Save entire screen for displaying later

[Robert E. Carneal]

There are a few cases where saving whatever is currently on the
screen would be helpful, and do [whatever] adn then put the
screen back the way it was. This is *not* correct, but will get
the gist of what I hope to do.

.program...
if Dateok$ <> "Y" then
PreserveScreen :' will save everything currestly displayed
Print "Excuse me, the date you entered is out of range."
Print "Use calendar to pick date."
{user enters correct date at this point}
RestoreScreen :' will make the screen the way it was
end if
..program..

Possible? The faster the method, the better, and I
know I have seen a way to do this, probably in the forum.

Thank you.

Robert

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[JOSE ROCA]

FUNCTION SaveScreen$ () PUBLIC

   DIM cell AS STRING PTR * 4000
   DIM stcell AS STRING PTR * 4000
   DIM Scr AS STRING

   Scr$ = SPACE$ (4000)
   cell = pbvScrnBuff
   stcell = STRPTR32 (Scr$)
   @stcell = @cell
   SaveScreen$ = Scr$

END FUNCTION

SUB RestoreScreen (Scr AS STRING) PUBLIC

   DIM cell AS STRING PTR * 4000
   DIM stcell AS STRING PTR * 4000

   IF LEN(Scr$) < 4000 THEN EXIT SUB
   cell = pbvScrnBuff
   stcell = STRPTR32 (Scr$)
   @cell = @stcell

END SUB

MyScreen$ = SaveScreen$
........
........
RestoreScreen MyScreen$

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[Tom Hanlin]

...that being for text-mode screens of 80x25 characters.

Graphics modes can be handled through the POINT function, though
that will be slow. Faster methods would require low-level display
programming. You can probably find examples in the Downloads.

------------------
Tom Hanlin
PowerBASIC Staff

[Robert E. Carneal]

Hose-

One inquiry please. Will the displayed routine maintain the
colors of the background and text as well?

Thank you.

Robert

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[JOSE ROCA]

Yes. It saves and restores characters and color attributes.


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[Gerhard Kropf]

Rem Save entire VGA Text Screen to VAR$

def seg = &HB800
Var$=peek$(0,4000)
def seg


Rem ReLoad previous saved VGA Text screen

def seg = &HB800
poke$ 0,Var$
def seg


I hope this helps a bit

Gerhard


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