Polygon.h

/*
 * Gamedev Framework (gf)
 * Copyright (C) 2016-2017 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.
 */
#ifndef GF_POLYGON_H
#define GF_POLYGON_H

#include <vector>

#include "ArrayRef.h"
#include "Matrix.h"
#include "Portability.h"
#include "Vector.h"

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

  struct Transform;

  enum class Winding {
    Clockwise,        
    Counterclockwise, 
  };

  class GF_API Polygon {
  public:
    Polygon() = default;

    Polygon(ArrayRef<Vector2f> points);

    template<typename Iterator>
    Polygon(Iterator first, Iterator last)
    : m_points(first, last)
    {

    }

    void addPoint(Vector2f point);

    std::size_t getPointCount() const;

    Vector2f getPoint(std::size_t index) const;

    Vector2f getCenter() const;

    Vector2f getSupport(Vector2f direction, const Transform& transform) const;

    Vector2f getSupport(Vector2f direction) const;

    const Vector2f *begin() const;

    const Vector2f *end() const;

    bool isConvex() const;

    Winding getWinding() const;


    float getArea() const;

    void applyTransform(const Matrix3f& mat);

  private:
    std::vector<Vector2f> m_points;
  };

#ifndef DOXYGEN_SHOULD_SKIP_THIS
}
#endif
}

#endif // GF_POLYGON_H