vtk-m/vtkm/worklet/contourtree/ContourTree.h
Kenneth Moreland bddad9b386 Remove TryExecute from filters
Now that the dispatcher does its own TryExecute, filters do not need to
do that. This change requires all worklets called by filters to be able
to execute without knowing the device a priori.
2018-10-16 15:59:53 -06:00

983 lines
38 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 2014 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
// Copyright 2014 UT-Battelle, LLC.
// Copyright 2014 Los Alamos National Security.
//
// Under the terms of Contract DE-NA0003525 with NTESS,
// the U.S. Government retains certain rights in this software.
//
// Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
// Laboratory (LANL), the U.S. Government retains certain rights in
// this software.
//============================================================================
// 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:
//
//
// i.e. based on PeakPitPruningCriticalSerial
//
// Under the old merge approach, we had an essentially breadth-first queue for transferring
// leaves from the merge trees to the contour tree.
//
// Most of these leaves are completely independent of each other, and can (on principle)
// be processed simultaneously. However, the interior of the tree is dependent on them
// having been dealt with already. This version, therefore, will make multiple passes,
// in each pass pruning all maxima then all minima, interspersed with updating the merge
// and split trees. To understand this, consider what happens in the merge algorithm when
// a maximum is added:
//
// 1. The vertex v is removed from the queue: it has one join neighbour, w
// 2. Edge (v,w) is removed from the join tree, along with vertex v
// 3. Edge (v,w) is added to the contour tree, with v, w if necessary
// 4. Vertex v is removed from the split tree, bridging edges past it if necessary
// 5. Vertex w is added to the queue iff it is now a leaf
//
// To parallelise this:
// For all vertices v
// Set contourArc[v] = NO_VERTEX_ASSIGNED
// Set nContourArcs = 0;
// While (nContourArcs) > 0 // might be one, or something else - base case isn't clear
// a. Use reduction to compute updegree from join tree, downdegree from split tree
// b. For each vertex v
// // omit previously processed vertices
// if (contourArc[v] == NO_VERTEX_ASSIGNED)
// continue;
// // Test for extremality
// i. If ((updegree[v] == 0) && (downdegree[v] == 1))
// { // Maximum
// contourArc[v] = joinArc[v];
// } // Maximum
// ii. Else if ((updegree[v] = 1) && (downdegree[v] == 0))
// { // Minimum
// contourArc[v] = splitArc[v];
// } // Minimum
// c. For (log n iterations)
// i. For each vertex v
// retrieve it's join neighbour j
// retrieve it's split neighbour s
// if v has no join neighbour (i.e. j == -1)
// skip (i.e. v is the root)
// else if j has a contour arc assigned
// set v's neighbour to j's neighbour
// if v has no split neighbour (i.e. s == -1)
// skip (i.e. v is the root)
// else if s has a contour arc assigned
// set v's neighbour to s's neighbour
//
// Initially, we will do this with all vertices, regular or otherwise, then restrict to
// the critical points. Number of iterations - regular vertices will slow this down, so
// the worst case is O(n) passes. Even if we restrict to critical points, W's in the tree
// will serialise, so O(n) still applies. I believe that the W edges can be suppressed,
// but let's leave that to optimisation for now.
