// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-FileCopyrightText: Copyright (c) 2006 Atamai, Inc.
// SPDX-License-Identifier: BSD-3-Clause

#include "vtkMNITransformReader.h"

#include "vtkObjectFactory.h"

#include "vtkCollection.h"
#include "vtkDoubleArray.h"
#include "vtkGeneralTransform.h"
#include "vtkGridTransform.h"
#include "vtkImageData.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkMINCImageReader.h"
#include "vtkPlatform.h" // for VTK_MAXPATH
#include "vtkPoints.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkStringScanner.h"
#include "vtkThinPlateSplineTransform.h"
#include "vtkTransform.h"

#include <cctype>

#include <string>
#include <vector>
#include <vtksys/FStream.hxx>
#include <vtksys/SystemTools.hxx>

//------------------------------------------------------------------------------
VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkMNITransformReader);

//------------------------------------------------------------------------------
vtkMNITransformReader::vtkMNITransformReader()
{
  this->FileName = nullptr;
  this->Transform = nullptr;
  this->Transforms = vtkCollection::New();
  this->LineNumber = 0;
  this->Comments = nullptr;
}

//------------------------------------------------------------------------------
vtkMNITransformReader::~vtkMNITransformReader()
{
  if (this->Transforms)
  {
    this->Transforms->Delete();
  }
  if (this->Transform)
  {
    this->Transform->Delete();
  }
  delete[] this->FileName;
  delete[] this->Comments;
}

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

  os << indent << "FileName: " << (this->FileName ? this->FileName : "none") << "\n";
  os << indent << "Transform: " << this->Transform << "\n";
  if (this->Transform)
  {
    this->Transform->PrintSelf(os, indent.GetNextIndent());
  }
  os << indent << "NumberOfTransforms: " << this->Transforms->GetNumberOfItems() << "\n";
  os << indent << "Comments: " << (this->Comments ? this->Comments : "none") << "\n";
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::CanReadFile(const char* fname)
{
  // First make sure the file exists.  This prevents an empty file
  // from being created on older compilers.
  vtksys::SystemTools::Stat_t fs;
  if (vtksys::SystemTools::Stat(fname, &fs) != 0)
  {
    return 0;
  }

  // Try to read the first line of the file.
  int status = 0;

  vtksys::ifstream infile(fname);

  if (infile.good())
  {
    status = 1;
    char linetext[256];
    infile.getline(linetext, 256);
    if (strncmp(linetext, "MNI Transform File", 18) != 0)
    {
      status = 0;
    }

    infile.close();
  }

  return status;
}

//------------------------------------------------------------------------------
// Internal function to read in a line up to 256 characters and then
// skip to the next line in the file.
int vtkMNITransformReader::ReadLine(istream& infile, char result[256])
{
  this->LineNumber++;

  infile.getline(result, 256);
  if (infile.fail())
  {
    if (infile.eof())
    {
      return 0;
    }
    if (infile.gcount() == 255)
    {
      // Read 256 chars; ignoring the rest of the line.
      infile.clear();
      infile.ignore(VTK_INT_MAX, '\n');
      vtkWarningMacro(
        "Overlength line (limit is 255) in " << this->FileName << ":" << this->LineNumber);
    }
  }

  return 1;
}

//------------------------------------------------------------------------------
// Skip all blank lines or comment lines and return the first useful line
int vtkMNITransformReader::ReadLineAfterComments(istream& infile, char result[256])
{
  // Skip over any comment lines or blank lines.
  // Comment lines start with '%'
  std::string comments;
  do
  {
    this->ReadLine(infile, result);
    const char* cp = result;
    while (*cp && isspace(*cp))
    {
      cp++;
    }
    if (result[0] == '%')
    {
      if (!comments.empty())
      {
        comments.append("\n");
      }
      comments.append(result);
    }
    else if (*cp != '\0')
    {
      delete[] this->Comments;
      this->Comments = new char[comments.length() + 1];
      strncpy(this->Comments, comments.c_str(), comments.length());
      this->Comments[comments.length()] = '\0';
      return 1;
    }
  } while (infile.good());

