class potentialField{
    public:
        // diffenet points used
        struct point{
            float x;
            float y;
        };
        
        struct attractivePoint{
            float x;
            float y;
            float weight;
        };
        
        struct repulsivePoint{
            float x;
            float y;
            float weight;
            float maxRange;
        };
      
        void addPoint(repulsivePoint p);        // adds a repulsive point to the potential field
        void addPoint(attractivePoint p);       // adds a attractive point to the potential field
        void setPoint(unsigned int index, attractivePoint p);	// set a specific point at index to a new point
        void setPoint(unsigned int index, repulsivePoint p);	// set a specific point at index to a new point
        std::vector<float> attractiveGrad(point p);		// find the gradient of the attractiveField
        std::vector<float> repulsiveGrad(point p);			// find the gradient of the repulsiveField
        std::vector<float> netGrad(point p);			// find the total gradient
        float magnitude(std::vector<float> vect);			// find the magnitued of a vector
        std::vector<float> normalize(std::vector<float> vect);	// normalize a vector
        std::vector<float> netGradNormalized(point p);		// get the normaized gradient vector IE it's direction.
      
        float distFromAttractivePoint(unsigned int i,point p);	// get the distance of point p from an index in the attractiveField
      
        void printPotentialField();				// print out the field so we can take a look at it.
      
    private:
        double findDist(point p,repulsivePoint t);
        double findDist(point p,attractivePoint t);
      
        std::vector< attractivePoint > attractiveField;
        std::vector< repulsivePoint > repulsiveField;
};