//
//=======================================================================================
#ifndef vtkm_worklet_contourtree_contourtree_h
#define vtkm_worklet_contourtree_contourtree_h
// local includes
#include <vtkm/worklet/contourtree/ChainGraph.h>
#include <vtkm/worklet/contourtree/CopyJoinSplit.h>
#include <vtkm/worklet/contourtree/CopyNeighbors.h>
#include <vtkm/worklet/contourtree/CopySupernodes.h>
#include <vtkm/worklet/contourtree/DegreeDelta.h>
#include <vtkm/worklet/contourtree/DegreeSubrangeOffset.h>
#include <vtkm/worklet/contourtree/FillSupernodes.h>
#include <vtkm/worklet/contourtree/FindLeaves.h>
#include <vtkm/worklet/contourtree/MergeTree.h>
#include <vtkm/worklet/contourtree/PrintVectors.h>
#include <vtkm/worklet/contourtree/RegularToCandidate.h>
#include <vtkm/worklet/contourtree/RegularToCriticalDown.h>
#include <vtkm/worklet/contourtree/RegularToCriticalUp.h>
#include <vtkm/worklet/contourtree/ResetDegrees.h>
#include <vtkm/worklet/contourtree/SetJoinAndSplitArcs.h>
#include <vtkm/worklet/contourtree/SetSupernodeInward.h>
#include <vtkm/worklet/contourtree/SkipVertex.h>
#include <vtkm/worklet/contourtree/SubrangeOffset.h>
#include <vtkm/worklet/contourtree/Types.h>
#include <vtkm/worklet/contourtree/UpdateOutbound.h>
#include <vtkm/Pair.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/ArrayHandleConcatenate.h>
#include <vtkm/cont/ArrayHandleConcatenate.h>
#include <vtkm/cont/ArrayHandlePermutation.h>
#include <vtkm/worklet/WorkletMapField.h>
//#define DEBUG_PRINT 1
//#define DEBUG_TIMING 1
namespace vtkm
{
namespace worklet
{
namespace contourtree
{
template <typename T, typename StorageType>
class ContourTree
{
public:
using IdArrayType = vtkm::cont::ArrayHandle<vtkm::Id>;
using ValueArrayType = vtkm::cont::ArrayHandle<T>;
using PermuteIndexType = vtkm::cont::ArrayHandlePermutation<IdArrayType, IdArrayType>;
using PermuteValueType = vtkm::cont::ArrayHandlePermutation<IdArrayType, ValueArrayType>;
// reference to the underlying data
const vtkm::cont::ArrayHandle<T, StorageType> values;
// vector of superarcs in the contour tree (stored as inward-pointing)
vtkm::cont::ArrayHandle<vtkm::Id> superarcs;
// vector of supernodes
vtkm::cont::ArrayHandle<vtkm::Id> supernodes;
// vector of supernodes still unprocessed
vtkm::cont::ArrayHandle<vtkm::Id> activeSupernodes;
// references to join & split trees
MergeTree<T, StorageType> &joinTree, &splitTree;
// references to join & split graphs
ChainGraph<T, StorageType> &joinGraph, &splitGraph;
// vectors of up & down degree used during computation
vtkm::cont::ArrayHandle<vtkm::Id> updegree, downdegree;
// vectors for tracking merge arcs
vtkm::cont::ArrayHandle<vtkm::Id> joinArcs, splitArcs;
// counter for how many iterations it took to compute
vtkm::Id nIterations;
// contour tree constructor
ContourTree(const vtkm::cont::ArrayHandle<T, StorageType>& Values,
MergeTree<T, StorageType>& JoinTree,
MergeTree<T, StorageType>& SplitTree,
ChainGraph<T, StorageType>& JoinGraph,
ChainGraph<T, StorageType>& SplitGraph);
// routines for computing the contour tree
// combines the list of active vertices for join & split trees
// then reduces them to eliminate regular vertices & non-connectivity critical points
void FindSupernodes();
// transfers leaves from join/split trees to contour tree
void TransferLeaves();
// collapses regular edges along leaf superarcs
void CollapseRegular(bool isJoin);
// compresses trees to remove transferred vertices
void CompressTrees();
// compresses active set of supernodes
void CompressActiveSupernodes();
// finds the degree of each supernode from the join & split trees
void FindDegrees();
// collect the resulting saddle peaks in sort pairs
void CollectSaddlePeak(vtkm::cont::ArrayHandle<vtkm::Pair<vtkm::Id, vtkm::Id>>& saddlePeak);
void DebugPrint(const char* message);
}; // class ContourTree
struct VertexAssigned : vtkm::worklet::WorkletMapField
{
public:
using ControlSignature = void(FieldIn<IdType> supernode,
WholeArrayIn<IdType> superarcs,
FieldOut<IdType> hasSuperArc);
using ExecutionSignature = _3(_1, _2);
using InputDomain = _1;
bool vertexIsAssigned;
VTKM_EXEC_CONT
VertexAssigned(bool VertexIsAssigned)
: vertexIsAssigned(VertexIsAssigned)
{
}
template <typename InPortalFieldType>
VTKM_EXEC vtkm::Id operator()(const vtkm::Id supernode, const InPortalFieldType& superarcs) const
{
if (vertexIsAssigned == false)
{
if (superarcs.Get(supernode) == NO_VERTEX_ASSIGNED)
