(*) CCTK_FNAME(get_grid_offsets) -> get_grid_offsets

(+) Added get_grid_offsets to thorn interface as GetFDGridOffsets
(+) Added another thorn interface function GetLSHIndexRanges
    to inquire actual local index ranges (in Fortran notation),
    which account for both the ghostzones and shiftout values


git-svn-id: https://svn.cct.lsu.edu/repos/numrel/LSUThorns/SummationByParts/trunk@109 f69c4107-0314-4c4f-9ad4-17e986b73f4a

4 files changed, 63 insertions, 6 deletions

diff --git a/interface.ccl b/interface.ccl
index d619180..381ac63 100644
--- a/interface.ccl
+++ b/interface.ccl
@@ -71,6 +71,16 @@ PROVIDES FUNCTION GetScalProdDiag WITH SBP_GetScalProdDiag LANGUAGE Fortran
 CCTK_REAL FUNCTION GetScalProdCoeff ()
 PROVIDES FUNCTION GetScalProdCoeff WITH GetCoeff LANGUAGE Fortran
 
+SUBROUTINE GetFDGridOffsets ( CCTK_INT OUT ARRAY offset )
+PROVIDES FUNCTION GetFDGridOffsets WITH get_grid_offsets LANGUAGE C
+
+SUBROUTINE GetLSHIndexRanges ( \
+                CCTK_POINTER_TO_CONST IN cctkGH, \
+                CCTK_INT OUT imn, CCTK_INT OUT imx, \
+                CCTK_INT OUT jmn, CCTK_INT OUT jmx, \
+                CCTK_INT OUT kmn, CCTK_INT OUT kmx )
+PROVIDES FUNCTION GetLSHIndexRanges WITH get_lsh_iranges LANGUAGE C
+ 
 CCTK_INT FUNCTION GetDomainSpecification \
   (CCTK_INT IN size, \
    CCTK_REAL OUT ARRAY physical_min, \
diff --git a/src/call_derivs.c b/src/call_derivs.c
index c92dd34..8b764fb 100644
--- a/src/call_derivs.c
+++ b/src/call_derivs.c
@@ -126,7 +126,7 @@ void DiffGv ( const CCTK_POINTER_TO_CONST cctkGH_, const CCTK_INT dir,
                                        const CCTK_REAL *delta,
                                        CCTK_REAL *dvar);
   
-  void CCTK_FCALL CCTK_FNAME(get_grid_offsets) (CCTK_INT *offset);
+  void get_grid_offsets (CCTK_INT *offset);
 
   ni = cctk_lsh[0]; nj = cctk_lsh[1]; nk = cctk_lsh[2];
  
@@ -162,7 +162,7 @@ void DiffGv ( const CCTK_POINTER_TO_CONST cctkGH_, const CCTK_INT dir,
   }
   if ( use_shiftout ) {
       /* get values of boundary_shiftout_* from CoordBase  */
-      CCTK_FNAME(get_grid_offsets) (offset);
+      get_grid_offsets (offset);
   }
 
 
diff --git a/src/dissipation.c b/src/dissipation.c
index 87f303d..a3b2bb6 100644
--- a/src/dissipation.c
+++ b/src/dissipation.c
@@ -145,7 +145,7 @@ void CCTK_FCALL CCTK_FNAME(dissipation_8_4_alt) (const CCTK_REAL *var,
                                              const CCTK_REAL *dx,
                                              const CCTK_REAL *epsdis,
                                              CCTK_REAL *rhs);
-void CCTK_FCALL CCTK_FNAME(get_grid_offsets) (CCTK_INT *offset);
+void get_grid_offsets (CCTK_INT *offset);
 
 static void
 apply (int const varindex, char const * const optstring, void * const arg);
@@ -193,7 +193,7 @@ apply (int const varindex, char const * const optstring, void * const arg)
   }
   if ( use_shiftout ) {
       /* get values of boundary_shiftout_* from CoordBase  */
-      CCTK_FNAME(get_grid_offsets) (offset);
+      get_grid_offsets (offset);
   }
 
   SBP_determine_onesided_stencil (cctkGH, onesided);
diff --git a/src/get_offset.c b/src/get_offset.c
index d1a35d9..a3b8b90 100644
--- a/src/get_offset.c
+++ b/src/get_offset.c
@@ -3,7 +3,13 @@
 #include "cctk_Functions.h"
 #include "cctk_Parameters.h"
 
-void CCTK_FCALL CCTK_FNAME(get_grid_offsets) (CCTK_INT *offset) {
+/***
+ * This is a utility function which reads values of shiftout parameters from 
+ * thorn CoordBase into an integer array offset[]. It is declared at the thorn
+ * interface as GetFDGridOffsets and can be called from Fortran routines.
+ * This is necessary since CCTK_ParameterGet is not available in Fortran.
+ */
+void get_grid_offsets (CCTK_INT *offset) {
 
   DECLARE_CCTK_PARAMETERS;
 
@@ -34,5 +40,46 @@ void CCTK_FCALL CCTK_FNAME(get_grid_offsets) (CCTK_INT *offset) {
     offset[5] = *shiftout_z_upper;
   }
 
-  
 }
+
+/***
+ * This function returns the effective values of local index ranges,
+ * taking into account ghost zones and boundary_shiftout_* values.
+ * If the use_shiftout=no, boundary offsets are set to zero.
+ * Index ranges are set in Fortran convention (starting from 1):
+ *  - imin <= i <= imax
+ *  - jmin <= j <= jmax
+ *  - kmin <= k <= kmax
+ * This function is declared in interface.ccl as GetLSHIndexRanges 
+ * to be used by other thorns, which need to know the actual index 
+ * ranges for the region where SBP thorn will apply derivative /
+ * dissipation operators.
+ */
+void get_lsh_iranges ( const CCTK_POINTER_TO_CONST cctkGH_, 
+                 CCTK_INT *imin, CCTK_INT *imax,
+                 CCTK_INT *jmin, CCTK_INT *jmax,
+                 CCTK_INT *kmin, CCTK_INT *kmax)  
+{
+    cGH const * restrict const cctkGH = cctkGH_;
+    DECLARE_CCTK_PARAMETERS
+    DECLARE_CCTK_ARGUMENTS
+
+    int i, offset[6];
+
+    for (i=0;i<6;i++) offset[i] = 0;
+    if (use_shiftout) get_grid_offsets (offset);
+
+    *imin = 1 + ((cctk_bbox[0]) ? offset[0] : cctk_nghostzones[0]);
+    *jmin = 1 + ((cctk_bbox[2]) ? offset[2] : cctk_nghostzones[1]);
+    *kmin = 1 + ((cctk_bbox[4]) ? offset[4] : cctk_nghostzones[2]);
+
+    *imax = cctk_lsh[0] - ((cctk_bbox[1]) ? offset[1] : cctk_nghostzones[0] );
+    *jmax = cctk_lsh[1] - ((cctk_bbox[3]) ? offset[3] : cctk_nghostzones[1] );
+    *kmax = cctk_lsh[2] - ((cctk_bbox[5]) ? offset[5] : cctk_nghostzones[2] );
+
+    /*** debug ***/
+    CCTK_VInfo (CCTK_THORNSTRING, "imn-kmx = {%d, %d, %d, %d, %d, %d}", 
+                *imin, *imax, *jmin, *jmax, *kmin, *kmax);
+}
+
+