/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkInterpolatedVelocityField.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkInterpolatedVelocityField.h"

#include "vtkDataSet.h"
#include "vtkGenericCell.h"
#include "vtkObjectFactory.h"

//----------------------------------------------------------------------------
vtkStandardNewMacro( vtkInterpolatedVelocityField );

//----------------------------------------------------------------------------
void vtkInterpolatedVelocityField::AddDataSet( vtkDataSet * dataset )
{
  if ( !dataset )
  {
    return;
  }

  // insert the dataset (do NOT register the dataset to 'this')
  this->DataSets->push_back( dataset );

  int size = dataset->GetMaxCellSize();
  if ( size > this->WeightsSize )
  {
    this->WeightsSize = size;
    delete[] this->Weights;
    this->Weights = new double[size];
  }
}

//----------------------------------------------------------------------------
void vtkInterpolatedVelocityField::SetLastCellId( vtkIdType c, int dataindex )
{
  this->LastCellId  = c;
  this->LastDataSet = ( *this->DataSets )[dataindex];

  // if the dataset changes, then the cached cell is invalidated
  // we might as well prefetch the cached cell either way
  if ( this->LastCellId != -1 )
  {
    this->LastDataSet->GetCell( this->LastCellId, this->GenCell );
  }

  this->LastDataSetIndex = dataindex;
}

//----------------------------------------------------------------------------
int vtkInterpolatedVelocityField::FunctionValues( double * x, double * f )
{
  vtkDataSet * ds;
  if(!this->LastDataSet && !this->DataSets->empty())
  {
    ds = ( *this->DataSets )[0];
    this->LastDataSet      = ds;
    this->LastDataSetIndex = 0;
  }
  else
  {
    ds = this->LastDataSet;
  }

  int retVal = this->FunctionValues( ds, x, f );

  if ( !retVal )
  {
    for( this->LastDataSetIndex = 0;
         this->LastDataSetIndex < static_cast<int>( this->DataSets->size() );
         this->LastDataSetIndex ++ )
    {
      ds = this->DataSets->operator[]( this->LastDataSetIndex );
      if( ds && ds != this->LastDataSet )
      {
        this->ClearLastCellId();
        retVal = this->FunctionValues( ds, x, f );
        if ( retVal )
        {
          this->LastDataSet = ds;
          return retVal;
        }
      }
    }
    this->LastCellId  = -1;
    this->LastDataSetIndex = 0;
    this->LastDataSet = (*this->DataSets)[0];
    return 0;
  }

  return retVal;
}

//----------------------------------------------------------------------------
int vtkInterpolatedVelocityField::SnapPointOnCell(double* pOrigin, double* pSnap)
{
  if (this->LastDataSet == NULL)
  {
    return 0;
  }
   if (!this->FindAndUpdateCell(this->LastDataSet, pOrigin))
   {
    return 0;
   }
  double dist2;
  this->GenCell->EvaluatePosition
    (pOrigin, pSnap, this->LastSubId, this->LastPCoords, dist2, this->Weights);
  return 1;
}

//----------------------------------------------------------------------------
void vtkInterpolatedVelocityField::PrintSelf( ostream & os, vtkIndent indent )
{
  this->Superclass::PrintSelf( os, indent );
}
