Loader = ref object of RootObj
  engine* {.cursor.}: MyouEngine
  shader_library*: string
  shader_textures*: Table[string, Texture]
  path_handler*: proc (path: string): string
  override_textures_sampler_type*: Table[string, string]

proc registerLoader(engine: MyouEngine; extensions: seq[string];
                    constructor: proc (e: MyouEngine): Loader) {....raises: [],
    tags: [].}

method loadImageImpl(self: Loader) {.base, ...raises: [], tags: [].}

method loadScene(self: Loader; name: string = ""; scene: Scene = nil;
                 callback: proc (err: string; scene: Scene)) {.base, ...raises: [],
    tags: [].}

method openAssetFile(self: Loader; path: string) {.base, ...raises: [], tags: [].}