rail_pictures_internal = function(elems)
  local keys =
  {
    {"straight_rail", "horizontal", 64, 128, 0, 0, true},
    {"straight_rail", "vertical", 128, 64, 0, 0, true},
    {"straight_rail", "diagonal-left-top", 96, 96, 0.5, 0.5, true},
    {"straight_rail", "diagonal-right-top", 96, 96, -0.5, 0.5, true},
    {"straight_rail", "diagonal-right-bottom", 96, 96, -0.5, -0.5, true},
    {"straight_rail", "diagonal-left-bottom", 96, 96, 0.5, -0.5, true},
    {"curved_rail", "vertical-left-top", 192, 288, 0.5, 0.5},
    {"curved_rail", "vertical-right-top", 192, 288, -0.5, 0.5},
    {"curved_rail", "vertical-right-bottom", 192, 288, -0.5, -0.5},
    {"curved_rail", "vertical-left-bottom", 192, 288, 0.5, -0.5},
    {"curved_rail" ,"horizontal-left-top", 288, 192, 0.5, 0.5},
    {"curved_rail" ,"horizontal-right-top", 288, 192, -0.5, 0.5},
    {"curved_rail" ,"horizontal-right-bottom", 288, 192, -0.5, -0.5},
    {"curved_rail" ,"horizontal-left-bottom", 288, 192, 0.5, -0.5}
  }
  local res = {}
  for _ , key in ipairs(keys) do
    local part = {}
    dashkey = key[1]:gsub("_", "-")
    for _ , elem in ipairs(elems) do
      part[elem[1]] =
      {
        filename = string.format("__base__/graphics/entity/%s/%s-%s-%s.png", dashkey, dashkey, key[2], elem[2]),
        priority = elem.priority or "extra-high",
        flags = elem.mipmap and { "trilinear-filtering" } or { "low-object" },
        width = key[3],
        height = key[4],
        shift = {key[5], key[6]},
        variation_count = (key[7] and elem.variations) or 1,
        hr_version =
        {
          filename = string.format("__base__/graphics/entity/%s/hr-%s-%s-%s.png", dashkey, dashkey, key[2], elem[2]),
          priority = elem.priority or "extra-high",
          flags = elem.mipmap and { "trilinear-filtering" } or { "low-object" },
          width = key[3]*2,
          height = key[4]*2,
          shift = {key[5], key[6]},
          scale = 0.5,
          variation_count = (key[7] and elem.variations) or 1
        }
      }
    end
    dashkey2 = key[2]:gsub("-", "_")
    res[key[1] .. "_" .. dashkey2] = part
  end
    res["rail_endings"] =
    {
       sheets =
       {
         {
           filename = "__base__/graphics/entity/rail-endings/rail-endings-background.png",
           priority = "high",
           flags = { "low-object" },
           width = 128,
           height = 128,
           hr_version =
           {
             filename = "__base__/graphics/entity/rail-endings/hr-rail-endings-background.png",
             priority = "high",
             flags = { "low-object" },
             width = 256,
             height = 256,
             scale = 0.5
           }
         },
         {         
           filename = "__base__/graphics/entity/rail-endings/rail-endings-metals.png",
           priority = "high",
           flags = { "trilinear-filtering" },
           width = 128,
           height = 128,
           hr_version =
            {
             filename = "__base__/graphics/entity/rail-endings/hr-rail-endings-metals.png",
             priority = "high",
             flags = { "trilinear-filtering" },
             width = 256,
             height = 256,
             scale = 0.5
           }
         }
       }
    }
  return res
end