vtk-m2/vtkm/worklet/connectivities/GraphConnectivity.h
2019-04-17 10:57:13 -06:00

113 lines
3.8 KiB
C++

//============================================================================
// 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.
//============================================================================
#ifndef vtk_m_worklet_connectivity_graph_connectivity_h
#define vtk_m_worklet_connectivity_graph_connectivity_h
#include <vtkm/worklet/connectivities/CellSetDualGraph.h>
#include <vtkm/worklet/connectivities/InnerJoin.h>
#include <vtkm/worklet/connectivities/UnionFind.h>
namespace vtkm
{
namespace worklet
{
namespace connectivity
{
namespace detail
{
class Graft : public vtkm::worklet::WorkletMapField
{
public:
using ControlSignature =
void(FieldIn index, FieldIn start, FieldIn degree, WholeArrayIn ids, WholeArrayInOut comp);
using ExecutionSignature = void(_1, _2, _3, _4, _5);
using InputDomain = _1;
// TODO: Use Scatter?
template <typename InPortalType, typename InOutPortalType>
VTKM_EXEC void operator()(vtkm::Id index,
vtkm::Id start,
vtkm::Id degree,
const InPortalType& conn,
InOutPortalType& comp) const
{
for (vtkm::Id offset = start; offset < start + degree; offset++)
{
vtkm::Id neighbor = conn.Get(offset);
if ((comp.Get(index) == comp.Get(comp.Get(index))) && (comp.Get(neighbor) < comp.Get(index)))
{
comp.Set(comp.Get(index), comp.Get(neighbor));
}
}
}
};
}
class GraphConnectivity
{
public:
using Algorithm = vtkm::cont::Algorithm;
template <typename InputPortalType, typename OutputPortalType>
void Run(const InputPortalType& numIndicesArray,
const InputPortalType& indexOffsetsArray,
const InputPortalType& connectivityArray,
OutputPortalType& componentsOut) const
{
bool allStar = false;
vtkm::cont::ArrayHandle<vtkm::Id> components;
vtkm::cont::ArrayHandle<bool> isStar;
vtkm::cont::ArrayHandle<vtkm::Id> cellIds;
Algorithm::Copy(
vtkm::cont::ArrayHandleCounting<vtkm::Id>(0, 1, numIndicesArray.GetNumberOfValues()),
cellIds);
Algorithm::Copy(cellIds, components);
do
{
vtkm::worklet::DispatcherMapField<detail::Graft> graftDispatcher;
graftDispatcher.Invoke(
cellIds, indexOffsetsArray, numIndicesArray, connectivityArray, components);
// Detection of allStar has to come before pointer jumping. Don't try to rearrange it.
vtkm::worklet::DispatcherMapField<IsStar> isStarDisp;
isStarDisp.Invoke(cellIds, components, isStar);
allStar = Algorithm::Reduce(isStar, true, vtkm::LogicalAnd());
vtkm::worklet::DispatcherMapField<PointerJumping> pointJumpingDispatcher;
pointJumpingDispatcher.Invoke(cellIds, components);
} while (!allStar);
// renumber connected component to the range of [0, number of components).
vtkm::cont::ArrayHandle<vtkm::Id> uniqueComponents;
Algorithm::Copy(components, uniqueComponents);
Algorithm::Sort(uniqueComponents);
Algorithm::Unique(uniqueComponents);
vtkm::cont::ArrayHandle<vtkm::Id> uniqueColor;
Algorithm::Copy(
vtkm::cont::ArrayHandleCounting<vtkm::Id>(0, 1, uniqueComponents.GetNumberOfValues()),
uniqueColor);
vtkm::cont::ArrayHandle<vtkm::Id> cellColors;
vtkm::cont::ArrayHandle<vtkm::Id> cellIdsOut;
InnerJoin().Run(
components, cellIds, uniqueComponents, uniqueColor, cellColors, cellIdsOut, componentsOut);
Algorithm::SortByKey(cellIdsOut, componentsOut);
}
};
}
}
}
#endif //vtk_m_worklet_connectivity_graph_connectivity_h