STYLE: Manual review of .Fill([0-9]*) patterns

Identified code style improvements based on manually
reviewing use of .Fill for assignment of values
when initialization could have been used.

Author: hjmjohnson

Modules/Core/Common/include/itkConnectedComponentAlgorithm.h

@@ -27,13 +27,13 @@ template <typename TIterator>
 TIterator *
 setConnectivity(TIterator * it, bool fullyConnected = false)
 {
-  typename TIterator::OffsetType offset;
+
   it->ClearActiveList();
   if (!fullyConnected)
   {
     // only activate the neighbors that are face connected
     // to the current pixel. do not include the center pixel
-    offset.Fill(0);
+    typename TIterator::OffsetType offset{};
     for (unsigned int d = 0; d < TIterator::Dimension; ++d)
     {
       offset[d] = -1;
@@ -50,11 +50,11 @@ setConnectivity(TIterator * it, bool fullyConnected = false)
     unsigned int centerIndex = it->GetCenterNeighborhoodIndex();
     for (unsigned int d = 0; d < centerIndex * 2 + 1; ++d)
     {
-      offset = it->GetOffset(d);
+      typename TIterator::OffsetType offset = it->GetOffset(d);
       it->ActivateOffset(offset);
     }
-    offset.Fill(0);
-    it->DeactivateOffset(offset);
+    typename TIterator::OffsetType offset_zeros{};
+    it->DeactivateOffset(offset_zeros);
   }
   return it;
 }
@@ -64,13 +64,13 @@ TIterator *
 setConnectivityPrevious(TIterator * it, bool fullyConnected = false)
 {
   // activate the "previous" neighbours
-  typename TIterator::OffsetType offset;
+
   it->ClearActiveList();
   if (!fullyConnected)
   {
     // only activate the neighbors that are face connected
     // to the current pixel. do not include the center pixel
-    offset.Fill(0);
+    typename TIterator::OffsetType offset{};
     for (unsigned int d = 0; d < TIterator::Dimension; ++d)
     {
       offset[d] = -1;
@@ -85,11 +85,11 @@ setConnectivityPrevious(TIterator * it, bool fullyConnected = false)
     unsigned int centerIndex = it->GetCenterNeighborhoodIndex();
     for (unsigned int d = 0; d < centerIndex; ++d)
     {
-      offset = it->GetOffset(d);
+      typename TIterator::OffsetType offset = it->GetOffset(d);
       it->ActivateOffset(offset);
     }
-    offset.Fill(0);
-    it->DeactivateOffset(offset);
+    typename TIterator::OffsetType offset_zeros{};
+    it->DeactivateOffset(offset_zeros);
   }
   return it;
 }
@@ -99,13 +99,13 @@ TIterator *
 setConnectivityLater(TIterator * it, bool fullyConnected = false)
 {
   // activate the "later" neighbours
-  typename TIterator::OffsetType offset;
+
   it->ClearActiveList();
   if (!fullyConnected)
   {
     // only activate the neighbors that are face connected
     // to the current pixel. do not include the center pixel
-    offset.Fill(0);
+    typename TIterator::OffsetType offset{};
     for (unsigned int d = 0; d < TIterator::Dimension; ++d)
     {
       offset[d] = 1;
@@ -120,11 +120,11 @@ setConnectivityLater(TIterator * it, bool fullyConnected = false)
     unsigned int centerIndex = it->GetCenterNeighborhoodIndex();
     for (unsigned int d = centerIndex + 1; d < 2 * centerIndex + 1; ++d)
     {
-      offset = it->GetOffset(d);
+      typename TIterator::OffsetType offset = it->GetOffset(d);
       it->ActivateOffset(offset);
     }
-    offset.Fill(0);
-    it->DeactivateOffset(offset);
+    typename TIterator::OffsetType offset_zeros{};
+    it->DeactivateOffset(offset_zeros);
   }
   return it;
 }

Modules/Core/Common/include/itkCrossHelper.h

@@ -49,27 +49,14 @@ class CrossHelper
   VectorType
   operator()(const VectorType & iU, const VectorType & iV) const
   {
-    VectorType oCross;
+    VectorType oCross{};
 
     if constexpr (Dimension > 2)
     {
       oCross[0] = iU[1] * iV[2] - iV[1] * iU[2];
       oCross[1] = iV[0] * iU[2] - iU[0] * iV[2];
       oCross[2] = iU[0] * iV[1] - iV[0] * iU[1];
-
-      if constexpr (Dimension > 3)
-      {
-        for (unsigned int dim = 3; dim < Dimension; ++dim)
-        {
-          oCross[dim] = 0.0;
-        }
-      }
-    }
-    else
-    {
-      oCross.Fill(0.);
     }
-
     return oCross;
   }
 };

