switch (FEAT_TRAINS,SELF, switch_hopper_wagon_layers, [

  STORE_TEMP((getbits(extra_callback_info1, 8, 8) < 4 ? CB_FLAG_MORE_SPRITES  : 0) + PALETTE_USE_DEFAULT, 0x100),

  getbits(extra_callback_info1, 8, 8)

]){

  0: spriteset_wagon_wheel;

  1: spriteset_hopper_wagon_back;

  2: spriteset_hopper_wagon_cargo;

  3: spriteset_hopper_wagon_front;

  return spriteset_hopper_wagon_back;

}

 

 

item(FEAT_TRAINS, ...) {

  property {

    misc_flags: TRAIN_FLAG_SPRITE_STACK;

  }

}