text: /*=========================================================================
  
    Program:   Visualization Toolkit
    Module:    vtkOpenGLVolumeMaskTransferFunction2D.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.
  
  =========================================================================*/
  
  #ifndef vtkOpenGLVolumeMaskTransferFunction2D_h
  #define vtkOpenGLVolumeMaskTransferFunction2D_h
  
  #include "vtkOpenGLVolumeLookupTable.h"
  #include "vtkRenderingVolumeOpenGL2Module.h" // For export macro
  
  #include "vtkNew.h" // for vtkNew
  
  // Forward declarations
  class vtkOpenGLRenderWindow;
  
  /**
   * \brief 2D Transfer function container.
   *
   * Manages the texture fetched by the fragment shader when TransferFunction2D
   * mode is active. Update() assumes the vtkImageData instance used as source
   * is of type VTK_FLOAT and has 4 components (vtkVolumeProperty ensures this
   * is the case when the function is set).
   *
   * \sa vtkVolumeProperty::SetTransferFunction2D
   */
  class VTKRENDERINGVOLUMEOPENGL2_EXPORT vtkOpenGLVolumeMaskTransferFunction2D
    : public vtkOpenGLVolumeLookupTable
  {
  public:
    vtkTypeMacro(vtkOpenGLVolumeMaskTransferFunction2D, vtkOpenGLVolumeLookupTable);
    void PrintSelf(ostream& os, vtkIndent indent) override;
  
    static vtkOpenGLVolumeMaskTransferFunction2D* New();
  
  protected:
    vtkOpenGLVolumeMaskTransferFunction2D();
  
    /**
     * Update the internal texture object using the 2D image data
     */
    void InternalUpdate(vtkObject* func, int blendMode, double sampleDistance, double unitDistance,
      int filterValue) override;
  
    /**
     * Compute the ideal texture size based on the number of labels and transfer
     * functions in the label map.
     */
    void ComputeIdealTextureSize(
      vtkObject* func, int& width, int& height, vtkOpenGLRenderWindow* renWin) override;
  
  private:
    vtkOpenGLVolumeMaskTransferFunction2D(const vtkOpenGLVolumeMaskTransferFunction2D&) = delete;
    void operator=(const vtkOpenGLVolumeMaskTransferFunction2D&) = delete;
  };
  
  #endif // vtkOpenGLVolumeMaskTransferFunction2D_h
  