return vtkm::Id(1);
else
return vtkm::Id(0);
}
else
{
if (superarcs.Get(supernode) != NO_VERTEX_ASSIGNED)
return vtkm::Id(1);
else
return vtkm::Id(0);
}
}
};
// creates contour tree
template <typename T, typename StorageType>
ContourTree<T, StorageType>::ContourTree(const vtkm::cont::ArrayHandle<T, StorageType>& Values,
MergeTree<T, StorageType>& JoinTree,
MergeTree<T, StorageType>& SplitTree,
ChainGraph<T, StorageType>& JoinGraph,
ChainGraph<T, StorageType>& SplitGraph)
: values(Values)
, joinTree(JoinTree)
, splitTree(SplitTree)
, joinGraph(JoinGraph)
, splitGraph(SplitGraph)
{
// first we have to get the correct list of supernodes
// this will also set the degrees of the vertices initially
FindSupernodes();
// and track how many iterations it takes
nIterations = 0;
// loop until no arcs remaining to be found
// tree can end with either 0 or 1 vertices unprocessed
// 0 means the last edge was pruned from both ends
// 1 means that there were two final edges meeting at a vertex
while (activeSupernodes.GetNumberOfValues() > 1)
{ // loop until no active vertices remaining
#ifdef DEBUG_PRINT
std::cout << "========================================" << std::endl;
std::cout << " " << std::endl;
std::cout << "Iteration " << nIterations << " Size " << activeSupernodes.GetNumberOfValues()
<< std::endl;
std::cout << " " << std::endl;
std::cout << "========================================" << std::endl;
#endif
// transfer all leaves to the contour tree
TransferLeaves();
// collapse regular vertices from leaves, upper then lower
CollapseRegular(true);
CollapseRegular(false);
// compress the join and split trees
CompressTrees();
// compress the active list of supernodes
CompressActiveSupernodes();
// recompute the vertex degrees
FindDegrees();
nIterations++;
}
} // constructor
// combines the list of active vertices for join & split trees
// then reduces them to eliminate regular vertices & non-connectivity critical points
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::FindSupernodes()
{
// both trees may have non-connectivity critical points, so we first make a joint list
// here, we will explicitly assume that the active lists are in numerical order
// which is how we are currently constructing them
vtkm::Id nCandidates =
joinGraph.valueIndex.GetNumberOfValues() + splitGraph.valueIndex.GetNumberOfValues();
vtkm::cont::ArrayHandle<vtkm::Id> candidates;
// take the union of the two sets of vertices
vtkm::cont::ArrayHandleConcatenate<IdArrayType, IdArrayType> candidateArray(
joinGraph.valueIndex, splitGraph.valueIndex);
vtkm::cont::Algorithm::Copy(candidateArray, candidates);
vtkm::cont::Algorithm::Sort(candidates);
vtkm::cont::Algorithm::Unique(candidates);
nCandidates = candidates.GetNumberOfValues();
vtkm::cont::ArrayHandleIndex candidateIndexArray(nCandidates);
// we need an array lookup to convert vertex ID's
vtkm::Id nValues = values.GetNumberOfValues();
vtkm::cont::ArrayHandle<vtkm::Id> regularToCritical;
vtkm::cont::ArrayHandleConstant<vtkm::Id> noVertArray(NO_VERTEX_ASSIGNED, nValues);
vtkm::cont::Algorithm::Copy(noVertArray, regularToCritical);
if (nCandidates > 0)
{
RegularToCriticalUp regularToCriticalUp;
vtkm::worklet::DispatcherMapField<RegularToCriticalUp> regularToCriticalUpDispatcher(
regularToCriticalUp);
regularToCriticalUpDispatcher.Invoke(candidateIndexArray, // input
candidates, // input
regularToCritical); // output (whole array)
}
// now that we have a complete list of active nodes from each, we can call the trees
// to connect them properly
joinTree.ComputeAugmentedSuperarcs();
joinTree.ComputeAugmentedArcs(candidates);
splitTree.ComputeAugmentedSuperarcs();
splitTree.ComputeAugmentedArcs(candidates);
// we create up & down degree arrays
vtkm::cont::ArrayHandleConstant<vtkm::Id> initCandidateArray(0, nCandidates);
vtkm::cont::ArrayHandle<vtkm::Id> upCandidate;
vtkm::cont::ArrayHandle<vtkm::Id> downCandidate;
vtkm::cont::Algorithm::Copy(initCandidateArray, upCandidate);
vtkm::cont::Algorithm::Copy(initCandidateArray, downCandidate);
// This next chunk changes in parallel - it has to count the up & down degree for each
// vertex. It's a simple loop in serial, but in parallel, what we have to do is:
// 1. Copy the lower ends of the edges, converting from regular ID to candidate ID
// 2. Sort the lower ends of the edges
// 3. For each value, store the beginning of the range
// 4. Compute the delta to get the degree.