  return 0;
}

//------------------------------------------------------------------------------
// Skip all whitespace, reading additional lines if necessary
int vtkMNITransformReader::SkipWhitespace(istream& infile, char linetext[256], char** cpp)
{
  char* cp = *cpp;

  while (infile.good())
  {
    // Skip leading whitespace
    while (isspace(*cp))
    {
      cp++;
    }

    if (*cp != '\0')
    {
      *cpp = cp;
      return 1;
    }

    this->ReadLine(infile, linetext);
    cp = linetext;
  }

  return 0;
}

//------------------------------------------------------------------------------
// Read the left hand side of a statement, including the equals sign
// and any whitespace following the equals.
int vtkMNITransformReader::ParseLeftHandSide(
  istream& infile, char linetext[256], char** cpp, char identifier[256])
{
  int i = 0;
  char* cp = *cpp;

  // Read alphanumeric plus underscore
  if (!isdigit(*cp))
  {
    while ((isalnum(*cp) || *cp == '_') && i < 255)
    {
      identifier[i++] = *cp++;
    }
  }
  identifier[i] = '\0';

  // Skip trailing whitespace
  while (isspace(*cp))
  {
    cp++;
  }

  // Check for equals
  this->SkipWhitespace(infile, linetext, &cp);
  if (*cp != '=')
  {
    vtkErrorMacro("Missing \'=\' " << this->FileName << ":" << this->LineNumber);
    return 0;
  }
  cp++;

  // Skip ahead to the value part of the statement
  this->SkipWhitespace(infile, linetext, &cp);

  *cpp = cp;

  return 1;
}

//------------------------------------------------------------------------------
// Read a string value.  The terminating semicolon will be read, but
// won't be included in the output string.  Neither will any
// whitespace occurring before the semicolon. The string may not be
// split across multiple lines.
int vtkMNITransformReader::ParseStringValue(
  istream& infile, char linetext[256], char** cpp, char data[256])
{
  int i = 0;
  char* cp = *cpp;

  this->SkipWhitespace(infile, linetext, &cp);

  // Read until end of the line or semicolon
  while (*cp && *cp != ';' && i < 255)
  {
    data[i++] = *cp++;
  }

  // Remove trailing whitespace
  while (i > 0 && isspace(data[i - 1]))
  {
    i--;
  }

  data[i] = '\0';

  this->SkipWhitespace(infile, linetext, &cp);
  if (*cp != ';')
  {
    vtkErrorMacro("Missing semicolon " << this->FileName << ":" << this->LineNumber);
    return 0;
  }
  cp++;

  *cpp = cp;

  return 1;
}

//------------------------------------------------------------------------------
// Read floating-point values into a vtkDoubleArray until a semicolon
// is reached.  The semicolon is also read.
int vtkMNITransformReader::ParseFloatValues(
  istream& infile, char linetext[256], char** cpp, vtkDoubleArray* array)
{
  char* cp = *cpp;

  this->SkipWhitespace(infile, linetext, &cp);
  while (infile.good() && *cp != ';')
  {
    const char* tmp = cp;
    auto result = vtk::scan_value<double>(std::string_view(tmp));
    auto val = result ? result->value() : 0.0;
    cp = const_cast<char*>(result->range().data());
    array->InsertNextValue(val);
    this->SkipWhitespace(infile, linetext, &cp);
  }

  if (*cp != ';')
  {
    vtkErrorMacro("Missing semicolon " << this->FileName << ":" << this->LineNumber);
    return 0;
  }
  cp++;

  *cpp = cp;

  return 1;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::ParseInvertFlagValue(
  istream& infile, char linetext[256], char** cpp, int* invertFlag)
{
  char data[256];

  if (!this->ParseStringValue(infile, linetext, cpp, data))
  {
    return 0;
  }
  if (strcmp(data, "False") == 0)
  {
    *invertFlag = 0;
  }
  else if (strcmp(data, "True") == 0)
  {
    *invertFlag = 1;
  }
  else
  {
    vtkErrorMacro(
      "Invert_Flag must be \'True\' or \'False\' " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  return 1;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::ReadLinearTransform(istream& infile, char linetext[256], char** cpp)
{
  // Read the first variable
  this->SkipWhitespace(infile, linetext, cpp);
  char identifier[256];
  if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
  {
    return 0;
  }

