How to grab desktop

Hi,

I remember seeing some code (using api) to grab the desktop, does anyone have it?

http://www.blitzbasic.com/codearcs/codearcs.php?code=654

Has anyone actually got this to work?

Just tried it and it works perfectly with debug off, but *only* in fullscreen mode.

Turn debug on, however, and it drops into the debugger at the line ShowWindow(BlitzHwnd,SW_HIDE) without throwing an error.

I think it's got issues. Sorry should have tested before posting (although that guy JoeRetro said it works great).

:/

I just don't see anything!

Do you have an example bb file?

The code pretty much worked as it is in the code archives, except I set a graphics mode and added a While/Wend loop.

I grabbed the desktop with image = GetDesktop(1).

The code is very "hit and miss" though... there has to be a more reliable solution.

You could also try temporarily setting your desktop resolution to 800x600 - I know that on some systems you can get problems with images larger than the current graphics mode.

Try this, doesn't work...

Graphics3D 800,600,16,1

Global dt

quit = False

While quit = False
	dt = GetDesktop(1)
	DrawImage dt, 0,0
	If KeyHit(1) 
		quit = True
	EndIf
Wend
	


Function GetDesktop(flag=0,update=0)

; ADAmor ZILTCH 2003
;
; This command must come after your GRAPHICS(3D) x,y command.
;
;  flag 0 = create texture
;       1 = create image
;
; if update is not 0 then it is the tex/image to update.

   DeskHwnd = GetDesktopWindow()

   ; Get screen coordinates
   fwidth  = GetSystemMetrics%(0)  ;RectWin\rightR  - RectWin\leftR
   fheight = GetSystemMetrics%(1)  ;RectWin\bottomR - RectWin\topR

   BlitzHwnd = GetActiveWindow()
   ShowWindow(BlitzHwnd,SW_HIDE)

   ; Get the device context of Desktop and allocate memory
   hdc = GetDC(DeskHwnd)
   Blitzhdc = GetDC(BlitzHwnd)

   ; Copy data
   BitBlt(Blitzhdc, 0, 0, fwidth, fheight, hdc, 0,0, SRCCOPY)

   ; Clean up handles
   ReleaseDC(DeskHwnd, hdc)
   ReleaseDC(BlitzHwnd, Blitzhdc)
   ShowWindow(BlitzHwnd,SW_SHOW)

   ; Create/update texture or image
   Select flag
     Case 0
       If update = 0 Then
         tex=CreateTexture(fwidth,fheight)
       Else
         tex=update
       End If
       CopyRect 0,0,fwidth,fheight,0,0,FrontBuffer(),TextureBuffer(tex)
       Return tex
     Case 1
       If update = 0 Then
         image=CreateImage(fwidth,fheight)
       Else
         image=update
       End If
       CopyRect 0,0,fwidth,fheight,0,0,FrontBuffer(),ImageBuffer(image)
       Return image
   End Select

End Function

It works most of the time. For instance, I have 3 test machines at home and the code works fine, but when a friend try it out on his machine it didn't quite work. The results show some icons missing or half drawn from the desktop. It appears as if the desktop was refreshing at the time of calling GetDesktopWindow. So this leaves me to believe that a) has something to do with the graphics card and/or b) something to do with the graphics card drivers. It worked fine on a Geforce 2MX, Geforce 4MX, Geforce 6600GT and ATI 8500 mobility, but did not work properly on a Geforce FX 5200.

@Boiled Sweets, I got your email and once I get home tonight (at work at the moment) I will send you some code that I use to capture/resize the desktop for my screensavers.

Hi JoeRetro,

ta, please send it to me address I use here (see my profile) as opposed to the one I sent from. Many thanks.

I'll see if I can find out how to get it working 100%