text: /*=========================================================================
  
   Program:   Visualization Toolkit
   Module:    vtkAMRUtilities.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   vtkAMRUtilities
   *
   *
   *  A concrete instance of vtkObject that employs a singleton design
   *  pattern and implements functionality for AMR specific operations.
   *
   * @sa
   *  vtkOverlappingAMR, vtkAMRBox
   */
  
  #ifndef vtkAMRUtilities_h
  #define vtkAMRUtilities_h
  
  #include "vtkCommonDataModelModule.h" // For export macro
  #include "vtkObject.h"
  #include <vector> // For C++ vector
  
  // Forward declarations
  class vtkDataArray;
  class vtkFieldData;
  class vtkOverlappingAMR;
  class vtkUniformGrid;
  class vtkUnsignedCharArray;
  
  class VTKCOMMONDATAMODEL_EXPORT vtkAMRUtilities : public vtkObject
  {
  public:
    // Standard Routines
    vtkTypeMacro(vtkAMRUtilities, vtkObject);
    void PrintSelf(ostream& os, vtkIndent indent) override;
  
    /**
     * This method detects and strips partially overlapping cells from a
     * given AMR dataset. If ghost layers are detected, they are removed and
     * new grid instances are created to represent the stripped
     * data-set otherwise, each block is shallow-copied.
  
     * .SECTION Assumptions
     * 1) The ghosted AMR data must have complete metadata information.
     */
    static void StripGhostLayers(
      vtkOverlappingAMR* ghostedAMRData, vtkOverlappingAMR* strippedAMRData);
  
    /**
     * A quick test of whether partially overlapping ghost cells exist. This test
     * starts from the highest-res boxes and checks if they have partially
     * overlapping cells. The code returns with true once partially overlapping
     * cells are detected. Otherwise, false is returned.
     */
    static bool HasPartiallyOverlappingGhostCells(vtkOverlappingAMR* amr);
  
    /**
     * Blank cells in overlapping AMR
     */
    static void BlankCells(vtkOverlappingAMR* amr);
  
  protected:
    vtkAMRUtilities() = default;
    ~vtkAMRUtilities() override = default;
  
    /**
     * Given the real-extent w.r.t. the ghosted grid, this method copies the
     * field data (point/cell) data on the stripped grid.
     */
    static void CopyFieldsWithinRealExtent(
      int realExtent[6], vtkUniformGrid* ghostedGrid, vtkUniformGrid* strippedGrid);
  
    /**
     * Copies the fields from the given source to the given target.
     */
    static void CopyFieldData(
      vtkFieldData* target, vtkIdType targetIdx, vtkFieldData* source, vtkIdType sourceIdx);
  
    /**
     * Strips ghost layers from the given grid according to the given ghost
     * vector which encodes the number of cells to remote from each of the
     * 6 sides {imin,imax,jmin,jmax,kmin,kmax}. For example, a ghost vector
     * of {0,2,0,2,0,0} would indicate that there exist 2 ghost cells on the
     * imax and jmax side.
     */
    static vtkUniformGrid* StripGhostLayersFromGrid(vtkUniformGrid* grid, int ghost[6]);
  
    static void BlankGridsAtLevel(vtkOverlappingAMR* amr, int levelIdx,
      std::vector<std::vector<unsigned int>>& children, const std::vector<int>& processMap);
  
  private:
    vtkAMRUtilities(const vtkAMRUtilities&) = delete;
    void operator=(const vtkAMRUtilities&) = delete;
  
    static void MergeGhostArrays(vtkDataArray* existingArray, vtkUnsignedCharArray* ghosts);
  };
  
  #endif /* vtkAMRUtilities_h */
  