Manages the multiple image sheets and sheet config files generated by TexturePacker's multipack mode. Returns a function that fetches sheet and frameIndex for specified image name.

multipackmanager

local M={}
multipackmanager=M

local require=require
local assert=assert
local pairs=pairs
local graphics=graphics
local pcall=pcall

setfenv(1,M)

function init(infodir,sheetdir,infoPrefix,imgPrefix)
  local infos={}
  local images={}
  local sheets={}

  if not sheetdir:find("/$") then
    sheetdir=sheetdir.."/"
  end

  local function load()
    local fileIndex=#infos
    local m=require (infodir .."."..infoPrefix..fileIndex)
    assert(m)
    local id=fileIndex+1
    infos[id]=m
    
    sheets[id]=graphics.newImageSheet(sheetdir..""..imgPrefix..fileIndex..".png",m:getSheet())

    for k,v in pairs(m.frameIndex) do
      assert(not images[k])
      images[k]=id
    end
  end

  while pcall(load) do
  end

  return function(img)
    local id=images[img]
    assert(id)
    return sheets[id],infos[id]:getFrameIndex(img)
  end
end

return M