#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_AREAS_ROTATEDRECTANGLE2_H
#define NUCLEX_GEOMETRY_AREAS_ROTATEDRECTANGLE2_H

#include "../Point2.h"
#include "../Vector2.h"
#include "../Math.h"
#include <cassert>

namespace Nuclex { namespace Geometry { namespace Areas {

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

  /// <summary>2D rectangle that has been rotated by an arbitrary angle</summary>
  template <typename TScalar>
  struct RotatedRectangle2 {

    /// <summary>Initializes a new rotated rectangle</summary>
    /// <param name="center">Coordinates of the rectangle's center</param>
    /// <param name="extents">Extents of the rectangle</param>
    /// <param name="angle">Angle by which the rectangle has been rotated</param>
    public: RotatedRectangle2(
      const Point2<TScalar> &center, const Vector2<TScalar> extents, TScalar angle
    ) : Center(center), Extents(extents), Angle(angle) {}

    /// <summary>Returns a point that lies in the center of the rectangle</summary>
    /// <returns>The center of the rectangle</returns>
    public: Point2<TScalar> GetCenter() const {
      return this->Center;
    }

    /// <summary>Calculates the area of the rectangle</summary>
    /// <returns>The area of the rectangle</returns>
    public: TScalar GetArea() const {
      return (this->Extents.X * 2) * (this->Extents.Y * 2);
    }

    /// <summary>Calculates the perimeter of the rectangle</summary>
    /// <returns>The rectangle's perimeter</returns>
    public: TScalar GetPerimeter() const {
      TScalar horizontal = (this->Extents.X * 4);
      TScalar vertical = (this->Extents.Y * 4);

      return horizontal + vertical;
    }

    /// <summary>Offsets the entire rectangle by the specified amount</summary>
    /// <param name="amountX">Amount the rectangle will be offset on the X axis</param>
    /// <param name="amountY">Amount the rectangle will be offset on the Y axis</param>
    public: void ShiftBy(TScalar amountX, TScalar amountY) {
      this->Center.X += amountX;
      this->Center.Y += amountY;
    }

    /// <summary>Offsets the entire rectangle by the specified amount</summary>
    /// <param name="amount">Amount the rectangle will be offset</param>
    public: void ShiftBy(const Vector2<TScalar> &amount) {
      this->Center += amount;
    }

    /// <summary>Moves the rectangle to the specified location</summary>
    /// <param name="x">X coordinate the rectangle's center will end up at</param>
    /// <param name="y">Y coordinate the rectangle's center will end up at</param>
    public: void PlaceAt(TScalar x, TScalar y) {
      this->Center.X = x;
      this->Center.Y = y;
    }

    /// <summary>Moves the rectangle to the specified location</summary>
    /// <param name="position">Position the rectangle's center will end up at</param>
    public: void PlaceAt(const Point2<TScalar> &position) {
      this->Center = position;
    }

    /// <summary>Triggers an assertion if the rectangle is flipped on any axis</summary>
    public: void EnforceNotFlipped() const {
      using namespace std;
      assert((this->Extents.X >= 0) && "Rectangle must not be flipped on the X axis");
      assert((this->Extents.Y >= 0) && "Rectangle must not be flipped on the Y axis");
    }

    /// <summary>Coordinates of the rectangle's center</summary>
    public: Point2<TScalar> Center;
    /// <summary>Extents of the rectangle</summary>
    public: Vector2<TScalar> Extents;
    /// <summary>Angle, in radians, by which the rectangle has been rotated</summary>
    public: TScalar Angle;

  };

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

}}} // namespace Nuclex::Geometry::Areas

#endif // NUCLEX_GEOMETRY_AREAS_ROTATEDRECTANGLE2_H