CarpetRegrid2: Keep sufficient separation between level boundaries

Take ghost zones, inner and outer buffer zones, and the prolongation
stencil size into account when calculating the necessary minimum
distance between refinement level boundaries.

darcs-hash:20061013211100-dae7b-367cc0eee54c5434ce8ddeb175d6ae03380fd6ac.gz

1 files changed, 11 insertions, 5 deletions

diff --git a/Carpet/CarpetRegrid2/src/regrid.cc b/Carpet/CarpetRegrid2/src/regrid.cc
index 1e3154b0c..32a590d54 100644
--- a/Carpet/CarpetRegrid2/src/regrid.cc
+++ b/Carpet/CarpetRegrid2/src/regrid.cc
@@ -280,7 +280,13 @@ namespace CarpetRegrid2 {
     
     // Ensure that the coarser grids contain the finer ones
     for (size_t rl = regions.size() - 1; rl >= 2; -- rl) {
-      ibbox coarse = * regions.at(rl-1).begin();
+      ibbox const coarse = * regions.at(rl-1).begin();
+      
+      i2vect const fdistance =
+        i2vect(ivect(0 * min_distance)) + dd.ghosts + dd.buffers;
+      i2vect const cdistance =
+        i2vect(ivect(min_distance + dd.inner_buffer_width +
+                     dd.prolongation_stencil_size()));
       
       regions.at(rl).normalize();
       ibboxset coarsified;
@@ -288,11 +294,11 @@ namespace CarpetRegrid2 {
            ibb != regions.at(rl).end();
            ++ ibb)
       {
-        ivect const distance (min_distance);
         ibbox const fbb = * ibb;
-        ibbox const cbb = fbb.expanded_for(coarse);
-        ibbox const ebb = cbb.expand (distance, distance);
-        coarsified |= ebb;
+        ibbox const efbb = fbb.expand (fdistance[0], fdistance[1]);
+        ibbox const cbb = efbb.expanded_for(coarse);
+        ibbox const ecbb = cbb.expand (cdistance[0], cdistance[1]);
+        coarsified |= ecbb;
       }
       
       regions.at(rl-1) |= coarsified;