Polygon.h

#pragma once
 
#include "../FoundationBase.h"
 
#include "Glm.hpp"
 
#include <vector>
 
namespace Cogs {
  namespace Geometry {
    class COGSFOUNDATION_API Polygon {
    public:
      using   List              = std::vector<Polygon>;
      using   PointList         = std::vector<glm::vec3>;
 
                                Polygon() = default;
                                Polygon(const PointList& initialPoints);
                                Polygon(const Polygon&) = default;
 
              void              setPoints(const PointList& pointList);
              void              addPoint(const glm::vec3& point);
              void              clearPoints();
              void              fixUp();
 
              const PointList&  getPoints() const                           { return points; }
              const glm::vec3&  getPoint(size_t idx) const                  { return points[idx]; }
              size_t            getNoOfPoints() const                       { return points.size(); }
              float             calcArea() const                            { return std::fabs(calcSignedArea(points.begin(), points.end())); }
              bool              isPointInside(const glm::vec3& p) const     { return isPointInside(p, points); }
 
              List              add(const Polygon& polygon) const;
              List              subtract(const Polygon& polygon) const;
 
    private:
              PointList         points;
 
      static  bool              isClockwise(const PointList& pointList);
      static  bool              isPointInside(const glm::vec3& p, const PointList& pointList);
      static  float             calcSignedArea(const PointList::const_iterator& start, const PointList::const_iterator& end);
    };
  }
}