module boxconv  
  use adj_mod
  use causint
  use double
  use chain_mod
  implicit none
  real ,private,  dimension (:), allocatable  :: tmp 
  contains
  subroutine boxconv_init ( nbox,ndat )
    integer, intent (in) :: nbox,ndat
    if (.not. allocated(tmp)) then
      allocate(tmp ( ndat+nbox)) 
    end if
    call double_init (nbox,ndat)
  end subroutine
  function boxconv_lop ( adj, add, x, y) result(stat)
    integer            :: stat 
    logical,intent(in) :: adj,add 
    real,dimension(:)  :: x,y 
    call adjnull (adj,add,x,y )
    call boxconv_lop2(adj,add,x,y )
    stat=0
  end function 
  subroutine boxconv_lop2(adj,add,x,y)
    logical,intent(in) :: adj,add 
    real, dimension (:)  :: x 
    real, dimension (:)  :: y 
    call chain (causint_lop, double_lop, adj, .true., x, y, tmp)
  end subroutine 
  subroutine boxconv_close()
    deallocate( tmp )
  end subroutine 
end module