/*@@
   @file      Bitant.c
   @date      Tue Nov  2 08:10:56 CET 1999
   @author    Gabrielle Allen
   @desc 
   Set up origin for bitant plane
   @enddesc 
 @@*/

#include "cctk.h"
#include "cctk_Arguments.h"
#include "cctk_Parameters.h"

static char *rcsid = "$Header$";

CCTK_FILEVERSION(CactusBase_CartGrid3D_Bitant_c)


void bitant_byspacing(CCTK_ARGUMENTS,
		      CCTK_REAL this_dx,
		      CCTK_REAL this_dy,
		      CCTK_REAL this_dz,
		      CCTK_REAL *x_origin,
		      CCTK_REAL *y_origin,
		      CCTK_REAL *z_origin)
{

  DECLARE_CCTK_ARGUMENTS
  DECLARE_CCTK_PARAMETERS

  if (CCTK_EQUALS(bitant_plane,"xy"))
  {

    if (no_origin && no_originx) 
    {
      *x_origin = (0.5 - cctk_gsh[0]/2)*this_dx;
    }
    else
    {
      *x_origin = (- cctk_gsh[0]/2)*this_dx;
    }

    if (no_origin && no_originy) 
    {
      *y_origin = (0.5 - cctk_gsh[1]/2)*this_dy;
    }
    else
    {
      *y_origin = (- cctk_gsh[1]/2)*this_dy;
    }

    if (no_origin && no_originz) 
    {
      *z_origin = (- cctk_nghostzones[2]+0.5)*this_dz;
    }
    else
    {
      *z_origin = (- cctk_nghostzones[2])*this_dz;
    }

  }
  else if (CCTK_EQUALS(bitant_plane,"xz"))
  {

    if (no_origin && no_originx) 
    {
      *x_origin = (0.5 - cctk_gsh[0]/2)*this_dx;
    }
    else
    {
      *x_origin = (- cctk_gsh[0]/2)*this_dx;
    }

    if (no_origin && no_originy) 
    {
      *y_origin = (- cctk_nghostzones[1]+0.5)*this_dy;
    }
    else
    {
      *y_origin = (- cctk_nghostzones[1])*this_dy;
    }

    if (no_origin && no_originz) 
    {
      *z_origin = (0.5 - cctk_gsh[2]/2)*this_dz;
    }
    else
    {
      *z_origin = (- cctk_gsh[2]/2)*this_dz;
    }

  }
  else if (CCTK_EQUALS(bitant_plane,"yz"))
  {

    if (no_origin && no_originx) 
    {
      *x_origin = (- cctk_nghostzones[0]+0.5)*this_dx;
    }
    else
    {
      *x_origin = (- cctk_nghostzones[0])*this_dx;
    }

    if (no_origin && no_originy) 
    {
      *y_origin = (0.5 - cctk_gsh[1]/2)*this_dy;
    }
    else
    {
      *y_origin = (- cctk_gsh[1]/2)*this_dy;
    }

    if (no_origin && no_originz) 
    {
      *z_origin = (0.5 - cctk_gsh[2]/2)*this_dz;
    }
    else
    {
      *z_origin = (- cctk_gsh[2]/2)*this_dz;
    }

  }

  return;
  

}