hierarchical_contour_tree/PermuteComparator.h

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//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt 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.
//============================================================================
// 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:
//
// (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
//     and/or other materials provided with the distribution.
//
// (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
//     specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
//
//=============================================================================
//
//  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_distributed_permute_comparator_h
#define vtk_m_worklet_contourtree_distributed_permute_comparator_h
 
#include <vtkm/Types.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/ExecutionObjectBase.h>
#include <vtkm/filter/scalar_topology/worklet/contourtree_augmented/Types.h>
 
namespace vtkm
{
namespace worklet
{
namespace contourtree_distributed
{
 
 
// comparator used for initial sort of data values
class PermuteComparatorImpl
{
public:
  using IdPortalType = vtkm::worklet::contourtree_augmented::IdArrayType::ReadPortalType;
 
  // constructor - takes vectors as parameters
  VTKM_CONT
  PermuteComparatorImpl(const vtkm::worklet::contourtree_augmented::IdArrayType& lookup,
                        vtkm::cont::DeviceAdapterId device,
                        vtkm::cont::Token& token)
    : LookupPortal(lookup.PrepareForInput(device, token))
  { // constructor
  } // constructor
 
  // () operator - gets called to do comparison
  VTKM_EXEC
  bool operator()(const vtkm::Id& i, const vtkm::Id& j) const
  { // operator()
    // first make sure we have the "top" end set correctly
    vtkm::Id indI = this->LookupPortal.Get(i);
    vtkm::Id indJ = this->LookupPortal.Get(j);
 
    // primary sort on indexed value
    if (indI < indJ)
    {
      return true;
    }
    if (indI > indJ)
    {
      return false;
    }
 
    // secondart sort on index
    if (i < j)
    {
      return true;
    }
    if (j < i)
    {
      return false;
    }
 
    // fallback just in case
    return false;
  } // operator()
 
private:
  IdPortalType LookupPortal;
 
}; // PermuteComparatorImpl
 
class PermuteComparator : public vtkm::cont::ExecutionObjectBase
{
public:
  // constructor - takes vectors as parameters
  VTKM_CONT
  PermuteComparator(const vtkm::worklet::contourtree_augmented::IdArrayType& lookup)
    : Lookup(lookup)
  {
  }
 
  VTKM_CONT PermuteComparatorImpl PrepareForExecution(vtkm::cont::DeviceAdapterId device,
                                                      vtkm::cont::Token& token) const
  {
    return PermuteComparatorImpl(this->Lookup, device, token);
  }
 
private:
  vtkm::worklet::contourtree_augmented::IdArrayType Lookup;
}; // PermuteComparator
 
} // namespace contourtree_augmented
} // namespace worklet
} // namespace vtkm
 
#endif