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

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

// VTK includes
#include "vtkCallbackCommand.h"
#include "vtkCellArray.h"
#include "vtkCellData.h"
#include "vtkDataArraySelection.h"
#include "vtkDoubleArray.h"
#include "vtkFloatArray.h"
#include "vtkGDAL.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkIntArray.h"
#include "vtkLookupTable.h"
#include "vtkMath.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkPoints.h"
#include "vtkShortArray.h"
#include "vtkSmartPointer.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkStringArray.h"
#include "vtkUniformGrid.h"
#include "vtkUnsignedCharArray.h"
#include "vtkUnsignedIntArray.h"
#include "vtkUnsignedShortArray.h"

// GDAL includes
#include <gdal_priv.h>
#include <ogr_spatialref.h>

// C/C++ includes
#include <cassert>
#include <cmath>
#include <iostream>
#include <sstream>
#include <vector>

vtkStandardNewMacro(vtkGDALRasterReader);

//------------------------------------------------------------------------------
class vtkGDALRasterReader::vtkGDALRasterReaderInternal
{
public:
  vtkGDALRasterReaderInternal(vtkGDALRasterReader* reader);
  ~vtkGDALRasterReaderInternal();

  void ReadMetaData(const std::string& fileName);
  void ReadData(const std::string& fileName);

  template <typename VTK_TYPE, typename RAW_TYPE>
  void GenericReadData();
  void ReleaseData();

  void GetOriginSpacing(double* origin, double* spacing, int* flip);

  template <typename VTK_TYPE, typename RAW_TYPE>
  void Convert(std::vector<RAW_TYPE>& rawUniformGridData, int targetWidth, int targetHeight,
    const std::vector<int>& groupIndex, const char* name, bool flipX, bool flipY);

  bool GetGeoCornerPoint(GDALDataset* dataset, double x, double y, double* out) const;

  const double* GetGeoCornerPoints();

  void ReadColorTable(GDALRasterBand* rasterBand, vtkLookupTable* colorTable) const;

  static void SelectionCallback(
    vtkObject* obj, unsigned long eventid, void* clientdata, void* calldata);

  std::string GetBandName(int bandIndex)
  {
    std::ostringstream ostr;
    ostr << "Band " << setfill('0') << setw(this->NumberOfDigitsForBands) << bandIndex;
    return ostr.str();
  }

  int NumberOfBands;
  int NumberOfDigitsForBands;
  int NumberOfBytesPerPixel;

  std::string PrevReadFileName;
  int RasterDimensions[2];

  GDALDataset* GDALData;
  GDALDataType TargetDataType;

  // Bad corner point
  double BadCornerPoint;

  // Upper left, lower left, upper right, lower right
  double CornerPoints[8];

  std::vector<int> HasNoDataValue;
  std::vector<double> NoDataValue;
  vtkIdType NumberOfCells;
  vtkDataArraySelection* CellArraySelection;
  vtkCallbackCommand* SelectionObserver;

  vtkSmartPointer<vtkUniformGrid> UniformGridData;
  vtkGDALRasterReader* Reader;
};

//------------------------------------------------------------------------------
vtkGDALRasterReader::vtkGDALRasterReaderInternal::vtkGDALRasterReaderInternal(
  vtkGDALRasterReader* reader)
  : NumberOfBands(0)
  , NumberOfDigitsForBands(0)
  , NumberOfBytesPerPixel(0)
  , GDALData(nullptr)
  , TargetDataType(GDT_Byte)
  , BadCornerPoint(-1)
  , NumberOfCells(0)
  , Reader(reader)
{
  for (int i = 0; i < 8; ++i)
  {
    this->CornerPoints[i] = this->BadCornerPoint;
  }
  this->RasterDimensions[0] = 0;
  this->RasterDimensions[1] = 0;
  this->CellArraySelection = vtkDataArraySelection::New();
  this->SelectionObserver = vtkCallbackCommand::New();
  this->SelectionObserver->SetCallback(
    &vtkGDALRasterReader::vtkGDALRasterReaderInternal::SelectionCallback);
  this->SelectionObserver->SetClientData(this);
  this->CellArraySelection->AddObserver(vtkCommand::ModifiedEvent, this->SelectionObserver);

  // Enable all the drivers.
  GDALAllRegister();
}

//------------------------------------------------------------------------------
vtkGDALRasterReader::vtkGDALRasterReaderInternal::~vtkGDALRasterReaderInternal()
{
  this->ReleaseData();
  this->CellArraySelection->Delete();
  this->CellArraySelection = nullptr;
  this->SelectionObserver->Delete();
  this->SelectionObserver = nullptr;
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::ReadMetaData(const std::string& fileName)
{
  if (fileName.compare(this->PrevReadFileName) == 0)
  {
    return;
  }

