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

  Program:   Visualization Toolkit
  Module:    vtkContourGrid.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 "vtkContourGrid.h"

#include "vtkCell.h"
#include "vtkCellArray.h"
#include "vtkCellData.h"
#include "vtkContourValues.h"
#include "vtkFloatArray.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkSimpleScalarTree.h"
#include "vtkUnstructuredGrid.h"
#include "vtkCutter.h"
#include "vtkMergePoints.h"
#include "vtkPointLocator.h"
#include "vtkIncrementalPointLocator.h"

#include <math.h>

vtkStandardNewMacro(vtkContourGrid);

// Construct object with initial range (0,1) and single contour value
// of 0.0.
vtkContourGrid::vtkContourGrid()
{
  this->ContourValues = vtkContourValues::New();

  this->ComputeNormals = 1;
  this->ComputeGradients = 0;
  this->ComputeScalars = 1;

  this->Locator = NULL;

  this->UseScalarTree = 0;
  this->ScalarTree = NULL;

  // by default process active point scalars
  this->SetInputArrayToProcess(0,0,0,vtkDataObject::FIELD_ASSOCIATION_POINTS,
                               vtkDataSetAttributes::SCALARS);
}

vtkContourGrid::~vtkContourGrid()
{
  this->ContourValues->Delete();
  if ( this->Locator )
    {
    this->Locator->UnRegister(this);
    this->Locator = NULL;
    }
  if ( this->ScalarTree )
    {
    this->ScalarTree->Delete();
    }
}

// Overload standard modified time function. If contour values are modified,
// then this object is modified as well.
unsigned long vtkContourGrid::GetMTime()
{
  unsigned long mTime=this->Superclass::GetMTime();
  unsigned long time;

  if (this->ContourValues)
    {
    time = this->ContourValues->GetMTime();
    mTime = ( time > mTime ? time : mTime );
    }
  if (this->Locator)
    {
    time = this->Locator->GetMTime();
    mTime = ( time > mTime ? time : mTime );
    }

  return mTime;
}

template <class T>
void vtkContourGridExecute(vtkContourGrid *self, vtkDataSet *input,
                           vtkPolyData *output,
                           vtkDataArray *inScalars, T *scalarArrayPtr,
                           int numContours, double *values, 
                           int computeScalars,
                           int useScalarTree,vtkScalarTree *&scalarTree)
{
  vtkIdType cellId, i;
  int abortExecute=0;
  vtkIncrementalPointLocator *locator = self->GetLocator();
  vtkIdList *cellPts;
  vtkCell *cell;
  double range[2];
  vtkCellArray *newVerts, *newLines, *newPolys;
  vtkPoints *newPts;
  vtkIdType numCells, estimatedSize;
  vtkPointData *inPd=input->GetPointData(), *outPd=output->GetPointData();
  vtkCellData *inCd=input->GetCellData(), *outCd=output->GetCellData();
  vtkDataArray *cellScalars;
  vtkUnstructuredGrid *grid = static_cast<vtkUnstructuredGrid *>(input);
  //In this case, we know that the input is an unstructured grid.
  vtkIdType numPoints, cellArrayIt = 0;
  int needCell = 0;
  vtkIdType *cellArrayPtr;
  T tempScalar;

  numCells = input->GetNumberOfCells();

  //
  // Create objects to hold output of contour operation. First estimate
  // allocation size.
  //
  estimatedSize=static_cast<vtkIdType>(pow(static_cast<double>(numCells),.75));
  estimatedSize *= numContours;
  estimatedSize = estimatedSize / 1024 * 1024; //multiple of 1024
  if (estimatedSize < 1024)
    {
    estimatedSize = 1024;
    }

  newPts = vtkPoints::New();
  newPts->Allocate(estimatedSize,estimatedSize);
  newVerts = vtkCellArray::New();
  newVerts->Allocate(estimatedSize,estimatedSize);
  newLines = vtkCellArray::New();
  newLines->Allocate(estimatedSize,estimatedSize);
  newPolys = vtkCellArray::New();
  newPolys->Allocate(estimatedSize,estimatedSize);
  cellScalars = inScalars->NewInstance();
  cellScalars->SetNumberOfComponents(inScalars->GetNumberOfComponents());
   cellScalars->Allocate(VTK_CELL_SIZE*inScalars->GetNumberOfComponents());
  
   // locator used to merge potentially duplicate points
  locator->InitPointInsertion (newPts, input->GetBounds(),estimatedSize);

