Re: [ros-diffs] [mbosma] 17213: Fix another bug thanks to GreatLord.

[Royce Mitchell III]

[e-mail] wrote:
> Fix another bug thanks to GreatLord.
>
> Modified: trunk/reactos/lib/ddraw/main/ddraw.c
>
> *Modified: trunk/reactos/lib/ddraw/main/ddraw.c*
>
> --- trunk/reactos/lib/ddraw/main/ddraw.c	2005-08-08 16:09:48 UTC (rev 17212)
> +++ trunk/reactos/lib/ddraw/main/ddraw.c	2005-08-08 16:18:44 UTC (rev 17213)
> @@ -24,7 +24,7 @@
>
> This->lpGUID = lpGUID;
>
> // get the HDC
> This->hdc = CreateDC (L"Display", NULL, NULL, NULL);
>
> This->hdc = GetWindowDC(GetDesktopWindow());
>
> This->Height = GetDeviceCaps(This->hdc, HORZRES);
> This->Width = GetDeviceCaps(This->hdc, VERTRES);
> This->Bpp = GetDeviceCaps(This->hdc, BITSPIXEL);

I wondered about this when I first saw it. What about GetDC(NULL) ?

Hi
I think it is not wrong with GetWindowDC(GetDesktopWindow());
for we need current desktop, to get the screen width, height and some other
data. so I think is pretty clear what it does. we can do same thing with
createdc then we need look wich graphic driver are in use. And I do not if
GetDC(NULL) work fine in ros.

Quoting Royce Mitchell III [e-mail]:
> [e-mail] wrote:
> > Fix another bug thanks to GreatLord.
> >
> > Modified: trunk/reactos/lib/ddraw/main/ddraw.c
> >
> > *Modified: trunk/reactos/lib/ddraw/main/ddraw.c*
> >
> > --- trunk/reactos/lib/ddraw/main/ddraw.c	2005-08-08 16:09:48 UTC (rev 17212)
> > +++ trunk/reactos/lib/ddraw/main/ddraw.c	2005-08-08 16:18:44 UTC (rev 17213)
> > @@ -24,7 +24,7 @@
> >
> > This->lpGUID = lpGUID;
> >
> > // get the HDC
> > This->hdc = CreateDC (L"Display", NULL, NULL, NULL);
> >
> > This->hdc = GetWindowDC(GetDesktopWindow());
> >
> > This->Height = GetDeviceCaps(This->hdc, HORZRES);
> > This->Width = GetDeviceCaps(This->hdc, VERTRES);
> > This->Bpp = GetDeviceCaps(This->hdc, BITSPIXEL);
>
> I wondered about this when I first saw it. What about GetDC(NULL) ?
>
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[Royce Mitchell III]

[e-mail] wrote:
> Hi
> I think it is not wrong with GetWindowDC(GetDesktopWindow());
> for we need current desktop, to get the screen width, height and some other
> data. so I think is pretty clear what it does. we can do same thing with
> createdc then we need look wich graphic driver are in use. And I do not if
> GetDC(NULL) work fine in ros.

If it doesn't work in ros, it should. If not, it should be easy to fix. 
To quote GetDC() documentation from MSDN:

/hWnd/
    [in] Handle to the window whose DC is to be retrieved. If this value
    is NULL, *GetDC* retrieves the DC for the entire screen.

(I frequently use GetDC(NULL) for calls to CreateCompatibleDC and 
CreateCompatibleBitmap).

In fact, GetWindowDC(NULL), appears to do the same thing as GetDC(NULL), 
but I personally prefer GetDC(NULL), because it's easier to type ;)