public sealed class MapLayer
{
    public byte[,] Foreground { get; private set; }              // Static tiles. Uses its own tileset.
    public byte[,] Background { get; private set; }              // Static tiles. Uses its own tileset.
    public Dictionary<byte, Point> Doodads { get; private set; } // Objects which consist of several tiles. Can be animated. Locked to tile grid.
    public Dictionary<byte, Point> Sprites { get; private set; } // Objects which are not tile-based. Can be animated. Can be placed anywhere.
}