  // Free up the last read data, if any.
  this->ReleaseData();

  this->GDALData = static_cast<GDALDataset*>(GDALOpen(fileName.c_str(), GA_ReadOnly));

  if (this->GDALData == nullptr)
  {
    std::cout << "NO GDALData loaded for file " << fileName << std::endl;
  }
  else
  {
    this->PrevReadFileName = fileName;
    this->NumberOfBands = this->GDALData->GetRasterCount();
    this->NumberOfDigitsForBands = ceil(log10(this->NumberOfBands + 1));
    this->HasNoDataValue.resize(this->NumberOfBands, 0);
    this->NoDataValue.resize(this->NumberOfBands, 0);
    for (int i = 0; i < this->NumberOfBands; ++i)
    {
      this->CellArraySelection->EnableArray(this->GetBandName(i + 1).c_str());
    }

    // Clear last read metadata
    this->Reader->MetaData.clear();

    this->RasterDimensions[0] = this->GDALData->GetRasterXSize();
    this->RasterDimensions[1] = this->GDALData->GetRasterYSize();

    GDALDriverH driver = GDALGetDatasetDriver(this->GDALData);
    this->Reader->DriverShortName = GDALGetDriverShortName(driver);
    this->Reader->DriverLongName = GDALGetDriverLongName(driver);

    char** papszMetaData = GDALGetMetadata(this->GDALData, nullptr);
    if (CSLCount(papszMetaData) > 0)
    {
      for (int i = 0; papszMetaData[i] != nullptr; ++i)
      {
        this->Reader->MetaData.push_back(papszMetaData[i]);
      }
    }
  }
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::ReadData(const std::string& fileName)
{
  // If data is not initialized by now, it means that we were unable to read
  // the file.
  if (!this->GDALData)
  {
    std::cerr << "Failed to read: " << fileName << std::endl;
    return;
  }

  // all bands have the same data type (true for most drivers)
  // https://lists.osgeo.org/pipermail/gdal-dev/2016-September/045166.html
  GDALRasterBand* rasterBand = this->GDALData->GetRasterBand(1);
  if (this->NumberOfBytesPerPixel == 0)
  {
    this->TargetDataType = rasterBand->GetRasterDataType();
    switch (this->TargetDataType)
    {
      case (GDT_Byte):
        this->NumberOfBytesPerPixel = 1;
        break;
      case (GDT_UInt16):
        this->NumberOfBytesPerPixel = 2;
        break;
      case (GDT_Int16):
        this->NumberOfBytesPerPixel = 2;
        break;
      case (GDT_UInt32):
        this->NumberOfBytesPerPixel = 4;
        break;
      case (GDT_Int32):
        this->NumberOfBytesPerPixel = 4;
        break;
      case (GDT_Float32):
        this->NumberOfBytesPerPixel = 4;
        break;
      case (GDT_Float64):
        this->NumberOfBytesPerPixel = 8;
        break;
      default:
        this->NumberOfBytesPerPixel = 0;
        break;
    }
  }

  // Initialize
  this->UniformGridData = vtkSmartPointer<vtkUniformGrid>::New();
  this->NumberOfCells = 0;

  switch (this->TargetDataType)
  {
    case (GDT_UInt16):
    {
      this->Reader->SetDataScalarTypeToUnsignedShort();
      this->GenericReadData<vtkUnsignedShortArray, unsigned short>();
      break;
    }
    case (GDT_Int16):
    {
      this->Reader->SetDataScalarTypeToShort();
      this->GenericReadData<vtkShortArray, short>();
      break;
    }
    case (GDT_UInt32):
    {
      this->Reader->SetDataScalarTypeToUnsignedInt();
      this->GenericReadData<vtkUnsignedIntArray, unsigned int>();
      break;
    }
    case (GDT_Int32):
    {
      this->Reader->SetDataScalarTypeToInt();
      this->GenericReadData<vtkIntArray, int>();
      break;
    }
    case (GDT_Float32):
    {
      this->Reader->SetDataScalarTypeToFloat();
      this->GenericReadData<vtkFloatArray, float>();
      break;
    }
    case (GDT_Float64):
    {
      this->Reader->SetDataScalarTypeToDouble();
      this->GenericReadData<vtkDoubleArray, double>();
      break;
    }
    case (GDT_Byte):
    default:
    {
      this->Reader->SetDataScalarTypeToUnsignedChar();
      this->GenericReadData<vtkUnsignedCharArray, unsigned char>();
      break;
    }
  }
}

