Use CreateResult mechanism for copying PDS fields.

vtkm/cont/PartitionedDataSet.cxx

@@ -143,6 +143,12 @@ void PartitionedDataSet::ReplacePartition(vtkm::Id index, const vtkm::cont::Data
   }
 }
 
+VTKM_CONT
+void PartitionedDataSet::CopyStructure(const vtkm::cont::PartitionedDataSet& source)
+{
+  this->Partitions = source.Partitions;
+}
+
 VTKM_CONT
 void PartitionedDataSet::PrintSummary(std::ostream& stream) const
 {

vtkm/cont/PartitionedDataSet.h

@@ -218,6 +218,10 @@ public:
   }
   //@}
 
+  /// Copies the structure i.e. partitions from the source. The fields are left unchanged.
+  VTKM_CONT
+  void CopyStructure(const vtkm::cont::PartitionedDataSet& source);
+
   VTKM_CONT
   void PrintSummary(std::ostream& stream) const;
 

vtkm/filter/NewFilter.cxx

@@ -88,7 +88,7 @@ vtkm::cont::PartitionedDataSet NewFilter::DoExecutePartitions(
     }
   }
 
-  return output;
+  return this->CreateResult(input, output);
 }
 
 vtkm::cont::DataSet NewFilter::Execute(const vtkm::cont::DataSet& input)
@@ -103,14 +103,7 @@ vtkm::cont::PartitionedDataSet NewFilter::Execute(const vtkm::cont::PartitionedD
                  (int)input.GetNumberOfPartitions(),
                  vtkm::cont::TypeToString<decltype(*this)>().c_str());
 
-  vtkm::cont::PartitionedDataSet output = this->DoExecutePartitions(input);
-
-  //Copy any fields.
-  vtkm::Id numFields = static_cast<vtkm::Id>(input.GetNumberOfFields());
-  for (vtkm::Id i = 0; i < numFields; i++)
-    output.AddField(input.GetField(i));
-
-  return output;
+  return this->DoExecutePartitions(input);
 }
 
 vtkm::cont::DataSet NewFilter::CreateResult(const vtkm::cont::DataSet& inDataSet) const
@@ -124,6 +117,20 @@ vtkm::cont::DataSet NewFilter::CreateResult(const vtkm::cont::DataSet& inDataSet
   return clone;
 }
 
+vtkm::cont::PartitionedDataSet NewFilter::CreateResult(
+  const vtkm::cont::PartitionedDataSet& input,
+  const vtkm::cont::PartitionedDataSet& output) const
+{
+  vtkm::cont::PartitionedDataSet clone;
+  clone.CopyStructure(output);
+  this->MapFieldsOntoOutput(
+    input, clone, [](vtkm::cont::PartitionedDataSet& out, const vtkm::cont::Field& fieldToPass) {
+      out.AddField(fieldToPass);
+    });
+
+  return clone;
+}
+
 vtkm::Id NewFilter::DetermineNumberOfThreads(const vtkm::cont::PartitionedDataSet& input)
 {
   vtkm::Id numDS = input.GetNumberOfPartitions();

vtkm/filter/NewFilter.h

@@ -326,6 +326,9 @@ protected:
   /// fields of `inDataSet` (as selected by the `FieldsToPass` state of the filter).
   ///
   VTKM_CONT vtkm::cont::DataSet CreateResult(const vtkm::cont::DataSet& inDataSet) const;
+  VTKM_CONT vtkm::cont::PartitionedDataSet CreateResult(
+    const vtkm::cont::PartitionedDataSet& input,
+    const vtkm::cont::PartitionedDataSet& output) const;
 
   /// \brief Create the output data set for `DoExecute`.
   ///
@@ -431,9 +434,9 @@ protected:
     const vtkm::cont::PartitionedDataSet& inData);
 
 private:
-  template <typename FieldMapper>
-  VTKM_CONT void MapFieldsOntoOutput(const vtkm::cont::DataSet& input,
-                                     vtkm::cont::DataSet& output,
+  template <typename DataType, typename FieldMapper>
+  VTKM_CONT void MapFieldsOntoOutput(const DataType& input,
+                                     DataType& output,
                                      FieldMapper&& fieldMapper) const
   {
     for (vtkm::IdComponent cc = 0; cc < input.GetNumberOfFields(); ++cc)

vtkm/filter/testing/UnitTestPartitionedDataSetFilters.cxx

@@ -115,7 +115,6 @@ void TestPartitionedDataSetFilters()
   result = cellAverage.Execute(partitions);
   Result_Verify<vtkm::FloatDefault>(result, cellAverage, partitions, std::string("pointvar"));
 
-
   //Make sure that any Fields are propagated to the output.
   partitionNum = 3;
   partitions = PartitionedDataSetBuilder<vtkm::FloatDefault>(partitionNum, "pointvar");