/*  dans Surfer-MPI-Quart, la direction "i" est la direction Z, i et k sont X et Y */ 

#define OFFSET 0.
#define MIRROR_P_X_0(a)  (a)
#define MIRROR_P_X_1(a)  (a)
#define MIRROR_P_X_2(a)  (OFFSET - (a))
#define MIRROR_P_Y_0(a)  (a)
#define MIRROR_P_Y_1(a)  (OFFSET - (a))
#define MIRROR_P_Y_2(a)  (a)
#define MIRROR_P_XY_0(a)  (a)
#define MIRROR_P_XY_1(a)  (OFFSET - (a))
#define MIRROR_P_XY_2(a)  (OFFSET - (a))

#define MIRROR_V_X_0(a)  (a)
#define MIRROR_V_X_1(a)  (a)
#define MIRROR_V_X_2(a)  ( - (a))
#define MIRROR_V_Y_0(a)  (a)
#define MIRROR_V_Y_1(a)  ( - (a))
#define MIRROR_V_Y_2(a)  (a)
#define MIRROR_V_XY_0(a)  (a)
#define MIRROR_V_XY_1(a)  ( - (a))
#define MIRROR_V_XY_2(a)  ( - (a))