vtk-m/vtkm/worklet/contourtree/Mesh3D_DEM_Triangulation.h
Kenneth Moreland d1a4aecc59 Improvements to moving data into ArrayHandle
We have made several improvements to adding data into an `ArrayHandle`.

## Moving data from an `std::vector`

For numerous reasons, it is convenient to define data in a `std::vector`
and then wrap that into an `ArrayHandle`. It is often the case that an
`std::vector` is filled and then becomes unused once it is converted to an
`ArrayHandle`. In this case, what we really want is to pass the data off to
the `ArrayHandle` so that the `ArrayHandle` is now managing the data and
not the `std::vector`.

C++11 has a mechanism to do this: move semantics. You can now pass
variables to functions as an "rvalue" (right-hand value). When something is
passed as an rvalue, it can pull state out of that variable and move it
somewhere else. `std::vector` implements this movement so that an rvalue
can be moved to another `std::vector` without actually copying the data.
`make_ArrayHandle` now also takes advantage of this feature to move rvalue
`std::vector`s.

There is a special form of `make_ArrayHandle` named `make_ArrayHandleMove`
that takes an rvalue. There is also a special overload of
`make_ArrayHandle` itself that handles an rvalue `vector`. (However, using
the explicit move version is better if you want to make sure the data is
actually moved.)

## Make `ArrayHandle` from initalizer list

A common use case for using `std::vector` (particularly in our unit tests)
is to quickly add an initalizer list into an `ArrayHandle`. Now you can
by simply passing an initializer list to `make_ArrayHandle`.

## Deprecated `make_ArrayHandle` with default shallow copy

For historical reasons, passing an `std::vector` or a pointer to
`make_ArrayHandle` does a shallow copy (i.e. `CopyFlag` defaults to `Off`).
Although more efficient, this mode is inherintly unsafe, and making it the
default is asking for trouble.

To combat this, calling `make_ArrayHandle` without a copy flag is
deprecated. In this way, if you wish to do the faster but more unsafe
creation of an `ArrayHandle` you should explicitly express that.

This requried quite a few changes through the VTK-m source (particularly in
the tests).

## Similar changes to `Field`

`vtkm::cont::Field` has a `make_Field` helper function that is similar to
`make_ArrayHandle`. It also features the ability to create fields from
`std::vector`s and C arrays. It also likewise had the same unsafe behavior
by default of not copying from the source of the arrays.

That behavior has similarly been depreciated. You now have to specify a
copy flag.

The ability to construct a `Field` from an initializer list of values has
also been added.
2020-07-23 10:53:38 -06:00

