#ifndef GEOMETRY

 #define GEOMETRY

 #include <QPolygonF>

 QRectF addBBox(QRectF r1, QRectF r2);

 bool isInBox(const QPointF &p, const QRectF &box);

 class Vector:public QPointF

 {

 public:

 	Vector ();

 	Vector (const QPointF &p);

 	Vector (qreal x, qreal y);

 	friend inline bool operator==(const Vector &v1, const Vector &v2 )

 	{ return v1.x()==v2.x() && v1.y()==v2.y(); }

 	virtual void normalize ();

 	virtual qreal dotProduct (const QPointF &b);

 	virtual void scale  (const qreal &f);

 	virtual void invert ();

 };

 class ConvexPolygon:public QPolygonF

 {

 public:

 	ConvexPolygon ();

 	ConvexPolygon (QPolygonF p);

 	void calcCentroid() ;

 	QPointF centroid() const;

 	qreal weight() const;

 	std::string toStdString ();

 	Vector at (const int &i) const ; 

 	virtual void translate ( const Vector &offset );

 	virtual void translate ( qreal dx, qreal dy );

 private:

 	Vector _centroid;

 	qreal _area;

 };

 class PolygonCollisionResult {

 public:

     // Are the polygons going to intersect forward in time?

     bool willIntersect;

     // Are the polygons currently intersecting?

     bool intersect;

     // The translation to apply to the first polygon to push the polygons apart.

     QPointF minTranslation;

 };

 void projectPolygon(Vector axis, ConvexPolygon polygon, qreal &min, qreal &max) ;

 qreal intervalDistance(qreal minA, qreal maxA, qreal minB, qreal maxB);

 PolygonCollisionResult polygonCollision(ConvexPolygon polygonA, 

                               ConvexPolygon polygonB, Vector velocity);

 #endif