!
!                    OSCILLOSCOPE EXPERIMENT
!
! this crapware is released by tTh under the
!             DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
!
program oscilloscope
  use genplotting
  implicit none

  real, dimension(4)    :: frequences

  write (0, '(A)') "----[ genplotting oscilloscope ]----"
  call srand(time())
  call genp_init (0, 'WS/oscilloscope.scratch')

  frequences(1) = 24.86
  frequences(2) = 29.77
  frequences(3) = 37.56
  frequences(4) = 49.3

  call do_oscilloscope(frequences, 2)

  call genp_end (0)
contains
! ---------------------------------------------------------
real function compute_a_value(clk, freq, phase)
  real, intent(in)    :: clk, freq, phase
  real                :: v, f
  f = freq*(clk+phase)
  v = sin(f) + (0.3 * sin(3*f)) + (0.1 * sin(5*f))
  compute_a_value = v
end function
! ---------------------------------------------------------
subroutine plot_a_trace(freq, phy, nbsteps, ypos, col)
  real, intent(in)        :: freq, phy, ypos
  integer, intent(in)     :: nbsteps, col

  integer          idx
  real             rstep, px, py
  logical          firstdot

  firstdot = .TRUE.
  do idx=0, nbsteps
    rstep = (real(idx)/real(nbsteps)) 
    px    = -10.0 + (20.0 * rstep)
    py = ypos + compute_a_value (rstep, freq, phy)
    if (firstdot) then
      call genp_move(px, py)   ;   firstdot = .false.
    else
      call genp_draw(px, py, col)
    endif
  enddo

end subroutine
! ---------------------------------------------------------
subroutine do_oscilloscope(freqs, col)
  real, intent(in), dimension(4)   :: freqs
  integer, intent(in)              :: col

  call plot_a_trace(freqs(1), 0.2, 120,  6.66, col)
  call plot_a_trace(freqs(2), 1.0, 120,  3.33, col)
  call plot_a_trace(freqs(3), 2.6, 120, -3.33, col)
  call plot_a_trace(freqs(4), 3.1, 120, -6.66, col)
  call genp_plot_axes(10.0)

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