1 files changed, 57 insertions, 0 deletions
diff --git a/src/findboundary.F90 b/src/findboundary.F90
new file mode 100644
index 0000000..1e16e97
--- /dev/null
+++ b/src/findboundary.F90
@@ -0,0 +1,57 @@
+! $Header$
+
+! Take a mask that contains only the values 0 and 1.
+! Return a mask where the outermost 0s have been replaced by 0.5s.
+
+#include "cctk.h"
+#include "cctk_Parameters.h"
+
+#include "maskvalues.h"
+
+subroutine excision_findboundary (ierr, cctkgh, mask, ni, nj, nk)
+  
+  implicit none
+  
+  DECLARE_CCTK_FUNCTIONS
+  DECLARE_CCTK_PARAMETERS
+  
+  ! Arguments
+  
+  ! out: zero for success, nonzero for error
+  integer      :: ierr
+  
+  ! in: pointer to Cactus GH
+  CCTK_POINTER :: cctkgh
+  
+  ! in: array sizes for grid functions
+  !     (you can pass in cctk_lsh(:) for these)
+  integer      :: ni,nj,nk
+  
+  ! inout: mask
+  CCTK_REAL    :: mask(ni,nj,nk)
+  
+  integer i,j,k
+  integer ii,jj,kk
+  logical bnd
+  
+  do k=2,nk-1
+     do j=2,nj-1
+        do i=2,ni-1
+           if (mask(i,j,k)==MASK_EXCISED) then
+              bnd = .false.
+              do kk=k-1,k+1
+                 do jj=j-1,j+1
+                    do ii=i-1,i+1
+                       bnd = bnd .or. mask(i,j,k)/=MASK_EXCISED
+                    end do
+                 end do
+              end do
+              if (bnd) mask(i,j,k) = MASK_BOUNDARY
+           end if
+        end do
+     end do
+  end do
+  
+  ierr = 0
+  
+end subroutine excision_findboundary