//------------------------------------------------------------------------------
template <typename VTK_TYPE, typename RAW_TYPE>
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::GenericReadData()
{
  // Pixel data.
  std::vector<RAW_TYPE> rawUniformGridData;

  // Color table
  vtkSmartPointer<vtkLookupTable> colorTable = vtkSmartPointer<vtkLookupTable>::New();

  // Possible bands
  GDALRasterBand* redBand = nullptr;
  int redIndex = 0;
  GDALRasterBand* greenBand = nullptr;
  int greenIndex = 0;
  GDALRasterBand* blueBand = nullptr;
  int blueIndex = 0;
  GDALRasterBand* alphaBand = nullptr;
  int alphaIndex = 0;
  GDALRasterBand* grayBand = nullptr;
  int grayIndex = 0;
  GDALRasterBand* paletteBand = nullptr;
  int paletteIndex = 0;
  std::vector<GDALRasterBand*> allBands(this->NumberOfBands, nullptr);

  int enabledBands = 0;
  for (int i = 1; i <= this->NumberOfBands; ++i)
  {
    GDALRasterBand* rasterBand = this->GDALData->GetRasterBand(i);
    this->HasNoDataValue[i - 1] = 0;
    this->NoDataValue[i - 1] = rasterBand->GetNoDataValue(&this->HasNoDataValue[i - 1]);
    if (!this->CellArraySelection->GetArraySetting(this->GetBandName(i).c_str()))
    {
      // not enabled
      continue;
    }
    allBands[i - 1] = rasterBand;
    ++enabledBands;
    if ((rasterBand->GetColorInterpretation() == GCI_RedBand ||
          rasterBand->GetColorInterpretation() == GCI_YCbCr_YBand) &&
      redIndex == 0)
    {
      redBand = rasterBand;
      redIndex = i;
    }
    else if ((rasterBand->GetColorInterpretation() == GCI_GreenBand ||
               rasterBand->GetColorInterpretation() == GCI_YCbCr_CbBand) &&
      greenIndex == 0)
    {
      greenBand = rasterBand;
      greenIndex = i;
    }
    else if ((rasterBand->GetColorInterpretation() == GCI_BlueBand ||
               rasterBand->GetColorInterpretation() == GCI_YCbCr_CrBand) &&
      blueIndex == 0)
    {
      blueBand = rasterBand;
      blueIndex = i;
    }
    else if (rasterBand->GetColorInterpretation() == GCI_AlphaBand && alphaIndex == 0)
    {
      alphaBand = rasterBand;
      alphaIndex = i;
    }
    else if (rasterBand->GetColorInterpretation() == GCI_GrayIndex && grayIndex == 0)
    {
      grayBand = rasterBand;
      grayIndex = i;
    }
    else if (rasterBand->GetColorInterpretation() == GCI_PaletteIndex && paletteIndex == 0)
    {
      paletteBand = rasterBand;
      paletteIndex = i;
    }
    else
    {
      // GCI_Undefined or duplicates for colors or gray
    }
  }

  const int& destWidth = this->Reader->TargetDimensions[0];
  const int& destHeight = this->Reader->TargetDimensions[1];

  // GDAL top left is at 0,0
  const int& windowX = 0;
  const int& windowY = 0;
  const int& windowWidth = this->RasterDimensions[0];
  const int& windowHeight = this->RasterDimensions[1];

  const int& pixelSpace = this->NumberOfBytesPerPixel;
  const int lineSpace = destWidth * pixelSpace;
  const int bandSpace = destWidth * destHeight * this->NumberOfBytesPerPixel;
  CPLErr err;

  double spacing[3];
  double origin[3];
  int flip[3];
  GetOriginSpacing(origin, spacing, flip);

  // destWidth, destHeight are the number of cells. Points are one more than cells
  this->UniformGridData->SetExtent(0, destWidth, 0, destHeight, 0, 0);
  this->UniformGridData->SetSpacing(spacing[0], spacing[1], spacing[2]);
  this->UniformGridData->SetOrigin(origin[0], origin[1], origin[2]);