// create a sorting vector
vtkm::cont::ArrayHandle<vtkm::Id> sortVector;
sortVector.Allocate(nCandidates);
// 1. Copy the lower ends of the edges, converting from regular ID to candidate ID
if (nCandidates > 0)
{
RegularToCandidate regularToCandidate;
vtkm::worklet::DispatcherMapField<RegularToCandidate> regularToCandidateDispatcher(
regularToCandidate);
regularToCandidateDispatcher.Invoke(candidates, // input
joinTree.mergeArcs, // input (whole array)
regularToCritical, // input (whole array)
sortVector); // output
}
// 2. Sort the lower ends of the edges
vtkm::cont::Algorithm::Sort(sortVector);
// 3. For each value, store the beginning & end of the range (in parallel)
// The 0th element is guaranteed to be NO_VERTEX_ASSIGNED, & can be skipped
// Otherwise, if the i-1th element is different, we are the offset for the subrange
// and store into the ith place
vtkm::cont::ArrayHandleCounting<vtkm::Id> subsetIndexArray(1, 1, nCandidates - 1);
if (nCandidates > 0)
{
SubrangeOffset subRangeOffset;
vtkm::worklet::DispatcherMapField<SubrangeOffset> subrangeOffsetDispatcher(subRangeOffset);
subrangeOffsetDispatcher.Invoke(subsetIndexArray, // index
sortVector, // input
upCandidate); // output
}
// 4. Compute the delta to get the degree.
if (nCandidates > 0)
{
DegreeDelta degreeDelta(nCandidates);
vtkm::worklet::DispatcherMapField<DegreeDelta> degreeDeltaDispatcher(degreeDelta);
degreeDeltaDispatcher.Invoke(subsetIndexArray, // input
sortVector, // input (whole array)
upCandidate); // output (whole array)
}
// Now repeat the same steps for the downdegree
// 1. Copy the upper ends of the edges, converting from regular ID to candidate ID
if (nCandidates > 0)
{
RegularToCriticalDown regularToCriticalDown;
vtkm::worklet::DispatcherMapField<RegularToCriticalDown> regularToCriticalDownDispatcher(
regularToCriticalDown);
regularToCriticalDownDispatcher.Invoke(candidates, // input
splitTree.mergeArcs, // input (whole array)
regularToCritical, // input (whole array)
sortVector); // output
}
// 2. Sort the lower ends of the edges
vtkm::cont::Algorithm::Sort(sortVector);
// 3. For each value, store the beginning & end of the range (in parallel)
// The 0th element is guaranteed to be NO_VERTEX_ASSIGNED, & can be skipped
// Otherwise, if the i-1th element is different, we are the offset for the subrange
// and store into the ith place
if (nCandidates > 0)
{
SubrangeOffset subRangeOffset;
vtkm::worklet::DispatcherMapField<SubrangeOffset> subrangeOffsetDispatcher(subRangeOffset);
subrangeOffsetDispatcher.Invoke(subsetIndexArray, // index
sortVector, // input
downCandidate); // output
}
// 4. Compute the delta to get the degree.
if (nCandidates > 0)
{
DegreeDelta degreeDelta(nCandidates);
vtkm::worklet::DispatcherMapField<DegreeDelta> degreeDeltaDispatcher(degreeDelta);
degreeDeltaDispatcher.Invoke(subsetIndexArray, // index
sortVector, // input
downCandidate); // in out
}
// create an index vector for whether the vertex is to be kept
vtkm::cont::ArrayHandle<vtkm::Id> isSupernode;
isSupernode.Allocate(nCandidates);
// fill the vector in
if (nCandidates > 0)
{
FillSupernodes fillSupernodes;
vtkm::worklet::DispatcherMapField<FillSupernodes> fillSupernodesDispatcher(fillSupernodes);
fillSupernodesDispatcher.Invoke(upCandidate, // input
downCandidate, // input
isSupernode); // output
}
// do a compaction to find the new index for each
// We end with 0 in position 0, and need one extra position to find the new size
vtkm::cont::ArrayHandle<vtkm::Id> supernodeID;
vtkm::cont::Algorithm::ScanExclusive(isSupernode, supernodeID);
// size is the position of the last element + the size of the last element (0/1)
vtkm::Id nSupernodes = supernodeID.GetPortalConstControl().Get(nCandidates - 1) +
isSupernode.GetPortalConstControl().Get(nCandidates - 1);
// allocate memory for our arrays
supernodes.ReleaseResources();
updegree.ReleaseResources();
downdegree.ReleaseResources();
supernodes.Allocate(nSupernodes);
updegree.Allocate(nSupernodes);
downdegree.Allocate(nSupernodes);
// now copy over the positions to compact
if (nCandidates > 0)
{
CopySupernodes copySupernodes;
vtkm::worklet::DispatcherMapField<CopySupernodes> copySupernodesDispatcher(copySupernodes);
