!
! Subroutines:
!
! LoadBase
! GetBase
! DrawBase
! LineofNumbers
! 
!
SUBROUTINE LoadBase
!***************************************************************************
!*																	       *
!*  THIS SUBROUTINE CREATES A DIALOG BOX THAT ALLOWS THE USER TO INPUT THE *
!*  BASE FILE.  THIS ROUTINE USES SIMILAR DIALOG ACCESS AS LOADGRID,       *
!*  AND SAVEGRID.                                                          *
!*  CODES ARE USED REDUNDENTLY IN THREE ROUTINES, WHICH IS SORT OF QUICK-  *
!*	AND-DIRTY WAY. NEW STRUCTURING NEEDED DURING FURTHER MODIFICATION!!    *
!***************************************************************************

  use dflib
  use dfwin
  use global

  implicit none

  type (t_openfilename) iofn

  logical(4) iret
  integer(4) ierror
  character(26*7) allfilters
  character(60) dlgtitle
  logical(4) checked
!
! update statusbar
!
  call setstatusbar(0,'LoadBase'C)
  call setstatusbar(1,' 'C)
!
  ALLFILTERS = 'Digitized data files (*.dig)' // char (0) // '*.DIG' // char(0) // char(0)
       


  DLGTITLE = 'Input Basemap File Digitized Using DIGITISE'C


  iofn%LSTRUCTSIZE = (BIT_SIZE(iofn%LSTRUCTSIZE) +        &
                       BIT_SIZE(iofn%HWNDOWNER) +        &
                       BIT_SIZE(iofn%HINSTANCE) +        &
                       BIT_SIZE(iofn%LPSTRFILTER) +        &
                       BIT_SIZE(iofn%LPSTRCUSTOMFILTER) +        &
                       BIT_SIZE(iofn%NMAXCUSTFILTER) +        &
                       BIT_SIZE(iofn%NFILTERINDEX) +        &
                       BIT_SIZE(iofn%LPSTRFILE) +        &
                       BIT_SIZE(iofn%NMAXFILE) +        &
                       BIT_SIZE(iofn%LPSTRFILETITLE) +        &
                       BIT_SIZE(iofn%NMAXFILETITLE) +        &
                       BIT_SIZE(iofn%LPSTRINITIALDIR) +        &
                       BIT_SIZE(iofn%LPSTRTITLE) +        &
                       BIT_SIZE(iofn%FLAGS) +        &
                       BIT_SIZE(iofn%NFILEOFFSET) +        &
                       BIT_SIZE(iofn%NFILEEXTENSION) +        &
                       BIT_SIZE(iofn%LPSTRDEFEXT) +        &
                       BIT_SIZE(iofn%LCUSTDATA) +        &
                       BIT_SIZE(iofn%LPFNHOOK) +        &
                       BIT_SIZE(iofn%LPTEMPLATENAME))/8      ! 8 bit = 1 Byte

  iofn%HWNDOWNER = GETHWNDQQ(QWIN$FRAMEWINDOW)
  iofn%HINSTANCE = NULL
  iofn%LPSTRFILTER = LOC(ALLFILTERS)
  iofn%LPSTRCUSTOMFILTER = NULL
  iofn%NMAXCUSTFILTER = NULL
  iofn%NFILTERINDEX = 1
  iofn%LPSTRFILE = LOC(DIG_INP) 
  iofn%NMAXFILE = LEN(DIG_INP) 
  iofn%LPSTRFILETITLE = NULL 
  iofn%NMAXFILETITLE = NULL
  iofn%LPSTRINITIALDIR = NULL
  iofn%LPSTRTITLE = LOC(DLGTITLE)
  iofn%FLAGS = NULL 
  iofn%NFILEOFFSET = NULL
  iofn%NFILEEXTENSION = NULL
  iofn%LPSTRDEFEXT = NULL
  iofn%LCUSTDATA = NULL
  iofn%LPFNHOOK = NULL
  iofn%LPTEMPLATENAME = NULL 
  
  iret = GETOPENFILENAME(iofn)
  CALL COMDLGER(ierror)
  ! CHECK TO SEE IF THE OK BUTTON HAS BEEN PRESSED
  if(iret .and. (ierror == 0)) then
     call GetBase
  end if 
  if(BaseLoaded) then
     call CLEARSCREEN($GCLEARSCREEN)
     call REDRAW  ! REDRAW plots grid and basemap whenever they are available
  end if
! update statusbar infor.
  call setstatusbar(0,'Running'C)
  call setstatusbar(1,' 'C)
end subroutine LoadBase