  // band indexes are 0 based
  std::vector<int> groupIndex;
  double completedBand = 0.0;
  if (this->Reader->CollateBands)
  {
    if (redBand && greenBand && blueBand)
    {
      allBands[redIndex - 1] = nullptr;
      groupIndex.push_back(redIndex - 1);
      allBands[greenIndex - 1] = nullptr;
      groupIndex.push_back(greenIndex - 1);
      allBands[blueIndex - 1] = nullptr;
      groupIndex.push_back(blueIndex - 1);
      if (alphaBand)
      {
        allBands[alphaIndex - 1] = nullptr;
        groupIndex.push_back(alphaIndex - 1);
        this->Reader->SetNumberOfScalarComponents(4);
        rawUniformGridData.resize(4 * destWidth * destHeight * pixelSpace);

        err = redBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 0 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        err = greenBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 1 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        err = blueBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 2 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        err = alphaBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 3 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        completedBand = 4.0;
      }
      else
      {
        this->Reader->SetNumberOfScalarComponents(3);
        rawUniformGridData.resize(3 * destWidth * destHeight * pixelSpace);

        err = redBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 0 * bandSpace),
          destWidth, destHeight, this->TargetDataType, 0, 0);
        assert(err == CE_None);
        err = greenBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 1 * bandSpace),
          destWidth, destHeight, this->TargetDataType, 0, 0);
        assert(err == CE_None);
        err = blueBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 2 * bandSpace),
          destWidth, destHeight, this->TargetDataType, 0, 0);
        assert(err == CE_None);
        completedBand = 3.0;
      }
    }
    else if (grayBand)
    {
      allBands[grayIndex - 1] = nullptr;
      groupIndex.push_back(grayIndex - 1);
      if (alphaBand)
      {
        allBands[alphaIndex - 1] = nullptr;
        groupIndex.push_back(alphaIndex - 1);
        // Luminance alpha
        this->Reader->SetNumberOfScalarComponents(2);
        rawUniformGridData.resize(2 * destWidth * destHeight * pixelSpace);

        err = grayBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 0 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        err = alphaBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 1 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        completedBand = 2.0;
      }
      else
      {
        // Luminance
        this->Reader->SetNumberOfScalarComponents(1);
        rawUniformGridData.resize(destWidth * destHeight * pixelSpace);
        err = grayBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
          static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 0 * bandSpace),
          destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
        assert(err == CE_None);
        completedBand = 1.0;
      }
    }
    else if (paletteBand)
    {
      allBands[paletteIndex - 1] = nullptr;
      groupIndex.push_back(paletteIndex - 1);
      // Read indexes
      this->Reader->SetNumberOfScalarComponents(1);
      rawUniformGridData.resize(destWidth * destHeight * pixelSpace);
      err = paletteBand->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
        static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 0 * bandSpace),
        destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
      assert(err == CE_None);

      this->ReadColorTable(paletteBand, colorTable);
      completedBand = 1.0;
    }
    this->Reader->UpdateProgress(completedBand / enabledBands);
    (void)err; // unused
    this->Convert<VTK_TYPE, RAW_TYPE>(
      rawUniformGridData, destWidth, destHeight, groupIndex, "Elevation", flip[0], flip[1]);
    this->UniformGridData->GetCellData()->SetActiveScalars("Elevation");
  }
  groupIndex.resize(1, 0);
  rawUniformGridData.resize(destWidth * destHeight * pixelSpace);
  for (size_t i = 0; i < allBands.size(); ++i)
  {
    // bands already used are set to nullptr
    if (allBands[i])
    {
      groupIndex[0] = i;
      err = allBands[i]->RasterIO(GF_Read, windowX, windowY, windowWidth, windowHeight,
        static_cast<void*>(reinterpret_cast<GByte*>(&rawUniformGridData[0]) + 0 * bandSpace),
        destWidth, destHeight, this->TargetDataType, pixelSpace, lineSpace);
      assert(err == CE_None);
      this->Convert<VTK_TYPE, RAW_TYPE>(rawUniformGridData, destWidth, destHeight, groupIndex,
        this->GetBandName(i + 1).c_str(), flip[0], flip[1]);
      completedBand += 1;
      this->Reader->UpdateProgress(completedBand / enabledBands);
    }
  }

  if (paletteBand)
  {
    this->UniformGridData->GetCellData()->GetScalars()->SetName("Categories");
    this->UniformGridData->GetCellData()->GetScalars()->SetLookupTable(colorTable);
  }
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::ReleaseData()
{
  if (this->GDALData)
  {
    GDALClose(this->GDALData);
  }
  this->CellArraySelection->RemoveAllArrays();
}

