message: ENH: add computeDistance() method w/raw doubles
  Adds a computeDistance() method to the SignedDistance class
  that takes raw doubles. This alleviates the need for application
  code to wrap the doubles into a primal::Point object. Instead,
  the method does this internally.
diff: @@ -83,7 +83,8 @@ public:
  * \note Default maxLevels is 5 if not specified.
  * \pre surfaceMesh != AXOM_NULLPTR
  */
  - SignedDistance( axom::mint::Mesh* surfaceMesh, int maxObjects,
  + SignedDistance( const mint::Mesh* surfaceMesh,
  + int maxObjects,
  int maxLevels=5 );
  /*!
  @@ -91,6 +92,21 @@ public:
  */
  ~SignedDistance();
  + /*!
  + * \brief Computes the distance of the given point to the input surface mesh.
  + *
  + * \param [in] x x-coordinate of the query point
  + * \param [in] y y-coordinate of the query point
  + * \param [in] z z-coordinate of the query point
  + *
  + * \return minDist minimum signed distance of the query point to the surface.
  + */
  + double computeDistance( double x, double y, double z=0.0 )
  + {
  + PointType pt = PointType::make_point( x, y, z );
  + return ( computeDistance( pt ) );
  + }
  +
  /*!
  * \brief Computes the distance of the given point to the surface mesh.
  * \param [in] queryPnt user-supplied point.
  @@ -224,7 +240,7 @@ private:
  SignedDistance() : m_surfaceMesh(AXOM_NULLPTR), m_bvhTree(AXOM_NULLPTR) { };
  private:
  - axom::mint::Mesh* m_surfaceMesh; /*!< User-supplied surface mesh. */
  + const mint::Mesh* m_surfaceMesh; /*!< User-supplied surface mesh. */
  BoxType m_boxDomain; /*!< bounding box containing surface mesh */
  BVHTreeType* m_bvhTree; /*!< Spatial acceleration data-structure. */
  @@ -260,7 +276,7 @@ private:
  //------------------------------------------------------------------------------
  template < int NDIMS >
  SignedDistance< NDIMS >::SignedDistance(
  - axom::mint::Mesh* surfaceMesh, int maxObjects, int maxLevels )
  + const mint::Mesh* surfaceMesh, int maxObjects, int maxLevels )
  {
  // Sanity checks
  SLIC_ASSERT( surfaceMesh != AXOM_NULLPTR );
  