exray

defmodule Exray.Core.Screenspace do

  @moduledoc """
  Transform 3D positions in the world to screenspace and vice versa
  """

  @loader Exray.Core.Screenspace.Loader

  alias Exray.Structs.Vector2
  alias Exray.Structs.Vector3
  alias Exray.Structs.Matrix
  alias Exray.Structs.Camera2D
  alias Exray.Structs.Camera3D
  alias Exray.Structs.Ray

  @doc """
  Get a ray trace from mouse position
  """
  @spec get_mouse_ray(mouse_position :: Vector2, camera :: Camera3D) :: mouse_ray :: Ray
  defdelegate get_mouse_ray(mouse_position, camera), to: @loader

  @doc """
  Get camera transform matrix (view matrix)
  """
  @spec get_camera_matrix(camera :: Camera3D) :: camera_matrix :: Matrix
  defdelegate get_camera_matrix(camera), to: @loader

  @doc """
  Get camera 2d transform matrix
  """
  @spec get_camera_matrix_2d(camera :: Camera2D) :: camera_matrix :: Matrix
  defdelegate get_camera_matrix_2d(camera), to: @loader

  @doc """
  Get the screen space position for a 3d world space position
  """
  @spec get_world_to_screen(position :: Vector3, camera :: Camera3D) :: world_to_screen :: Vector2
  defdelegate get_world_to_screen(position, camera), to: @loader

  @doc """
  Get the world space position for a 2d camera screen space position
  """
  @spec get_screen_to_world_2d(position :: Vector2, camera :: Camera2D) :: screen_to_world :: Vector2
  defdelegate get_screen_to_world_2d(position, camera), to: @loader

  @doc """
  Get size position for a 3d world space position
  """
  @spec get_world_to_screen_ex(position :: Vector3, camera :: Camera3D, width :: integer, height :: integer) :: world_to_screen_ex :: Vector2
  defdelegate get_world_to_screen_ex(position, camera, width, height), to: @loader

  @doc """
  Get the screen space position for a 2d camera world space position
  """
  @spec get_world_to_screen_2d(position :: Vector2, camera :: Camera2D) :: world_to_screen_2d :: Vector2
  defdelegate get_world_to_screen_2d(position, camera), to: @loader

end