Modules/Core/Common/include/itkImageAlgorithm.hxx

@@ -240,10 +240,11 @@ ImageAlgorithm::EnlargeRegionOverBox(const typename InputImageType::RegionType &
     }
 
     using InputPointType = Point<SpacePrecisionType, InputImageType::ImageDimension>;
+    const InputPointType inputPoint =
+      inputImage->template TransformContinuousIndexToPhysicalPoint<SpacePrecisionType, SpacePrecisionType>(
+        currentInputCornerIndex);
     using OutputPointType = Point<SpacePrecisionType, OutputImageType::ImageDimension>;
-    InputPointType  inputPoint;
-    OutputPointType outputPoint;
-    inputImage->TransformContinuousIndexToPhysicalPoint(currentInputCornerIndex, inputPoint);
+    OutputPointType outputPoint{};
     if (transform != nullptr)
     {
       outputPoint = transform->TransformPoint(inputPoint);
@@ -253,7 +254,6 @@ ImageAlgorithm::EnlargeRegionOverBox(const typename InputImageType::RegionType &
       // if InputDimension < OutputDimension then embed point in Output space.
       // else if InputDimension == OutputDimension copy the points.
       // else if InputDimension > OutputDimension project the point to first N-Dimensions of Output space.
-      outputPoint.Fill(0.0);
       for (unsigned int d = 0; d < std::min(inputPoint.GetPointDimension(), outputPoint.GetPointDimension()); ++d)
       {
         outputPoint[d] = inputPoint[d];

Modules/Core/Common/include/itkImageIORegion.h

@@ -251,11 +251,8 @@ class ImageIORegionAdaptor
           ImageRegionType &         outImageRegion,
           const ImageIndexType &    largestRegionIndex)
   {
-    ImageSizeType  size;
-    ImageIndexType index;
-
-    size.Fill(1); // initialize with default values
-    index.Fill(0);
+    auto           size = MakeFilled<ImageSizeType>(1); // initialize with default values
+    ImageIndexType index{};
 
     //
     // The ImageRegion and ImageIORegion objects may have different dimensions.

Modules/Core/Common/include/itkImageRegion.hxx

@@ -231,12 +231,9 @@ ImageRegion<VImageDimension>::Slice(const unsigned int dim) const -> SliceRegion
       "The dimension to remove: " << dim << " is greater than the dimension of the image: " << VImageDimension);
   }
 
-  Index<SliceDimension> sliceIndex;
-  Size<SliceDimension>  sliceSize;
-
-  sliceIndex.Fill(0);
-  sliceSize.Fill(0);
-  unsigned int ii = 0;
+  Index<SliceDimension> sliceIndex{};
+  Size<SliceDimension>  sliceSize{};
+  unsigned int          ii = 0;
   for (unsigned int i = 0; i < VImageDimension; ++i)
   {
     if (i != dim)

Modules/Core/Common/include/itkNeighborhood.hxx

@@ -70,12 +70,7 @@ template <typename TPixel, unsigned int VDimension, typename TContainer>
 void
 Neighborhood<TPixel, VDimension, TContainer>::SetRadius(const SizeValueType s)
 {
-  SizeType k;
-
-  for (DimensionValueType i = 0; i < VDimension; ++i)
-  {
-    k[i] = s;
-  }
+  auto k = MakeFilled<SizeType>(s);
   this->SetRadius(k);
 }
 

Modules/Core/Common/include/itkTriangleCell.hxx

@@ -295,11 +295,10 @@ TriangleCell<TCellInterface>::ComputeBarycenter(CoordinateType * iWeights, Point
     p[i] = iPoints->GetElement(m_PointIds[i]);
   }
 
-  PointType oP;
+  PointType oP{};
 
   if (sum_weights != 0.)
   {
-    oP.Fill(0.);
     for (i = 0; i < 3; ++i)
     {
       oP += p[i].GetVectorFromOrigin() * iWeights[i] / sum_weights;

Modules/Core/Common/include/itkTriangleHelper.hxx

@@ -106,14 +106,11 @@ TriangleHelper<TPoint>::ComputeBarycenter(const CoordinateType & iA1,
                                           const CoordinateType & iA3,
                                           const PointType &      iP3) -> PointType
 {
-  PointType oPt;
-
   CoordinateType total = iA1 + iA2 + iA3;
-
+  PointType      oPt{};
   if (Math::AlmostEquals(total, CoordinateType{}))
   {
     // in such case there is no barycenter;
-    oPt.Fill(0.);
     return oPt;
   }