#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_LINES_GENERATORS_SEGMENT3GENERATOR_H
#define NUCLEX_GEOMETRY_LINES_GENERATORS_SEGMENT3GENERATOR_H

#include "Nuclex/Geometry/Config.h"
#include "Nuclex/Geometry/Lines/Segment3.h"

namespace Nuclex { namespace Geometry { namespace Lines { namespace Generators {

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

  /// <summary>Point and area generation methods for 3D line segments</summary>
  template <typename TScalar>
  class Segment3Generator {

    /// <summary>Determines the closest point to another point upon the line segment</summary>
    /// <param name="segment">Line segment on which the closest point will be found</param>
    /// <param name="point">Point to which the closest point will be determined</param>
    /// <returns>The closest point upon the line segment to the specified point</returns>
    public: static Point3<TScalar> GetClosestPointUpon(
      const Segment3<TScalar> &segment, const Point3<TScalar> &point
    ) {
      Vector3<TScalar> direction = (segment.End - segment.Start);

      TScalar t = Vector3<TScalar>::Dot(point - segment.Start, direction);
      if(t < 0) {
        return segment.Start;
      } else {
        TScalar squaredSegmentLength = direction.GetSquaredLength();
        if(t > squaredSegmentLength) {
          return segment.End;
        } else {
          return segment.Start + (direction * (t / squaredSegmentLength));
        }
      }
    }

    /// <summary>Returns a random point upon the line segment</summary>
    /// <param name="segment">Line segment upon which a random point will be generated</param>
    /// <param name="random">Random number generator that will be used</param>
    /// <returns>A random point upon the line segment</returns>
    public: template <typename TRandomNumberEngine>
    static Point3<TScalar> GetRandomPointUpon(
      const Segment3<TScalar> &segment, TRandomNumberEngine &random
    ) {
      TScalar t = Math<TScalar>::Random(random, 1);
      return Point3<TScalar>::Lerp(segment.Start, segment.End, t);
    }

  };

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

}}}} // namespace Nuclex::Geometry::Lines::Generators

#endif // NUCLEX_GEOMETRY_LINES_GENERATORS_SEGMENT3GENERATOR_H