text: /*=========================================================================
   *
   *  Copyright Insight Software Consortium
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *         http://www.apache.org/licenses/LICENSE-2.0.txt
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   *=========================================================================*/
  
  #ifndef itkFreeSurferAsciiMeshIO_h
  #define itkFreeSurferAsciiMeshIO_h
  #include "ITKIOMeshExport.h"
  
  #include "itkMeshIOBase.h"
  
  #include <fstream>
  
  namespace itk
  {
  /** \class FreeSurferAsciiMeshIO
   * \brief This class defines how to read and write freesurfer ASCII surface format.
   * To use IO factory, define the suffix as *.fsa.
   * \ingroup IOFilters
   * \ingroup ITKIOMesh
   */
  
  class ITKIOMesh_EXPORT FreeSurferAsciiMeshIO:public MeshIOBase
  {
  public:
    ITK_DISALLOW_COPY_AND_ASSIGN(FreeSurferAsciiMeshIO);
  
    /** Standard class type aliases. */
    using Self = FreeSurferAsciiMeshIO;
    using Superclass = MeshIOBase;
    using ConstPointer = SmartPointer< const Self >;
    using Pointer = SmartPointer< Self >;
  
    using SizeValueType = Superclass::SizeValueType;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(FreeSurferAsciiMeshIO, MeshIOBase);
  
    /*-------- This part of the interfaces deals with reading data. ----- */
  
    /** Determine if the file can be read with this MeshIO implementation.
    * \param FileNameToRead The name of the file to test for reading.
    * \post Sets classes MeshIOBase::m_FileName variable to be FileNameToWrite
    * \return Returns true if this MeshIO can read the file specified.
    */
    bool CanReadFile(const char *FileNameToRead) override;
  
    /** Set the spacing and dimension information for the set filename. */
    void ReadMeshInformation() override;
  
    /** Reads the data from disk into the memory buffer provided. */
    void ReadPoints(void *buffer) override;
  
    void ReadCells(void *buffer) override;
  
    void ReadPointData(void *buffer) override;
  
    void ReadCellData(void *buffer) override;
  
    /*-------- This part of the interfaces deals with writing data. ----- */
  
    /** Determine if the file can be written with this MeshIO implementation.
     * \param FileNameToWrite The name of the file to test for writing.
     * \post Sets classes MeshIOBase::m_FileName variable to be FileNameToWrite
     * \return Returns true if this MeshIO can write the file specified.
     */
    bool CanWriteFile(const char *FileNameToWrite) override;
  
    /** Set the spacing and dimension information for the set filename. */
    void WriteMeshInformation() override;
  
    /** Writes the data to disk from the memory buffer provided. Make sure
     * that the IORegions has been set properly. */
    void WritePoints(void *buffer) override;
  
    void WriteCells(void *buffer) override;
  
    void WritePointData(void *buffer) override;
  
    void WriteCellData(void *buffer) override;
  
    void Write() override;
  
  protected:
    /** Write points to output stream */
    template< typename T >
    void WritePoints(T *buffer, std::ofstream & outputFile, T label = itk::NumericTraits< T >::ZeroValue())
    {
      outputFile.precision(6);
      SizeValueType index = 0;
      for ( SizeValueType ii = 0; ii < this->m_NumberOfPoints; ii++ )
        {
        for ( unsigned int jj = 0; jj < this->m_PointDimension; jj++ )
          {
          outputFile << std::fixed << buffer[index++] << "  ";
          }
        outputFile << label << '\n';
        }
    }
  
    template< typename T >
    void WriteCells(T *buffer, std::ofstream & outputFile, T label = itk::NumericTraits< T >::ZeroValue())
    {
      constexpr unsigned int numberOfCellPoints = 3;
      SizeValueType      index = 0;
  
      auto * data = new T[this->m_NumberOfCells * numberOfCellPoints];
  
      ReadCellsBuffer(buffer, data);
  
      for ( SizeValueType ii = 0; ii < this->m_NumberOfCells; ii++ )
        {
        for ( unsigned int jj = 0; jj < numberOfCellPoints; jj++ )
          {
          outputFile << data[index++] << "  ";
          }
        outputFile << label << '\n';
        }
      delete[] data;
    }
  
    /** Read cells from a data buffer, used when writting cells */
    template< typename TInput, typename TOutput >
    void ReadCellsBuffer(TInput *input, TOutput *output)
      {
      if ( input && output )
        {
        for ( SizeValueType ii = 0; ii < this->m_NumberOfCells; ii++ )
          {
          for ( unsigned int jj = 0; jj < 3; jj++ )
            {
            /** point identifiers start from the third elements, first element is cellType, the second is numberOfPoints */
            output[ii * 3 + jj] = static_cast< TOutput >( input[5 * ii + jj + 2] );
            }
          }
        }
      }
  
  protected:
    FreeSurferAsciiMeshIO();
    ~FreeSurferAsciiMeshIO() override;
    void PrintSelf(std::ostream & os, Indent indent) const override;
  
    void OpenFile();
  
    void CloseFile();
  
  private:
    std::ifstream m_InputFile;
  };
  } // end namespace itk
  
  #endif
  