anchor.diff:                          ifine = (ibc-1)*refratio + ii
                           jfine = (jbc-1)*refratio + jj
                           if (is_block_bdry(0) .eq. 1) then
  +c                          # get info from fine block corner 0
                              kf = areafine(ifine,jfine)
                              qf =   qfine(ifine,jfine,mq)
                           elseif (is_block_bdry(3) .eq. 1) then
  +c                          # get info from fine block corner 3
                              kf = areafine(mx+1-ifine,my+1-jfine)
                              qf =   qfine(mx+1-ifine,my+1-jfine,mq)
                           endif
  
positive.code:                         ifine = (ibc-1)*refratio + ii
                          jfine = (jbc-1)*refratio + jj
                          if (is_block_bdry(0) .eq. 1) then
                             kf = areafine(ifine,my+1-jfine)
                             qf =   qfine(ifine,my+1-jfine,mq)
                          elseif (is_block_bdry(2) .eq. 1) then
                             kf = areafine(mx+1-ifine,jfine)
                             qf =   qfine(mx+1-ifine,jfine,mq)
                          endif
  
negative.code:                         ifine = (ibc-1)*refratio + ii
                          jfine = (jbc-1)*refratio + jj
                          if (is_block_bdry(1) .eq. 1) then
  c                          # get info from fine block corner 3
                             kf = areafine(mx+1-ifine,my+1-jfine)
                             qf =   qfine(mx+1-ifine,my+1-jfine,mq)
                          elseif (is_block_bdry(2) .eq. 1) then
  c                          # get info from fine block corner 0
                             kf = areafine(ifine,jfine)
                             qf =   qfine(ifine,jfine,mq)
                          endif
  