Line data    Source code

       1             : 
       2             : #ifndef BL_ORIENTATION_H
       3             : #define BL_ORIENTATION_H
       4             : #include <AMReX_Config.H>
       5             : 
       6             : #include <AMReX_BLassert.H>
       7             : #include <AMReX_SPACE.H>
       8             : #include <AMReX_GpuQualifiers.H>
       9             : 
      10             : #include <iosfwd>
      11             : 
      12             : namespace amrex {
      13             : 
      14             : enum class Direction : int { AMREX_D_DECL(x = 0, y = 1, z = 2) };
      15             : 
      16             : class OrientationIter;
      17             : 
      18             : /**
      19             : * \brief Encapsulation of the Orientation of the Faces of a Box
      20             : *
      21             : * This class encapsulates the orientation of the faces of a Box by
      22             : * providing an ordering of each of the faces of a Box in AMREX_SPACEDIM
      23             : * dimensions.  This allows iterating over all the faces of a Box.  The
      24             : * ordering first traverses the AMREX_SPACEDIM low sides from direction 0 ..
      25             : * AMREX_SPACEDIM-1 and then the AMREX_SPACEDIM high sides from direction 0 ..
      26             : * AMREX_SPACEDIM-1.
      27             : */
      28             : class Orientation
      29             : {
      30             : public:
      31             : 
      32             :     friend class OrientationIter;
      33             :     //! In each dimension a face is either low or high.
      34             :     enum Side { low = 0, high = 1 };
      35             :     //! The default constructor.
      36             :     constexpr Orientation () noexcept = default;
      37             :     //! Set the orientation of a side.
      38             :     AMREX_GPU_HOST_DEVICE
      39             :     Orientation (int dir, Side side) noexcept
      40             :         :
      41             :         val(AMREX_SPACEDIM*side + dir)
      42             :     {
      43             :         BL_ASSERT(0 <= dir && dir < AMREX_SPACEDIM);
      44             :     }
      45             :     AMREX_GPU_HOST_DEVICE
      46             :     constexpr Orientation (Direction dir, Side side) noexcept
      47             :         : val(AMREX_SPACEDIM*side + static_cast<int>(dir))
      48             :     {}
      49             : 
      50             :     //! Logical equality.
      51             :     AMREX_GPU_HOST_DEVICE
      52             :     bool operator== (const Orientation& o) const noexcept { return val == o.val; }
      53             :     //! Logical inequality.
      54             :     AMREX_GPU_HOST_DEVICE
      55             :     bool operator!= (const Orientation& o) const noexcept { return val != o.val; }
      56             :     //! Less-than.
      57             :     AMREX_GPU_HOST_DEVICE
      58             :     bool operator<  (const Orientation& o) const noexcept { return val < o.val; }
      59             :     //! Less-than or equal.
      60             :     AMREX_GPU_HOST_DEVICE
      61             :     bool operator<= (const Orientation& o) const noexcept { return val <= o.val; }
      62             :     //! Greater-than.
      63             :     AMREX_GPU_HOST_DEVICE
      64             :     bool operator>  (const Orientation& o) const noexcept { return val > o.val; }
      65             :     //! Greater-than or equal.
      66             :     AMREX_GPU_HOST_DEVICE
      67             :     bool operator>= (const Orientation& o) const noexcept { return val >= o.val; }
      68             :     /**
      69             :     * \brief This conversion operator maps an orientation into a
      70             :     * unique integer in the range [0 .. 2*AMREX_SPACEDIM-1]
      71             :     * according to the above ordering.
      72             :     */
      73             :     AMREX_GPU_HOST_DEVICE
      74             :     constexpr operator int () const noexcept { return val; }
      75             :     //! Return opposite orientation.
      76             :     [[nodiscard]] AMREX_GPU_HOST_DEVICE
      77             :     Orientation flip () const noexcept
      78             :     {
      79             :         return Orientation(val < AMREX_SPACEDIM ? val+AMREX_SPACEDIM : val-AMREX_SPACEDIM);
      80             :     }
      81             :     //! Returns the coordinate direction.
      82             :     [[nodiscard]] AMREX_GPU_HOST_DEVICE
      83           0 :     int coordDir () const noexcept { return val%AMREX_SPACEDIM; }
      84             :     //! Returns the orientation of the face -- low or high.
      85             :     [[nodiscard]] AMREX_GPU_HOST_DEVICE
      86             :     Side faceDir () const noexcept { return Side(val/AMREX_SPACEDIM); }
      87             :     //! Returns true if Orientation is low.
      88             :     [[nodiscard]] AMREX_GPU_HOST_DEVICE
      89           0 :     bool isLow () const noexcept { return val < AMREX_SPACEDIM; }
      90             :     //! Returns true if Orientation is high.
      91             :     [[nodiscard]] AMREX_GPU_HOST_DEVICE
      92             :     bool isHigh () const noexcept { return val >= AMREX_SPACEDIM; }
      93             :     //! Read from an istream.
