!
!       project "gravity field"
!
program essai
  use realfield
  implicit none

  type(massbody)          :: planet
  integer                 :: foo
  planet%posx = 1337.314
  planet%posy = 1664.666
  planet%mass = 1e4

  do foo=1, 10
    call build_a_field(800, 600, planet)
    planet%posy = planet%posy + 51.45
  enddo

  STOP 'YOLO'

contains        !------------------------------------------
!
subroutine build_a_field(szx, szy, moon)
  integer, intent(in)                :: szx, szy
  type(massbody), intent(in)         :: moon

  integer                            :: ix, iy
  real                               :: fx, fy
  real                               :: grav, maxi, mini
  integer                            :: errcode
  real, dimension(:,:), allocatable  :: field

  allocate(field(szx, szy), stat=errcode)
   
  do ix=1, szx
    fx = real(ix)
    do iy=1, szy
      fy = real(iy)
      grav = compute_gravity(ix, iy, moon) / 2180800.0
      field(ix,iy) = grav
    enddo
  enddo

  maxi = maxval(field)
  mini = minval(field)
  print *, "field: ", mini, maxi, maxi-mini

  deallocate(field)

end subroutine

                !------------------------------------------

end program