copySupernodesDispatcher.Invoke(isSupernode, // input
candidates, // input
supernodeID, // input
upCandidate, // input
downCandidate, // input
regularToCritical, // output (whole array)
supernodes, // output (whole array)
updegree, // output (whole array)
downdegree); // output (whole array)
}
// now we call the merge tree again to reset the merge arcs
joinTree.ComputeAugmentedArcs(supernodes);
splitTree.ComputeAugmentedArcs(supernodes);
// next we create the working arrays of merge arcs
nSupernodes = supernodes.GetNumberOfValues();
vtkm::cont::ArrayHandleIndex supernodeIndexArray(nSupernodes);
joinArcs.ReleaseResources();
splitArcs.ReleaseResources();
joinArcs.Allocate(nSupernodes);
splitArcs.Allocate(nSupernodes);
// and copy them across, setting IDs for both ends
SetJoinAndSplitArcs setJoinAndSplitArcs;
vtkm::worklet::DispatcherMapField<SetJoinAndSplitArcs> setJoinAndSplitArcsDispatcher(
setJoinAndSplitArcs);
setJoinAndSplitArcsDispatcher.Invoke(supernodes, // input
joinTree.mergeArcs, // input (whole array)
splitTree.mergeArcs, // input (whole array)
regularToCritical, // input (whole array)
joinArcs, // output
splitArcs); // output
vtkm::cont::ArrayHandleConstant<vtkm::Id> newsuperarcs(NO_VERTEX_ASSIGNED, nSupernodes);
superarcs.ReleaseResources();
vtkm::cont::Algorithm::Copy(newsuperarcs, superarcs);
// create the active supernode vector
activeSupernodes.ReleaseResources();
activeSupernodes.Allocate(nSupernodes);
vtkm::cont::ArrayHandleIndex supernodeSeq(nSupernodes);
vtkm::cont::Algorithm::Copy(supernodeSeq, activeSupernodes);
#ifdef DEBUG_PRINT
DebugPrint("Supernodes Found");
#endif
} // FindSupernodes()
// transfers leaves from join/split trees to contour tree
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::TransferLeaves()
{
FindLeaves findLeaves;
vtkm::worklet::DispatcherMapField<FindLeaves> findLeavesDispatcher(findLeaves);
findLeavesDispatcher.Invoke(activeSupernodes, // input
updegree, // input (whole array)
downdegree, // input (whole array)
joinArcs, // input (whole array)
splitArcs, // input (whole array)
superarcs); // i/o (whole array)
#ifdef DEBUG_PRINT
DebugPrint("Leaves Transferred");
#endif
} // TransferLeaves()
// collapses regular edges along leaf superarcs
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::CollapseRegular(bool isJoin)
{
// we'll have a vector for tracking outwards
vtkm::Id nSupernodes = supernodes.GetNumberOfValues();
vtkm::cont::ArrayHandleConstant<vtkm::Id> nullArray(0, nSupernodes);
vtkm::cont::ArrayHandle<vtkm::Id> outbound;
outbound.Allocate(nSupernodes);
vtkm::cont::ArrayCopy(nullArray, outbound);
// and a reference for the inwards array and to the degrees
vtkm::cont::ArrayHandle<vtkm::Id> inbound;
vtkm::cont::ArrayHandle<vtkm::Id> indegree;
vtkm::cont::ArrayHandle<vtkm::Id> outdegree;
if (isJoin)
{
vtkm::cont::ArrayCopy(joinArcs, inbound);
vtkm::cont::ArrayCopy(downdegree, indegree);
vtkm::cont::ArrayCopy(updegree, outdegree);
}
else
{
vtkm::cont::ArrayCopy(splitArcs, inbound);
vtkm::cont::ArrayCopy(updegree, indegree);
vtkm::cont::ArrayCopy(downdegree, outdegree);
}
// loop to copy join/split
CopyJoinSplit copyJoinSplit;
vtkm::worklet::DispatcherMapField<CopyJoinSplit> copyJoinSplitDispatcher(copyJoinSplit);
copyJoinSplitDispatcher.Invoke(activeSupernodes, // input
inbound, // input (whole array)
indegree, // input (whole array)
outdegree, // input (whole array)
outbound); // output (whole array)
// Compute the number of log steps required in this pass
vtkm::Id nLogSteps = 1;
vtkm::Id nActiveSupernodes = activeSupernodes.GetNumberOfValues();
for (vtkm::Id shifter = nActiveSupernodes; shifter != 0; shifter >>= 1)
nLogSteps++;
// loop to find the now-regular vertices and collapse past them without altering
// the existing join & split arcs
for (vtkm::Id iteration = 0; iteration < nLogSteps; iteration++)
{
UpdateOutbound updateOutbound;
vtkm::worklet::DispatcherMapField<UpdateOutbound> updateOutboundDispatcher(updateOutbound);
updateOutboundDispatcher.Invoke(activeSupernodes, // input
outbound); // i/o (whole array)
}
// at this point, the outbound vector chains everything outwards to the leaf
// any vertices on the last outbound leaf superarc point to the leaf
