text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkAppendPolyData.h
  
    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.
  
  =========================================================================*/
  /**
   * @class   vtkAppendPolyData
   * @brief   appends one or more polygonal datasets together
   *
   *
   * vtkAppendPolyData is a filter that appends one of more polygonal datasets
   * into a single polygonal dataset. All geometry is extracted and appended,
   * but point and cell attributes (i.e., scalars, vectors, normals) are
   * extracted and appended only if all datasets have the point and/or cell
   * attributes available.  (For example, if one dataset has point scalars but
   * another does not, point scalars will not be appended.)
   *
   * @sa
   * vtkAppendFilter
   */
  
  #ifndef vtkAppendPolyData_h
  #define vtkAppendPolyData_h
  
  #include "vtkFiltersCoreModule.h" // For export macro
  #include "vtkPolyDataAlgorithm.h"
  
  class vtkCellArray;
  class vtkDataArray;
  class vtkPoints;
  class vtkPolyData;
  
  class VTKFILTERSCORE_EXPORT vtkAppendPolyData : public vtkPolyDataAlgorithm
  {
  public:
    static vtkAppendPolyData* New();
  
    vtkTypeMacro(vtkAppendPolyData, vtkPolyDataAlgorithm);
    void PrintSelf(ostream& os, vtkIndent indent) override;
  
    //@{
    /**
     * UserManagedInputs allows the user to set inputs by number instead of
     * using the AddInput/RemoveInput functions. Calls to
     * SetNumberOfInputs/SetInputConnectionByNumber should not be mixed with calls
     * to AddInput/RemoveInput. By default, UserManagedInputs is false.
     */
    vtkSetMacro(UserManagedInputs, vtkTypeBool);
    vtkGetMacro(UserManagedInputs, vtkTypeBool);
    vtkBooleanMacro(UserManagedInputs, vtkTypeBool);
    //@}
  
    /**
     * Add a dataset to the list of data to append. Should not be
     * used when UserManagedInputs is true, use SetInputByNumber instead.
     */
    void AddInputData(vtkPolyData*);
  
    /**
     * Remove a dataset from the list of data to append. Should not be
     * used when UserManagedInputs is true, use SetInputByNumber (nullptr) instead.
     */
    void RemoveInputData(vtkPolyData*);
  
    //@{
    /**
     * Get any input of this filter.
     */
    vtkPolyData* GetInput(int idx);
    vtkPolyData* GetInput() { return this->GetInput(0); }
    //@}
  
    /**
     * Directly set(allocate) number of inputs, should only be used
     * when UserManagedInputs is true.
     */
    void SetNumberOfInputs(int num);
  
    // Set Nth input, should only be used when UserManagedInputs is true.
    void SetInputConnectionByNumber(int num, vtkAlgorithmOutput* input);
    void SetInputDataByNumber(int num, vtkPolyData* ds);
  
    //@{
    /**
     * ParallelStreaming is for a particular application.
     * It causes this filter to ask for a different piece
     * from each of its inputs.  If all the inputs are the same,
     * then the output of this append filter is the whole dataset
     * pieced back together.  Duplicate points are create
     * along the seams.  The purpose of this feature is to get
     * data parallelism at a course scale.  Each of the inputs
     * can be generated in a different process at the same time.
     */
    vtkSetMacro(ParallelStreaming, vtkTypeBool);
    vtkGetMacro(ParallelStreaming, vtkTypeBool);
    vtkBooleanMacro(ParallelStreaming, vtkTypeBool);
    //@}
  
    //@{
    /**
     * Set/get the desired precision for the output types. See the documentation
     * for the vtkAlgorithm::DesiredOutputPrecision enum for an explanation of
     * the available precision settings.
     */
    vtkSetMacro(OutputPointsPrecision, int);
    vtkGetMacro(OutputPointsPrecision, int);
    //@}
  
    int ExecuteAppend(vtkPolyData* output, vtkPolyData* inputs[], int numInputs)
      VTK_SIZEHINT(inputs, numInputs);
  
  protected:
    vtkAppendPolyData();
    ~vtkAppendPolyData() override;
  
    // Flag for selecting parallel streaming behavior
    vtkTypeBool ParallelStreaming;
    int OutputPointsPrecision;
  
    // Usual data generation method
    int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
    int RequestUpdateExtent(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
    int FillInputPortInformation(int, vtkInformation*) override;
  
    // An efficient templated way to append data.
    void AppendData(vtkDataArray* dest, vtkDataArray* src, vtkIdType offset);
  
    // An efficient way to append cells.
    void AppendCells(vtkCellArray* dest, vtkCellArray* src, vtkIdType offset);
  
  private:
    // hide the superclass' AddInput() from the user and the compiler
    void AddInputData(vtkDataObject*)
    {
      vtkErrorMacro(<< "AddInput() must be called with a vtkPolyData not a vtkDataObject.");
    }
  
    vtkTypeBool UserManagedInputs;
  
  private:
    vtkAppendPolyData(const vtkAppendPolyData&) = delete;
    void operator=(const vtkAppendPolyData&) = delete;
  };
  
  #endif
  