Circ.h

/*
 * Gamedev Framework (gf)
 * Copyright (C) 2016-2018 Julien Bernard
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 *
 * Part of this file comes from SFML, with the same license:
 * Copyright (C) 2007-2015 Laurent Gomila (laurent@sfml-dev.org)
 */
#ifndef GF_CIRC_H
#define GF_CIRC_H

#include "Portability.h"
#include "Vector.h"
#include "VectorOps.h"

namespace gf {
#ifndef DOXYGEN_SHOULD_SKIP_THIS
inline namespace v1 {
#endif

  template<typename T>
  struct Circ {
    Vector<T, 2> center; 
    T radius; 

    constexpr Circ() noexcept
    : center(0, 0)
    , radius(0)
    {

    }

    constexpr Circ(const Vector<T, 2>& circCenter, T circRadius) noexcept
    : center(circCenter)
    , radius(circRadius)
    {

    }

    Circ(const Circ&) = default;

    Circ& operator=(const Circ&) = default;

    constexpr Vector<T, 2> getCenter() const noexcept {
      return center;
    }

    constexpr T getRadius() const noexcept {
      return radius;
    }

    constexpr bool isEmpty() const noexcept {
      return radius == 0;
    }

    constexpr Vector<T, 2> getTop() const noexcept {
      return { center.x, center.y - radius };
    }

    constexpr Vector<T, 2> getBottom() const noexcept {
      return { center.x, center.y + radius };
    }

    constexpr Vector<T, 2> getLeft() const noexcept {
      return { center.x - radius, center.y };
    }

    constexpr Vector<T, 2> getRight() const noexcept {
      return { center.x + radius, center.y };
    }

    inline bool contains(const Vector<T, 2>& point) const noexcept {
      return gf::squareDistance(center, point) <= gf::square(radius);
    }

    inline bool intersects(const Circ<T>& other) const noexcept {
      return gf::squareDistance(center, other.center) <= gf::square(radius + other.radius);
    }

  };


  using CircF = Circ<float>;

  using CircI = Circ<int>;

  using CircU = Circ<unsigned>;

  using CircZ = Circ<std::size_t>;

// MSVC does not like extern template
#ifndef _MSC_VER
  extern template struct Circ<float>;
  extern template struct Circ<int>;
  extern template struct Circ<unsigned>;
#endif

  template<typename T>
  inline
  bool operator==(const Circ<T>& lhs, const Circ<T>& rhs) {
    return lhs.center == rhs.center && lhs.radius == rhs.radius;
  }

  template<typename T>
  inline
  bool operator!=(const Circ<T>& lhs, const Circ<T>& rhs) {
    return lhs.center != rhs.center || lhs.radius != rhs.radius;
  }

#ifndef DOXYGEN_SHOULD_SKIP_THIS
}
#endif
}


#endif // GF_CIRC_H