// Now, any regular leaf vertex points out to a leaf, so the condition we test is
// a. outbound is not -1 (i.e. vertex is regular)
// b. superarc[outbound] is not -1 (i.e. outbound is a leaf)
SetSupernodeInward setSupernodeInward;
vtkm::worklet::DispatcherMapField<SetSupernodeInward> setSupernodeInwardDispatcher(
setSupernodeInward);
setSupernodeInwardDispatcher.Invoke(activeSupernodes, // input
inbound, // input (whole array)
outbound, // input (whole array)
indegree, // input (whole array)
outdegree, // input (whole array)
superarcs); // i/o (whole array)
outbound.ReleaseResources();
#ifdef DEBUG_PRINT
DebugPrint(isJoin ? "Upper Regular Nodes Collapsed" : "Lower Regular Nodes Collapsed");
#endif
} // CollapseRegular()
// compresses trees to remove transferred vertices
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::CompressTrees()
{
// Compute the number of log steps required in this pass
vtkm::Id nActiveSupernodes = activeSupernodes.GetNumberOfValues();
vtkm::Id nLogSteps = 1;
for (vtkm::Id shifter = nActiveSupernodes; shifter != 0; shifter >>= 1)
nLogSteps++;
// loop to update the merge trees
for (vtkm::Id logStep = 0; logStep < nLogSteps; logStep++)
{
SkipVertex skipVertex;
vtkm::worklet::DispatcherMapField<SkipVertex> skipVertexDispatcher(skipVertex);
skipVertexDispatcher.Invoke(activeSupernodes, // input
superarcs, // input (whole array)
joinArcs, // i/o (whole array)
splitArcs); // i/o (whole array)
}
#ifdef DEBUG_PRINT
DebugPrint("Trees Compressed");
#endif
} // CompressTrees()
// compresses active set of supernodes
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::CompressActiveSupernodes()
{
// copy only if the superarc is not set
vtkm::cont::ArrayHandle<vtkm::Id> noSuperarcArray;
noSuperarcArray.Allocate(activeSupernodes.GetNumberOfValues());
VertexAssigned vertexAssigned(false);
vtkm::worklet::DispatcherMapField<VertexAssigned> vertexAssignedDispatcher(vertexAssigned);
vertexAssignedDispatcher.Invoke(activeSupernodes, superarcs, noSuperarcArray);
vtkm::cont::ArrayHandle<vtkm::Id> compressSupernodes;
vtkm::cont::Algorithm::CopyIf(activeSupernodes, noSuperarcArray, compressSupernodes);
activeSupernodes.ReleaseResources();
vtkm::cont::ArrayCopy(compressSupernodes, activeSupernodes);
#ifdef DEBUG_PRINT
DebugPrint("Active Supernodes Compressed");
#endif
} // CompressActiveSupernodes()
// recomputes the degree of each supernode from the join & split trees
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::FindDegrees()
{
if (activeSupernodes.GetNumberOfValues() == 0)
return;
vtkm::Id nActiveSupernodes = activeSupernodes.GetNumberOfValues();
ResetDegrees resetDegrees;
vtkm::worklet::DispatcherMapField<ResetDegrees> resetDegreesDispatcher(resetDegrees);
resetDegreesDispatcher.Invoke(activeSupernodes, // input
updegree, // output (whole array)
downdegree); // output (whole array)
// create a temporary sorting array
vtkm::cont::ArrayHandle<vtkm::Id> sortVector;
sortVector.Allocate(nActiveSupernodes);
vtkm::cont::ArrayHandleIndex activeSupernodeIndexArray(nActiveSupernodes);
// 1. Copy the neighbours for each active edge
if (nActiveSupernodes > 0)
{
CopyNeighbors copyNeighbors;
vtkm::worklet::DispatcherMapField<CopyNeighbors> copyNeighborsDispatcher(copyNeighbors);
copyNeighborsDispatcher.Invoke(activeSupernodeIndexArray, // input
activeSupernodes, // input (whole array)
joinArcs, // input (whole array)
sortVector); // output
}
// 2. Sort the neighbours
vtkm::cont::Algorithm::Sort(sortVector);
// 3. For each value, store the beginning & end of the range (in parallel)
// The 0th element is guaranteed to be NO_VERTEX_ASSIGNED, & can be skipped
// Otherwise, if the i-1th element is different, we are the offset for the subrange
// and store into the ith place
vtkm::cont::ArrayHandleCounting<vtkm::Id> subsetIndexArray(1, 1, nActiveSupernodes - 1);
if (nActiveSupernodes > 1)
{
DegreeSubrangeOffset degreeSubrangeOffset;
vtkm::worklet::DispatcherMapField<DegreeSubrangeOffset> degreeSubrangeOffsetDispatcher(
degreeSubrangeOffset);
degreeSubrangeOffsetDispatcher.Invoke(subsetIndexArray, // input
sortVector, // input (whole array)
updegree); // output (whole array)
}
// 4. Compute the delta to get the degree.
