PERF: Do not compute half cell sizes multiple times; cache them
PERF: Do not compute half cell sizes multiple times; cache them

Change-Id: I459a5515aa777f9f8a962d8fc0e611c786881030

berendkleinhaneveld/VTK,johnkit/vtk-dev,hendradarwin/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,SimVascular/VTK,johnkit/vtk-dev,sumedhasingla/VTK,demarle/VTK,keithroe/vtkoptix,hendradarwin/VTK,sankhesh/VTK,demarle/VTK,jmerkow/VTK,sankhesh/VTK,keithroe/vtkoptix,collects/VTK,demarle/VTK,ashray/VTK-EVM,keithroe/vtkoptix,jmerkow/VTK,sankhesh/VTK,keithroe/vtkoptix,sumedhasingla/VTK,ashray/VTK-EVM,keithroe/vtkoptix,mspark93/VTK,johnkit/vtk-dev,sankhesh/VTK,mspark93/VTK,candy7393/VTK,ashray/VTK-EVM,mspark93/VTK,msmolens/VTK,johnkit/vtk-dev,mspark93/VTK,mspark93/VTK,keithroe/vtkoptix,hendradarwin/VTK,hendradarwin/VTK,candy7393/VTK,gram526/VTK,biddisco/VTK,SimVascular/VTK,candy7393/VTK,msmolens/VTK,msmolens/VTK,biddisco/VTK,biddisco/VTK,SimVascular/VTK,collects/VTK,mspark93/VTK,hendradarwin/VTK,jmerkow/VTK,ashray/VTK-EVM,sumedhasingla/VTK,sumedhasingla/VTK,biddisco/VTK,demarle/VTK,johnkit/vtk-dev,sumedhasingla/VTK,sumedhasingla/VTK,msmolens/VTK,sankhesh/VTK,berendkleinhaneveld/VTK,jmerkow/VTK,candy7393/VTK,collects/VTK,jmerkow/VTK,SimVascular/VTK,keithroe/vtkoptix,biddisco/VTK,ashray/VTK-EVM,msmolens/VTK,sankhesh/VTK,mspark93/VTK,collects/VTK,msmolens/VTK,biddisco/VTK,sumedhasingla/VTK,ashray/VTK-EVM,hendradarwin/VTK,jmerkow/VTK,SimVascular/VTK,gram526/VTK,sankhesh/VTK,gram526/VTK,keithroe/vtkoptix,jmerkow/VTK,demarle/VTK,biddisco/VTK,SimVascular/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,gram526/VTK,candy7393/VTK,gram526/VTK,hendradarwin/VTK,berendkleinhaneveld/VTK,demarle/VTK,msmolens/VTK,berendkleinhaneveld/VTK,demarle/VTK,sankhesh/VTK,johnkit/vtk-dev,ashray/VTK-EVM,mspark93/VTK,collects/VTK,candy7393/VTK,demarle/VTK,sumedhasingla/VTK,SimVascular/VTK,gram526/VTK,collects/VTK,candy7393/VTK,gram526/VTK,SimVascular/VTK,berendkleinhaneveld/VTK,candy7393/VTK,johnkit/vtk-dev,gram526/VTK,msmolens/VTK