//------------------------------------------------------------------------------
template <typename VTK_TYPE, typename RAW_TYPE>
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::Convert(
  std::vector<RAW_TYPE>& rawUniformGridData, int targetWidth, int targetHeight,
  const std::vector<int>& groupIndex, const char* name, bool flipX, bool flipY)
{
  if (!this->UniformGridData)
  {
    return;
  }

  double targetIndex;
  double sourceIndex;
  double min = rawUniformGridData[0], max = rawUniformGridData[0];

  vtkSmartPointer<VTK_TYPE> scArr(vtkSmartPointer<VTK_TYPE>::New());
  scArr->SetName(name);
  scArr->SetNumberOfComponents(groupIndex.size());
  scArr->SetNumberOfTuples(targetWidth * targetHeight);

  for (int j = 0; j < targetHeight; ++j)
  {
    int jIndex = flipY ? (targetHeight - 1 - j) : j;
    for (int i = 0; i < targetWidth; ++i)
    {
      int iIndex = flipX ? (targetWidth - 1 - i) : i;
      // Each band GDALData is stored in width * height size array.
      for (size_t bi = 0; bi < groupIndex.size(); ++bi)
      {
        int bandIndex = groupIndex[bi];
        RAW_TYPE TNoDataValue = 0;
        if (this->HasNoDataValue[bandIndex])
        {
          // GDAL returns NoData as double, so it is possible that max float
          // converted to double to be greater than max float, resulting in
          // warnings for clang -fsanitize=undefined
          double doubleNoData = this->NoDataValue[bandIndex];
          if (doubleNoData > std::numeric_limits<RAW_TYPE>::max())
          {
            TNoDataValue = std::numeric_limits<RAW_TYPE>::max();
          }
          else if (doubleNoData < std::numeric_limits<RAW_TYPE>::lowest())
          {
            TNoDataValue = std::numeric_limits<RAW_TYPE>::lowest();
          }
          else
          {
            TNoDataValue = static_cast<RAW_TYPE>(doubleNoData);
          }
        }

        targetIndex = i * groupIndex.size() + j * targetWidth * groupIndex.size() + bi;
        sourceIndex = iIndex + jIndex * targetWidth + bi * targetWidth * targetHeight;

        RAW_TYPE tmp = rawUniformGridData[sourceIndex];
        if (this->HasNoDataValue[bandIndex] && tmp == TNoDataValue)
        {
          this->UniformGridData->BlankCell(targetIndex);
        }
        else
        {
          if (tmp < min)
            min = tmp;
          if (tmp > max)
            max = tmp;
          this->NumberOfCells++;
        }

        scArr->InsertValue(targetIndex, rawUniformGridData[sourceIndex]);
      }
    }
  }
  this->UniformGridData->GetCellData()->AddArray(scArr);
}

//------------------------------------------------------------------------------
bool vtkGDALRasterReader::vtkGDALRasterReaderInternal::GetGeoCornerPoint(
  GDALDataset* dataset, double x, double y, double* out) const
{
  bool retVal = false;

  if (!dataset)
  {
    std::cerr << "Empty GDAL dataset" << std::endl;
    return retVal;
  }

  if (!out)
  {
    return retVal;
  }

  double dfGeoX = 0;
  double dfGeoY = 0;
  double adfGeoTransform[6];

  const char* gcpProj = this->GDALData->GetGCPProjection();
  const GDAL_GCP* gcps = this->GDALData->GetGCPs();

  if (gcpProj == nullptr || gcps == nullptr)
  {
    // Transform the point into georeferenced coordinates
    if (GDALGetGeoTransform(this->GDALData, adfGeoTransform) == CE_None)
    {
      dfGeoX = adfGeoTransform[0] + adfGeoTransform[1] * x + adfGeoTransform[2] * y;
      dfGeoY = adfGeoTransform[3] + adfGeoTransform[4] * x + adfGeoTransform[5] * y;

      retVal = true;
    }
    else
    {
      dfGeoX = x;
      dfGeoY = y;

      retVal = false;
    }
  }
  else
  {
    // 1st pass: we should really have a call to the reader that returns
    // the homography, but for now, look for matching corner and pass back
    // the matching corner point ("0" pixel on input means "0.5" as far as
    // GDAL goes
    bool leftCorner = (x == 0);
    bool upperCorner = (y == 0);
    for (int i = 0; i < 4; ++i)
    {
      bool gcpLeftCorner = (gcps[i].dfGCPPixel == 0.5);
      bool gcpUpperCorner = (gcps[i].dfGCPLine == 0.5);
      if (gcpLeftCorner == leftCorner && gcpUpperCorner == upperCorner)
      {
        dfGeoX = gcps[i].dfGCPX;
        dfGeoY = gcps[i].dfGCPY;
      }
    }
  }

  out[0] = dfGeoX;
  out[1] = dfGeoY;

  return retVal;
}

//------------------------------------------------------------------------------
const double* vtkGDALRasterReader::vtkGDALRasterReaderInternal::GetGeoCornerPoints()
{
  this->GetGeoCornerPoint(this->GDALData, 0, 0, &this->CornerPoints[0]);
  this->GetGeoCornerPoint(this->GDALData, 0, this->RasterDimensions[1], &this->CornerPoints[2]);
  this->GetGeoCornerPoint(
    this->GDALData, this->RasterDimensions[0], this->RasterDimensions[1], &this->CornerPoints[4]);
  this->GetGeoCornerPoint(this->GDALData, this->RasterDimensions[0], 0, &this->CornerPoints[6]);