if (nActiveSupernodes > 1)
{
DegreeDelta degreeDelta(nActiveSupernodes);
vtkm::worklet::DispatcherMapField<DegreeDelta> degreeDeltaDispatcher(degreeDelta);
degreeDeltaDispatcher.Invoke(subsetIndexArray, // input
sortVector, // input
updegree); // in out
}
// Now repeat the same steps for the downdegree
// 1. Copy the neighbours for each active edge
if (nActiveSupernodes > 0)
{
CopyNeighbors copyNeighbors;
vtkm::worklet::DispatcherMapField<CopyNeighbors> copyNeighborsDispatcher(copyNeighbors);
copyNeighborsDispatcher.Invoke(activeSupernodeIndexArray, // input
activeSupernodes, // input (whole array)
splitArcs, // input (whole array)
sortVector); // output
}
// 2. Sort the neighbours
vtkm::cont::Algorithm::Sort(sortVector);
// 3. For each value, store the beginning & end of the range (in parallel)
// The 0th element is guaranteed to be NO_VERTEX_ASSIGNED, & can be skipped
// Otherwise, if the i-1th element is different, we are the offset for the subrange
// and store into the ith place
if (nActiveSupernodes > 1)
{
DegreeSubrangeOffset degreeSubrangeOffset;
vtkm::worklet::DispatcherMapField<DegreeSubrangeOffset> degreeSubrangeOffsetDispatcher(
degreeSubrangeOffset);
degreeSubrangeOffsetDispatcher.Invoke(subsetIndexArray, // input
sortVector, // input (whole array)
downdegree); // output (whole array)
}
// 4. Compute the delta to get the degree.
if (nActiveSupernodes > 1)
{
DegreeDelta degreeDelta(nActiveSupernodes);
vtkm::worklet::DispatcherMapField<DegreeDelta> degreeDeltaDispatcher(degreeDelta);
degreeDeltaDispatcher.Invoke(subsetIndexArray, // input
sortVector, // input (whole array)
downdegree); // in out (whole array)
}
#ifdef DEBUG_PRINT
DebugPrint("Degrees Recomputed");
#endif
} // FindDegrees()
// small class for storing the contour arcs
class EdgePair
{
public:
vtkm::Id low, high;
// constructor - defaults to -1
EdgePair(vtkm::Id Low = -1, vtkm::Id High = -1)
: low(Low)
, high(High)
{
}
};
// comparison operator <
bool operator<(const EdgePair LHS, const EdgePair RHS)
{
if (LHS.low < RHS.low)
return true;
if (LHS.low > RHS.low)
return false;
if (LHS.high < RHS.high)
return true;
if (LHS.high > RHS.high)
return false;
return false;
}
struct SaddlePeakSort
{
VTKM_EXEC_CONT bool operator()(const vtkm::Pair<vtkm::Id, vtkm::Id>& a,
const vtkm::Pair<vtkm::Id, vtkm::Id>& b) const
{
if (a.first < b.first)
return true;
if (a.first > b.first)
return false;
if (a.second < b.second)
return true;
if (a.second > b.second)
return false;
return false;
}
};
// sorted print routine
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::CollectSaddlePeak(
vtkm::cont::ArrayHandle<vtkm::Pair<vtkm::Id, vtkm::Id>>& saddlePeak)
{
// Collect the valid saddle peak pairs
std::vector<vtkm::Pair<vtkm::Id, vtkm::Id>> superarcVector;
for (vtkm::Id supernode = 0; supernode < supernodes.GetNumberOfValues(); supernode++)
{
// ID of regular node
vtkm::Id regularID = supernodes.GetPortalConstControl().Get(supernode);
// retrieve ID of target supernode
vtkm::Id superTo = superarcs.GetPortalConstControl().Get(supernode);
// if this is true, it is the last pruned vertex
if (superTo == NO_VERTEX_ASSIGNED)
continue;
// retrieve the regular ID for it
