- Change the "Cards" to whatever you want
end