276 lines
12 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.
//============================================================================
// Copyright (c) 2016, Los Alamos National Security, LLC
// All rights reserved.
//
// Copyright 2016. Los Alamos National Security, LLC.
// This software was produced under U.S. Government contract DE-AC52-06NA25396
// for Los Alamos National Laboratory (LANL), which is operated by
// Los Alamos National Security, LLC for the U.S. Department of Energy.
// The U.S. Government has rights to use, reproduce, and distribute this
// software. NEITHER THE GOVERNMENT NOR LOS ALAMOS NATIONAL SECURITY, LLC
// MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY LIABILITY FOR THE
// USE OF THIS SOFTWARE. If software is modified to produce derivative works,
// such modified software should be clearly marked, so as not to confuse it
// with the version available from LANL.
//
// Additionally, 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 Los Alamos National Security, LLC, Los Alamos
// National Laboratory, LANL, the U.S. Government, 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 LOS ALAMOS NATIONAL SECURITY, LLC 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 LOS ALAMOS
// NATIONAL SECURITY, LLC 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, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE 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 based on 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.
//=======================================================================================
//
// COMMENTS:
//
// Essentially, a vector of data values. BUT we will want them sorted to simplify
// processing - i.e. it's the robust way of handling simulation of simplicity
//
// On the other hand, once we have them sorted, we can discard the original data since
// only the sort order matters
//
// Since we've been running into memory issues, we'll start being more careful.
// Clearly, we can eliminate the values if we sort, but in this iteration we are
// deferring doing a full sort, so we need to keep the values.
//
//=======================================================================================
#ifndef vtkm_worklet_contourtree_mesh3d_dem_triangulation_h
#define vtkm_worklet_contourtree_mesh3d_dem_triangulation_h
#include <vtkm/cont/ArrayGetValues.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/ArrayHandleCounting.h>
#include <vtkm/cont/ArrayHandleIndex.h>
#include <vtkm/cont/ArrayHandleZip.h>
#include <vtkm/worklet/DispatcherMapField.h>
#include <vtkm/worklet/contourtree/ChainGraph.h>
#include <vtkm/worklet/contourtree/LinkComponentCaseTable3D.h>
#include <vtkm/worklet/contourtree/Mesh3D_DEM_SaddleStarter.h>
#include <vtkm/worklet/contourtree/Mesh3D_DEM_VertexOutdegreeStarter.h>
#include <vtkm/worklet/contourtree/Mesh3D_DEM_VertexStarter.h>
#include <vtkm/worklet/contourtree/PrintVectors.h>
#include <vtkm/worklet/contourtree/Types.h>
//#define DEBUG_PRINT 1
//#define DEBUG_TIMING 1
namespace vtkm
{
namespace worklet
{
namespace contourtree
{
template <typename T, typename StorageType>
class Mesh3D_DEM_Triangulation
{
public:
// original data array
const vtkm::cont::ArrayHandle<T, StorageType>& values;
// size of the mesh
vtkm::Id nRows, nCols, nSlices, NumVertices, nLogSteps;
// array with neighbourhood masks
vtkm::cont::ArrayHandle<vtkm::Id> neighbourhoodMask;
// case table information for finding neighbours
vtkm::cont::ArrayHandle<vtkm::IdComponent> neighbourOffsets3D;
vtkm::cont::ArrayHandle<vtkm::UInt16> linkComponentCaseTable3D;
// constructor
Mesh3D_DEM_Triangulation(const vtkm::cont::ArrayHandle<T, StorageType>& Values,
vtkm::Id NRows,
vtkm::Id NCols,
vtkm::Id NSlices);
// sets all vertices to point along an outgoing edge (except extrema)
void SetStarts(vtkm::cont::ArrayHandle<vtkm::Id>& chains, bool descending);
// sets outgoing paths for saddles
void SetSaddleStarts(ChainGraph<T, StorageType>& mergeGraph, bool descending);
};
// creates input mesh
template <typename T, typename StorageType>
Mesh3D_DEM_Triangulation<T, StorageType>::Mesh3D_DEM_Triangulation(
const vtkm::cont::ArrayHandle<T, StorageType>& Values,
vtkm::Id NRows,
vtkm::Id NCols,
vtkm::Id NSlices)
: values(Values)
, nRows(NRows)
, nCols(NCols)
, nSlices(NSlices)
, neighbourOffsets3D()
, linkComponentCaseTable3D()
{
NumVertices = nRows * nCols * nSlices;
// compute the number of log-jumping steps (i.e. lg_2 (NumVertices))
nLogSteps = 1;
for (vtkm::Id shifter = NumVertices; shifter > 0; shifter >>= 1)
nLogSteps++;
neighbourOffsets3D = vtkm::cont::make_ArrayHandle(
vtkm::worklet::contourtree::neighbourOffsets3D, 42, vtkm::CopyFlag::Off);
linkComponentCaseTable3D = vtkm::cont::make_ArrayHandle(
vtkm::worklet::contourtree::linkComponentCaseTable3D, 16384, vtkm::CopyFlag::Off);
}
