SWP_NOMOVE = 2
      SWP_NOZORDER = 4
      WHITENESS = &FF0062
      WM_SIZE = 5
      WM_HSCROLL = &114
      WM_VSCROLL = &115
      WS_HSCROLL = &100000
      WS_VSCROLL = &200000

      CanvasX% = 800
      CanvasY% = 800
      WindowX% = 700
      WindowY% = 700

      IF WindowX%=0 THEN WindowX%=@vdu%!208
      IF WindowY%=0 THEN WindowY%=@vdu%!212
      IF CanvasX%=0 THEN CanvasX%=WindowX%
      IF CanvasY%=0 THEN CanvasY%=WindowY%
      SYS "SetWindowPos", @hwnd%, 0, 0, 0, WindowX%, WindowY%, SWP_NOMOVE + SWP_NOZORDER

      DIM BITMAPINFOHEADER{Size%, Width%, Height%, Planes{l&,h&}, BitCount{l&,h&}, \
      \                    Compression%, SizeImage%, XPelsPerMeter%, YPelsPerMeter%, \
      \                    ClrUsed%, ClrImportant%}

      DIM bmi{Header{} = BITMAPINFOHEADER{}}

      bmi.Header.Size% = DIM(BITMAPINFOHEADER{})
      bmi.Header.Width% = CanvasX%
      bmi.Header.Height% = CanvasY%
      bmi.Header.Planes.l& = 1
      bmi.Header.BitCount.l& = 24

      SYS "CreateDIBSection", @memhdc%, bmi{}, 0, ^Bits%, 0, 0 TO hbitmap%
      IF hbitmap% = 0 ERROR 100, "Couldn't create DIBSection"

      SYS "SelectObject", @memhdc%, hbitmap% TO oldhbm%
      SYS "DeleteObject", oldhbm%

      INSTALL @lib$+"EVENTLIB"
      PROC_eventinit
      PROC_eventregister(WM_SIZE, PROCmove())
      PROC_eventregister(WM_HSCROLL, PROCmove())
      PROC_eventregister(WM_VSCROLL, PROCmove())
      REM SYS "GetWindowLong", @hwnd%, -16 TO ws%
      REM SYS "SetWindowLong", @hwnd%, -16, ws% OR WS_HSCROLL OR WS_VSCROLL
      VDU 23,22,WindowX%;WindowY%;8,16,16,128
      ORIGIN 0,2*(@vdu%!212-CanvasY%)
      VDU 24,0;0;CanvasX%*2-2;CanvasY%*2-2;
      CLG
      LINE 0,0,CanvasX%*2-2,CanvasY%*2-2
      LINE 0,CanvasY%*2-2,CanvasX%*2-2,0

      VDU 23,23,2;0;0;0;
      OFF : VDU 5 : VDU 30

      MOVE 0,CanvasY%*2-200
      REPEAT
        WAIT 10
        cx% = RND(CanvasX%*2)
        cy% = RND(CanvasY%*2)
        cr% = RND(200)
        GCOL RND(15)
        CIRCLE FILL cx%, cy%, cr%
        GCOL 0
        CIRCLE cx%, cy%, cr%
        GCOL 4,0
        MOVE cx%-8*INTLOG(cr%)-8,cy%+16
        IF cr% > 24 PRINT ;cr%;
        PROC_eventpoll
        PROCscroll(-1)
      UNTIL FALSE
      END

      DEF PROCscroll(Y%)
      PRIVATE S%
      IF S% THEN ENDPROC
      S%=TRUE
      LOCAL rc{}
      DIM rc{l%,t%,r%,b%}
      SYS "GetRgnBox", @vdu.hr%, rc{}
      SYS "ScrollDC", @memhdc%, 0, Y%, rc{}, 0, 0, 0
      SYS "ScrollWindow", @hwnd%, 0, Y%, 0, 0
      IF Y%<0 THEN
        SYS "PatBlt", @memhdc%, 0, CanvasY%-ABS(Y%), CanvasX%, ABS(Y%), WHITENESS
      ELSE
        SYS "PatBlt", @memhdc%, 0, 0, CanvasX%, ABS(Y%), WHITENESS
      ENDIF
      REM PROCclr(Bits%,CanvasX%*ABS(Y%),255)
      S%=FALSE
      ENDPROC

      DEF FNTAB(X%,Y%) : X% = X%*16 : Y% = 2*CanvasY%-Y%*24
      = CHR$25+CHR$4+CHR$(X%)+CHR$(X%DIV256)+CHR$(Y%)+CHR$(Y%DIV256)

      DEF PROCclr(B%,C%,A%) : REM b=start c=len a=value
      PRIVATE E%
      CASE bmi.Header.BitCount.l& OF
        WHEN 24 : C%*=3
        WHEN 32 : C%*=4
      ENDCASE
      IF E%=0 THEN
        LOCAL F%,G%,H%,I%,L%
        DIM E% 45 : L%=E%+45
        FOR I%=8 TO 10 STEP 2
          P%=E%
          [OPT I%
          mov edx,eax
          shl edx,8
          or eax,edx
          mov edx,eax
          shl edx,16
          or eax,edx
          mov edx,eax
          .H%
          mov al,cl
          and al,3
          jz G%
          mov [ebx+ecx],dl
          dec ecx
          jmp short H%
          .G%
          mov eax,edx
          mov edx,4
          shr ecx,2
          .F%
          mov [ebx],eax
          add ebx,edx
          loop F%
          ret
          ]
        NEXT I%
      ENDIF
      CALL E%
      ENDPROC

