CarpetRegrid2: Support rotating symmetries

darcs-hash:20060925221137-dae7b-d016ec0a27faeda88b8335eb074d3dcf87b3b222.gz

3 files changed, 55 insertions, 0 deletions

diff --git a/Carpet/CarpetRegrid2/param.ccl b/Carpet/CarpetRegrid2/param.ccl
index ac15a7c0c..41414eda2 100644
--- a/Carpet/CarpetRegrid2/param.ccl
+++ b/Carpet/CarpetRegrid2/param.ccl
@@ -29,6 +29,16 @@ CCTK_INT regrid_every "Regrid every n time steps" STEERABLE=always
 
 
 
+BOOLEAN symmetry_rotating90 "Ensure a 90 degree rotating symmetry about the z axis"
+{
+} no
+
+BOOLEAN symmetry_rotating180 "Ensure a 180 degree rotating symmetry about the z axis"
+{
+} no
+
+
+
 ################################################################################
 
 CCTK_INT num_levels_1 "Number of refinement levels for this centre" STEERABLE=always
diff --git a/Carpet/CarpetRegrid2/src/paramcheck.cc b/Carpet/CarpetRegrid2/src/paramcheck.cc
index 51830038e..fd55929e3 100644
--- a/Carpet/CarpetRegrid2/src/paramcheck.cc
+++ b/Carpet/CarpetRegrid2/src/paramcheck.cc
@@ -29,6 +29,10 @@ namespace CarpetRegrid2 {
     {
       CCTK_PARAMWARN ("The number of requested refinement levels is larger than the maximum number of levels specified by Carpet::max_refinement_levels");
     }
+    
+    if (symmetry_rotating90) {
+      CCTK_PARAMWARN ("symmetry_rotating90 is not yet implemented");
+    }
   }
   
 } // namespace CarpetRegrid2
diff --git a/Carpet/CarpetRegrid2/src/regrid.cc b/Carpet/CarpetRegrid2/src/regrid.cc
index fdadb2880..7210c9b7d 100644
--- a/Carpet/CarpetRegrid2/src/regrid.cc
+++ b/Carpet/CarpetRegrid2/src/regrid.cc
@@ -394,6 +394,47 @@ namespace CarpetRegrid2 {
            bb.stride());
         
         clipped |= clipped_bb;
+        
+        if (symmetry_rotating90) {
+          assert (0);           // There is also a paramwarn about this
+        }
+        
+        if (symmetry_rotating180) {
+          // Make the boxes rotating-180 symmetric
+          if (lower_is_outside_lower[0]) {
+            ivect const ilo = clipped_bb.lower();
+            ivect const iup = clipped_bb.upper();
+            ivect const istr = clipped_bb.stride();
+            
+            // Origin
+            rvect const axis (physical_lower[0],
+                              (physical_lower[1] + physical_upper[1]) / 2,
+                              physical_lower[2]); // z component is unused
+            ivect const iaxis0 = rpos2ipos  (axis, origin, scale, hh, rl);
+            assert (all (iaxis0 % istr == 0));
+            ivect const iaxis1 = rpos2ipos1 (axis, origin, scale, hh, rl);
+            assert (all (iaxis1 % istr == 0));
+            ivect const offset = iaxis1 - iaxis0;
+            assert (all (offset % istr == 0));
+            assert (all (offset >= 0 and offset < 2*istr));
+            assert (all ((iaxis0 + iaxis1 - offset) % (2*istr) == 0));
+            ivect const iaxis = (iaxis0 + iaxis1 - offset) / 2;
+            
+            // Mirror about the y axis, cutting off most of the extent
+            // in the positive x direction
+            ivect const new_ilo (ilo[0],
+                                 (2*iaxis[1]+offset[1]) - iup[1],
+                                 ilo[2]);
+            ivect const new_iup ((2*iaxis[0]+offset[0]) - ilo[0],
+                                 (2*iaxis[1]+offset[1]) - ilo[1],
+                                 iup[2]);
+            ivect const new_istr (istr);
+            
+            ibbox const new_bb (new_ilo, new_iup, new_istr);
+            
+            clipped |= new_bb;
+          }
+        }
       }
       
       regions.at(rl) = clipped;