  return this->CornerPoints;
}

void vtkGDALRasterReader::vtkGDALRasterReaderInternal::GetOriginSpacing(
  double* origin, double* spacing, int* flip)
{
  const double* d = GetGeoCornerPoints();
  // 4,5 are the x,y coordinates for the opposite corner to 0,1
  double geoSpacing[] = { (d[4] - d[0]) / this->RasterDimensions[0],
    (d[5] - d[1]) / this->RasterDimensions[1], 1 };

  spacing[0] = std::abs(geoSpacing[0]);
  spacing[1] = std::abs(geoSpacing[1]);
  spacing[2] = geoSpacing[2];
  flip[0] = geoSpacing[0] < 0;
  flip[1] = geoSpacing[1] < 0;
  flip[2] = 0;
  origin[0] = std::min(d[0], d[4]);
  origin[1] = std::min(d[1], d[5]);
  origin[2] = 0;
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::ReadColorTable(
  GDALRasterBand* rasterBand, vtkLookupTable* colorTable) const
{
  GDALColorTable* gdalTable = rasterBand->GetColorTable();
  if (gdalTable->GetPaletteInterpretation() != GPI_RGB)
  {
    std::cerr << "Color table palette type not supported " << gdalTable->GetPaletteInterpretation()
              << std::endl;
    return;
  }

  char** categoryNames = rasterBand->GetCategoryNames();

  colorTable->IndexedLookupOn();
  int numEntries = gdalTable->GetColorEntryCount();
  colorTable->SetNumberOfTableValues(numEntries);
  std::stringstream ss;
  for (int i = 0; i < numEntries; ++i)
  {
    const GDALColorEntry* gdalEntry = gdalTable->GetColorEntry(i);
    double r = static_cast<double>(gdalEntry->c1) / 255.0;
    double g = static_cast<double>(gdalEntry->c2) / 255.0;
    double b = static_cast<double>(gdalEntry->c3) / 255.0;
    double a = static_cast<double>(gdalEntry->c4) / 255.0;
    colorTable->SetTableValue(i, r, g, b, a);

    // Copy category name to lookup table annotation
    if (categoryNames)
    {
      // Only use non-empty names
      if (strlen(categoryNames[i]) > 0)
      {
        colorTable->SetAnnotation(vtkVariant(i), categoryNames[i]);
      }
    }
    else
    {
      // Create default annotation
      ss.str("");
      ss.clear();
      ss << "Category " << i;
      colorTable->SetAnnotation(vtkVariant(i), ss.str());
    }
  }
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::vtkGDALRasterReaderInternal::SelectionCallback(vtkObject* vtkNotUsed(obj),
  unsigned long vtkNotUsed(eventid), void* clientdata, void* vtkNotUsed(calldata))
{
  static_cast<vtkGDALRasterReader::vtkGDALRasterReaderInternal*>(clientdata)->Reader->Modified();
}

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

  os << indent << "TargetDimensions: " << this->TargetDimensions[0] << indent
     << this->TargetDimensions[1] << "\n";
  os << indent << "RasterDimensions: " << this->Impl->RasterDimensions[0] << indent
     << this->Impl->RasterDimensions[1] << "\n";
  os << indent << "DomainMetaData: " << this->DomainMetaData << "\n";
  os << indent << "DriverShortName: " << this->DriverShortName << "\n";
  os << indent << "DriverLongName: " << this->DriverLongName << "\n";

  if (!this->Domains.empty())
  {
    os << indent << "Domain"
       << "\n";
    for (std::size_t i = 0; i < this->Domains.size(); ++i)
    {
      os << indent << this->Domains[i] << "\n";
    }
  }

  if (!this->MetaData.empty())
  {
    os << indent << "MetaData"
       << "\n";
    for (std::size_t i = 0; i < this->MetaData.size(); ++i)
    {
      os << indent << this->MetaData[i] << "\n";
    }
  }
}