  // interpolate data along edge
  // if we did not ask for scalars to be computed, don't copy them
  if (!computeScalars)
    {
    outPd->CopyScalarsOff();
    }
  outPd->InterpolateAllocate(inPd,estimatedSize,estimatedSize);
  outCd->CopyAllocate(inCd,estimatedSize,estimatedSize);

  // If enabled, build a scalar tree to accelerate search
  //
  if ( !useScalarTree )
    {
    // Three passes over the cells to process lower dimensional cells first.
    // For poly data output cells need to be added in the order:
    // verts, lines and then polys, or cell data gets mixed up.
    // A better solution is to have an unstructured grid output.
    // I create a table that maps cell type to cell dimensionality,
    // because I need a fast way to get cell dimensionality.
    // This assumes GetCell is slow and GetCellType is fast.
    // I do not like hard coding a list of cell types here, 
    // but I do not want to add GetCellDimension(vtkIdType cellId)
    // to the vtkDataSet API.  Since I anticipate that the output
    // will change to vtkUnstructuredGrid.  This temporary solution 
    // is acceptable.
    //
    int cellType;
    unsigned char cellTypeDimensions[VTK_NUMBER_OF_CELL_TYPES];
    vtkCutter::GetCellTypeDimensions(cellTypeDimensions);
    int dimensionality;
    // We skip 0d cells (points), because they cannot be cut (generate no data).
    for (dimensionality = 1; dimensionality <= 3; ++dimensionality)
      {
      // Loop over all cells; get scalar values for all cell points
      // and process each cell.
      //
      cellArrayIt = 0;
      cellArrayPtr = grid->GetCells()->GetPointer();
      for (cellId=0; cellId < numCells && !abortExecute; cellId++)
        {
        numPoints = cellArrayPtr[cellArrayIt];
        // I assume that "GetCellType" is fast.
        cellType = input->GetCellType(cellId);
        if (cellType >= VTK_NUMBER_OF_CELL_TYPES)
          { // Protect against new cell types added.
          vtkGenericWarningMacro("Unknown cell type " << cellType);
          cellArrayIt += 1+numPoints;
          continue;
          }
        if (cellTypeDimensions[cellType] != dimensionality)
          {
          cellArrayIt += 1+numPoints;
          continue;
          }
        cellArrayIt++;
        
        //find min and max values in scalar data
        range[0] = scalarArrayPtr[cellArrayPtr[cellArrayIt]];
        range[1] = scalarArrayPtr[cellArrayPtr[cellArrayIt]];
        cellArrayIt++;
        
        for (i = 1; i < numPoints; i++)
          {
          tempScalar = scalarArrayPtr[cellArrayPtr[cellArrayIt]];
          cellArrayIt++;
          if (tempScalar <= range[0])
            {
            range[0] = tempScalar;
            } //if tempScalar <= min range value
          if (tempScalar >= range[1])
            {
            range[1] = tempScalar;
            } //if tempScalar >= max range value
          } // for all points in this cell
        
        if (dimensionality == 3 &&  ! (cellId % 5000) ) 
          {
          self->UpdateProgress (static_cast<double>(cellId)/numCells);
          if (self->GetAbortExecute())
            {
            abortExecute = 1;
            break;
            }
          }
        
        for (i = 0; i < numContours; i++)
          {
          if ((values[i] >= range[0]) && (values[i] <= range[1]))
            {
            needCell = 1;
            } // if contour value in range for this cell
          } // end for numContours
        
        if (needCell)
          {
          cell = input->GetCell(cellId);
          cellPts = cell->GetPointIds();
          inScalars->GetTuples(cellPts,cellScalars);
          
          for (i=0; i < numContours; i++)
            {
            if ((values[i] >= range[0]) && (values[i] <= range[1]))
              {
              cell->Contour(values[i], cellScalars, locator,
                            newVerts, newLines, newPolys, inPd, outPd,
                            inCd, cellId, outCd);
              } // if contour value in range of values for this cell
            } // for all contour values
          } // if contour goes through this cell
        needCell = 0;
        } // for all cells
      } // For all dimensions.
    } //if using scalar tree
  else
    {
    // Note: This will have problems when input contains 2D and 3D cells.
    // CellData will get scrabled because of the implicit ordering of
    // verts, lines and polys in vtkPolyData.  The solution
    // is to convert this filter to create unstructured grid.
    //
    if ( scalarTree == NULL )
      {
      scalarTree = vtkSimpleScalarTree::New();
      }
    scalarTree->SetDataSet(input);
    //
    // Loop over all contour values.  Then for each contour value, 
    // loop over all cells.
    //
    for (i=0; i < numContours; i++)
      {
      for ( scalarTree->InitTraversal(values[i]); 
          (cell=scalarTree->GetNextCell(cellId,cellPts,cellScalars)) != NULL; )
        {
        cell->Contour(values[i], cellScalars, locator,
                      newVerts, newLines, newPolys, inPd, outPd,
                      inCd, cellId, outCd);
           //don't want to call Contour any more than necessary
        } //for all cells
      } //for all contour values
    } //using scalar tree

