!              THE GENPLOTTING MODULE
!
! new Thu Apr 23 01:13.37 PM UTC 2026
!
module genplotting
  implicit none

  real      ::    xmin, xmax, ymin, ymax
  private   ::    xmin, xmax, ymin, ymax

  real      ::    xoffset, yoffset, xscale, yscale
  private   ::    xoffset, yoffset, xscale, yscale

  integer   ::    outunit
  private   ::    outunit

contains
! ---------------------------------------------------------
subroutine genp_init (foo, fname)
  integer, intent(in)             :: foo
  character (len=*), intent(in)   :: fname

  if (FOO .NE. 0)   THEN
    WRITE(0, '("FOO .NE. 0")')
    CALL EXIT(1) 
  END IF

  outunit = 6          ! stdout
  if (len(fname) .gt. 0) then
    write (0, '("genplot init opening : ", A)') fname
    open(newunit=outunit,file=fname)
  endif

  xmin = 9e9       ;       xmax = -9e9
  ymin = 9e9       ;       ymax = -9e9
  xoffset = 0.0    ;       yoffset = 0.0
  xscale  = 0.0    ;       yscale  = 0.0
end subroutine
! ---------------------------------------------------------
subroutine genp_set_offset(ox, oy)
  real, intent(in)     :: ox, oy
  xoffset = ox      ;      yoffset = oy
end subroutine
subroutine genp_get_offset(ox, oy)
  real, intent(out)     :: ox, oy
  ox = xoffset      ;      oy = yoffset
end subroutine
! ---------------------------------------------------------
subroutine genp_move (px, py)
  real, intent(in)        :: px, py
  real                    :: lx, ly
  lx = px + xoffset     ;     ly = py + yoffset
  write (outunit, '(2F12.5, I5)') lx, ly, -1
  if (lx .lt. xmin)      xmin = lx
  if (lx .gt. xmax)      xmax = lx
  if (ly .lt. ymin)      ymin = ly
  if (ly .gt. ymax)      ymax = ly
end subroutine
! ---------------------------------------------------------
subroutine genp_draw (px, py, color)
  real, intent(in)        :: px, py
  integer, intent(in)     :: color
  real                    :: lx, ly
  lx = px + xoffset     ;     ly = py + yoffset
  write (outunit, '(2F12.5, I5)') lx, ly, color
  if (lx .lt. xmin)      xmin = lx
  if (lx .gt. xmax)      xmax = lx
  if (ly .lt. ymin)      ymin = ly
  if (ly .gt. ymax)      ymax = ly
end subroutine
! ---------------------------------------------------------
subroutine genp_line(xa, ya, xb, yb, color)
  real,    intent(in)     :: xa, ya, xb, yb
  integer, intent(in)     :: color
  call genp_move(xa, ya)
  call genp_draw(xb, yb, color)
end subroutine
! ---------------------------------------------------------
subroutine genp_end (foo)
  integer, intent(in)    :: foo

  write (0, '("--- genp_end ---")')
  write (0, '("minmax X", 2F16.5)') xmin, xmax
  write (0, '("minmax Y", 2F16.5)') ymin, ymax

  write (outunit, '(2F16.5, I6)') xmin*1.05, ymin*1.05, -1
  write (outunit, '(2F16.5, I6)') xmin*1.05, ymax*1.05,  0
  write (outunit, '(2F16.5, I6)') xmax*1.05, ymax*1.05,  0
  write (outunit, '(2F16.5, I6)') xmax*1.05, ymin*1.05,  0
  write (outunit, '(2F16.5, I6)') xmin*1.05, ymin*1.05,  0
  close (outunit)

  if (6 .ne. outunit) then
    write (0, '("genp_end on ", I6, " is ", I6)') outunit, foo
  endif

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

end module genplotting