! 
!          fonctions de base de gestion des bloubs
! 

module bloubspace

  implicit none

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

  type t_bloubs
    character(8)         :: nick
    logical              :: alive
    integer              :: num
    real                 :: px, py, pz
    real                 :: vx, vy, vz
    real                 :: radius
    integer              :: age
  end type t_bloubs

  contains               ! -----------------------------------------

  subroutine random_pv (blb)
    type(t_bloubs), intent (inout)  :: blb

    blb%px = 1.3 * (rand() - 0.50)
    blb%py = 0.50 + rand() * 0.50
    blb%pz = 2.0 * (rand() - 0.50)

    blb%vx = (rand() - 0.5) / 2.500
    blb%vy = (rand() - 0.5) / 4.000
    blb%vz = (rand() - 0.5) / 2.500

    blb%alive = .TRUE.

  end subroutine
  ! ----------------------------------------------------------------

  subroutine display_bloub (blb, message)
    type(t_bloubs), intent (in)  :: blb
    character(*),   intent (in)  :: message

    character(5)                 :: life

    if (blb%alive) then
      life = "alive"
    else
      life = "dead"
    endif
    write (0, '(4X, A)') '+--------------- ' // message // " -------"
    write (0, '(4X,A3,A8,2X,I6,4X,A5,4X,I5)') '|  ',       &
                                 blb%nick, blb%num, life, blb%age
    write (0, '(4X,A3,3X,3(F8.3, 4X))') '| P', blb%px, blb%py, blb%pz
    write (0, '(4X,A3,3X,3(F8.3, 4X))') '| V', blb%vx, blb%vy, blb%vz
    write (0, '()')

  end subroutine
  ! ----------------------------------------------------------------

  subroutine move_bloub (blb, coef)
    type(t_bloubs), intent (inout)  :: blb
    real,           intent (in)     :: coef

    ! we must check that this bloub is alive ?

    blb%px  = blb%px + (blb%vx * coef)
    blb%py  = blb%py + (blb%vy * coef)
    blb%pz  = blb%pz + (blb%vz * coef)

  end subroutine
  ! ----------------------------------------------------------------
  subroutine bound_a_blob (blb)
    type(t_bloubs), intent (inout)  :: blb

    if (5.0 .lt. blb%px) then
      blb%vx = -1.0 * blb%vx
      blb%px = 5.0
      blb%age = blb%age + 1
    endif
    if (-5.0 .gt. blb%px) then
      blb%vx = -1.0 * blb%vx
      blb%px = -5.0
      blb%age = blb%age + 1
    endif

    if (0.0 .gt. blb%py) then
      blb%vy = -1.0 * blb%vy
      blb%py = 0.0
      blb%age = blb%age + 1
    endif
    if (5.0 .lt. blb%py) then
      blb%vy = -1.0 * blb%vy
      blb%age = blb%age + 1
      blb%py = 5.0
    endif

    if (5.0 .lt. blb%pz) then
      blb%vz = -1.0 * blb%vz
      blb%age = blb%age + 1
      blb%pz = 5.0
    endif
    if (-5.0 .gt. blb%pz) then
      blb%vz = -1.0 * blb%vz
      blb%age = blb%age + 1
      blb%pz = -5.0
    endif

  end subroutine

  ! ----------------------------------------------------------------
  function distance_of_bloubs(bla, blb)
    type(t_bloubs), intent(in)   :: bla, blb
    real                         :: distance_of_bloubs

    real            :: dx, dy, dz

    dx = (bla%px-blb%px)**2
    dy = (bla%py-blb%py)**2
    dz = (bla%pz-blb%pz)**2

    distance_of_bloubs = sqrt(dx + dy +dz)

  end function

  ! ----------------------------------------------------------------
  !          kill a bloub under condition(s)

  subroutine green_soylent (blb)
    type(t_bloubs), intent (inout)  :: blb
    if (blb%age .gt. 5) then
      blb%alive = .FALSE.
    endif
  end subroutine
  ! ----------------------------------------------------------------


end module