vtkThreshold: Test component modes and magnitude

Test untested component modes and newly added magnitude option.
This is not tested on vtk-m, because of issue #804 (vtk/vtk-m)

Filters/Core/Testing/Cxx/CMakeLists.txt

@@ -88,4 +88,16 @@ vtk_add_test_cxx(vtkFiltersCoreCxxTests tests
   TestContourImplicitArrays.cxx
   )
 
-vtk_test_cxx_executable(vtkFiltersCoreCxxTests tests)
+# This test fails on vtk-m due to bug #804 (vtk/vtkm)
+# TODO: Remove from condition when fixed
+if (NOT VTK_ENABLE_VTKM_OVERRIDES)
+  vtk_add_test_cxx(vtkFiltersCoreCxxTests no_vtkm_tests
+    TestThresholdComponents.cxx,NO_VALID)
+endif()
+
+set(all_tests
+  ${tests}
+  ${no_vtkm_tests}
+  )
+
+vtk_test_cxx_executable(vtkFiltersCoreCxxTests all_tests)

Filters/Core/Testing/Cxx/TestThresholdComponents.cxx

+// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+// SPDX-License-Identifier: BSD-3-Clause
+#include "vtkCellData.h"
+#include "vtkDataObject.h"
+#include "vtkDataSetAttributes.h"
+#include "vtkFloatArray.h"
+#include "vtkImageData.h"
+#include "vtkNew.h"
+#include "vtkPointData.h"
+#include "vtkSmartPointer.h"
+#include "vtkSphereSource.h"
+#include "vtkThreshold.h"
+#include "vtkUnsignedCharArray.h"
+#include "vtkUnstructuredGrid.h"
+
+int TestThresholdComponents(int, char*[])
+{
+  vtkNew<vtkSphereSource> source;
+  source->GenerateNormalsOn();
+
+  vtkNew<vtkThreshold> filter;
+  filter->SetInputConnection(source->GetOutputPort());
+  filter->SetInputArrayToProcess(0, 0, 0, 0, "Normals");
+
+  filter->SetThresholdFunction(vtkThreshold::THRESHOLD_UPPER);
+  filter->SetUpperThreshold(0.0);
+  filter->AllScalarsOff();
+
+  filter->SetComponentModeToUseSelected();
+  filter->SetSelectedComponent(0);
+  filter->Update();
+
+  if (filter->GetOutput()->GetNumberOfCells() != 66)
+  {
+    std::cerr << "Unexpected cell count after thresholding component X. Got: "
+              << filter->GetOutput()->GetNumberOfCells() << ", expected: 66." << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  filter->SetSelectedComponent(1);
+  filter->Update();
+
+  if (filter->GetOutput()->GetNumberOfCells() != 76)
+  {
+    std::cerr << "Unexpected cell count after thresholding component Y. Got: "
+              << filter->GetOutput()->GetNumberOfCells() << ", expected: 76." << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  filter->SetSelectedComponent(2);
+  filter->Update();
+
+  if (filter->GetOutput()->GetNumberOfCells() != 56)
+  {
+    std::cerr << "Unexpected cell count after thresholding component Z. Got: "
+              << filter->GetOutput()->GetNumberOfCells() << ", expected: 56." << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  filter->SetSelectedComponent(3);
+  filter->Update();
+
+  if (filter->GetOutput()->GetNumberOfCells() != 96)
+  {
+    std::cerr << "Unexpected cell count after thresholding magnitude. Got: "
+              << filter->GetOutput()->GetNumberOfCells() << ", expected: 96." << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  filter->SetComponentModeToUseAll();
+  filter->Update();
+
+  if (filter->GetOutput()->GetNumberOfCells() != 31)
+  {
+    std::cerr << "Unexpected cell count after thresholding all components. Got: "
+              << filter->GetOutput()->GetNumberOfCells() << ", expected: 31." << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  filter->SetComponentModeToUseAny();
+  filter->Update();
+
+  if (filter->GetOutput()->GetNumberOfCells() != 92)
+  {
+    std::cerr << "Unexpected cell count after thresholding any component. Got: "
+              << filter->GetOutput()->GetNumberOfCells() << ", expected: 92." << std::endl;
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}