Remove references to VTK-m header files from VTK filters

For better encapsulation (and simplification of the build), do not
expose VTK-m code itself from the vtkAcceleratorsVTKm package.

Accelerators/Vtkm/vtkmClip.cxx

@@ -30,6 +30,7 @@
 
 #include "vtkmlib/ArrayConverters.h"
 #include "vtkmlib/DataSetConverters.h"
+#include "vtkmlib/ImplicitFunctionConverter.h"
 #include "vtkmlib/PolyDataConverter.h"
 #include "vtkmlib/Storage.h"
 #include "vtkmlib/UnstructuredGridConverter.h"
@@ -61,7 +62,8 @@ void vtkmClip::PrintSelf(std::ostream &os, vtkIndent indent)
 vtkmClip::vtkmClip()
   : ClipValue(0.),
     ComputeScalars(true),
-    ClipFunction(nullptr)
+    ClipFunction(nullptr),
+    ClipFunctionConverter(new tovtkm::ImplicitFunctionConverter)
 {
   // Clip active point scalars by default
   this->SetInputArrayToProcess(0, 0, 0, vtkDataObject::FIELD_ASSOCIATION_POINTS,
@@ -90,7 +92,7 @@ void vtkmClip::SetClipFunction(vtkImplicitFunction *clipFunction)
   if (this->ClipFunction != clipFunction)
   {
     this->ClipFunction = clipFunction;
-    this->ClipFunctionConverter.Set(clipFunction);
+    this->ClipFunctionConverter->Set(clipFunction);
     this->Modified();
   }
 }
@@ -151,7 +153,7 @@ int vtkmClip::RequestData(vtkInformation *,
   vtkmInputFilterPolicy policy;
   if (this->ClipFunction)
   {
-    auto function = this->ClipFunctionConverter.Get();
+    auto function = this->ClipFunctionConverter->Get();
     if (function.GetValid())
     {
       functionFilter.SetImplicitFunction(function);

Accelerators/Vtkm/vtkmClip.h

@@ -27,12 +27,17 @@
 
 #include "vtkAcceleratorsVTKmModule.h" // For export macro
 #include "vtkUnstructuredGridAlgorithm.h"
-#include "vtkmlib/ImplicitFunctionConverter.h" // For ImplicitFunctionConverter
 
-#include <memory> // For std::shared_ptr
+#include <memory> // For std::unique_ptr
 
 class vtkImplicitFunction;
 
+namespace tovtkm {
+
+class ImplicitFunctionConverter;
+
+} // namespace tovtkm
+
 class VTKACCELERATORSVTKM_EXPORT vtkmClip : public vtkUnstructuredGridAlgorithm
 {
 public:
@@ -77,7 +82,7 @@ protected:
   bool ComputeScalars;
 
   vtkImplicitFunction *ClipFunction;
-  tovtkm::ImplicitFunctionConverter ClipFunctionConverter;
+  std::unique_ptr<tovtkm::ImplicitFunctionConverter> ClipFunctionConverter;
 
 private:
   vtkmClip(const vtkmClip&) = delete;

Accelerators/Vtkm/vtkmLevelOfDetail.h

@@ -49,7 +49,6 @@
 
 #include "vtkPolyDataAlgorithm.h"
 #include "vtkAcceleratorsVTKmModule.h" //required for correct implementation
-#include "vtkmConfig.h" //required for general vtkm setup
 
 class VTKACCELERATORSVTKM_EXPORT vtkmLevelOfDetail : public vtkPolyDataAlgorithm
 {