ArrayTransforms.h

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//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
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//
//  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
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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 SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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// IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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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)
//==============================================================================
 
// include guard
#ifndef vtk_m_worklet_contourtree_augmented_array_transforms_h
#define vtk_m_worklet_contourtree_augmented_array_transforms_h
 
// global libraries
#include <vtkm/cont/Algorithm.h>
#include <vtkm/cont/ArrayCopyDevice.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/ArrayHandlePermutation.h>
#include <vtkm/cont/ArrayHandleTransform.h>
 
// local includes
#include <vtkm/filter/scalar_topology/worklet/contourtree_augmented/Types.h>
 
 
namespace vtkm
{
namespace worklet
{
namespace contourtree_augmented
{
 
 
// permute routines
template <typename ValueType, typename ArrayType>
inline void PermuteArray(const ArrayType& input, IdArrayType& permute, ArrayType& output)
{ // permuteValues()
  using transform_type =
    vtkm::cont::ArrayHandleTransform<IdArrayType, MaskedIndexFunctor<ValueType>>;
  using permute_type = vtkm::cont::ArrayHandlePermutation<transform_type, ArrayType>;
 
  // resize the output, i.e., output.resize(permute.size());
  vtkm::Id permNumValues = permute.GetNumberOfValues();
  vtkm::Id outNumValues = output.GetNumberOfValues();
  if (permNumValues > outNumValues)
  {
    output.Allocate(permNumValues);
  }
  else if (permNumValues < outNumValues)
  {
    output.Allocate(permNumValues, vtkm::CopyFlag::On);
  } // else the output has already the correct size
 
  // The following is equivalent to doing the following in serial
  //
  // for (vtkm::Id entry = 0; entry < permute.size(); entry++)
  //     output[entry] = input[MaskedIndex(permute[entry])];
  //
  // Apply the MaskedIndex functor to the permute array. ArrayHandleTransform is a fancy vtkm array, i.e.,
  // the function is applied on-the-fly without creating a copy of the array.
  transform_type maskedPermuteIndex =
    vtkm::cont::make_ArrayHandleTransform(permute, MaskedIndexFunctor<ValueType>());
  // Permute the input array based on the maskedPermuteIndex array. Again, ArrayHandlePermutation is a
  // fancy vtkm array so that we do not actually copy any data here
  permute_type permutedInput(maskedPermuteIndex, input);
  // Finally, copy the permuted values to the output array
  vtkm::cont::ArrayCopyDevice(permutedInput, output);
} // permuteValues()
 
 
// transform functor used in ContourTreeMesh to flag indicies as other when using the CombinedVectorClass
struct MarkOther
{
  VTKM_EXEC_CONT
  MarkOther() {}
 
  VTKM_EXEC_CONT
  vtkm::Id operator()(vtkm::Id idx) const { return idx | CV_OTHER_FLAG; }
};
 
// transform functor needed for ScanExclusive calculation. Return 1 if vertex is critical else 0.
struct OneIfCritical
{
  VTKM_EXEC_CONT
  OneIfCritical() {}
 
  VTKM_EXEC_CONT
  vtkm::Id operator()(vtkm::Id x) const { return x != 1 ? 1 : 0; }
};
 
// transform functor needed for ScanExclusive calculation in FindSuperAndHyperNodes. Return 1 if vertex is a supernode, else 0.
struct OneIfSupernode
{
  VTKM_EXEC_CONT
  OneIfSupernode() {}
 
  VTKM_EXEC_CONT
  vtkm::Id operator()(vtkm::Id x) const { return IsSupernode(x) ? 1 : 0; }
};
 
// transform functor needed for ScanExclusive calculation in FindSuperAndHyperNodes. Return 1 if vertex is a hypernode, else 0.
struct OneIfHypernode
{
  VTKM_EXEC_CONT
  OneIfHypernode() {}
 
  VTKM_EXEC_CONT
  vtkm::Id operator()(vtkm::Id x) const { return IsHypernode(x) ? 1 : 0; }
};
 
 
} // namespace contourtree_augmented
} // worklet
} // vtkm
 
// tail of include guard
#endif