public ISet <Layer> GetDrawLayers(Camera camera) { Layer entityLayer = new Layer(camera) { Order = layers.Count }; foreach (IEntity entity in entities.AllEntities(camera.DrawRectangle)) { entityLayer.Sprites.Add(entity); } ISet <Layer> returnLayers = new SortedSet <Layer> { entityLayer }; returnLayers.UnionWith(layers); return(returnLayers); }