!
!         BUILD A STAR FIELD
!
program starfield
  use genplotting
  implicit none
  write (0, '(A)') "----[ genplotting starfield ]----"
  call genp_init (0, 'starfield.scratch')
  call do_starfield (451)
  call genp_end (0)
contains
! ---------------------------------------------------------
subroutine plot_a_star(at_x, at_y, sz, color)
  real, intent(in)        :: at_x, at_y, sz
  integer, intent(in)     :: color
  integer                 :: idx
  real                    :: rad, xv, yv
  write(0, '("plot a star ", 2F8.3)') at_x, at_y
  call genp_set_offset(at_x, at_y)
  do idx=0, 360, 36
    rad = 0.042 + (real(idx) * (3.14159 / 180))
    xv = sz * sin(rad)    ;    yv = sz * cos(rad)
    call genp_move(0.0, 0.0)
    call genp_draw(xv, yv, color)
  enddo
end subroutine
! ---------------------------------------------------------
subroutine do_starfield (nbstar)
  integer, intent(in)     :: nbstar
  integer         idx, color
  real            px, py, sz
  do idx=0, nbstar
    px = (rand(0) * 10.00) - 5.00
    py = (rand(0) * 10.00) - 5.00
    sz = (rand(0) *  0.16) + 0.16
    color = 1 + mod(idx, 7)
    call plot_a_star(px, py, sz, color)
  end do
end subroutine
! ---------------------------------------------------------
end program