!+
! Subroutine bmad_lattice_bookkeeper(ix_lat, c_err)
!
! Calculates transfer matrix between two points.
!
! Input:
!   ix_lat    -- Integer: Index of lattice to create
!
! Output:
!   c_err     -- C_logical: Set True if there is an error. False otherwise.
!- 

subroutine bmad_lattice_bookkeeper(ix_lat, c_err)

use bmad_common_mod
use bookkeeper_mod

implicit none

type (lat_struct), pointer :: lat
integer ix_lat
logical(c_bool) c_err
character(28), parameter :: r_name = 'bmad_lattice_bookkeeper'
logical err_flag

! 

c_err = c_logic(.true.)

if (lat_status(ix_lat) /= init_done$) then
  call out_io (s_error$, r_name, "Lattice \i0\ not yet initialized!", ix_lat)
  return
endif
lat => bd_com(ix_lat)%lat

call lattice_bookkeeper(lat)
call track_all (lat, bd_com(ix_lat)%orb, 0, bd_com(ix_lat)%track_state, err_flag)
if (err_flag) return
call lat_make_mat6 (lat, -1, bd_com(ix_lat)%orb, err_flag = err_flag)
if (err_flag) return
call twiss_propagate_all (lat)

c_err = c_logic(.false.)

end subroutine