  //
  // Update ourselves.  Because we don't know up front how many verts, lines,
  // polys we've created, take care to reclaim memory. 
  //
  output->SetPoints(newPts);
  newPts->Delete();
  cellScalars->Delete();
  
  if (newVerts->GetNumberOfCells())
    {
    output->SetVerts(newVerts);
    }
  newVerts->Delete();

  if (newLines->GetNumberOfCells())
    {
    output->SetLines(newLines);
    }
  newLines->Delete();

  if (newPolys->GetNumberOfCells())
    {
    output->SetPolys(newPolys);
    }
  newPolys->Delete();

  locator->Initialize();//releases leftover memory
  output->Squeeze();
}

//
// Contouring filter for unstructured grids.
//
int vtkContourGrid::RequestData(
  vtkInformation *vtkNotUsed(request),
  vtkInformationVector **inputVector,
  vtkInformationVector *outputVector)
{
  // get the info objects
  vtkInformation *inInfo = inputVector[0]->GetInformationObject(0);
  vtkInformation *outInfo = outputVector->GetInformationObject(0);

  // get the input and output
  vtkUnstructuredGrid *input = vtkUnstructuredGrid::SafeDownCast(
    inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkPolyData *output = vtkPolyData::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));

  vtkDataArray *inScalars;
  void *scalarArrayPtr;
  vtkIdType numCells;
  int numContours = this->ContourValues->GetNumberOfContours();
  double *values = this->ContourValues->GetValues();
  int computeScalars = this->ComputeScalars;
  int useScalarTree = this->UseScalarTree;
  vtkScalarTree *&scalarTree = this->ScalarTree;

  vtkDebugMacro(<< "Executing contour filter");

  if ( this->Locator == NULL )
    {
    this->CreateDefaultLocator();
    }

  numCells = input->GetNumberOfCells();
  inScalars = this->GetInputArrayToProcess(0,inputVector);
  if ( ! inScalars || numCells < 1 )
    {
    vtkDebugMacro(<<"No data to contour");
    return 1;
    }

  scalarArrayPtr = inScalars->GetVoidPointer(0);
        
  switch (inScalars->GetDataType())
    {
    vtkTemplateMacro(
      vtkContourGridExecute(this, input, output, inScalars,
                            static_cast<VTK_TT *>(scalarArrayPtr),
                            numContours, values,computeScalars, useScalarTree, 
                            scalarTree));
    default:
      vtkErrorMacro(<< "Execute: Unknown ScalarType");
      return 1;
    }

  return 1;
}

// Specify a spatial locator for merging points. By default, 
// an instance of vtkMergePoints is used.
void vtkContourGrid::SetLocator(vtkIncrementalPointLocator *locator)
{
  if ( this->Locator == locator ) 
    {
    return;
    }
  if ( this->Locator )
    {
    this->Locator->UnRegister(this);
    this->Locator = NULL;
    }
  if ( locator )
    {
    locator->Register(this);
    }
  this->Locator = locator;
  this->Modified();
}

void vtkContourGrid::CreateDefaultLocator()
{
  if ( this->Locator == NULL )
    {
    this->Locator = vtkMergePoints::New();
    this->Locator->Register(this);
    this->Locator->Delete();
    }
}

int vtkContourGrid::FillInputPortInformation(int, vtkInformation *info)
{
  info->Set(vtkAlgorithm::INPUT_REQUIRED_DATA_TYPE(), "vtkUnstructuredGrid");
  return 1;
}

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

  os << indent << "Compute Gradients: " 
     << (this->ComputeGradients ? "On\n" : "Off\n");
  os << indent << "Compute Normals: " 
     << (this->ComputeNormals ? "On\n" : "Off\n");
  os << indent << "Compute Scalars: " 
     << (this->ComputeScalars ? "On\n" : "Off\n");
  os << indent << "Use Scalar Tree: " 
     << (this->UseScalarTree ? "On\n" : "Off\n");

  this->ContourValues->PrintSelf(os,indent.GetNextIndent());

  if ( this->Locator )
    {
    os << indent << "Locator: " << this->Locator << "\n";
    }
  else
    {
    os << indent << "Locator: (none)\n";
    }
}