//------------------------------------------------------------------------------
vtkGDALRasterReader::vtkGDALRasterReader()
  : vtkImageReader2()
{
  this->Impl = new vtkGDALRasterReaderInternal(this);

  this->SetNumberOfInputPorts(0);
  this->SetNumberOfOutputPorts(1);

  this->DataOrigin[0] = 0.0;
  this->DataOrigin[1] = 0.0;
  this->DataOrigin[2] = 0.0;

  this->DataSpacing[0] = 1.0;
  this->DataSpacing[1] = 1.0;
  this->DataSpacing[2] = 1.0;

  this->DataExtent[0] = -1;
  this->DataExtent[1] = -1;
  this->DataExtent[2] = -1;
  this->DataExtent[3] = -1;
  this->DataExtent[4] = -1;
  this->DataExtent[5] = -1;

  this->TargetDimensions[0] = -1;
  this->TargetDimensions[1] = -1;

  this->CollateBands = true;
}

//------------------------------------------------------------------------------
vtkGDALRasterReader::~vtkGDALRasterReader()
{
  delete this->Impl;

  if (this->FileName)
  {
    this->SetFileName(0);
  }
}

//------------------------------------------------------------------------------
int vtkGDALRasterReader::CanReadFile(const char* fname)
{
  GDALDataset* dataset = static_cast<GDALDataset*>(GDALOpen(fname, GA_ReadOnly));
  bool canRead = (dataset != nullptr);
  GDALClose(dataset);
  return canRead;
}

//------------------------------------------------------------------------------
const char* vtkGDALRasterReader::GetProjectionString() const
{
  return this->Projection.c_str();
}

//------------------------------------------------------------------------------
const double* vtkGDALRasterReader::GetGeoCornerPoints()
{
  return this->Impl->GetGeoCornerPoints();
}

//------------------------------------------------------------------------------
const std::vector<std::string>& vtkGDALRasterReader::GetMetaData()
{
  return this->MetaData;
}

//------------------------------------------------------------------------------
std::vector<std::string> vtkGDALRasterReader::GetDomainMetaData(const std::string& domain)
{
  std::vector<std::string> domainMetaData;

  char** papszMetadata = GDALGetMetadata(this->Impl->GDALData, domain.c_str());

  if (CSLCount(papszMetadata) > 0)
  {
    for (int i = 0; papszMetadata[i] != nullptr; ++i)
    {
      domainMetaData.push_back(papszMetadata[i]);
    }
  }

  return domainMetaData;
}

//------------------------------------------------------------------------------
const std::string& vtkGDALRasterReader::GetDriverShortName()
{
  return this->DriverShortName;
}

//------------------------------------------------------------------------------
const std::string& vtkGDALRasterReader::GetDriverLongName()
{
  return this->DriverLongName;
}

vtkIdType vtkGDALRasterReader::GetNumberOfCells()
{
  return this->Impl->NumberOfCells;
}

#ifdef _MSC_VER
#define strdup _strdup
#endif

//------------------------------------------------------------------------------
int vtkGDALRasterReader::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  if (this->TargetDimensions[0] <= 0 || this->TargetDimensions[1] <= 0)
  {
    vtkWarningMacro(<< "Invalid target dimensions");
  }

  this->Impl->ReadData(this->FileName);
  if (!this->Impl->GDALData)
  {
    vtkErrorMacro("Failed to read " << this->FileName);
    return 0;
  }

  // Get the projection.
  this->ProjectionWKT = this->Impl->GDALData->GetProjectionRef();
  OGRSpatialReference spRef(this->ProjectionWKT.c_str());

  char* projection;
  spRef.exportToProj4(&projection);
  this->Projection = projection;
  CPLFree(projection);

  // Add the map-projection as field data
  vtkSmartPointer<vtkStringArray> projectionData = vtkSmartPointer<vtkStringArray>::New();
  projectionData->SetName("MAP_PROJECTION");
  projectionData->SetNumberOfComponents(1);
  projectionData->SetNumberOfTuples(1);
  projectionData->SetValue(0, this->Projection);
  this->Impl->UniformGridData->GetFieldData()->AddArray(projectionData);

  // Add NoDataValue as field data
  // GDALDatset can have 1 value for each raster band
  // Use NaN for undefined values
  vtkSmartPointer<vtkDoubleArray> noDataArray = vtkSmartPointer<vtkDoubleArray>::New();
  noDataArray->SetName("NO_DATA_VALUE");
  noDataArray->SetNumberOfComponents(1);
  noDataArray->SetNumberOfTuples(this->Impl->NumberOfBands);
  for (int i = 0; i < this->Impl->NumberOfBands; ++i)
  {
    double noDataValue = vtkMath::Nan();
    if (this->Impl->HasNoDataValue[i])
    {
      noDataValue = this->Impl->NoDataValue[i];
    }
    noDataArray->SetValue(i, noDataValue);
  }
  this->Impl->UniformGridData->GetFieldData()->AddArray(noDataArray);

  // Check if file has been changed here.
  // If changed then throw the vtxId time and load a new one.
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  if (!outInfo)
  {
    return 0;
  }

  vtkDataObject* dataObj = outInfo->Get(vtkDataObject::DATA_OBJECT());
  if (!dataObj)
  {
    return 0;
  }

  vtkUniformGrid::SafeDownCast(dataObj)->ShallowCopy(this->Impl->UniformGridData);
  return 1;
}