      DEF PROCmove(msg%,wp%,lp%) : REM ENDPROC
      REM PRINT msg%,wp%,lp%
      PRIVATE sih{}, siv{}
      LOCAL flag%
      DIM sih{cbSize%, fMask%, nMin%, nMax%, nPage%, nPos%, nTrackPos%}
      DIM siv{cbSize%, fMask%, nMin%, nMax%, nPage%, nPos%, nTrackPos%}
      sih.cbSize% = DIM(sih{})
      siv.cbSize% = DIM(siv{})
      sih.fMask% = 7
      siv.fMask% = 7
      sih.nMax% = CanvasX%
      siv.nMax% = CanvasY%

      CASE msg% OF
        WHEN WM_SIZE:
          sih.nPage% = lp% AND &FFFF
          siv.nPage% = lp% >>> 16
    
          LOCAL rc{},xs%,ys%,xmax%,ymax%,flag%,sx%,sy%,hbar%,vbar%
          DIM rc{l%,t%,r%,b%}
          SYS "GetSystemMetrics", 0 TO xs% : xs%-=20 :REM screen
          SYS "GetSystemMetrics", 1 TO ys% : ys%-=20
          SYS "GetSystemMetrics", 2 TO sx% : REM scrollbar
          SYS "GetSystemMetrics", 3 TO sy%
    
          IF sih.nPage%<CanvasX% THEN hbar%=1 ELSE hbar%=0 : sih.nPage%=CanvasX%+1
          IF siv.nPage%<CanvasY% THEN vbar%=1 ELSE vbar%=0 : siv.nPage%=CanvasY%+1
    
          IF CanvasX%>xs% THEN xmax%=xs% ELSE xmax%=CanvasX%+vbar%*sx%
          IF CanvasY%>ys% THEN ymax%=ys% ELSE ymax%=CanvasY%+hbar%*sy%
    
          REM IF sih.nPage%=CanvasX% THEN ymax%=ymax%-sy% ELSE ymax%=ymax%+sy%
          REM IF siv.nPage%=CanvasY% THEN xmax%=xmax%-sx% ELSE xmax%=xmax%+sx%
    
          rc.r%=xmax% : rc.b%=ymax%
          SYS "GetWindowLong", @hwnd%, -16 TO style%
          SYS "AdjustWindowRect", rc{}, style%, 0  : REM menu or not ??? , taskbar ??????
          xmax%=rc.r%-rc.l% : IF xmax%>xs% THEN xmax%=xs%
          ymax%=rc.b%-rc.t% : IF ymax%>ys% THEN ymax%=ys%
    
          SYS "GetWindowRect", @hwnd%, rc{}
          rc.r%=rc.r%-rc.l%
          rc.b%=rc.b%-rc.t%
    
          IF rc.r% > xmax% THEN
            WindowX%=xmax%+vbar%*sx%
            flag%=1
          ELSE
            WindowX%=rc.r%+vbar%*sx%: REM no need to "setwindowpos"  unless Y needs
          ENDIF
    
          IF rc.b% > ymax% THEN
            WindowY%=ymax%+hbar%*sy%
            flag%=1
          ELSE
            WindowY%=rc.b%+hbar%*sy%
          ENDIF
    
          IF INKEY(-1) THEN TRACE STEP ON
    
        WHEN WM_HSCROLL:
          CASE wp% AND &FFFF OF
            WHEN 0: sih.nPos% -= 1
            WHEN 1: sih.nPos% += 1
            WHEN 2: sih.nPos% -= sih.nPage%
            WHEN 3: sih.nPos% += sih.nPage%
            WHEN 5: sih.nPos% = wp% >> 16
          ENDCASE
        WHEN WM_VSCROLL:
          CASE wp% AND &FFFF OF
            WHEN 0: siv.nPos% -= 1
            WHEN 1: siv.nPos% += 1
            WHEN 2: siv.nPos% -= siv.nPage%
            WHEN 3: siv.nPos% += siv.nPage%
            WHEN 5: siv.nPos% = wp% >> 16
          ENDCASE
      ENDCASE

      IF sih.nPos% > sih.nMax%-sih.nPage% sih.nPos% = sih.nMax%-sih.nPage%
      IF siv.nPos% > siv.nMax%-siv.nPage% siv.nPos% = siv.nMax%-siv.nPage%
      IF sih.nPos% < sih.nMin% sih.nPos% = sih.nMin%
      IF siv.nPos% < siv.nMin% siv.nPos% = siv.nMin%
      SYS "SetScrollInfo", @hwnd%, 0, sih{}, 1
      SYS "SetScrollInfo", @hwnd%, 1, siv{}, 1
      @ox% = sih.nPos%
      @oy% = siv.nPos%
      SYS "InvalidateRect", @hwnd%, 0, 0
      *REFRESH
      IF flag% THEN SYS "SetWindowPos", @hwnd%, 0, 0, 0, WindowX%, WindowY%, SWP_NOMOVE + SWP_NOZORDER
      ENDPROC


 

      ON MOVE PRINT "ON MOVE received" : RETURN

      DIM sih{cbSize%, fMask%, nMin%, nMax%, nPage%, nPos%, nTrackPos%}
      DIM siv{cbSize%, fMask%, nMin%, nMax%, nPage%, nPos%, nTrackPos%}
      sih.cbSize% = DIM(sih{})
      siv.cbSize% = DIM(siv{})
      sih.fMask% = 7
      siv.fMask% = 7
      sih.nMax% = @vdu%!208
      siv.nMax% = @vdu%!212
      sih.nPage% = sih.nMax%+1
      siv.nPage% = siv.nMax%+1
      SYS "SetScrollInfo", @hwnd%, 0, sih{}, 1
      SYS "SetScrollInfo", @hwnd%, 1, siv{}, 1

      REPEAT
        WAIT 1
      UNTIL FALSE
      END