#pragma region CPL License
/*
Nuclex Native Framework
Copyright (C) 2002-2015 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#pragma endregion // CPL License

#ifndef NUCLEX_GEOMETRY_ANGLE_H
#define NUCLEX_GEOMETRY_ANGLE_H

#include "Nuclex/Geometry/Config.h"
#include "Nuclex/Geometry/Math.h"

#include <cstddef>

namespace Nuclex { namespace Geometry {

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Definition for standard radiant angles (PI units per half-turn)</summary>
  template<typename TScalar>
  struct RadiantAngleDefinition {
    /// <summary>Units required to do one full turn</summary>
    public: static const TScalar OneTurn = Math<TScalar>::Perigon();
    /// <summary>Units required to do half a turn</summary>
    public: static const TScalar HalfTurn = Math<TScalar>::PI();
  };

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Definition for the classical 360 degree system</summary>
  template<typename TScalar>
  struct DegreeAngleDefinition {
    /// <summary>Units required to do one full turn</summary>
    public: static const TScalar OneTurn = 360;
    /// <summary>Units required to do half a turn</summary>
    public: static const TScalar HalfTurn = 180;
  };

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Definition for the clock angle degree system favored by pilots</summary>
  template<typename TScalar>
  struct ClockAngleDefinition {
    /// <summary>Units required to do one full turn</summary>
    public: static const TScalar OneTurn = 12;
    /// <summary>Units required to do half a turn</summary>
    public: static const TScalar HalfTurn = 6;
  };

  // ------------------------------------------------------------------------------------------- //

  /// <summary>Stores an angle using a customizable unit</summary>
  /// <typeparam name="TScalar">Scalar type used to store the angle units</typeparam>
  /// <typeparam name="TAngleDefinition">
  ///   Definition of the units used to represent angles
  /// </typeparam>
  template<typename TScalar, typename TAngleDefinition = RadiantAngleDefinition<TScalar>>
  struct Angle {
    /// <summary>Angle units in one full turn</summary>
    public: static const TScalar OneTurn = TAngleDefinition::OneTurn;
    /// <summary>Initializes an angle with the given direction</summary>
    public: Angle(TScalar value) : value(value) {}
    /// </summary>Converts an angle from another 
    public: template<typename TForeignAngleDefinition>
    Angle(Angle<TScalar, TForeignAngleDefinition> otherAngle) {}
    /// <summary>Accesses the amount of units storing the angle's direction</summary>
    public: operator TScalar() { return this->value; }
    /// <summary>Units storing the angle's direction</summary>
    private: TScalar value;

    //public: template<typename TForeignAngleDefinition>
    //static operator Angle<TScalar, 
  };

  // ------------------------------------------------------------------------------------------- //

  /// <summary>An angle using radiant as the unit (2*PI is one full turn)</summary>
  template<typename TScalar>
  using Radiant = Angle<TScalar, RadiantAngleDefinition<TScalar>>;

  /// <summary>An angle using classical degrees (360 degrees are one full turn)</summary>
  template<typename TScalar>
  using Degrees = Angle<TScalar, DegreeAngleDefinition<TScalar>>;

  /// <summary>An angle specified in clocks (= hours) for rough directions</summary>
  template<typename TScalar>
  using Clocks = Angle<TScalar, ClockAngleDefinition<TScalar>>;

  // ------------------------------------------------------------------------------------------- //

}} // namespace Nuclex::Geometry

#endif // NUCLEX_GEOMETRY_ANGLE_H