ENH: add min/max method to PDRblock::location (#1216)

- grid(i,j,k) method for returning the grid point at an i-j-k location

src/mesh/blockMesh/PDRblockMesh/PDRblock.H

@@ -110,6 +110,12 @@ public:
             //- True if the location is within the range
             inline bool contains(const scalar p) const;
 
+            //- The first() value is considered the min value.
+            inline const scalar& min() const;
+
+            //- The last() value is considered the max value.
+            inline const scalar& max() const;
+
             //- Mid-point location, zero for an empty list.
             inline scalar centre() const;
 
@@ -305,6 +311,12 @@ public:
         //- Cell dimensions at i,j,k position.
         inline vector span(const labelVector& ijk) const;
 
+        //- Grid point at i,j,k position.
+        inline point grid(const label i, const label j, const label k) const;
+
+        //- Grid point at i,j,k position.
+        inline point grid(const labelVector& ijk) const;
+
         //- Cell centre at i,j,k position.
         inline point C(const label i, const label j, const label k) const;
 

src/mesh/blockMesh/PDRblockMesh/PDRblockI.H

@@ -62,6 +62,18 @@ inline bool Foam::PDRblock::location::contains(const scalar p) const
 }
 
 
+inline const Foam::scalar& Foam::PDRblock::location::min() const
+{
+    return scalarList::empty() ? pTraits<scalar>::rootMax : first();
+}
+
+
+inline const Foam::scalar& Foam::PDRblock::location::max() const
+{
+    return scalarList::empty() ? pTraits<scalar>::rootMin : last();
+}
+
+
 inline Foam::scalar Foam::PDRblock::location::centre() const
 {
     return scalarList::empty() ? 0 : (0.5*first() + 0.5*last());
@@ -206,6 +218,29 @@ inline Foam::vector Foam::PDRblock::span(const labelVector& ijk) const
 }
 
 
+inline Foam::point Foam::PDRblock::grid
+(
+    const label i,
+    const label j,
+    const label k
+) const
+{
+    return point(grid_.x()[i], grid_.y()[j], grid_.z()[k]);
+}
+
+
+inline Foam::point Foam::PDRblock::grid(const labelVector& ijk) const
+{
+    return
+        point
+        (
+            grid_.x()[ijk.x()],
+            grid_.y()[ijk.y()],
+            grid_.z()[ijk.z()]
+        );
+}
+
+
 inline Foam::point Foam::PDRblock::C
 (
     const label i,