MergeSortedListsWithoutDuplicatesWorklet.h

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//============================================================================
//  Copyright (c) Kitware, Inc.
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//  See LICENSE.txt for details.
//  This software is distributed WITHOUT ANY WARRANTY; without even
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//  PURPOSE.  See the above copyright notice for more information.
//
//  Copyright 2014 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-NA0003525 with NTESS,
//  the U.S. Government retains certain rights in this software.
//
//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
//  Laboratory (LANL), the U.S. Government retains certain rights in
//  this software.
//============================================================================
// Copyright (c) 2018, The Regents of the University of California, through
// Lawrence Berkeley National Laboratory (subject to receipt of any required approvals
// from the U.S. Dept. of Energy).  All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
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// (1) Redistributions of source code must retain the above copyright notice, this
//     list of conditions and the following disclaimer.
//
// (2) Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
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// (3) Neither the name of the University of California, Lawrence Berkeley National
//     Laboratory, U.S. Dept. of Energy nor the names of its contributors may be
//     used to endorse or promote products derived from this software without
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//=============================================================================
//
//  This code is an extension of the algorithm presented in the paper:
//  Parallel Peak Pruning for Scalable SMP Contour Tree Computation.
//  Hamish Carr, Gunther Weber, Christopher Sewell, and James Ahrens.
//  Proceedings of the IEEE Symposium on Large Data Analysis and Visualization
//  (LDAV), October 2016, Baltimore, Maryland.
//
//  The PPP2 algorithm and software were jointly developed by
//  Hamish Carr (University of Leeds), Gunther H. Weber (LBNL), and
//  Oliver Ruebel (LBNL)
//==============================================================================
 
#ifndef vtk_m_worklet_contourtree_augmented_contourtree_mesh_inc_merge_sorted_lists_worklet_h
#define vtk_m_worklet_contourtree_augmented_contourtree_mesh_inc_merge_sorted_lists_worklet_h
 
#include <vtkm/filter/scalar_topology/worklet/contourtree_augmented/Types.h>
#include <vtkm/worklet/WorkletMapField.h>
 
namespace vtkm
{
namespace worklet
{
namespace contourtree_augmented
{
namespace mesh_dem_contourtree_mesh_inc
{
 
struct MergeSortedListsWithoutDuplicatesWorklet : public vtkm::worklet::WorkletMapField
{
  using ControlSignature = void(FieldIn, FieldIn, FieldOut, FieldOut);
 
  template <typename InGroupType, typename OutGroupType>
  VTKM_EXEC void operator()(const InGroupType& list1,
                            const InGroupType& list2,
                            OutGroupType& combinedList,
                            vtkm::IdComponent& numberOfUniqueElements) const
  {
    VTKM_ASSERT(list1.GetNumberOfComponents() + list2.GetNumberOfComponents() <=
                combinedList.GetNumberOfComponents());
 
    numberOfUniqueElements = 0;
 
    vtkm::IdComponent pos1 = 0;
    vtkm::IdComponent pos2 = 0;
    while (pos1 < list1.GetNumberOfComponents() && pos2 < list2.GetNumberOfComponents())
    {
      if (list1[pos1] < list2[pos2])
      {
        combinedList[numberOfUniqueElements++] = list1[pos1++];
      }
      else if (list1[pos1] == list2[pos2])
      {
        combinedList[numberOfUniqueElements++] = list1[pos1++];
        ++pos2;
      }
      else
      {
        VTKM_ASSERT(list1[pos1] > list2[pos2]);
        combinedList[numberOfUniqueElements++] = list2[pos2++];
      }
    }
    // Either list1 or list2 may have additional elements but not both, so the following is safe
    while (pos1 < list1.GetNumberOfComponents())
    {
      combinedList[numberOfUniqueElements++] = list1[pos1++];
    }
    while (pos2 < list2.GetNumberOfComponents())
    {
      combinedList[numberOfUniqueElements++] = list2[pos2++];
    }
  }
}; // MergeSortedListsWithoutDuplicatesWorklet
 
} // namespace mesh_dem_contourtree_mesh_inc
} // namespace contourtree_augmented
} // namespace worklet
} // namespace vtkm
 
#endif