vtkm::Id regularTo = supernodes.GetPortalConstControl().Get(superTo);
// how we print depends on which end has lower ID
if (regularID < regularTo)
{ // from is lower
// extra test to catch duplicate edge
if (superarcs.GetPortalConstControl().Get(superTo) != supernode)
superarcVector.push_back(vtkm::make_Pair(regularID, regularTo));
} // from is lower
else
superarcVector.push_back(vtkm::make_Pair(regularTo, regularID));
} // per vertex
// Setting saddlePeak reference to the make_ArrayHandle directly does not work
vtkm::cont::ArrayHandle<vtkm::Pair<vtkm::Id, vtkm::Id>> tempArray =
vtkm::cont::make_ArrayHandle(superarcVector);
// now sort it
vtkm::cont::Algorithm::Sort(tempArray, SaddlePeakSort());
vtkm::cont::Algorithm::Copy(tempArray, saddlePeak);
#ifdef DEBUG_PRINT
const vtkm::Id arcVecSize = static_cast<vtkm::Id>(superarcVector.size());
for (vtkm::Id superarc = 0; superarc < arcVecSize; superarc++)
{
std::cout << std::setw(PRINT_WIDTH) << saddlePeak.GetPortalControl().Get(superarc).first << " ";
std::cout << std::setw(PRINT_WIDTH) << saddlePeak.GetPortalControl().Get(superarc).second
<< std::endl;
}
#endif
} // CollectSaddlePeak()
// debug routine
template <typename T, typename StorageType>
void ContourTree<T, StorageType>::DebugPrint(const char* message)
{
std::cout << "---------------------------" << std::endl;
std::cout << std::string(message) << std::endl;
std::cout << "---------------------------" << std::endl;
std::cout << std::endl;
// print out the supernode arrays
vtkm::Id nSupernodes = supernodes.GetNumberOfValues();
printHeader(nSupernodes);
printIndices("Supernodes", supernodes);
vtkm::cont::ArrayHandle<vtkm::Id> supervalues;
vtkm::cont::ArrayCopy(PermuteValueType(supernodes, values), supervalues);
printValues("Value", supervalues);
printIndices("Up degree", updegree);
printIndices("Down degree", downdegree);
printIndices("Join arc", joinArcs);
printIndices("Split arc", splitArcs);
printIndices("Superarcs", superarcs);
std::cout << std::endl;
// print out the active supernodes
vtkm::Id nActiveSupernodes = activeSupernodes.GetNumberOfValues();
printHeader(nActiveSupernodes);
printIndices("Active Supernodes", activeSupernodes);
vtkm::cont::ArrayHandle<vtkm::Id> activeUpdegree;
vtkm::cont::ArrayCopy(PermuteIndexType(activeSupernodes, updegree), activeUpdegree);
printIndices("Active Up Degree", activeUpdegree);
vtkm::cont::ArrayHandle<vtkm::Id> activeDowndegree;
vtkm::cont::ArrayCopy(PermuteIndexType(activeSupernodes, downdegree), activeDowndegree);
printIndices("Active Down Degree", activeDowndegree);
vtkm::cont::ArrayHandle<vtkm::Id> activeJoinArcs;
vtkm::cont::ArrayCopy(PermuteIndexType(activeSupernodes, joinArcs), activeJoinArcs);
printIndices("Active Join Arcs", activeJoinArcs);
vtkm::cont::ArrayHandle<vtkm::Id> activeSplitArcs;
vtkm::cont::ArrayCopy(PermuteIndexType(activeSupernodes, splitArcs), activeSplitArcs);
printIndices("Active Split Arcs", activeSplitArcs);
vtkm::cont::ArrayHandle<vtkm::Id> activeSuperarcs;
vtkm::cont::ArrayCopy(PermuteIndexType(activeSupernodes, superarcs), activeSuperarcs);
printIndices("Active Superarcs", activeSuperarcs);
std::cout << std::endl;
} // DebugPrint()
}
}
}
#endif