vtkPeriodicDataArray: Support GetVoidPointer

This is needed by vtkWriter subclasses.

Common/DataModel/vtkPeriodicDataArray.h

@@ -301,6 +301,12 @@ public:
   vtkGetMacro(Normalize, bool);
   ///@}
 
+  /**
+   * Use of this method is discouraged, it creates a memory copy of the data into
+   * a contiguous AoS-ordered buffer internally.
+   */
+  void* GetVoidPointer(vtkIdType valueIdx) override;
+
 protected:
   vtkPeriodicDataArray();
   ~vtkPeriodicDataArray() override;
@@ -361,10 +367,11 @@ private:
 
   friend class vtkGenericDataArray<vtkPeriodicDataArray<Scalar>, Scalar>;
 
-  Scalar* TempScalarArray;               // Temporary array used by GetTypedTuple methods
-  double* TempDoubleArray;               // Temporary array used by GetTuple vethods
-  vtkIdType TempTupleIdx;                // Location of currently stored Temp Tuple to use as cache
-  vtkAOSDataArrayTemplate<Scalar>* Data; // Original data
+  Scalar* TempScalarArray;                // Temporary array used by GetTypedTuple methods
+  double* TempDoubleArray;                // Temporary array used by GetTuple vethods
+  vtkIdType TempTupleIdx;                 // Location of currently stored Temp Tuple to use as cache
+  vtkAOSDataArrayTemplate<Scalar>* Data;  // Original data
+  vtkAOSDataArrayTemplate<Scalar>* Cache; // Only used by void pointer
 
   bool InvalidRange = true;
   double PeriodicRange[6]; // Transformed periodic range

Common/DataModel/vtkPeriodicDataArray.txx

@@ -683,6 +683,18 @@ void vtkPeriodicDataArray<Scalar>::InvalidateRange()
   this->InvalidRange = true;
 }
 
+//------------------------------------------------------------------------------
+template <class Scalar>
+void* vtkPeriodicDataArray<Scalar>::GetVoidPointer(vtkIdType valueIdx)
+{
+  if (!this->Cache)
+  {
+    this->Cache = vtkAOSDataArrayTemplate<Scalar>::New();
+    this->Cache->DeepCopy(this);
+  }
+  return this->Cache->GetVoidPointer(valueIdx);
+}
+
 //------------------------------------------------------------------------------
 template <class Scalar>
 vtkPeriodicDataArray<Scalar>::vtkPeriodicDataArray()
@@ -692,6 +704,7 @@ vtkPeriodicDataArray<Scalar>::vtkPeriodicDataArray()
   this->TempDoubleArray = nullptr;
   this->TempTupleIdx = -1;
   this->Data = nullptr;
+  this->Cache = nullptr;
   this->MaxId = -1;
   this->Size = 0;
 
@@ -706,5 +719,10 @@ template <class Scalar>
 vtkPeriodicDataArray<Scalar>::~vtkPeriodicDataArray()
 {
   this->Initialize();
+  if (this->Cache)
+  {
+    this->Cache->Delete();
+    this->Cache = nullptr;
+  }
 }
 VTK_ABI_NAMESPACE_END