      94             :     friend std::istream& operator>> (std::istream& is, Orientation& o);
      95             : 
      96             :     //! Int value of the x-lo-face
      97             :     AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
      98             :     static constexpr int xlo () noexcept { return 0; }
      99             : 
     100             :     //! Int value of the x-hi-face
     101             :     AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
     102             :     static constexpr int xhi () noexcept { return AMREX_SPACEDIM; }
     103             : 
     104             :     //! Int value of the y-lo-face
     105             :     AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
     106             :     static constexpr int ylo () noexcept { return 1; }
     107             : 
     108             :     //! Int value of the y-hi-face
     109             :     AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
     110             :     static constexpr int yhi () noexcept { return 1+AMREX_SPACEDIM; }
     111             : 
     112             :     //! Int value of the z-lo-face
     113             :     AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
     114             :     static constexpr int zlo () noexcept { return 2; }
     115             : 
     116             :     //! Int value of the z-hi-face
     117             :     AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
     118             :     static constexpr int zhi () noexcept { return 2+AMREX_SPACEDIM; }
     119             : 
     120             : private:
     121             :     //! Used internally.
     122             :     AMREX_GPU_HOST_DEVICE
     123             :     Orientation (int v) noexcept : val(v) {}
     124             :     //
     125             :     //! The data.
     126             :     int val = -1;
     127             : };
     128             : 
     129             : //! Write to an ostream in ASCII format.
     130             : std::ostream& operator<< (std::ostream& os, const Orientation& o);
     131             : 
     132             : 
     133             : //! An Iterator over the Orientation of Faces of a Box
     134             : class OrientationIter
     135             : {
     136             : 
     137             : public:
     138             :     //! The default constructor.
     139             :     constexpr OrientationIter () noexcept = default;
     140             :     //! Construct an iterator on the Orientation.
     141             :     AMREX_GPU_HOST_DEVICE
     142             :     OrientationIter (const Orientation& _face) noexcept
     143             :         :
     144             :         face(_face) {}
     145             :     //! Reset (rewind) the iterator.
     146             :     AMREX_GPU_HOST_DEVICE
     147             :     void rewind () noexcept { face = 0; }
     148             :     //! Return the orientation of the face.
     149             :     AMREX_GPU_HOST_DEVICE
     150             :     Orientation operator() () const noexcept { BL_ASSERT(isValid()); return Orientation(face); }
     151             :     //! Cast to void*.  Used to test if iterator is valid.
     152             :     AMREX_GPU_HOST_DEVICE
     153             :     operator void* () noexcept { return 0 <= face && face < 2*AMREX_SPACEDIM ? this : nullptr; }
     154             :     //! Is the iterator valid?
     155             :     [[nodiscard]] AMREX_GPU_HOST_DEVICE
     156             :     bool isValid () const noexcept { return 0 <= face && face < 2*AMREX_SPACEDIM; }
     157             :     //! Pre-decrement.
     158             :     AMREX_GPU_HOST_DEVICE
     159             :     OrientationIter& operator-- () noexcept { BL_ASSERT(isValid()); --face; return *this; }
     160             :     //! Pre-increment.
     161             :     AMREX_GPU_HOST_DEVICE
     162             :     OrientationIter& operator++ () noexcept { BL_ASSERT(isValid()); ++face; return *this; }
     163             :     //! Post-decrement.
     164             :     AMREX_GPU_HOST_DEVICE
     165             :     OrientationIter operator-- (int) noexcept
     166             :     {
     167             :         BL_ASSERT(isValid()); OrientationIter it(face); --face; return it;
     168             :     }
     169             :     //! Post-increment.
     170             :     AMREX_GPU_HOST_DEVICE
     171             :     OrientationIter operator++ (int) noexcept
     172             :     {
     173             :         BL_ASSERT(isValid()); OrientationIter it(face); ++face; return it;
     174             :     }
     175             :     //! The equality operator.
     176             :     AMREX_GPU_HOST_DEVICE
     177             :     bool operator== (const OrientationIter& oi) const noexcept
     178             :     {
     179             :         BL_ASSERT(isValid() && oi.isValid()); return face == oi.face;
     180             :     }
     181             :     //! The inequality operator.
     182             :     AMREX_GPU_HOST_DEVICE
     183             :     bool operator!= (const OrientationIter& oi) const noexcept
     184             :     {
     185             :         BL_ASSERT(isValid() && oi.isValid()); return face != oi.face;
     186             :     }
     187             : 
     188             : private:
     189             : 
     190             :     int face = 0;
     191             :     //! Construct an iterator on the face.
     192             :     AMREX_GPU_HOST_DEVICE
     193             :     OrientationIter (int _face) noexcept : face(_face) {}
     194             : };
     195             : 
     196             : }
     197             : 
     198             : #endif /*BL_ORIENTATION_H*/