  // Check for Invert_Flag
  int invertFlag = 0;
  if (strcmp(identifier, "Invert_Flag") == 0)
  {
    if (!this->ParseInvertFlagValue(infile, linetext, cpp, &invertFlag))
    {
      return 0;
    }

    this->SkipWhitespace(infile, linetext, cpp);
    if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
    {
      return 0;
    }
  }

  // Check for Linear_Transform
  if (strcmp(identifier, "Linear_Transform") != 0)
  {
    vtkErrorMacro("Expected \'Linear_Transform\' in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  // Read twelve array elements from the file
  vtkDoubleArray* array = vtkDoubleArray::New();
  if (!this->ParseFloatValues(infile, linetext, cpp, array))
  {
    return 0;
  }

  if (array->GetNumberOfTuples() != 12)
  {
    vtkErrorMacro("Linear transform must have exactly 12 elements " << this->FileName << ":"
                                                                    << this->LineNumber);
    array->Delete();
    return 0;
  }

  // Fill in the last row of the 4x4 matrix
  array->InsertNextValue(0.0);
  array->InsertNextValue(0.0);
  array->InsertNextValue(0.0);
  array->InsertNextValue(1.0);

  // Create the transform
  vtkTransform* transform = vtkTransform::New();
  transform->Concatenate(array->GetPointer(0));
  array->Delete();
  if (invertFlag)
  {
    transform->Inverse();
  }

  this->Transforms->AddItem(transform);
  transform->Delete();

  return 1;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::ReadThinPlateSplineTransform(
  istream& infile, char linetext[256], char** cpp)
{
  // Read the first variable
  this->SkipWhitespace(infile, linetext, cpp);
  char identifier[256];
  if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
  {
    return 0;
  }

  // Check for Invert_Flag
  int invertFlag = 0;
  if (strcmp(identifier, "Invert_Flag") == 0)
  {
    if (!this->ParseInvertFlagValue(infile, linetext, cpp, &invertFlag))
    {
      return 0;
    }

    this->SkipWhitespace(infile, linetext, cpp);
    if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
    {
      return 0;
    }
  }

  // Number_Dimensions: vtkThinPlateSplineTransform supports 2 and 3
  if (strcmp(identifier, "Number_Dimensions") != 0)
  {
    vtkErrorMacro(
      "Expected \'Number_Dimensions\' in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  char data[256];
  if (!this->ParseStringValue(infile, linetext, cpp, data))
  {
    return 0;
  }

  int numDimensions = data[0] - '0';
  if (data[1] != '\0' || numDimensions < 2 || numDimensions > 3)
  {
    vtkErrorMacro(
      "Number_Dimensions must be 2 or 3 in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  // Read the points
  this->SkipWhitespace(infile, linetext, cpp);
  if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
  {
    return 0;
  }

  if (strcmp(identifier, "Points") != 0)
  {
    vtkErrorMacro("Expected \'Points\' in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  vtkDoubleArray* points = vtkDoubleArray::New();
  if (!this->ParseFloatValues(infile, linetext, cpp, points))
  {
    points->Delete();
    return 0;
  }

  if (points->GetNumberOfTuples() % numDimensions != 0)
  {
    points->Delete();
    vtkErrorMacro("Points list not divisible by Number_Dimensions in " << this->FileName << ":"
                                                                       << this->LineNumber);
    return 0;
  }

