#include "vtkSpring.h"

#include "vtkObjectFactory.h"
#include "vtkIdList.h"
#include "vtkPoints.h"
#include "vtkPointData.h"
#include "vtkDoubleArray.h"
#include "vtkCellArray.h"
#include "vtkMath.h"

#include "vtkParticle.h"
#include "vtkParticleCollection.h"

vtkCxxRevisionMacro(vtkSpring, "$Revision: 0.1 $");
vtkStandardNewMacro(vtkSpring);

//----------------------------------------------------------------------------
vtkSpring::vtkSpring()
{
  this->K = 0.0;
  this->Distance = 0.0;
  this->Damping = 0.0;
  this->TimeStep = 0.0;
  this->RestLength = 0.0;
  this->Direction[0] = 0.0;
  this->Direction[1] = 0.0;
  this->Direction[2] = 0.0;
  this->Particles = vtkParticleCollection::New();
}

//----------------------------------------------------------------------------
vtkSpring::~vtkSpring()
{
  if(this->Particles) this->Particles->Delete();
}

//----------------------------------------------------------------------------
double * vtkSpring::GetDirection()
{
  return this->Direction;
}

//----------------------------------------------------------------------------
void vtkSpring::GetDirection(double Direction[3])
{
  Direction[0] = this->Direction[0];
  Direction[1] = this->Direction[1];
  Direction[2] = this->Direction[2];
}

//----------------------------------------------------------------------------
void vtkSpring::SetParticle(vtkIdType id, vtkParticle * particle)
{
  this->Particles->InsertParticle(id, particle);
}

//----------------------------------------------------------------------------
void vtkSpring::InsertNextParticle(vtkParticle * particle)
{
  this->Particles->InsertNextParticle(particle);
}

//----------------------------------------------------------------------------
vtkParticle * vtkSpring::GetParticle(vtkIdType id)
{
  return this->Particles->GetParticle(id);
}

//----------------------------------------------------------------------------
bool vtkSpring::ContainsParticle(vtkParticle * particle)
{
  for(vtkIdType i = 0; i < this->Particles->GetNumberOfItems(); i++)
  {
    vtkParticle * local = this->GetParticle(i);
    if(local && (local->GetId() == particle->GetId())){
      return 1;
    }
  }
  return 0;
}

//----------------------------------------------------------------------------
void vtkSpring::Init()
{
  double * p0 = this->GetParticle(0)->GetPosition();
  double * p1 = this->GetParticle(1)->GetPosition();
  //Note vtkMath returns squared-distance
  this->RestLength = sqrt(vtkMath::Distance2BetweenPoints(p0, p1));
  vtkMath::Subtract(p0, p1, this->Direction);
  vtkMath::Normalize(this->Direction);
}

//----------------------------------------------------------------------------
void vtkSpring::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);
  os << indent << "Id: " << this->Id << "\n";
  os << indent << "DistanceCoefficient: " << this->Distance << "\n";
  os << indent << "DampingCoefficient: " << this->Damping << "\n";
  os << indent << "Distance: " << this->RestLength << "\n";
  os << indent << "Direction: (" << this->Direction[0] << ", "
                  << this->Direction[1] << ", "
                  << this->Direction[2] << ")\n\n";
  os << indent << "Particle0Id: " << this->Particles->GetParticle(0)->GetId() << "\n";
  os << indent << "Particle1Id: " << this->Particles->GetParticle(1)->GetId() << "\n";
}