text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkExtractVectorComponents.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   vtkExtractVectorComponents
   * @brief   extract components of vector as separate scalars
   *
   * vtkExtractVectorComponents is a filter that extracts vector components as
   * separate scalars. This is accomplished by creating three different outputs.
   * Each output is the same as the input, except that the scalar values will be
   * one of the three components of the vector. These can be found in the
   * VxComponent, VyComponent, and VzComponent.
   * Alternatively, if the ExtractToFieldData flag is set, the filter will
   * put all the components in the field data. The first component will be
   * the scalar and the others will be non-attribute arrays.
   *
   * @warning
   * This filter is unusual in that it creates multiple outputs.
   * If you use the GetOutput() method, you will be retrieving the x vector
   * component.
   */
  
  #ifndef vtkExtractVectorComponents_h
  #define vtkExtractVectorComponents_h
  
  #include "vtkDataSetAlgorithm.h"
  #include "vtkFiltersExtractionModule.h" // For export macro
  
  class vtkDataSet;
  
  class VTKFILTERSEXTRACTION_EXPORT vtkExtractVectorComponents : public vtkDataSetAlgorithm
  {
  public:
    static vtkExtractVectorComponents* New();
    vtkTypeMacro(vtkExtractVectorComponents, vtkDataSetAlgorithm);
    void PrintSelf(ostream& os, vtkIndent indent) override;
  
    /**
     * Specify the input data or filter.
     */
    virtual void SetInputData(vtkDataSet* input);
  
    /**
     * Get the output dataset representing velocity x-component. If output is
     * nullptr then input hasn't been set, which is necessary for abstract
     * objects. (Note: this method returns the same information as the
     * GetOutput() method with an index of 0.)
     */
    vtkDataSet* GetVxComponent();
  
    /**
     * Get the output dataset representing velocity y-component. If output is
     * nullptr then input hasn't been set, which is necessary for abstract
     * objects. (Note: this method returns the same information as the
     * GetOutput() method with an index of 1.)
     * Note that if ExtractToFieldData is true, this output will be empty.
     */
    vtkDataSet* GetVyComponent();
  
    /**
     * Get the output dataset representing velocity z-component. If output is
     * nullptr then input hasn't been set, which is necessary for abstract
     * objects. (Note: this method returns the same information as the
     * GetOutput() method with an index of 2.)
     * Note that if ExtractToFieldData is true, this output will be empty.
     */
    vtkDataSet* GetVzComponent();
  
    //@{
    /**
     * Determines whether the vector components will be put
     * in separate outputs or in the first output's field data
     */
    vtkSetMacro(ExtractToFieldData, vtkTypeBool);
    vtkGetMacro(ExtractToFieldData, vtkTypeBool);
    vtkBooleanMacro(ExtractToFieldData, vtkTypeBool);
    //@}
  
  protected:
    vtkExtractVectorComponents();
    ~vtkExtractVectorComponents() override;
  
    int RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
    vtkTypeBool ExtractToFieldData;
    int OutputsInitialized;
  
  private:
    vtkExtractVectorComponents(const vtkExtractVectorComponents&) = delete;
    void operator=(const vtkExtractVectorComponents&) = delete;
  };
  
  #endif
  