#ifndef _Spring_h_
#define _Spring_h_

#include "PointMass.h"

class Spring
    {
    public:
     Spring(PointMass& p0,PointMass& p1,float k=1.0,float len=-1);
     void apply(void);
     void drawLine(void);
     inline const PointMass& point0(void) { return *p0_; }
     inline const PointMass& point1(void) { return *p1_; }
     inline float restLength(void) { return restLength_; }
     inline float springConstant(void) { return springConstant_; }
     void setRestLength(float len);
     void setSpringConstant(float k);
    private:
     PointMass *p0_, *p1_;
     float restLength_, springConstant_;
    };

#endif