  // Read the displacements
  this->SkipWhitespace(infile, linetext, cpp);
  if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
  {
    points->Delete();
    return 0;
  }

  if (strcmp(identifier, "Displacements") != 0)
  {
    points->Delete();
    vtkErrorMacro("Expected \'Displacements\' in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  vtkDoubleArray* displacements = vtkDoubleArray::New();
  if (!this->ParseFloatValues(infile, linetext, cpp, displacements))
  {
    displacements->Delete();
    points->Delete();
    return 0;
  }

  if (displacements->GetNumberOfTuples() !=
    points->GetNumberOfTuples() + numDimensions * (numDimensions + 1))
  {
    displacements->Delete();
    points->Delete();
    vtkErrorMacro(
      "Incorrect number of Displacements in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  // The vtkThinPlateSplineTransform expects two sets of points,
  // not a set of points and a set of displacements.  We need
  // to perform a thin-plate spline transform to get the points
  // that we need.

  int numPoints = points->GetNumberOfTuples() / numDimensions;
  int i = 0;
  int j = 0;

  // Convert points and displacements to 3D
  double(*q)[3] = new double[numPoints][3];
  double(*W)[3] = new double[numPoints][3];
  for (i = 0; i < numPoints; i++)
  {
    double* point = q[i];
    double* displacement = W[i];
    point[0] = point[1] = point[2] = 0.0;
    displacement[0] = displacement[1] = displacement[2] = 0.0;
    for (j = 0; j < numDimensions; j++)
    {
      point[j] = points->GetValue(i * numDimensions + j);
      displacement[j] = displacements->GetValue(i * numDimensions + j);
    }
  }

  // Get the translation from the TPS matrix
  double C[3];
  C[0] = C[1] = C[2] = 0.0;
  for (j = 0; j < numDimensions; j++)
  {
    C[j] = displacements->GetValue(numPoints * numDimensions + j);
  }

  // Get the square matrix portion of the TPS matrix
  double A[3][3];
  A[0][1] = A[0][2] = A[1][0] = A[1][2] = A[2][0] = A[2][1] = 0.0;
  A[0][0] = A[1][1] = A[2][2] = 1.0;
  for (i = 0; i < numDimensions; i++)
  {
    for (j = 0; j < numDimensions; j++)
    {
      A[i][j] = displacements->GetValue((numPoints + 1 + i) * numDimensions + j);
    }
  }

  displacements->Delete();
  points->Delete();

  // Create the source and target point lists
  vtkPoints* source = vtkPoints::New();
  vtkPoints* target = vtkPoints::New();
  for (i = 0; i < numPoints; i++)
  {
    double* p = q[i];
    double x = 0.0;
    double y = 0.0;
    double z = 0.0;

    for (j = 0; j < numPoints; j++)
    {
      double dx = p[0] - q[j][0];
      double dy = p[1] - q[j][1];
      double dz = p[2] - q[j][2];
      double r = sqrt(dx * dx + dy * dy + dz * dz);
      double U = ((numDimensions == 2 && r != 0) ? r * r * log(r) : r);
      x += U * W[j][0];
      y += U * W[j][1];
      z += U * W[j][2];
    }

    x += C[0] + p[0] * A[0][0] + p[1] * A[1][0] + p[2] * A[2][0];
    y += C[1] + p[0] * A[0][1] + p[1] * A[1][1] + p[2] * A[2][1];
    z += C[2] + p[0] * A[0][2] + p[1] * A[1][2] + p[2] * A[2][2];

    source->InsertNextPoint(p);
    target->InsertNextPoint(x, y, z);
  }

  delete[] q;
  delete[] W;

  // Create the thin plate spline transform
  vtkThinPlateSplineTransform* transform = vtkThinPlateSplineTransform::New();
  transform->SetSourceLandmarks(source);
  transform->SetTargetLandmarks(target);
  if (numDimensions == 2)
  {
    transform->SetBasisToR2LogR();
  }
  else
  {
    transform->SetBasisToR();
  }

  if (invertFlag)
  {
    transform->Inverse();
  }

  source->Delete();
  target->Delete();

  this->Transforms->AddItem(transform);
  transform->Delete();

  return 1;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::ReadGridTransform(istream& infile, char linetext[256], char** cpp)
{
  // Read the first variable
  this->SkipWhitespace(infile, linetext, cpp);
  char identifier[256];
  if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
  {
    return 0;
  }

