add a new aliased function

  HorizonCentroid()
so other thorns can query the horizon centroid


git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/AHFinderDirect/trunk@1469 f88db872-0e4f-0410-b76b-b9085cfa78c5

1 files changed, 54 insertions, 5 deletions

diff --git a/src/driver/aliased_functions.cc b/src/driver/aliased_functions.cc
index 50da3dd..03d49ed 100644
--- a/src/driver/aliased_functions.cc
+++ b/src/driver/aliased_functions.cc
@@ -4,6 +4,7 @@
 // <<<access to persistent data>>>
 // AHFinderDirect_local_coordinate_origin - provide our local coordinate origin
 // AHFinderDirect_horizon_was_found - query if a given horizon was found
+// AHFinderDirect_horizon_centroid - query horizon centroid & if it was found
 // AHFinderDirect_radius_in_direction - provide r(angle) function
 //
 
@@ -62,7 +63,7 @@ extern struct state state;
 // Arguments:
 // horizon_number = (in) The horizon to inquire about; must be in the range
 //			 1 to N_horizons inclusive.
-// *origin_[xyz]_ptr = (out) The local coordinate origin is stored here.
+// *p_origin_[xyz] = (out) The local coordinate origin is stored here.
 //
 // Results:
 // This function returns 0 for ok, or -1 if the horizon number is invalid.
@@ -70,7 +71,7 @@ extern struct state state;
 extern "C"
   CCTK_INT AHFinderDirect_local_coordinate_origin
     (CCTK_INT horizon_number,
-     CCTK_REAL* origin_x_ptr, CCTK_REAL* origin_y_ptr, CCTK_REAL* origin_z_ptr)
+     CCTK_REAL* p_origin_x, CCTK_REAL* p_origin_y, CCTK_REAL* p_origin_z)
 {
 const struct verbose_info& verbose_info = state.verbose_info;
 
@@ -90,9 +91,12 @@ const struct AH_data& AH_data = *state.AH_data_array[horizon_number];
 assert(AH_data.ps_ptr != NULL);
 const patch_system& ps = *AH_data.ps_ptr;
 
-*origin_x_ptr = ps.origin_x();
-*origin_y_ptr = ps.origin_y();
-*origin_z_ptr = ps.origin_z();
+assert(p_origin_x != NULL);
+assert(p_origin_y != NULL);
+assert(p_origin_z != NULL);
+*p_origin_x = ps.origin_x();
+*p_origin_y = ps.origin_y();
+*p_origin_z = ps.origin_z();
 
 return 0;						// *** NORMAL RETURN ***
 }
@@ -139,6 +143,51 @@ return AH_data.found_flag ? 1 : 0;
 
 //
 // This function is called (via the Cactus flesh function-aliasing mechanism)
+// by other thorns to query whether or not the specified horizon was found
+// the last time we searched for it, and if so, to determine the horizon
+// centroid.
+//
+// Results:
+// This function returns:
+//  1 if the horizon was found; in this case  *centroid_[xyz]_ptr
+//    are set to the centroid position 
+//  0 if the horizon was not found; in this case  *centroid_[xyz]_ptr
+//    set to zeros
+//  negative for an error
+//
+extern "C"
+  CCTK_INT AHFinderDirect_horizon_centroid
+    (CCTK_INT horizon_number,
+     CCTK_REAL* p_centroid_x, CCTK_REAL* p_centroid_y, CCTK_REAL* p_centroid_z)
+{
+const struct verbose_info& verbose_info = state.verbose_info;
+
+if (!  ((horizon_number >= 1) && (horizon_number <= state.N_horizons))  )
+   then {
+	CCTK_VWarn(1, __LINE__, __FILE__, CCTK_THORNSTRING,
+"AHFinderDirect_horizon_centroid():\n"
+"        horizon_number=%d must be in the range [1,N_horizons=%d]!\n"
+		   ,
+		   int(horizon_number), state.N_horizons);
+	return -1;					// *** ERROR RETURN ***
+	}
+
+assert(state.AH_data_array[horizon_number] != NULL);
+const struct AH_data& AH_data = *state.AH_data_array[horizon_number];
+const struct BH_diagnostics& BH_diagnostics = AH_data.BH_diagnostics;
+
+assert(p_centroid_x != NULL);
+assert(p_centroid_y != NULL);
+assert(p_centroid_z != NULL);
+*p_centroid_x = BH_diagnostics.centroid_x;
+*p_centroid_y = BH_diagnostics.centroid_y;
+*p_centroid_z = BH_diagnostics.centroid_z;
+}
+
+//******************************************************************************
+
+//
+// This function is called (via the Cactus flesh function-aliasing mechanism)
 // by other thorns to find out a given AH's radius in the direction from
 // its local coordinate origin to a given (x,y,z) coordinate or coordinates.
 //