icon builder function

table.deepestcopy = function (tablein)
  -- use to copy a non-referential table, will break for infinitely referential tables
  local tableout = {}
  local key = nil
  local thing = nil

  for key, thing in pairs(tablein) do
    if type(thing) == "table" then
      tableout[key] = table.deepestcopy(thing)
    else
      tableout[key] = thing
    end
  end

  return tableout
end

local local_create_icon = function(base_icons, new_icons, options)
    if type(base_icons) ~= "table" then return base_icons end
    if type(options) ~= "table" then options = {} end
    local icon = nil

    if not options.rescale then options.rescale = 1 end
    if not options.origin then options.origin = {0,0} end
    if not new_icons then
        if options.from ~= nil and type(options.from) == "table" then
            if options.from.icons then new_icons = options.from.icons
            elseif options.from.icon then new_icons = {{icon = options.from.icon}}
            else error("Table given had no icons.") end

            for _, icon in pairs(new_icons) do
                if not icon.icon_size then icon.icon_size = options.from.icon_size end
                if not icon.icon_size then error("Had icon "..icon.icon.." but size is missing.")
                end
            end
        else
          error("Couldn't build icons: no icons and no table to build from.")
        end
    end

    local icons = table.deepestcopy(new_icons)

    for _, icon in pairs(base_icons) do
        if not icon.scale then icon.scale = 1 end
        if not icon.shift then icon.shift = {0,0} end
    end

    if options.type == nil or options.type == "recipe" then
        for _, icon in pairs(icons) do
            if not icon.icon_size then icon.icon_size = 32 end
        end
    end

    local extra_scale
    for _, icon in pairs(icons) do
        if not icon.scale then icon.scale = 1 end
        if not icon.shift then icon.shift = {0,0} end

        extra_scale = 1
        if base_icons[1] then
            if (base_icons[1].icon_size * base_icons[1].scale) ~= (icon.icon_size * icon.scale) then
                extra_scale = (base_icons[1].icon_size * base_icons[1].scale) / (icon.icon_size)
            end
        else
            if (icons[1].icon_size * icons[1].scale) ~= (icon.icon_size * icon.scale) then
                extra_scale = (icons[1].icon_size * icons[1].scale) / (icon.icon_size)
            end
        end

        icon.shift[1] = icon.shift[1]/icon.scale
        icon.shift[2] = icon.shift[2]/icon.scale

        icon.scale = icon.scale * options.rescale * extra_scale
        icon.shift[1] = icon.shift[1] * icon.scale + options.origin[1] * icon.scale * icon.icon_size
        icon.shift[2] = icon.shift[2] * icon.scale + options.origin[2] * icon.scale * icon.icon_size
    end

    for _, icon in pairs(icons) do
        table.insert(base_icons, icon)
    end
--[[
    for _, icon in pairs(base_icons) do
        if icon.shift and icon.shift[1] == 0 and icon.shift[2] == 0 then icon.shift = nil end
        if icon.scale and icon.scale == 1 then icon.scale = nil end
    end
--]]
    return base_icons
end