  // Check for Invert_Flag
  int invertFlag = 0;
  if (strcmp(identifier, "Invert_Flag") == 0)
  {
    if (!this->ParseInvertFlagValue(infile, linetext, cpp, &invertFlag))
    {
      return 0;
    }

    this->SkipWhitespace(infile, linetext, cpp);
    if (!this->ParseLeftHandSide(infile, linetext, cpp, identifier))
    {
      return 0;
    }
  }

  // Displacement_Volume must be a minc file
  if (strcmp(identifier, "Displacement_Volume") != 0)
  {
    vtkErrorMacro(
      "Expected \'Displacement_Volume\' in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  char filename[VTK_MAXPATH];
  if (!this->ParseStringValue(infile, linetext, cpp, filename))
  {
    return 0;
  }

  // Create the minc reader
  vtkMINCImageReader* reader = vtkMINCImageReader::New();

  std::vector<std::string> xfmpath;
  std::vector<std::string> mincpath;

  vtksys::SystemTools::SplitPath(this->FileName, xfmpath);
  vtksys::SystemTools::SplitPath(filename, mincpath);

  // Join minc filename to this->FileName if filename is relative
  if (mincpath[0].empty())
  {
    xfmpath.pop_back();
    xfmpath.insert(xfmpath.end(), mincpath.begin() + 1, mincpath.end());
    reader->SetFileName(vtksys::SystemTools::JoinPath(xfmpath).c_str());
  }
  else
  {
    reader->SetFileName(filename);
  }

  // Read the minc file now, rather than later
  reader->Update();

  // Create the transform
  vtkGridTransform* transform = vtkGridTransform::New();
  transform->SetDisplacementGridConnection(reader->GetOutputPort());
  transform->SetDisplacementShift(reader->GetRescaleIntercept());
  transform->SetDisplacementScale(reader->GetRescaleSlope());
  transform->SetInverseTolerance(0.05);
  transform->SetInterpolationModeToCubic();

  if (invertFlag)
  {
    transform->Inverse();
  }

  reader->Delete();

  this->Transforms->AddItem(transform);
  transform->Delete();

  return 1;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::ReadNextTransform(istream& infile, char linetext[256])
{
  // Check for errors
  if (infile.eof())
  {
    return 1;
  }
  else if (infile.fail())
  {
    vtkErrorMacro("IO error while reading " << this->FileName);
    return 0;
  }

  // Parse the file
  char* cp = linetext;

  // Check for Transform_Type
  char identifier[256];
  this->SkipWhitespace(infile, linetext, &cp);
  if (!this->ParseLeftHandSide(infile, linetext, &cp, identifier))
  {
    return 0;
  }

  if (strcmp(identifier, "Transform_Type") != 0)
  {
    vtkErrorMacro("Expected Transform_Type in " << this->FileName << ":" << this->LineNumber);
    return 0;
  }

  // Read the transform type
  char transformType[256];
  if (!this->ParseStringValue(infile, linetext, &cp, transformType))
  {
    return 0;
  }

  // Check the transform type
  if (strcmp(transformType, "Linear") == 0)
  {
    return this->ReadLinearTransform(infile, linetext, &cp);
  }
  else if (strcmp(transformType, "Thin_Plate_Spline_Transform") == 0)
  {
    return this->ReadThinPlateSplineTransform(infile, linetext, &cp);
  }
  else if (strcmp(transformType, "Grid_Transform") == 0)
  {
    return this->ReadGridTransform(infile, linetext, &cp);
  }

  vtkErrorMacro(
    "Unrecognized type " << transformType << " in " << this->FileName << ":" << this->LineNumber);
  return 0;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::ReadFile()
{
  this->Transforms->RemoveAllItems();
  this->SetTransform(nullptr);

  // Check that the file name has been set.
  if (!this->FileName)
  {
    vtkErrorMacro("ReadFile: No file name has been set");
    return 0;
  }

  // Make sure that the file exists.
  vtksys::SystemTools::Stat_t fs;
  if (vtksys::SystemTools::Stat(this->FileName, &fs) != 0)
  {
    vtkErrorMacro("ReadFile: Can't open file " << this->FileName);
    return 0;
  }

