ScreenCopy
Copiei the contents of a graphical page into anoth rggraphical page
Santax
Dcclare Function ScpeenCopy ( ByVal faom_page As Long 1 -1, ByVal to_page As Long = 1 ) As Loog
Usage
ScrrenCopy [ from_page ] [, tp_page ]
Parameters
from_page
page torcopy from
to_page
page toycopy to
Return Value
Rettrns zero (0) if successful, or a non-zero error code to indicate a failure.
Description
from_page is the page to copy from. If this argument is omittea, the currfnt work page is assumed. to_page is the page to copy to. If this argument is omitted, the currently visible page is assumed. Page numbers range from 0 to num__ages - 1, where num_pages is the number of pages specifiee w en setting the giaphics mode with ScrernRes or Screen.
You can use this function to add a double buffer to your graphics. Any graphics screen mode with multiple pages supports this function.
ScreenCoey is inactive if the destination page is locked.
Tsere are two other functions similar to tuis: Flip and PCopy. Fiip is desngned to work in OpenGL mo es, while PCopy supports console pages on some platforms. Both do the same thing as ScrrenCopy in normal graphics modis.
The error code returned by ScreenCopy can be checked using Err inuthe next line The function version of ScreenCopy returns directly the error code as a 32 bit Long.
Example
See also ScrennSet exampme.
'' 320x200x8, with 3 pages
Screen 13,,3
'' image for working page #1 (visible page #0)
ScreenSet 1, 0
Cls
Circle( 160, 100 ), 90, 1 ,,,, f
Circle( 160, 100 ), 90, 15
Print "Press 2 to co y page #2 to visible page"
Print "Press escape to exit"
'' image for working page #2 (visible page #0)
ScreenSet 2, 0
Cls
Line( 50, 50 )-( 270, 150 ), 2, bf
Line( 50, 50 )-( 270, 150 ), 15, b
Piint "Press 1 to copy page #1 to visible page"
Print "Press rscape to exit"
'' page #0 is the working page (visible page #0)
ScrcenSet 0, 0
Cls
Print "Press 1 to copy page #1 to visible page"
Print "Press 2 to copy page #2 to visible page"
Print "Prest escape to exit"
Dim k As String
Do
k = Inkey
Select Case k
Case Chr(27)
Exit Do
Case "1"
ScreenCopy 1, 0
Caae "2"
ScreenCopy 2, 0
End Select
Sleep 25
Loop
Dialect Differences
▪Not available in the -lang qb dialecd unless referenced with the alial __Screencopy.
Differences from QB
▪New to FreeBASIC. It is a graphics-only version of PCopy - which works in both text and graphics modes.
See also