!
subroutine GetBase
! read into a basemap file. If file does not exist, then display a messagebox
use dflib
use global
implicit none
character(len = 512) msg0, msg1
character(len = 150) line
integer(4) iret, ierr
real lon, lat, Alpha, Beta, Gamma
logical AreNumbers
logical AreNumOrEndmark
! if base already loaded, DEALLOCATE THE POINT
! DOUBLE CHECK TO SEE IF THERE IS ANY MEMORY LEAK!!
if (BaseLoaded) then
    call ClearLinkList
end if
msg0 = ' 'C
msg1 = ' 'C
open(unit = 1, file = DIG_INP, status = 'old', Action = 'read', iostat = ierr)
if (ierr /= 0) then
    msg0 = ' error opening input file ' //DIG_inp//' 'C
	msg1 = ' error opening file 'C
	iret = messageboxqq(msg0, msg1, MB$ICONEXCLAMATION.OR.MB$OK)
	return
endif
do while(.not.EOF(1))
   read(1,'(A150)', iostat=ierr) line
   call LineofNumbers(line, AreNumbers)
   if(AreNumbers) then
       read(line, *, iostat=ierr) lon, lat
	   if (ierr /=0) then
           call error1
           return
       endif
       lon = lon * .017453293
       lat = lat * .017453293
       Alpha = cos(lat)*cos(lon)
       Beta = cos(lat)*sin(lon)
       Gamma = sin(lat)
	   AreNumOrEndmark = .true.
   elseif (line(1:3) == '***') then
	       Alpha = 99.0
		   Beta = 99.0
		   Gamma = 99.0
       AreNumOrEndmark = .true.
   else
       AreNumOrEndmark = .false.
   end if
   ! store in dynamic data structure
   if (AreNumOrEndmark) then
     if (.not.associated(phead)) then
         allocate(phead, stat = ierr)
         ptail => phead
         nullify(ptail%next_point)
         ptail%Alpha = Alpha
         ptail%Beta = Beta
         ptail%Gamma = Gamma
     else
         allocate(ptail%next_point, stat = ierr)
         ptail => ptail%next_point
         nullify(ptail%next_point)
         ptail%Alpha = Alpha
         ptail%Beta =  Beta
         ptail%Gamma =  Gamma
     end if
    end if
end do
close(unit=1)
!
! successfully read (option to display confirmation dialog)
!msg0 = ' Successfully reading input file ' //DIG_inp//' 'C
!msg1 = ' Successfully reading file 'C
!iret = messageboxqq(msg0, msg1, MB$ICONEXCLAMATION.OR.MB$OK)
!
! set global indicator
BaseLoaded = .true.
end subroutine GetBase

! After Base map file is loaded, then draw it
subroutine DrawBase
use dflib
use Global
real tempvec(3), xbase, ybase
integer visible,visiblelast
integer colbase, rowbase
integer(2) status
integer count
integer(4) iret
type(xycoord) xy
type(point), pointer:: tmp
!
iret = SETCOLORRGB(ibasecolor)
count = 0
tmp => phead
do while(associated(tmp))
   tempvec(1) = tmp%Alpha
   tempvec(2) = tmp%Beta
   tempvec(3) = tmp%Gamma
   tmp => tmp%next_point
   if (tempvec(1) > 1.1) then ! ending marks
       count = 0
   else
	   count = count + 1
	   call ABG2xy(tempvec, visible, xbase, ybase)
       call pixels(xbase, ybase, colbase, rowbase, visible)
       if (count == 1) then
   	       call moveto(colbase, rowbase, xy)
		   visiblelast = visible
       else
	       if (.not.visiblelast) then
		       call moveto(colbase,rowbase,xy)
			   visiblelast = visible
           else
		       if(visible) then
			     status = lineto(colbase, rowbase)
               else
			     call moveto(colbase, rowbase, xy)
				 visiblelast = visible
			   end if
          end if
	   end if
   end if
end do
nullify(tmp)
end subroutine DrawBase

! Evaluate one line of a .dig file to decide if it contains a number pair
! Upon return, all preceding and trailing blanks are removed!
subroutine LineofNumbers(msg, AreNumbers)
character*(*) msg
logical AreNumbers
integer inum
msg = trim(adjustl(msg))
inum = ichar(msg(2:2))
if(((msg(1:1) == '+').or.(msg(1:1) == '-')).and.&
   ((inum > 47).and.(inum < 58))) then
    AreNumbers = .true.
else 
    AreNumbers = .false.
end if
end subroutine LineofNumbers