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Tools/Win64/VTK/include/vtk-9.0/vtkGenericDataArrayLookupHe...

162 lines
3.8 KiB
C++

/*=========================================================================
Program: Visualization Toolkit
Module: vtkGenericDataArrayLookupHelper.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 vtkGenericDataArrayLookupHelper
* @brief internal class used by
* vtkGenericDataArray to support LookupValue.
*
*/
#ifndef vtkGenericDataArrayLookupHelper_h
#define vtkGenericDataArrayLookupHelper_h
#include "vtkIdList.h"
#include <algorithm>
#include <cmath>
#include <unordered_map>
#include <vector>
namespace detail
{
template <typename T, bool>
struct has_NaN;
template <typename T>
struct has_NaN<T, true>
{
static bool isnan(T x) { return std::isnan(x); }
};
template <typename T>
struct has_NaN<T, false>
{
static bool isnan(T) { return false; }
};
template <typename T>
bool isnan(T x)
{
// Select the correct partially specialized type.
return has_NaN<T, std::numeric_limits<T>::has_quiet_NaN>::isnan(x);
}
} // namespace detail
template <class ArrayTypeT>
class vtkGenericDataArrayLookupHelper
{
public:
typedef ArrayTypeT ArrayType;
typedef typename ArrayType::ValueType ValueType;
vtkGenericDataArrayLookupHelper() = default;
~vtkGenericDataArrayLookupHelper() { this->ClearLookup(); }
void SetArray(ArrayTypeT* array)
{
if (this->AssociatedArray != array)
{
this->ClearLookup();
this->AssociatedArray = array;
}
}
vtkIdType LookupValue(ValueType elem)
{
this->UpdateLookup();
auto indices = FindIndexVec(elem);
if (indices == nullptr)
{
return -1;
}
return indices->front();
}
void LookupValue(ValueType elem, vtkIdList* ids)
{
ids->Reset();
this->UpdateLookup();
auto indices = FindIndexVec(elem);
if (indices)
{
ids->Allocate(static_cast<vtkIdType>(indices->size()));
for (auto index : *indices)
{
ids->InsertNextId(index);
}
}
}
//@{
/**
* Release any allocated memory for internal data-structures.
*/
void ClearLookup()
{
this->ValueMap.clear();
this->NanIndices.clear();
}
//@}
private:
vtkGenericDataArrayLookupHelper(const vtkGenericDataArrayLookupHelper&) = delete;
void operator=(const vtkGenericDataArrayLookupHelper&) = delete;
void UpdateLookup()
{
if (!this->AssociatedArray || (this->AssociatedArray->GetNumberOfTuples() < 1) ||
(!this->ValueMap.empty() || !this->NanIndices.empty()))
{
return;
}
vtkIdType num = this->AssociatedArray->GetNumberOfValues();
this->ValueMap.reserve(num);
for (vtkIdType i = 0; i < num; ++i)
{
auto value = this->AssociatedArray->GetValue(i);
if (::detail::isnan(value))
{
NanIndices.push_back(i);
}
this->ValueMap[value].push_back(i);
}
}
// Return a pointer to the relevant vector of indices if specified value was
// found in the array.
std::vector<vtkIdType>* FindIndexVec(ValueType value)
{
std::vector<vtkIdType>* indices{ nullptr };
if (::detail::isnan(value) && !this->NanIndices.empty())
{
indices = &this->NanIndices;
}
const auto& pos = this->ValueMap.find(value);
if (pos != this->ValueMap.end())
{
indices = &pos->second;
}
return indices;
}
ArrayTypeT* AssociatedArray{ nullptr };
std::unordered_map<ValueType, std::vector<vtkIdType> > ValueMap;
std::vector<vtkIdType> NanIndices;
};
#endif
// VTK-HeaderTest-Exclude: vtkGenericDataArrayLookupHelper.h