blit and BufferedPaintDC

[Declan McMullen]

Yup. Maybe something to do with the graphics context and blit ?

On Tue, Apr 22, 2008 at 8:59 AM, Xavier Miller <xavier.miller at cauwe.org>
wrote:

> Did you released the DC before you read the bitmap ?
> (DC.SelectObject(wxNULL_BITMAP) or free the DC)
>
> Declan McMullen a =E9crit :
>
> > I'm screenshotting the contents of my own dc. All it had in it is an
> > image and some other graphical elements drawn on top. If I use a
> > BufferedPaintDC only it works fine,
> > if I use a GraphiccontextDC the blit fails.
> >
> >
> > On Tue, Apr 22, 2008 at 8:14 AM, Xavier Miller <xavier.miller at cauwe.org=
<mailto:
> > xavier.miller at cauwe.org>> wrote:
> >
> >    Hello,
> >
> >    What do you screenshot ? If it is a graphic-accelerated application
> >    (DVD player, game), it will not work because the drawing is managed
> >    by the graphical card and not the OS.
> >
> >    Xavier.
> >
> >    Declan McMullen a =E9crit :
> >
> >        Ive tried turning off double buffering and I still get an
> >        entitrely black bitmap.
> >        If i set the bitmap to match another bitmap its fine, so It
> >        seems the blit definitely isnt
> >        copying the content of the dc to the memory dc
> >
> >        Any ideas ?
> >
> >        On Sun, Apr 20, 2008 at 4:42 PM, Declan McMullen
> >        <declan.mcmullen at gmail.com <mailto:declan.mcmullen at gmail.com>
> >        <mailto:declan.mcmullen at gmail.com
> >        <mailto:declan.mcmullen at gmail.com>>> wrote:
> >
> >
> >           Is it possible to use blit with a double buffered paint dc ?
> >           I have the following function
> >
> >
> >           wxBitmap WorkspaceView::getScreenShot(wxDC& dc)
> >
> >           {
> >
> >           wxSize screenSize =3D dc.GetSize();
> >
> >           wxBitmap screenBitmap(screenSize.GetWidth(),
> >        screenSize.GetHeight());
> >
> >           wxMemoryDC memDC;
> >
> >           memDC.SelectObject(screenBitmap);
> >
> >           memDC.Blit(0, 0, screenSize.GetWidth(),
> >        screenSize.GetHeight(), &dc,
> >           0, 0);
> >
> >           memDC.SelectObject(wxNullBitmap);
> >
> >           return screenBitmap;
> >
> >           }
> >
> >
> >
> >           What I wanted to do with it was make a bitmap I could use for
> >           printing, i.e just put everything
> >
> >           thats on the screen into a bitmap, send that image to my
> > printout
> >           object and print it.
> >
> >           All I'm getting though is a completely black image and I'm
> >        thinking
> >           its due to my double buffering ?
> >
> >
> >           Is it possible for me to get the contents of the buffer
> >        itself and
> >           use that ?
> >
> >
> >
> >           --    http://www.computing.dcu.ie/~dmcmullen<http://www.compu=
ting.dcu.ie/%7Edmcmullen>
> >        <http://www.computing.dcu.ie/%7Edmcmullen>
> >           <http://www.computing.dcu.ie/%7Edmcmullen>
> >
> >           declan.mcmullen at computing.dcu.ie
> >        <mailto:declan.mcmullen at computing.dcu.ie>
> >           <mailto:declan.mcmullen at computing.dcu.ie
> >        <mailto:declan.mcmullen at computing.dcu.ie>>
> >
> >           School of Computing
> >           Postgrad Bay A
> >
> >
> >
> >
> >        --        http://www.computing.dcu.ie/~dmcmullen<http://www.comp=
uting.dcu.ie/%7Edmcmullen>
> >        <http://www.computing.dcu.ie/%7Edmcmullen>
> >        declan.mcmullen at computing.dcu.ie
> >        <mailto:declan.mcmullen at computing.dcu.ie>
> >        <mailto:declan.mcmullen at computing.dcu.ie
> >        <mailto:declan.mcmullen at computing.dcu.ie>>
> >
> >        School of Computing
> >        Postgrad Bay A
> >
> >
> >
> >  ----------------------------------------------------------------------=
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> > --
> > http://www.computing.dcu.ie/~dmcmullen<http://www.computing.dcu.ie/%7Ed=
mcmullen>
> > declan.mcmullen at computing.dcu.ie <mailto:
> > declan.mcmullen at computing.dcu.ie>
> > School of Computing
> > Postgrad Bay A
> >
> >
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-- =

http://www.computing.dcu.ie/~dmcmullen
declan.mcmullen at computing.dcu.ie
School of Computing
Postgrad Bay A
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