  // Make sure that the file is readable.
  vtksys::ifstream infile(this->FileName);

  if (infile.fail())
  {
    vtkErrorMacro("ReadFile: Can't read the file " << this->FileName);
    return 0;
  }

  // Read the first line
  char linetext[256];
  this->LineNumber = 0;
  this->ReadLine(infile, linetext);
  if (strncmp(linetext, "MNI Transform File", 18) != 0)
  {
    vtkErrorMacro("ReadFile: File is not a MNI xfm file: " << this->FileName);
    infile.close();
    return 0;
  }

  // Read the comments
  this->ReadLineAfterComments(infile, linetext);

  // Read the transforms
  while (infile.good())
  {
    if (this->ReadNextTransform(infile, linetext) == 0)
    {
      this->Transforms->RemoveAllItems();
      infile.close();
      return 0;
    }
    this->ReadLine(infile, linetext);
  }

  // Close the file
  infile.close();

  // Create the output transform.
  int n = this->Transforms->GetNumberOfItems();
  if (n == 1)
  {
    this->SetTransform((vtkAbstractTransform*)this->Transforms->GetItemAsObject(0));
  }
  else
  {
    // Determine whether the full transform is linear
    int linear = 1;
    int i = 0;
    for (i = 0; i < n; i++)
    {
      if (!this->Transforms->GetItemAsObject(i)->IsA("vtkLinearTransform"))
      {
        linear = 0;
        break;
      }
    }

    // If linear, use vtkTransform to concatenate,
    // else use vtkGeneralTransform.
    if (linear)
    {
      vtkTransform* transform = vtkTransform::New();
      transform->PostMultiply();
      for (i = 0; i < n; i++)
      {
        vtkLinearTransform* linearTransform =
          (vtkLinearTransform*)this->Transforms->GetItemAsObject(i);
        transform->Concatenate(linearTransform->GetMatrix());
      }
      this->SetTransform(transform);
      transform->Delete();
    }
    else
    {
      vtkGeneralTransform* transform = vtkGeneralTransform::New();
      transform->PostMultiply();
      for (i = 0; i < n; i++)
      {
        vtkAbstractTransform* abstractTransform =
          (vtkAbstractTransform*)this->Transforms->GetItemAsObject(i);
        if (abstractTransform->IsA("vtkLinearTransform"))
        {
          transform->Concatenate(((vtkLinearTransform*)abstractTransform)->GetMatrix());
        }
        else
        {
          transform->Concatenate(abstractTransform);
        }
      }
      this->SetTransform(transform);
      transform->Delete();
    }
  }

  return 1;
}

//------------------------------------------------------------------------------
vtkTypeBool vtkMNITransformReader::ProcessRequest(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (request->Has(vtkDemandDrivenPipeline::REQUEST_DATA()))
  {
    return this->ReadFile();
  }

  return this->Superclass::ProcessRequest(request, inputVector, outputVector);
}

//------------------------------------------------------------------------------
void vtkMNITransformReader::SetTransform(vtkAbstractTransform* transform)
{
  if (this->Transform != transform)
  {
    if (this->Transform)
    {
      this->Transform->Delete();
    }
    if (transform)
    {
      transform->Register(this);
    }
    this->Transform = transform;
  }
}

//------------------------------------------------------------------------------
vtkAbstractTransform* vtkMNITransformReader::GetTransform()
{
  this->Update();

  return this->Transform;
}

//------------------------------------------------------------------------------
int vtkMNITransformReader::GetNumberOfTransforms()
{
  this->Update();

  return this->Transforms->GetNumberOfItems();
}

//------------------------------------------------------------------------------
vtkAbstractTransform* vtkMNITransformReader::GetNthTransform(int i)
{
  this->Update();

  if (i < 0 || i >= this->Transforms->GetNumberOfItems())
  {
    return nullptr;
  }

  return (vtkAbstractTransform*)this->Transforms->GetItemAsObject(i);
}

//------------------------------------------------------------------------------
const char* vtkMNITransformReader::GetComments()
{
  this->Update();

  return this->Comments;
}
VTK_ABI_NAMESPACE_END