#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_CURVE3_H
#define NUCLEX_GEOMETRY_LINES_CURVE3_H

#include "Nuclex/Geometry/Config.h"
#include "Nuclex/Geometry/Point3.h"

namespace Nuclex { namespace Geometry { namespace Lines {

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

  /// <summary>Three-dimensional curved line</summary>
  template <typename TScalar>
  struct Curve3 {
  
    /// <summary>Initializes the cubic bezier curve using the specified coordinates</summary>
    /// <param name="p0">Point at which the cubic bezier curve begins</param>
    /// <param name="p1">Point giving direction and magnitude at the curve start</param>
    /// <param name="p2">Point giving direction and magnitude at the curve end</param>
    /// <param name="p3">Point at which the cubic bezier curve ends</param>
    public: Curve3(
      const Point3<TScalar> &p0,
      const Point3<TScalar> &p1,
      const Point3<TScalar> &p2,
      const Point3<TScalar> &p3
    ) : P0(p0), P1(p1), P2(p2), P3(p3) {}

    /// <summary>Offsets the entire curve by the specified amount</summary>
    /// <param name="offset">Amount the curve will be offset</param>
    public: void ShiftBy(const Vector3<TScalar> &offset) {
      this.P0 += offset;
      this.P1 += offset;
      this.P2 += offset;
      this.P3 += offset;
    }

    /// <summary>Offsets the entire curve by the specified amount</summary>
    /// <param name="x">Amount the curve will be offset on the X axis</param>
    /// <param name="y">Amount the curve will be offset on the Y axis</param>
    /// <param name="z">Amount the curve will be offset on the Z axis</param>
    public: void ShiftBy(TScalar x, TScalar y, TScalar z) {
      this.P0.X += x;
      this.P0.Y += y;
      this.P0.Z += z;
      this.P1.X += x;
      this.P1.Y += y;
      this.P1.Z += z;
      this.P2.X += x;
      this.P2.Y += y;
      this.P2.Z += z;
      this.P3.X += x;
      this.P3.Y += y;
      this.P3.Z += z;
    }

    /// <summary>Interpolates a point along the curve</summary>
    /// <param name="t">Time (0.0 .. 1.0) at which the point will be interpolated</param>
    /// <returns>The point at the specified time</returns>
    public: TScalar Interpolate(TScalar t) const {
      return (
        Math<TScalar>::Power(1 - t, 3) * this->P0 +
        3 * Math<TScalar>::Power(1 - t, 2) * t * this->P1 +
        3 * (1 - t) * Math<TScalar>::Power(t, 2) * this->P2 +
        Math<TScalar>::Power(t, 3) * this->P3
      );
    }

    /// <summary>Position of the curve's starting point</summary>
    public: Point3<TScalar> P0;
    /// <summary>Position towards which the curve's starting point extends</summary>
    public: Point3<TScalar> P1;
    /// <summary>Position from which the curve enters its ending point</summary>
    public: Point3<TScalar> P2;
    /// <summary>Position at which the curve ends</summary>
    public: Point3<TScalar> P3;

  };

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

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

#endif // NUCLEX_GEOMETRY_LINES_CURVE3_H