# This is a simplified representation of what the device does

struct GridEntity {
    Prop: PropAsset      # The 3D model
    Name: string         # "MyCoolTree"
    Size: vector2        # 1x1, 2x2
}

struct UnlockPack {
    Entities: list<GridEntity> # List of allowed props
    IsUnlocked: bool           # True if player earned it
}

class GridEntity_Manager {
    # The list of all possible props
    Available_Props: list<GridEntity>
    
    # The list of packs
    Packs: list<UnlockPack>
    
    # Function called when player opens build menu
    function Get_Buildable_Props(Player: Player) -> list<GridEntity>:
        Result: list<GridEntity> = []
        
        for Pack in Packs:
            if Pack.IsUnlocked:
                # Add all props in this pack to the result
                for Entity in Pack.Entities:
                    Result.Add(Entity)
                    
        return Result
}