// sets outgoing paths for saddles
template <typename T, typename StorageType>
void Mesh3D_DEM_Triangulation<T, StorageType>::SetStarts(vtkm::cont::ArrayHandle<vtkm::Id>& chains,
bool ascending)
{
// create the neighbourhood mask
neighbourhoodMask.Allocate(NumVertices);
// For each vertex set the next vertex in the chain
vtkm::cont::ArrayHandleIndex vertexIndexArray(NumVertices);
Mesh3D_DEM_VertexStarter<T> vertexStarter(nRows, nCols, nSlices, ascending);
vtkm::worklet::DispatcherMapField<Mesh3D_DEM_VertexStarter<T>> vertexStarterDispatcher(
vertexStarter);
vertexStarterDispatcher.Invoke(vertexIndexArray, // input
values, // input (whole array)
chains, // output
neighbourhoodMask); // output
} // SetStarts()
// sets outgoing paths for saddles
template <typename T, typename StorageType>
void Mesh3D_DEM_Triangulation<T, StorageType>::SetSaddleStarts(
ChainGraph<T, StorageType>& mergeGraph,
bool ascending)
{
// we need a temporary inverse index to change vertex IDs
vtkm::cont::ArrayHandle<vtkm::Id> inverseIndex;
vtkm::cont::ArrayHandle<vtkm::Id> isCritical;
vtkm::cont::ArrayHandle<vtkm::Id> outdegree;
vtkm::cont::ArrayHandleIndex vertexIndexArray(NumVertices);
Mesh3D_DEM_VertexOutdegreeStarter vertexOutdegreeStarter(nRows, nCols, nSlices, ascending);
vtkm::worklet::DispatcherMapField<Mesh3D_DEM_VertexOutdegreeStarter>
vertexOutdegreeStarterDispatcher(vertexOutdegreeStarter);
vertexOutdegreeStarterDispatcher.Invoke(vertexIndexArray, // input
neighbourhoodMask, // input
mergeGraph.arcArray, // input (whole array)
neighbourOffsets3D, // input (whole array)
linkComponentCaseTable3D, // input (whole array)
outdegree, // output
isCritical); // output
vtkm::cont::Algorithm::ScanExclusive(isCritical, inverseIndex);
// now we can compute how many critical points we carry forward
vtkm::Id nCriticalPoints = vtkm::cont::ArrayGetValue(NumVertices - 1, inverseIndex) +
vtkm::cont::ArrayGetValue(NumVertices - 1, isCritical);
// allocate space for the join graph vertex arrays
mergeGraph.AllocateVertexArrays(nCriticalPoints);
// compact the set of vertex indices to critical ones only
vtkm::cont::Algorithm::CopyIf(vertexIndexArray, isCritical, mergeGraph.valueIndex);
// we initialise the prunesTo array to "NONE"
vtkm::cont::ArrayHandleConstant<vtkm::Id> notAssigned(NO_VERTEX_ASSIGNED, nCriticalPoints);
vtkm::cont::Algorithm::Copy(notAssigned, mergeGraph.prunesTo);
// copy the outdegree from our temporary array
// : mergeGraph.outdegree[vID] <= outdegree[mergeGraph.valueIndex[vID]]
vtkm::cont::Algorithm::CopyIf(outdegree, isCritical, mergeGraph.outdegree);
// copy the chain maximum from arcArray
// : mergeGraph.chainExtremum[vID] = inverseIndex[mergeGraph.arcArray[mergeGraph.valueIndex[vID]]]
using IdArrayType = vtkm::cont::ArrayHandle<vtkm::Id>;
using PermuteIndexType = vtkm::cont::ArrayHandlePermutation<IdArrayType, IdArrayType>;
vtkm::cont::ArrayHandle<vtkm::Id> tArray;
tArray.Allocate(nCriticalPoints);
vtkm::cont::Algorithm::CopyIf(mergeGraph.arcArray, isCritical, tArray);
vtkm::cont::Algorithm::Copy(PermuteIndexType(tArray, inverseIndex), mergeGraph.chainExtremum);
// and set up the active vertices - initially to identity
vtkm::cont::ArrayHandleIndex criticalVertsIndexArray(nCriticalPoints);
vtkm::cont::Algorithm::Copy(criticalVertsIndexArray, mergeGraph.activeVertices);
// now we need to compute the firstEdge array from the outdegrees
vtkm::cont::Algorithm::ScanExclusive(mergeGraph.outdegree, mergeGraph.firstEdge);
vtkm::Id nCriticalEdges = vtkm::cont::ArrayGetValue(nCriticalPoints - 1, mergeGraph.firstEdge) +
vtkm::cont::ArrayGetValue(nCriticalPoints - 1, mergeGraph.outdegree);
// now we allocate the edge arrays
mergeGraph.AllocateEdgeArrays(nCriticalEdges);
// and we have to set them, so we go back to the vertices
Mesh3D_DEM_SaddleStarter saddleStarter(nRows, // input
nCols, // input
nSlices, // input
ascending); // input
vtkm::worklet::DispatcherMapField<Mesh3D_DEM_SaddleStarter> saddleStarterDispatcher(
saddleStarter);
vtkm::cont::ArrayHandleZip<vtkm::cont::ArrayHandle<vtkm::Id>, vtkm::cont::ArrayHandle<vtkm::Id>>
outDegFirstEdge = vtkm::cont::make_ArrayHandleZip(mergeGraph.outdegree, mergeGraph.firstEdge);
saddleStarterDispatcher.Invoke(criticalVertsIndexArray, // input
outDegFirstEdge, // input (pair)
mergeGraph.valueIndex, // input
neighbourhoodMask, // input (whole array)
mergeGraph.arcArray, // input (whole array)
inverseIndex, // input (whole array)
neighbourOffsets3D, // input (whole array)
linkComponentCaseTable3D, // input (whole array)
mergeGraph.edgeNear, // output (whole array)
mergeGraph.edgeFar, // output (whole array)
mergeGraph.activeEdges); // output (whole array)
// finally, allocate and initialise the edgeSorter array
vtkm::cont::ArrayCopy(mergeGraph.activeEdges, mergeGraph.edgeSorter);
} // SetSaddleStarts()
}
}
}
#endif