text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkImageAppend.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   vtkImageAppend
   * @brief   Collects data from multiple inputs into one image.
   *
   * vtkImageAppend takes the components from multiple inputs and merges
   * them into one output. The output images are append along the "AppendAxis".
   * Except for the append axis, all inputs must have the same extent.
   * All inputs must have the same number of scalar components.
   * A future extension might be to pad or clip inputs to have the same extent.
   * The output has the same origin and spacing as the first input.
   * The origin and spacing of all other inputs are ignored.  All inputs
   * must have the same scalar type.
   */
  
  #ifndef vtkImageAppend_h
  #define vtkImageAppend_h
  
  #include "vtkFiltersCoreModule.h" // For export macro
  #include "vtkThreadedImageAlgorithm.h"
  
  class VTKFILTERSCORE_EXPORT vtkImageAppend : public vtkThreadedImageAlgorithm
  {
  public:
    static vtkImageAppend* New();
    vtkTypeMacro(vtkImageAppend, vtkThreadedImageAlgorithm);
    void PrintSelf(ostream& os, vtkIndent indent) override;
  
    /**
     * Replace one of the input connections with a new input.  You can
     * only replace input connections that you previously created with
     * AddInputConnection() or, in the case of the first input,
     * with SetInputConnection().
     */
    virtual void ReplaceNthInputConnection(int idx, vtkAlgorithmOutput* input);
  
    ///@{
    /**
     * Assign a data object as input. Note that this method does not
     * establish a pipeline connection. Use SetInputConnection() to
     * setup a pipeline connection.
     */
    void SetInputData(int idx, vtkDataObject* input);
    void SetInputData(vtkDataObject* input) { this->SetInputData(0, input); }
    ///@}
  
    ///@{
    /**
     * Get one input to this filter. This method is only for support of
     * old-style pipeline connections.  When writing new code you should
     * use vtkAlgorithm::GetInputConnection(0, num).
     */
    vtkDataObject* GetInput(int idx);
    vtkDataObject* GetInput() { return this->GetInput(0); }
    ///@}
  
    /**
     * Get the number of inputs to this filter. This method is only for
     * support of old-style pipeline connections.  When writing new code
     * you should use vtkAlgorithm::GetNumberOfInputConnections(0).
     */
    int GetNumberOfInputs() { return this->GetNumberOfInputConnections(0); }
  
    ///@{
    /**
     * This axis is expanded to hold the multiple images.
     * The default AppendAxis is the X axis.
     * If you want to create a volue from a series of XY images, then you should
     * set the AppendAxis to 2 (Z axis).
     */
    vtkSetMacro(AppendAxis, int);
    vtkGetMacro(AppendAxis, int);
    ///@}
  
    ///@{
    /**
     * By default "PreserveExtents" is off and the append axis is used.
     * When "PreseveExtents" is on, the extent of the inputs is used to
     * place the image in the output.  The whole extent of the output is
     * the union of the input whole extents.  Any portion of the
     * output not covered by the inputs is set to zero.  The origin and
     * spacing is taken from the first input.
     */
    vtkSetMacro(PreserveExtents, vtkTypeBool);
    vtkGetMacro(PreserveExtents, vtkTypeBool);
    vtkBooleanMacro(PreserveExtents, vtkTypeBool);
    ///@}
  
  protected:
    vtkImageAppend();
    ~vtkImageAppend() override;
  
    vtkTypeBool PreserveExtents;
    int AppendAxis;
    // Array holds the AppendAxisExtent shift for each input.
    int* Shifts;
  
    int RequestInformation(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
  
    int RequestUpdateExtent(vtkInformation*, vtkInformationVector**, vtkInformationVector*) override;
  
    void ThreadedRequestData(vtkInformation* request, vtkInformationVector** inputVector,
      vtkInformationVector* outputVector, vtkImageData*** inData, vtkImageData** outData, int ext[6],
      int id) override;
  
    // see vtkAlgorithm for docs.
    int FillInputPortInformation(int, vtkInformation*) override;
  
    void InitOutput(int outExt[6], vtkImageData* outData);
  
    void InternalComputeInputUpdateExtent(int* inExt, int* outExt, int* inWextent, int whichInput);
  
    // overridden to allocate all of the output arrays, not just active scalars
    void AllocateOutputData(vtkImageData* out, vtkInformation* outInfo, int* uExtent) override;
    vtkImageData* AllocateOutputData(vtkDataObject* out, vtkInformation* outInfo) override;
  
    // overridden to prevent shallow copies across, since we have to do it elementwise
    void CopyAttributeData(
      vtkImageData* in, vtkImageData* out, vtkInformationVector** inputVector) override;
  
  private:
    vtkImageAppend(const vtkImageAppend&) = delete;
    void operator=(const vtkImageAppend&) = delete;
  };
  
  #endif
  