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

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

#include "vtkCell.h"
#include "vtkCellData.h"
#include "vtkCutter.h"
#include "vtkMath.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkPlane.h"
#include "vtkPointData.h"
#include "vtkPolyData.h"
#include "vtkThreshold.h"
#include "vtkUnstructuredGrid.h"

vtkStandardNewMacro(vtkCutMaterial);

// Instantiate object with no input and no defined output.
vtkCutMaterial::vtkCutMaterial()
{
  this->MaterialArrayName = NULL;
  this->SetMaterialArrayName("material");
  this->Material = 0;
  this->ArrayName = NULL;
  
  this->UpVector[0] = 0.0;
  this->UpVector[1] = 0.0;
  this->UpVector[2] = 1.0;
  
  this->MaximumPoint[0] = 0.0;
  this->MaximumPoint[1] = 0.0;
  this->MaximumPoint[2] = 0.0;
 
  this->CenterPoint[0] = 0.0;
  this->CenterPoint[1] = 0.0;
  this->CenterPoint[2] = 0.0;
  
  this->Normal[0] = 0.0;
  this->Normal[1] = 1.0;
  this->Normal[2] = 0.0;
  
  this->PlaneFunction = vtkPlane::New();
}

vtkCutMaterial::~vtkCutMaterial()
{
  this->PlaneFunction->Delete();
  this->PlaneFunction = NULL;

  this->SetMaterialArrayName(NULL);
  this->SetArrayName(NULL);
}

int vtkCutMaterial::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
  vtkDataSet *input = vtkDataSet::SafeDownCast(
    inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkPolyData *output = vtkPolyData::SafeDownCast(
    outInfo->Get(vtkDataObject::DATA_OBJECT()));

  vtkThreshold *thresh;
  vtkCutter *cutter;
  double *bds;
  
  // Check to see if we have the required field arrays.
  if (this->MaterialArrayName == NULL || this->ArrayName == NULL)
    {
    vtkErrorMacro("Material and Array names must be set.");
    return 0;
    }
  
  if (input->GetCellData()->GetArray(this->MaterialArrayName) == NULL)
    {
    vtkErrorMacro("Could not find cell array " << this->MaterialArrayName);
    return 0;
    }
  if (input->GetCellData()->GetArray(this->ArrayName) == NULL)
    {
    vtkErrorMacro("Could not find cell array " << this->ArrayName);
    return 0;
    }
  
  // It would be nice to get rid of this in the future.
  thresh = vtkThreshold::New();
  thresh->SetInput(input);
  thresh->SetInputArrayToProcess(0,0,0,vtkDataObject::FIELD_ASSOCIATION_CELLS,
                                 this->MaterialArrayName);
  thresh->ThresholdBetween(this->Material-0.5, this->Material+0.5);
  thresh->Update();
  
  bds = thresh->GetOutput()->GetBounds();
  this->CenterPoint[0] = 0.5 * (bds[0] + bds[1]);
  this->CenterPoint[1] = 0.5 * (bds[2] + bds[3]);
  this->CenterPoint[2] = 0.5 * (bds[4] + bds[5]);
  
  this->ComputeMaximumPoint(thresh->GetOutput());
  this->ComputeNormal();
  
  this->PlaneFunction->SetOrigin(this->CenterPoint);
  this->PlaneFunction->SetNormal(this->Normal);
  
  cutter = vtkCutter::New();
  cutter->SetInput(thresh->GetOutput());
  cutter->SetCutFunction(this->PlaneFunction);
  cutter->SetValue(0, 0.0);
  cutter->Update();

  output->CopyStructure(cutter->GetOutput());
  output->GetPointData()->PassData(
           cutter->GetOutput()->GetPointData());
  output->GetCellData()->PassData(
           cutter->GetOutput()->GetCellData());

  cutter->Delete();
  thresh->Delete();

  return 1;
}

void vtkCutMaterial::ComputeNormal()
{
  double tmp[3];
  double mag;
  
  if (this->UpVector[0] == 0.0 && this->UpVector[1] == 0.0 && this->UpVector[2] == 0.0)
    {
    vtkErrorMacro("Zero magnitude UpVector.");
    this->UpVector[2] = 1.0;
    }
  
  tmp[0] = this->MaximumPoint[0] - this->CenterPoint[0];
  tmp[1] = this->MaximumPoint[1] - this->CenterPoint[1];
  tmp[2] = this->MaximumPoint[2] - this->CenterPoint[2];
  vtkMath::Cross(tmp, this->UpVector, this->Normal);
  mag = vtkMath::Normalize(this->Normal);
  // Rare singularity
  while (mag == 0.0)
    { 
    tmp[0] = vtkMath::Random();
    tmp[1] = vtkMath::Random();
    tmp[2] = vtkMath::Random();
    vtkMath::Cross(tmp, this->UpVector, this->Normal);
    mag = vtkMath::Normalize(this->Normal);
    }
}

void vtkCutMaterial::ComputeMaximumPoint(vtkDataSet *input)
{
  vtkDataArray *data;
  vtkIdType idx, bestIdx, num;
  double comp, best;
  vtkCell *cell;
  double *bds;
  
  // Find the maximum value.
  data = input->GetCellData()->GetArray(this->ArrayName);
  if (data == NULL)
    {
    vtkErrorMacro("What happened to the array " << this->ArrayName);
    return;
    }

  num = data->GetNumberOfTuples();
  if (num <= 0)
    {
    vtkErrorMacro("No values in array " << this->ArrayName);
    return;
    }
    
  best = data->GetComponent(0, 0);
  bestIdx = 0;
  for (idx = 1; idx < num; ++idx)
    {
    comp = data->GetComponent(idx, 0);
    if (comp > best)
      {
      best = comp;
      bestIdx = idx;
      }
    }
  
  // Get the cell with the larges value.
  cell = input->GetCell(bestIdx);
  bds = cell->GetBounds();
  this->MaximumPoint[0] = (bds[0] + bds[1]) * 0.5;
  this->MaximumPoint[1] = (bds[2] + bds[3]) * 0.5;
  this->MaximumPoint[2] = (bds[4] + bds[5]) * 0.5;  
}

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

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

  os << indent << "ArrayName: ";
  if ( this->ArrayName)
    {
    os << this->ArrayName << endl;
    }
  else
    {
    os << "(None)" << endl;
    }
  os << indent << "MaterialArrayName: " << this->MaterialArrayName << endl;
  os << indent << "Material: " << this->Material << endl;
  
  os << indent << "UpVector: " << this->UpVector[0] << ", "
     << this->UpVector[1] << ", " << this->UpVector[2] << endl;
  
  os << indent << "MaximumPoint: " << this->MaximumPoint[0] << ", "
     << this->MaximumPoint[1] << ", " << this->MaximumPoint[2] << endl;
  os << indent << "CenterPoint: " << this->CenterPoint[0] << ", "
     << this->CenterPoint[1] << ", " << this->CenterPoint[2] << endl;
  os << indent << "Normal: " << this->Normal[0] << ", "
     << this->Normal[1] << ", " << this->Normal[2] << endl;
}