//------------------------------------------------------------------------------
int vtkGDALRasterReader::RequestInformation(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  // get the info objects
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  if (!outInfo)
  {
    vtkErrorMacro("Invalid output information object");
    return 0;
  }

  if (!this->FileName)
  {
    vtkErrorMacro("Requires valid input file name");
    return 0;
  }

  this->Impl->ReadMetaData(this->FileName);
  if (!this->Impl->GDALData)
  {
    vtkErrorMacro("Failed to read " << this->FileName);
    return 0;
  }

  if (this->Impl->RasterDimensions[0] <= 0 || this->Impl->RasterDimensions[1] <= 0)
  {
    vtkErrorMacro("Invalid image dimensions");
    return 0;
  }

  if (this->TargetDimensions[0] == -1 || this->TargetDimensions[1] == -1)
  {
    this->TargetDimensions[0] = this->Impl->RasterDimensions[0];
    this->TargetDimensions[1] = this->Impl->RasterDimensions[1];
  }

  if (this->DataExtent[0] == -1)
  {
    this->DataExtent[0] = 0;
    // RasterDimensions counts number of cells, DataExtent counts number of points
    // which is one more than number of cells
    this->DataExtent[1] = this->Impl->RasterDimensions[0];
    this->DataExtent[2] = 0;
    this->DataExtent[3] = this->Impl->RasterDimensions[1];
    this->DataExtent[4] = 0;
    this->DataExtent[5] = 0;
  }

  double origin[3];
  double spacing[3];
  int flip[3];
  this->Impl->GetOriginSpacing(origin, spacing, flip);
  this->DataOrigin[0] = origin[0];
  this->DataOrigin[1] = origin[1];
  this->DataOrigin[2] = origin[2];
  this->DataSpacing[0] = spacing[0];
  this->DataSpacing[1] = spacing[1];
  this->DataSpacing[2] = spacing[2];

  outInfo->Set(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), this->DataExtent, 6);
  outInfo->Set(vtkDataObject::SPACING(), this->DataSpacing, 3);
  outInfo->Set(vtkDataObject::ORIGIN(), this->DataOrigin, 3);
  outInfo->Set(vtkGDAL::FLIP_AXIS(), flip, 3);
  outInfo->Set(vtkGDAL::MAP_PROJECTION(), this->Impl->GDALData->GetProjectionRef());

  return 1;
}

//------------------------------------------------------------------------------
int* vtkGDALRasterReader::GetRasterDimensions()
{
  return this->Impl->RasterDimensions;
}

//------------------------------------------------------------------------------
int vtkGDALRasterReader::FillOutputPortInformation(int port, vtkInformation* info)
{
  if (port == 0)
  {
    info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkUniformGrid");
    // info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkImageData");
    return 1;
  }
  else
  {
    vtkErrorMacro("Port: " << port << " is not a valid port");
    return 0;
  }
}

//------------------------------------------------------------------------------
double vtkGDALRasterReader::GetInvalidValue(size_t bandIndex, int* hasNoData)
{
  if (bandIndex >= this->Impl->NoDataValue.size())
  {
    vtkErrorMacro("bandIndex >= " << this->Impl->NoDataValue.size() << ": " << bandIndex);
    return 0;
  }
  if (hasNoData)
  {
    *hasNoData = this->Impl->HasNoDataValue[bandIndex];
  }
  return this->Impl->NoDataValue[bandIndex];
}

//------------------------------------------------------------------------------
int vtkGDALRasterReader::GetNumberOfCellArrays()
{
  return this->Impl->CellArraySelection->GetNumberOfArrays();
}

//------------------------------------------------------------------------------
const char* vtkGDALRasterReader::GetCellArrayName(int index)
{
  return this->Impl->CellArraySelection->GetArrayName(index);
}

//------------------------------------------------------------------------------
int vtkGDALRasterReader::GetCellArrayStatus(const char* name)
{
  return this->Impl->CellArraySelection->ArrayIsEnabled(name);
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::SetCellArrayStatus(const char* name, int status)
{
  if (status)
  {
    this->Impl->CellArraySelection->EnableArray(name);
  }
  else
  {
    this->Impl->CellArraySelection->DisableArray(name);
  }
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::DisableAllCellArrays()
{
  this->Impl->CellArraySelection->DisableAllArrays();
}

//------------------------------------------------------------------------------
void vtkGDALRasterReader::EnableAllCellArrays()
{
  this->Impl->CellArraySelection->EnableAllArrays();
}
