if Code.ensure_loaded?(Membrane.VideoCompositor) do
  defmodule Membrane.RTC.Engine.Endpoint.HLS.MobileLayout do
    @moduledoc """
    Module representing function for updating video layout for the HLS stream.

    1) Only main presenter
         _ _ _ _
        |       |
        |       |
        |       |
        |       |
        |       |
         - - - -
    2) Main presenter and one side presenter
         _ _ _ _
        |       |
        |       |
        |       |
         - -    |
        |   |   |
         - - - -

    3) Main presenter and two side presenters
         _ _ _ _
        |       |
        |       |
        |       |
         - - - -
        |   |   |
         - - - -
    """

    @behaviour Membrane.RTC.Engine.Endpoint.HLS.CustomLayoutMaker
    @impl true
    def track_stream_format(%{width: width, height: height}, _track_no, padding),
      do: %{
        width: round(1 / 2 * width) - padding * 2,
        height: round(1 / 4 * height) - padding * 2
      }

    @impl true
    def track_stream_position(%{width: width, height: height}, track_no, padding),
      do: {round(track_no / 2 * width) + padding, height - round(1 / 4 * height) + padding}
  end
end