//---------------------------------------------------------------------------

#include    "system.hpp"
#include    "classes.hpp"
#include "opengl/glew.h"
#include "opengl/glut.h"
#pragma hdrstop

#include "Spring.h"
#include "Usefull.h"


__fastcall TSpring::TSpring()
{
    vForce1=vForce2= vector3(0,0,0);
    Ks= 0;
    Kd= 0;
    restLen= 0;
}

__fastcall TSpring::~TSpring()
{

}

void __fastcall TSpring::Init(double nrestLen, double nKs, double nKd)
{
    Ks= nKs;
    Kd= nKd;
    restLen= nrestLen;
}

bool __fastcall TSpring::ComputateForces(vector3 pPosition1, vector3 pPosition2)
{

	double		dist, Hterm, Dterm;
	vector3		springForce,deltaV,deltaP;
//		p1 = &system[spring->p1];
  //		p2 = &system[spring->p2];
//		VectorDifference(&p1->pos,&p2->pos,&deltaP);	// Vector distance
    deltaP= pPosition1 - pPosition2;
//		dist = VectorLength(&deltaP);					// Magnitude of deltaP
	dist = deltaP.Length();
    if (dist==0)
    {
        vForce1=vForce2=vector3(0,0,0);
        return false;
    }

//		Hterm = (dist - spring->restLen) * spring->Ks;	// Ks * (dist - rest)
	Hterm= (dist - restLen) * Ks;	// Ks * (dist - rest)

//		VectorDifference(&p1->v,&p2->v,&deltaV);		// Delta Velocity Vector
    deltaV= pPosition1 - pPosition2;

//		Dterm = (DotProduct(&deltaV,&deltaP) * spring->Kd) / dist; // Damping Term
	//Dterm = (DotProduct(deltaV,deltaP) * Kd) / dist;
    Dterm= 0;

//		ScaleVector(&deltaP,1.0f / dist, &springForce);	// Normalize Distance Vector
//		ScaleVector(&springForce,-(Hterm + Dterm),&springForce);	// Calc Force
    springForce= deltaP/dist*(-(Hterm + Dterm));
//		VectorSum(&p1->f,&springForce,&p1->f);			// Apply to Particle 1
  //		VectorDifference(&p2->f,&springForce,&p2->f);	// - Force on Particle 2
    vForce1= springForce;
    vForce2= springForce;

 return true;
}

void __fastcall TSpring::Render()
{

}


//---------------------------------------------------------------------------

#pragma package(smart_init)